{"paper_id":"64677954-0dbd-428f-9d40-d8cb4c079edd","body_text":"Comparative efficacy of titanium oxide nanoparticles and zinc oxide nanoparticles against lead tolerance, growth performance and nutrient profiling of Brassica Napus L. grown under Lead contaminated soil | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Comparative efficacy of titanium oxide nanoparticles and zinc oxide nanoparticles against lead tolerance, growth performance and nutrient profiling of Brassica Napus L. grown under Lead contaminated soil Adiba Khan Sehrish, Shoaib Ahmad, Sarah Owdah Alomrani, Rohina Tabassam, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3684389/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The lead (Pb) has been regarded as toxic metal that negatively impact both plant growth and human health. Due to limited information available about the application of titanium dioxide (TiO 2 -NPs) and Zinc oxide nanoparticles (ZnO-NPs) for the alleviation of Pb stress in crop particularly in Brassica napus L. The current experiment was aimed to investigate the efficacy of foliar application TiO 2 and ZnO-NPs on Pb uptake and growth performance. The results of our study demonstrated that TiO 2 and ZnO-NPs foliar application at (25, 50 and 100 mg/L) significantly decreased Pb uptake and simultaneously improved plant growth attributes, including shoot and root length, shoot and root fresh weight. Additionally, the NPs foliar application significantly augmented plant photosynthetic pigment (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids) and gas exchange parameters compared to control. The biochemical analysis showed increased in plant antioxidative enzymes activities (peroxidase, Catalase, Superoxide dismutase) and reduction in oxidative stress (malondialdehyde, hydrogen peroxide, electrolyte leakage) under Pb stress upon NPs application. Importantly, foliar application of 100mg/L significantly reduced the uptake and translocation of pb in plant root and shoot with 45.7% and 84.1% respectively, as compared to control without nanoparticles. Furthermore, foliar application of TiO 2 and ZnO-NPs enhance shoot zinc (Zn), iron (Fe), manganese (Mn), magnesium (Mg) calcium (Ca) and Potassium (K) when compared to control without nanoparticles. Interestingly concentrations of macro and micro nutrients with the type and dose of nanoparticles were varied. The highest concentrations of Ca (69.8%), Mn (67.3%) and Zn (78.7%) were found at 100mg/L ZnO-NPs foliar application while, the highest concentrations of Fe (79.4%), Mg (72.1%) and K (81.4%) were observed at 100mg/L TiO 2 -NPs. Overall, application of nanoparticles especially, TiO 2 - NPs for Brassica napus L. is promising strategy for sustainable agriculture towards alleviating Pb toxicity and ensuring food security. Nanoparticles Brassica napus L. Lead (Pb) Chlorophyll contents Antioxidant activities Nutrient Content Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 1. Introduction Heavy metals have emerged as a prominent class of environmental toxins among abiotic stresses (Rizwan et al. 2016 ; Aborisade et al. 2023 ). The presence of heavy metals in soil seriously exacerbated food security due to their adverse effects crop productivity on and food quality. Additionally, Heavy metals (HMs) buildup in plant parts including seeds, shoots, and roots can cause agricultural toxicity and reduce plant productivity (Adrees et al. 2015 ; Rai et al. 2019 ; Manzoor et al. 2023 ). The accumulation of HMs in plant tissues through the food chain can pose a significant risk to both human and animal populations. The molecular, physiological and biochemical processes with in the plant impacted, when concentration of heavy metals in exceeds specific thresholds level (De Caroli et al. 2020; Rashid et al. 2023 ). Lead (Pb) is the second most harmful heavy metal due to its non-degradability in nature and has been classified as carcinogenic (Nag and Cummins, 2022 ; Mahamood et al. 2023 ). Pb contamination in soil from natural and anthropogenic sources harms soil biota and environment. Both stable and isotopic form of Pb, naturally found in the environment can accumulate in vegetation, affecting plant development and food safety (Mitra et al. 2020 ). Excessive level of Pb in soil have a deleterious impact on plant biomass, lead to restricted photosynthetic activity, chlorosis, cell and chromosomal damage, increased oxidative stress and disruption of the water cycle (Debnath et al. 2019 ; Mahamood et al. 2023 , Fatemi et al. 2023). Pb accumulation retards plant growth by affecting reactive oxygen species (ROS) balance such as hydrogen peroxide (H 2 O 2 ) and superoxide(O 2 − ), that are very crucial to plant physiology and morphology. It also affects biochemical molecules and involved in disrupting ionic homeostasis and cellular integrity of plants. Consequently, the availability of nutrients by plants is hindered (Ma et al. 2020; Rashid et al. 2023 ). Furthermore, Pb can enter the body through the food chain and its accumulation can disturbs numerous body functions, including the reproductive systems, neurological system, bone fractures, anemia and neurotoxicity (Amos-Kroohs et al. 2016 ; Tran et al. 2023 ). Therefore, it is imperative to develop novel and efficient strategies for mitigating environmental health concerns and ensuring global food security. Nanotechnology is an emerging tool for the development of sustainable agriculture with its potentials uses in agroecosystems (Ahmad et al. 2018 ; Diao et al. 2020 ; Faraz et al. 2020 ). Many studies have shown that heavy metal uptake by crops can be reduced through nanoparticles (NPs). Titanium oxide nanoparticles (TiO 2 -NPs) and Zinc oxide nanoparticles (ZnO-NPs) are two examples of different nanomaterials with unique characteristics and modes of action. ZnO-NPs have been recognized for their substantial role in mitigating HMs stress in plants due to their significant involvement in many metabolic pathways, stimulating certain genes and increasing the availability of essential nutrients and amino acids to plants (Faizan et al. 2020 ; Silva et al. 2022 ; Huang et al. 2022). Both TiO 2 and ZnO NPs were applied foliar or in the soil to increase plant tolerance to heavy metals (Kurtinová and Šebesta, 2023 ). Numerous studies have demonstrated that ZnO-NPs can effectively diminish metal accumulation by increasing zinc concentrations and oxidative stress tolerance (Ali et al. 2019 ; Wu et al. 2020; Chen et al. 2023 ). ZnO-NPs foliar application increased wheat growth and metabolism by decreasing Pb uptake (Raghib et al. 2020 ). Additionally, the application of ZnO-NPs markedly improved the enzymatic activity i.e., CAT, SOD, APX and POD under metal stress, demonstrating the defensive role of NPs in the metal stress environment (Ahmad et al. 2020 ). TiO 2 -NPs are a growth promoter and enhance plant defense mechanism and physiology (Lei et al., 2008 ; Kolenčík et al. 2021 ). Recent studies observed that TiO 2 NPs interact with the Brassica juncea L. root system and effectively remove Cd from the soil as a hyperaccumulator (Liao et al. 2023 ). TiO 2 nanoparticles greatly increased the growth, photosynthetic activity and Cd tolerance in Brassica plants under 10 mg/kg Cd contaminated soil (Bakshi and Kumar, 2023 ). TiO 2 -NPs reduce rice Pb bioaccumulation to varying degrees, but high exposure levels significantly decrease it (Cai et al. 2017 ) There is a lack of comprehensive understanding regarding ZnO-NPs and TiO 2 -NPs role in alleviating Pb toxicity in Brassica napus L. and overall effect on plant growth performance. Agriculture is the foundation of developing nations' economy and the food source for the world's expanding population (Manzoor et al. 2023 ). Around 42.2 hectares of land are used to cultivate Brassica napus, a crop used for food and fodder worldwide (Naheed et al. 2021 , Rahman et al. 2016 ). The Brassica napus L. family is often ranked third in terms of food provision, behind pulses and cereals, and is the second-highest-yielding crop in terms of oil production (Safdar et al. 2023 , Naheed et al. 2021 ; Borges et al. 2023 ). Brassica napus L. is an important oilseed crop in Pakistan because of its contribution to current edible oil production. The Brassicaceae family of plants, which includes canola ( Brassica napus L.) and Indian mustard ( Brassica juncea L.), has been widely used in phytoextraction and as a hyperaccumulator due to metal accumulation in shoots and high metal tolerance, and also their rapid growth, high biomass production (Hidalgo et al. 2023 ). Hence, efforts were made to enhance its agronomic and economic significance by several means, such as enhancing disease resistance, optimizing oil extraction, and improving seed size and reducing metal stress (Srivastava et al. 2021 ; Gatasheh et al. 2023 ). The current study aimed to evaluate and compare the efficacy of TiO 2 and ZnO-NPs role in alleviating Pb toxicity in Brassica napus L. plants via modulation antioxidant enzymes. Furthermore, effects of NPs on Brassica napus L. morphological and physiological parameters under Pb stress was examined under Pb stress with ultimate goal of exploring TiO 2 and ZnO NPs as highly efficient, non-toxic, and sustainable strategy for Pb mitigation in agricultural crops. 2. Material and Methods 2.1. ZnO and TiO 2 nanoparticles preparation and characterization 2.1.1 Regents Zinc acetate dihydrate (Zn (CH 3 COO) 2 .2H 2 O) ≥ 99%, methanol (CH 3 OH), and Sodium Hydroxide (NaOH) 117 ≥ 99% and Nitride Chloride TiCl 4 (≥ 99.0%), NH 3 (Ammonia) were purchased from Alfa Aesar, Karlsruhe, Germany. 2.1.2. ZnO and TiO 2 nanoparticles preparation The synthesis of zinc nanoparticles (Zn NPs) was carried out using a sol-gel method with minor modifications, as described by Vishwakarma and Sing in 2020. In order to prepare a sol, zinc Acetate dihydrate was dissolved with methanol at room temperature. Subsequently, the solution was subjected to ultrasonication at 25℃ for a duration of 120 minutes. Then, clear transparent sol was obtained with no precipitate and turbidity. Sodium Hydroxide (NaOH) 0.02 M solution, was added and ultrasonically stirred for duration of 60 mins. Filter and wash precipitate with excess methanol to eliminate any impurity. Precipitates were dried on a hot plate at 80℃ temperature for 15 minutes. Following that, the precipitates were annealed at 400℃ for 30 minutes. TiO 2 NPs were prepared by a sol-gel method slight modification (Poursani et al., 2016 ). In brief, Titanium tetra chloride (TiCl 4 ) was added to deionized water with stirring at 1000 rpm. Ammonia (NH3) solution was added gradually (dropwise) to adjust PH (7.8) of the solution with continuous stirring until gel was formed. After formation of TiOH 2 colloids, the sediment was separated by filtration and dried at 70˚C for 24 hours. Then, calcination was done at 400˚C in furnace for 4 hours in the Environmental Toxicology & Chemistry lab, Government College University (GCU), Faisalabad, Punjab, Pakistan. 2.1.3 Instrumental analysis Scanning electron microscope (SEM) (German ZEISS Sigma 300) was performed to analyze nanoparticles surface morphology. The X-ray diffraction (XRD) data for ZnO and TiO 2 was obtained using a Bruker D8 Advance X-ray diffractometer, which was equipped with radiation and operated in the 2-theta range of 25–65°. 2.2. Soil sample collection and analysis The soil used in this experiment was collected from the agriculture field Faisalabad, Punjab, Pakistan. Sample of the soil were collected from the surface (0–200 mm) using scoop shovel, dried in the air, and sifted through 2mm sift for analysis and pot culturing. Soil chemical and physical properties were determined such as soil texture (silt clay), pH (7.80), Zn (0.453 mg kg − 1 ), electrical conductivity (6.71 dS m − 1 ), SAR (22 mmol L − 1 ), Ca 2+ + Mg + 2 (18 meq L − 1 ), available phosphorous (2.78 mg kg − 1 ), and available Pb (21.23 mg kg − 1 ). 2.3. Plant materials and growth conditions A pot experiment was conducted in a natural environment (day/night 23.3/16°C, relative humidity 39 ± 3%) in a botanical garden GC University, Faisalabad, Punjab, Pakistan. The pots used for experiment were cylindrical plastic pots (130 g, 7.8 cm diameter, 8.7 cm height). The experiment was carried under complete randomized designed (CRD) with three replicates. Each pot was filled with five kg soil and spiked with Pb (300 mg Kg − 1 ) using Lead acetate Pb (C 2 H 3 O 2 ) 2 and incubated for two months for Pb stabilization (Ahmed et al. 2023 ). Seeds of Brassica napus L. ( cv. Super Canola) disinfected with hydrogen peroxide (H 2 O 2 ) 2.5% v/v solution for 20 mins followed by distilled water wash to eliminate any contaminant. Seeds were incubated in darkness at 25 ℃ for three days before sowing in the pots (Farooq et al. 2016). After germination, the recommended dose of NPK (120:80:40 kg ha − 1 ) was applied in order to avoid any nutritional deficiency. Before, foliar application of nanoparticles (NPs) was ultra-sonicated for 30 min with distilled to disperse properly. Foliar application of ZnO and TiO 2 NPs at 25,50 & 100mg L − 1 concentration was applied according to the treatment plan. Simultaneously, controlled plants were sprayed with the distilled water. In total, five sprays were applied to each treatment after one week of interval. During the growing period, the plants were irrigated using tap water with a pH value of 7.42, as measured by a pH meter (Portable Meter Hanna HI-9812-51). 2.4. Measurement of growth parameters Growth parameters including height (cm) of the plant were determined by stainless steel meter rod and then dry weight were determined by electrical weigh balance (OHAUS-PR224) subsequent to the drying process the oven (72 hours at 70°C) (Model: 101-OAB Digital Lab Thermostatic Electric Incubator). Plants were grinded with the help of grinder into fine powder for further analysis. 2.5. Measurement of chlorophyll pigment and SPAD values To determine the concentration of chlorophyll, plant leaves weighing 0.15 g, were crushed. The resulting crushed leaves were then placed into a testing tube (10 mL) containing 4 mL of a buffer solution (1:1 ratio) containing ethanol and acetone. Subsequently, the tube was incubated in darkness for a period of 5 hours. The centrifugation was performed at 3000 rpm for a duration of 10 minutes in order to collect the supernatant and measured by spectrophotometer (Labman LMSPUV1900 Double Beam UV-VIS Spectrophotometer). (Lichtenthaler, 1987 ). The SPAD value of leaves was determined with portable SPAD meter (atLEAF CHL STD chlorophyll meter 502). 2.6. Gas exchange parameters Infrared Gas Analyzer (3051c Plant Photosynthesis meter) was used to examine the parameters of gas exchange on a shiny day (12:00–13:00). Fully extended leaves were taken from each pot to measure the water use efficacy, stomatal conductance, transpiration rate, and photosynthetic rate. 2.7. determination of antioxidant enzymes and oxidants To prepare antioxidant enzyme extract leaf samples were ground using a pestle and mortar in a phosphate buffer solution with a pH of 7.8. The mixture was centrifuged for 10 min duration at 13,000 rpm to obtain supernatant (enzyme extract) antioxidant enzyme activity analysis. Enzyme extract 0.10 (mL)was added in 50 (mM) PBS phosphate buffer solution 0.3 (mL) at pH (6.0) and 300 (mM) of hydrogen peroxide (H 2 O 2 ) to measure peroxidase activity (POD). The spectrophotometer (Labman LMSPUV1900 Double Beam UV-VIS) was used to measure the reaction mixture at 240 nm after 30s of incubation at room temperature. Superoxidase (SOD) activity was measured according to Zhang ( 1992 ). The reaction 3 (mL) was prepared 1.5 (mL) 0.05 M Na 3 PO 4 , 0.01 (mL) enzyme extract, 130 (mM) methionine, 20 µM riboflavin, 750 µM NBT, with 0.1 mM EDTA-NA 2 and quantified using a spectrophotometer. Catalase (CAT) activity was measured by Aebi ( 1984 ). The reaction solution for APX contained 0.2 (mL) enzyme extract, 50 (mM) 100 nmol of phosphate buffer and 300 nmol of 10 mM H 2 O 2 . The spectrophotometer was set at 240 nm to record absorbance Nakano and Asda, (1981). The analysis of malondialdehyde (MDA) in plant tissues was conducted in regard to the approaches described by Heath and Packer, 1968 . In brief, leaf sample 0.5g was homogenized in a solution containing 0.5% thiobarbituric acid (TBA) and centrifuged for 15 mins at 3000 rpm). Subsequently the obtained supernatant was added with 20% TCA solution and allow it to boil at 95 ℃ temperature. After this the mixture was cooled on ice before measurement. The absorbance at 532 nanometer (nm) was measured using a spectrophotometer (Labman LMSPUV1900 Double Beam UV-VIS Spectrophotometer). To determine H 2 O 2 content, leaf sample was pulverized in 10 mL of 0.1% TCA solution, and then the supernatant (enzyme extract) was obtained after 15 minutes of centrifugation at 12,000 rpm. A mixture consisting of 5 (mL) by 0.5% TBA and 5 (mL) 20% TCA were added to 1(ml) of enzyme extract was prepared and subjected boiling at 95°C for a period of 30 minutes. After cooling the mixture naturally, it was centrifuged at 12,000 rpm for a period of 15 minutes. The of absorbance for the supernatant was measured at 410 nanometers (nm) using UV–vis spectrophotometer (Labman LMSPUV1900 Double Beam UV-VIS Spectrophotometer) The electrolyte leakage (EL) in the leaves was determined according to modified method described by Dionisio-Sese and Tobita, ( 1998 ). In brief, leaf samples were soaked in a deionized water at a temperature of 30℃ for a period of 4 hours and allow to cool until room temperature. The value of the EC was measured quickly and labelled as EC 1 . After incubating the treated samples at 121°C for a further thirty minutes, the second EC calculation, labelled as EC 2 , was performed. The EL was calculated by the ratio of the percentage of EC 1 to EC 2 as follows: Electrolyte Leakage % = (EC 1 / EC 2 ) *100 (1) 2.9. Metal estimation Pb and micro and macro nutrients concentration was measured in root and shoot samples. HNO 3 : HClO 4 (3:1 v/v) solution was used to digest the plant sample (0.5 g) and left it overnight under fume hood. The mixture was than digested using method described by (Rehman et al. 2015 ) and filtered through 0.22 µm filters. The filtered samples were subsequently used to measure metal nutrients concentrations in the samples using ICP-OES (Optima 7000DV ICP-OES, Perkin Elmer) 2.10. Statistical analyses Data analysis using SPSS Statistix 8.1 (ANOVA) with a 5% probability level was analyzed. Tukey's HSD post hoc test was employed to analyze the significance among the triplicates and OriginPro2023b (Origin Lab Cooperation, Northampton, MA, USA) was used for plotting figure. 3. Results 3.1. TiO 2 and ZnO nanoparticles characterization SEM analyses showed the size, shape, and structure of the synthesized ZnO-NPs. ZnO-NPs hexagonal shape, uniform distribution, and nanoscale range were demonstrated by their micrographs. ZnO-NPs showed phases in all XRD patterns. All of peaks observed at 2 theta positions were 31.732°, 34.364°, 36.207°, 47.469°, 56.526°, 62.754°, 67.851°, 68.995° along with their corresponding reflected planes (100), (002), (101), (102), (110), (103), (112), (201) respectively with JCPDS No. 01-080-0074.The XRD pattern of prepared ZnO-NPs is shown in Fig. 1 . Under scanning electron microscopy, TiO 2 nanoparticles has predominantly spherical shaped clusters with adequate dispersion at 100nm. (Fig a). These nanoparticles showed clean shape and evenly distributed particles at 200nm magnification. (Fig. b). The XRD pattern of TiO 2 -NPs peaks observed at 2 theta positions were 25.335°, 38.611°, 48.104°, 53.921°, 55.138 along with their corresponding reflected planes (101), (112), (200), (105), (211) respectively with JCPDS No. 01-083-2243. The crystal system of prepared TiO 2 nanostructure is tetragonal given in Fig. 2 . 3.2. The effect of ZnO and TiO 2 nanoparticles on growth TiO 2 and ZnO -NPs foliar application in dose additive manner enhanced growth rate of Brassica napus L. grown under Pb contaminated soil. The lowest shoot length of plant was observed in plants without any supplementation of NPs (control). Specifically, shoot and root length grown in Pb contaminated soil significantly enhanced with increasing level of NPs by 82.31% and 74.01% for 100mg/L for TiO 2 and 75.41% and 63.44% for 100mg/L ZnO -NPs respectively. When compared with the control without NPs, the application of TiO 2 and ZnO -NPs lead to significant enhancement in root fresh weight and root dry weight which was increased by 77.72%, 85.37% for 100mg/L for TiO 2 and 61.13%, 76.56% for 100mg/L ZnO -NPs treatment respectively(Fig. 3 ).Similarly shoot fresh weight and shoot dry weight dramatically increased up to 68.93% and 89.31% by foliar spray of 100 mg/L TiO 2 and up to 57.89% and 78.77% by application of ZnO -NPs as compared to control treatment without NPs, respectively. The highest increase in number of leaves were observed with 100mg/L TiO 2 by 90.43% as compared to control (Fig. 4 ). 3.3. The Effect of TiO 2 and ZnO nanoparticles on photosynthetic pigment TiO 2 and ZnO -NPs foliar application showed significant influence on physiological attributes of Brassica napus L. grown in Pb contaminated soil. Under 100mg/L TiO 2 and ZnO-NPs treatment, the chlorophyll a content was about 66.35% and 62.89% higher as compared to respective control without NPs .Chlorophyll b content was about 86.43% and 77.23% at higher application rate of TiO 2 and ZnO-NPs (100mg/L) that of control .Similarly, a prominent increase in carotenoid content was observed at 100mg/L TiO 2 NPs followed by 100 mg/L ZnO -NPs with increasing value of 89.73% and 76.80% respectively, as compared to control with foliar application of nanoparticles (Fig. 5 ). The imperative role of role of TiO 2 and ZnO-NPs was also observed in improving SPAD values. The highest SPAD value was found as 52.09 at 100 mg /L TiO 2 followed by 100 mg /L ZnO-NPs 49.14 and 50 mg/L TiO 2 (45.49) and 50 mg /L ZnO-NPs (43.96), which was 79.11%, 68.97%, 56.28%, 44.29% higher than control without NPs, respectively (Fig. 5 ). However, a slight increase was observed statically at 25mg/L in both TiO 2 and ZnO-NPs. 3.4. Effect of TiO 2 and ZnO nanoparticles gas exchange parameters The resulted depicted that plants treated with TiO 2 and ZnO-NPs substantially increased gas exchange parameters. When compared with control (without Nps) all treatments with Nps boosted gas exchange metrics (Table.1). At 50 mg/L TiO 2 and ZnO-NPs concentration, the percent increase of the photosynthetic rate ( Pn ), transpiration rate ( Tr ), water use efficiency ( WUE ) and stomatal conductance (Sc) in plant under Pb stress was 70.78%, 75.40%, 71.55%, 69.23% and 50.27%, 63.41, 66.89%, 65.86%, 59.43% respectively, as compared to control without nanoparticles. However, the maximum increase in photosynthetic rate, transpiration rate, water use efficiency, and stomatal conductance, in plants was observed at 100mg/L TiO 2 NPs followed by 100mg/L ZnO-NPs which was 86.78, 89.32%, 84.79%, 74.65% and 77.67% 79.65%, 72.65%, 68% respectively, as compared to control with nanoparticles. All measured gas exchange parameters showed non-significant increase at 25 mg/L concentration in both nanoparticles’ treatment (TiO 2 and ZnO-NPs). 3.5. Effect of TiO 2 and ZnO nanoparticles on oxidant and antioxidant activities The results of indicated that plant grown under Pb contaminated soil without any nanoparticle’s treatment depicted oxidative stress as compared to NPs treatment. The foliar application of TiO 2 and ZnO-NPs significantly increased antioxidant enzymatic activities superoxidase (SOD), peroxidase (POD), catalase (CAT), Ascorbate peroxidase (APX) in leaves as shown in (Fig. 6 ) while simultaneously reduced the oxidant malondialdehyde (MDA), hydrogen peroxide (H 2 O 2) and electrolyte leakage (EL) with increasing concentration of NPs (Fig. 7 ).The application of TiO 2 and ZnO-NPs at 100 mg/L significantly increased CAT (87.74%), SOD (85.88%), POD (87.86%), APX (79.91%) activities and CAT (74.19%), SOD (73.58%), POD (76.98%), APX (73.58%) respectively. In addition, the antioxidant activities at 100 mg/L ZnO-NPs were significantly lower than that of 100 mg/L TiO 2 treatment. Likewise, the maximum decrease in oxidant enzymatic activity of MDA (52.37%), H 2 O 2 (59.91%) and EL (74.82%) was observed at 100 mg/L TiO 2 compared with control without nanoparticles, with the values dropped to MDA (46.98%), H 2 O 2 (53.19%) and EL (68.37%) at 100 mg/L ZnO-NPs. 3.6. Pb accumulation and fractions in plant parts The results depicted that Pb accumulation in plant parts diminished with increasing concentration of both Nps (Fig. 8 ). The highest shoot and root Pb concentrations were estimated to be higher at control without NPs. In contrast, the lowest Pb concentration were found where higher level of NPs (TiO 2 and ZnO-NPs) was applied. Specifically, TiO 2 100 mg/L significantly diminished the shoot Pb in plant which was decreased by 84.16% followed by 100 mg/L ZnO-NPs (76.77%) and 50 mg/L TiO 2 Nps (69.58%) as compared to control without NPs. Application of 50 mg/L ZnO-NPs and 25 mg/L or 25 mg/L TiO 2 -NPs also significantly reduced Pb accumulation but slight as compared to above mentioned treatments. A similar trend was also observed in root Pb accumulation as inhibition of Pb was observed with increasing concentration of both NPs (TiO 2 NPs and ZnO-NPs) with the highest reduction in root Pb was found at 100 mg/L TiO 2 and ZnO-NPs by 45.77% and 42.33% respectively, as compared to control without Nps. The application at 50 mg/L TiO 2 -NPs and ZnO-NPs also showed promising results when compared with control. 3.7. Effect TiO 2 -NPs and ZnO-NPs on nutrient Profiling under Pb Stress The lowest micro and macro nutrients were recorded in root and shoot of Brassica napus L. grown under Pb stress (without NPs treatment). While, the foliar application TiO 2 and ZnO-NPs significantly enhanced root and shoot zinc (Zn), iron (Fe), calcium (Ca), manganese (Mn), magnesium (Mg) and Potassium (K) concentrations as compared to control without nanoparticles treatment (Table.2). Our results revealed that 100 mg/L TiO 2 NPs significantly increased Mg, Fe, K, Mn, Zn and Ca concentrations of root by 53.37% ,68.34%, 70.78%, 28.74%, 63.37%, 71.86% and shoot by 72.13% ,79.43%, 81.25%, 62.78%, 58.45% respectively as compared to control. Interestingly root Ca (81.65%), Zn (75.76%) and Mn (35.99%) and shoot Ca (69.89%), Zn (78.76%) and Mn (68.76%) were found to be higher at 100 mg/L ZnO-NPs followed by 100mg/L TiO 2 NPs. 4. Discussion Heavy metal pollution in soil limit crop growth and production, consequently threatens food security (United Nations, 2019). Nanoparticles in agriculture can increase crop quantity and quality with improving heavy metal tolerance (Zhou et al. 2021). ZnO and TiO 2 -NPs have great unique and disparate properties among different nanoparticles. The foliar application of these nanoparticles considered to be effective than soil application (Lian et al. 2020 ). Our results showed that foliar application of NPs improved growth parameters in brassica plant and reduced Pb induced toxicity which was evidenced by an increment in shoot and root fresh weight, shoot and root length and number of leaves over the control treatment without NPs (Fig. 3 – 4 ). The plant grown under Lead (Pb) stress showed poor growth which is consistent with many previous studies (Islam et al. 2008 ; Shakoor et al. 2014 ; Fatemi et al. 2020 a). Pb accumulation resulted in retarded germination and low biomass in brassica plant (Faiz et al. 2022 ; Ahmed et al. 2023 ). The decrease in biomass under control treatment without nanoparticles might be due to the accumulation of toxic metals led to excessive ROS generation, which can damage plant cell membrane (Aborisade et al. 2023 ). The foliar application of NPs especially at 100 mg/L TiO 2 -NPs significantly ameliorated the Pb toxicity and showed high biomass increment suggesting that TiO 2 was more efficient in promoting plant growth and positively affected Brassica napus L. biomass which is consistent with previous studies (Rizwan et al. 2019 ; Lian et al. 2019; Ogunkunle et al. 2020 ). The improvement of biomass could potentially be attributed to the reduction Pb concentration and higher mineral nutrients in NPs-treated plants (Rizwan et al. 2019 ). Increased leaf chlorophyll concentration boosts photosynthesis, making it an important measure for estimating plant photosynthetic efficiency (Ahmed et al. 2023 ). Many studies have documented that the existence of Pb in soil has a detrimental effect on the production of chlorophyll and carotenoid pigments in several agricultural plants. The current study demonstrated that foliar application of TiO 2 and ZnO-NPs significantly boosted leaf chlorophyll and carotenoid levels (Fig. 5 ). Increased photosynthetic content has been observed to promotes growth, photosynthesis and alleviation of metal toxicity. (Sardar et al. 2022 ). The current results are coherence with the work of many previous studies (Ebrahimi et al., 2016 ; Ahmed et al. 2023 ). The foliar application TiO 2 resulted in a substantial increase in the photosynthetic pigment in wheat and maize crop (Irshad et al. 2021 ; Lian et al. 2020 ). Cowpea plants showed increased chlorophyll concentrations after 100 mg/L foliar sprays of TiO 2 -NPs (Ogunkunle et al. 2020 ). The increase in chlorophyll content can potentially be attributed to the beneficial impact of TiO 2 on enzymatic activities associated with nitrogen metabolism. This, in turn, facilitates the uptake of nitrate by plants and favors the production of organic nitrogen, such as proteins (Song et al. 2013 ; Mishra et al. 2014 ; Ahmed et al. 2023 ). TiO 2 -NPs have also been shown to improve leaf PSII electron donation by attaching to the PSII reaction center complex that may lead to better photosynthetic rate (Hong et al. 2015 ). The current study improved concentration of chlorophyll content with ZnO- NPs is consistent with the previous studies. It has been observed that that ZnO NPs can boost plant Zn concentration, which regulates various physiological and biochemical activities (Qiao et al. 2015 ; Rizwan et al. 2019 ; Raghib et al. 2020 ; Ahmad et al. 2022 ). Gas exchange parameters act as stress biomarker of metal stress in plant. The results of our study showed that Pb stress negatively affecting the photosynthetic rate, Transpiration rate, stomatal conductance and intracellular CO 2 concentration. Higher Pb concentrations in plant leaves impede photosynthesis, hinder electron transport and close stomata to reduce CO 2 assimilation (Akinci et al. 2010 ). However, foliar application of TiO 2 -NPs and ZnO-NPs significantly enhance Brassica napus L. gas exchange parameters (Table.1). It is estimated that application of TiO 2 -NPs increased activity of RuBisCO activase, a key enzyme in the Calvin cycle. Higher activity of this enzyme facilitates the process of carbon dioxide fixation and augments photosynthetic activity in plants (Gao et al. 2013 ). TiO 2 -NPs enhanced chlorophyll production, plant quantum yield, and photosynthetic system chemical energy (Sardar et al. 2022 ). ZnO-NPs potentially enhanced the gas exchange parameters in our study. It is well evident that ZnO-NPs can improve photosynthetic rates in rice and soybean plant grown in metal contaminated soil (Fiazan et al. 2018; Ahmad et al. 2020 ). ZnO-NPs 50 mg/L foliar application significantly increase photosynthetic rate, stomatal conductance in Pb stressed soil (Alhammad et al. 2023 ). Environmental stress including heavy metal induce generation ROS such as H 2 O 2 and O 2 − . This oxidative stress can result in detrimental effects, including the degradation of cellular membranes, biomolecules and structural damage (Irshad et al. 2020 ). MDA is generated during the lipid peroxidation and triggered by ROS production (Gaschler et al. 2017; Tripathi et al. 2017 ). Conversely, it is possible that increased levels of antioxidant activity could reduce the oxidative stress induced by heavy metal by scavenging excessive reactive oxygen species (ROS). The result of the present study portrayed that foliar application of TiO 2 -NPs and ZnO-NPs reduced oxidative stress by decreasing H 2 O 2 , MDA and EL content in plant and improved the SOD, POD and CAT activities in plant over the control (Pb contaminated soil). SOD scavenges O 2− to H 2 O 2 , while CAT decomposes H 2 O 2 into water and oxygen molecule (Rizwan et al. 2019 ). Our results are confirmed by several studies that TiO 2 -NPs reduce the indicators of ROS (MDA, H 2 O 2, EL) in different plants and can boost resistance to oxidative stress (Song et al. 2012 ; Rizwan et al. 2019 ; Chen et al. 2023 ). The application of zinc oxide nanoparticles (ZnO-NPs) at concentrations of 50 and 100 mg/L on the leaves of soybean plants for a duration of two weeks resulted in a decrease in the levels of H 2 O 2 and MDA by increasing CAT, SOD, APX, boosting soybean tolerance under metal stress (Ahmed et al. 2020). ZnO-NPs improved antioxidant enzymes capacity in Oryza sativa by scavenging ROS. The ZnO-NPs nanoparticles have the ability to interact with the plasma membrane of cells, leading to the scavenging of ROS and providing protection to the cell membrane against oxidative damage (Jalil et al. 2023 ). In our results the growth of Brassica napus L. showed decrease growth under Pb stress without any NPs treatment. Pb primarily enters the root through the apoplastic pathway or calcium ion channels. Other studies have also demonstrated that there is a higher accumulation of Pb in the roots compared to the shoot depending on the concentration of Pb (Rizwan et al. 2018 ; Fatemi et al. 2021). Our results showed significant decrease in Pb concentrations by the foliar application of TiO 2 -NPs and ZnO-NPs at highest concentrations (100mg/L) (Fig. 8 ). The lower level of these NPs did not significantly affect Pb concentration in shoot. Decreasing metal accumulation in plants via TiO 2 -NPs by was confirmed by several studies (Wang et al. 2015 ; Ji et al. 2017; Rizwan et al. 2019 ; Kumari et al. 2022 ). The application of TiO 2 -NPs resulted in positive effects on the physiological attributes of wheat and maize plants. Additionally, the application of TiO 2 NPs led to a reduction in the levels of Cd in the biomass, roots, and shoots of cowpea wheat and plants (Irshad et al. 2021 ; Chen et al. 2023 ). Kumar et al. 2023 and reported that exogenous application of TiO 2 NPs created hinderance in the translocation and accumulation of metal might be ascribed to the binding of Cr transporter ions, such as sulphate or iron, with TiO 2 nanoparticles. TiO 2 -NPs exposure to rice plants decreased Pb bioaccumulation ≥ 80% in dose additive manner (Cai et al. 2017 ). The efficacy of ZnO-NPs in significantly reducing metal concentration has been reported by my studies (Sharifan et al. 2020; Pishkar et al. 2022 ; Ghori et al. 2023). One of the recent types of research observed that ZnO-NPs can enter through stomatal channels to leaf epidermis and release Zn ions into the apoplast and by taken up by mesophyll cells. Therefore, ZnO-NPs leads to reduction of metal stress in plants (Rizwan et al. 2019 ; Zhu et al. 2020). The observed reduction in Pb concentration in plants treated with nanoparticles (NPs) may also be attributed to the augmentation of antioxidant activities and biomass in the treated plants, thus resulting in an overall reduction in metal concentration in the plant. It is recognized that an excess of lead significantly hinders the entry of various ions to their respective absorption sites on the roots. The process of depolarization of the plasma membrane in different cells of the root leads to a decrease in the electromotive force required for the uptake of mineral nutrients (Sardar et al. 2021). In present study it is evident that plants with Pb stress showed lower concentration of nutrients. However, it has been observed that TiO 2 -NPs and ZnO-NPs significantly transformed the mineral balance by change in micro nutrients (Zn, Fe, Mn) and macro nutrients (Ca, Mg, K). Foliar application of TiO 2 -NPs significantly enhanced Fe, Zn, K, Mg in (Table 2 ) while decreased in Ca and Mn was observed in Brassica napus L. as compared to ZnO-NPs. In a study by Dağhan et al. ( 2020 ) TiO 2 NPs were found to decrease K and Mn levels and increase Fe and Cu absorption in Triticum vulgare L. TiO 2 -NPs enhances the absorption of Fe via stimulating the up-regulation of genes associated with Fe acquisition (Lyu et al. 2017). Additionally, it was shown that the presence of titanium dioxide nanoparticles (at a concentration of 500 mg kg − 1 ) resulted in increased zinc levels in barley kernels (Pošćić et al. 2016 ). The decrease in Ca as compared to ZnO-NPs may be because of decrease in mobility and absorption of calcium as a result of the formation of complexes between negatively charged pure TiO 2 NPs and calcium ions (Ca 2+ ) at the interface between roots and soil Wang et al. ( 2021 ). Application of ZnO-NPs foliar application increased the leaf concentration of macro and micro nutrients and enhanced plant stress tolerance. The positive effect of ZnO-NPs on nutrients has been documented by many studies (Kolenčík et al. 2019 ; Pishkar et al. 2022 ). The finding of the current study suggested that TiO 2 -NPs and ZnO-NPs could be very effective strategy to mitigate Pb toxicity however, more pronounced impact on Brassica napus L. was observed in scenario of TiO 2 NPs. Table 1 Effect of ZnO-NPs and TiO 2 -NPs on gas exchange parameters of Brassica napus L. grown under lead contaminated soil. Values are the means ± Standard deviation (n = 3) different letters indicate significate difference among treatment at p ≤ 0.05. Treatment Photosynthetic rate (µ mol CO 2 m − 2 s − 1 ) Transpiration rate (mol H 2 O m − 2 s − 1 ) Water Use Efficiency (%) Stomatal Conductance (mol m − 2 s − 1 ) (Ck) Pb 5.42 ± 0.31d 0.909 ± 0.040d 60.48 ± 5.13 e 0.0106 ± 0.0011c ZnO-NPs 25 (mg/L) 6.74 ± 0.65cd 1.214 ± 0.78c 109.27 ± 10.5 cd 0.0255 ± 0.0012bc TiO 2 -NPs 25 (mg/L) 7.46 ± 0.79bc 1.394 ± 0.149bc 114.21 ± 10.83 c 0.0266 ± 0.0037b ZnO-NPs 50 (mg/L) 8.14 ± 1.15abc 1.486 ± 0.019bc 118.43 ± 28.01 bc 0.0383 ± 0.0210ab TiO 2− NPs 50 (mg/L) 9.25 ± 1.01bc 1.595 ± 0.159 ab 121.28 ± 25.77 b 0.0393 ± 0.0064ab ZnO-NPs 100 (mg/L) 10.31 ± 0.94 ab 1.788 ± 0.056a 125.24 ± 28.41 ab 0.0404 ± 0.0010a TiO 2 -NPs 100 (mg/L) 10.76 ± 2.26a 1.812 ± 0.0174a 128.0 ± 16.08 a 0.0411 ± 0.0009a Table 2 Effect of ZnO-NPs and TiO 2 -NPs on nutritional profile in root and shoot of Brassica napus L. grown under lead contaminated soil. Different letters indicate significate difference among treatment at p ≤ 0.05. Values are the means ± Standard deviation (n = 3). Treatments Shoots Macronutrients (mg g − 1 DW) Micronutrients (µg g − 1 DW) Ca K Mg Mn Fe Zn Pb (Ck) 15573.53 ± 303.97f 21319.47 ± 214.31f 13609.80 ± 349.20 e 19.44 ± 2.97e 184.97 ± 9.31e 14.15 ± 2.07e ZnO-NPs 25 (mg/L) 21617.40 ± 390.62d 344229.0 ± 285.73e 22378.07 ± 418.20d 25.67 ± 1.29d 224.43 ± 15.77d 18.55 ± 1.07de TiO 2 -NPs 25 (mg/L) 18540.03 ± 554.95e 30105.20 ± 446.17e 22666.43 ± 916.29d 21.10 ± 1.71e 273.0 ± 12.62c 16.21 ± 2.52de ZnO-NPs 50 (mg/L) 23435.77 ± 258.88c 38635.60 ± 310.56c 24582.13 ± 334.06c 31.53 ± 1.32bc 309.13 ± 15.66b 36.43 ± 1.87b TiO 2 -NPs 50 (mg/L) 22341.90 ± 75.55d 36240.37 ± 588.77d 25217.73 ± 224.71bc 28.61 ± 0.84cd 337.33 ± 5.84ab 20.91 ± 2.03d ZnO-NPs 100 (mg/L) 26296.0 ± 852.41a 42469.60 ± 224.57a 2689.33 ± 341.26ab 35.75 ± 0.80a 361.97 ± 4.82a 64.98 ± 3.74a TiO 2 -NPs 100 (mg/L) 24650.57 ± 465.95b 40774.40 ± 211.53b 27121.03 ± 688.30 a 33.35 ± 1.67ab 367.57 ± 18.01a 28.03 ± 1.33c Treatments Roots Macronutrients (mg g − 1 DW) Micronutrients (µg g − 1 DW) Ca K Mg Mn Fe Zn Pb (Ck) 763.73 ± 21.72f 1060.07 ± 36.77g 9492.34 ± 319.69f 92.28 ± 2.54e 63.29 ± 10.55d 5.12 ± 1.53e ZnO-NPs 25 (mg/L) 1243.50 ± 20.07d 1351.10 ± 27.70f 11285.80 ± 152.09e 108.48 ± 2.28 c 114.43 ± 6.23c 7.99 ± 0.52de TiO 2 –NPs 25 (mg/L) 1153.53 ± 31.57e 1470.27 ± 17.06e 11855.43 ± 237.16e 102.59 ± 3.83d 115.92 ± 8.91c 5.60 ± 0.24e ZnO-NPs 50 (mg/L) 1407.47 ± 12.20bc 1560.17 ± 36.52d 12621.47 ± 215.69d 115.95 ± 1.58b 119.33 ± 6.35b 21.80 ± 0.91b TiO 2 -NPs 50 (mg/L) 1357.70 ± 30.77c 1670.27 ± 43.51c 13508.40 ± 271.60c 113.41 ± 1.01bc 121.28 ± 5.91b 9.67 ± 0.65d ZnO-NPs 100 (mg/L) 1516.50 ± 20.62a 1797.90 ± 45.20b 14233.70 ± 298.66b 122.73 ± 1.50 a 125.28 ± 5.91ab 32.31 ± 2.32a TiO 2 -NPs 100 (mg/L) 1446.37 ± 11.95b 1894.40 ± 28.56a 15508.03 ± 328.92a 118.81 ± 2.21ab 129.26 ± 4.46a 15.27 ± 1.51c 5. Conclusion The present study has highlighted that potential impact of TiO 2 and ZnO-NPs on Brassica napus L. under Pb stress. The foliar application of 100 TiO 2 -Nps significantly enhanced Brassica napus L. growth and physiology. TiO 2 and ZnO-NPs reduced oxidative stress by upregulation of leaf antioxidant enzyme activity. The foliar application of TiO 2 and ZnO-NPs significantly reduced Pb uptake with increasing the rate of NPs by improving plant defensive mechanism. Our study also demonstrated that application of TiO 2 and ZnO-NPs enhanced Zn, Fe, Mg, Mn, Ca and K in Brassica napus L. root and shoot by reducing Pb concentration in plant parts and by maintaining the ionic balance. Overall study concluded that both TiO 2 and ZnO-NPs could be affective strategy to reduce Pb bioavailability with more pronounced effect found with TiO 2 -NPs.Furthur studies needed to focus on gene expression related to Pb uptake in plant by TiO 2 and ZnO-NPs under different conditions. Declarations Acknowledgements The authors wish to acknowledge the State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University and Environmental Toxicology & Chemistry laboratory, Government College University, Faisalabad. Authors contribution Adiba Khan Sehrish: Performed the design of experiment, Formal analysis, carried out the experiment and original drafted the manuscript. Shoaib Ahmad: writing – review and editing. Sarah Owdah Alomrani: Formal analysis. Rohina Tabassam: data visualization. Hafeez Ur Rahim: Methodology. Azeem Ahmad: Revising it critically for intellectual content. Arslan Tauqeer: writing – review. Shafaqat Ali: Supervision, Experiment design, Resources, Funding acquisition, Investigation. Funding This work was financial supported under project No. 5634/Punjab/NRPU/R&D/HEC/2016. Data Availability All data generated or analyzed during the study are included in this article. Ethics approval and consent to participate The current study didn’t involve human and human data. Consent for publication This study does not human subjects. The authors have not submitted to a preprint server before submitting it to Environmental Science and Pollution Research . Competing interests The authors declare that they have no known competing interests. References Aborisade MA, Geng H, Oba BT, Kumar A, Ndudi EA, Battamo A Y, Zhao L (2023). Remediation of soil polluted with Pb and Cd and alleviation of oxidative stress in Brassica rapa plant using nanoscale zerovalent iron supported with coconut-husk biochar. J. Plant Physiol. 154023. Adrees M, Ali S, Rizwan M, Zia-ur-Rehman M, Ibrahim M, Abbas F, Irshad M K (2015). Mechanisms of silicon-mediated alleviation of heavy metal toxicity in plants: a review. Ecotoxicol. Environ. Saf. 119, 186-197. Aebi H, (1984). [13] Catalase in vitro. In Methods in enzymology (Vol. 105, pp. 121-126). Academic press. Ahmad P, Alyemeni M N, Al-Huqail A A, Alqahtani M A, Wijaya L, Ashraf M, Bajguz A (2020). Zinc oxide nanoparticles application alleviates arsenic (As) toxicity in soybean plants by restricting the uptake of as and modulating key biochemical attributes, antioxidant enzymes, ascorbate-glutathione cycle and glyoxalase system. Plants. 9(7), 825. Ahmad B, Shabbir A, Jaleel H, Khan MMA, Sadiq Y, (2018). Efficacy of titanium dioxide nanoparticles in modulating photosynthesis, peltate glandular trichomes and essential oil production and quality in Mentha piperita L. Curr. Plant Biol. 13, 6-15. Ahmed KBM, Khan MMA, Shabbir A, Ahmad B, Uddin M, Azam A (2023). Comparative effect of foliar application of silicon, titanium and zinc nanoparticles on the performance of vetiver-a medicinal and aromatic plant. Silicon. 15(1), 153-166. Akinci IE, Akinci S, Yilmaz K (2010). Response of tomato ( Solanum lycopersicum L.) to lead toxicity: Growth, element uptake, chlorophyll and water content. Afr. J. Agric. Res. 5(6), 416-423. Ahmad S, Mfarrej MFB, El-Esawi MA, Waseem M, Alatawi A, Nafees M, Ali S (2022). Chromium-resistant Staphylococcus aureus alleviates chromium toxicity by developing synergistic relationships with zinc oxide nanoparticles in wheat. Ecotoxicol. Environ. Saf. 230, 113142. Alhammad BA, Ahmad A, Seleiman MF, (2023). Nano-Hydroxyapatite and ZnO-NPs Mitigate Pb Stress in Maize. Agronomy. 13(4), 1174. Ali S, Rizwan M, Noureen S, Anwar S, Ali B, Naveed M, Ahmad P (2019). Combined use of biochar and zinc oxide nanoparticle foliar spray improved the plant growth and decreased the cadmium accumulation in rice ( Oryza sativa L.) plant. Environ. Sci. Pollut. Res. 26, 11288-11299. Amos-Kroohs RM, Graham DL, Grace CE, Braun A A, Schaefer TL, Skelton MR, Williams MT (2016). Developmental stress and lead (Pb): Effects of maternal separation and/or Pb on corticosterone, monoamines, and blood Pb in rats. Neurotoxicology. 54, 22-33. Bakshi M, & Kumar A (2023). Co-application of TiO 2 nanoparticles and hyperaccumulator Brassica juncea L. for effective Cd removal from soil: Assessing the feasibility of using nano-phytoremediation. J. Environ. Manage. 341, 118005. Borges CE, Vo dos Santos Veloso R, da Conceição CA, Mendes DS, Ramirez-Cabral NY, Shabani F, da Silva RS (2023). Forecasting Brassica napus production under climate change with a mechanistic species distribution model. Sci. Rep. 13(1), 12656. Cai F, Wu X, Zhang H, Shen X, Zhang M, Chen W, Wang X (2017). Impact of TiO 2 nanoparticles on lead uptake and bioaccumulation in rice ( Oryza sativa L.). NanoImpact. 5, 101-108. Chen F, Li Y, Irshad MA, Hussain A, Nawaz R, Qayyum MF, Ali S (2023). Effect of titanium dioxide nanoparticles and co-composted biochar on growth and Cd uptake by wheat plants: A field study. Environ. Res. 231, 116057. Chen F, Li Y, Zia-ur-Rehman M, Hussain SM, Qayyum MF, Rizwan M, Ali S (2023). Combined effects of zinc oxide nanoparticles and melatonin on wheat growth, chlorophyll contents, cadmium (Cd) and zinc uptake under Cd stress. Sci. Total Environ. 864, 161061. Dağhan H, Gülmezoğlu N, Köleli N, Karakaya B (2020). Impact of titanium dioxide nanoparticles (TiO 2 -NPs) on growth and mineral nutrient uptake of wheat ( Triticum vulgare L.). Biotech. Studies, 29(2), 69-76. Debnath B, Singh WS, Manna K (2019). Sources and toxicological effects of lead on human health. India J Med specialities. 10(2), 66-71. Diao ZH, Yan L, Dong FX, Qian W, Deng Q H, Kong LJ, Chu W (2020). Degradation of 2, 4-dichlorophenol by a novel iron based system and its synergism with Cd (II) immobilization in a contaminated soil. J. Chem. Eng. 379, 122313. Dionisio-Sese ML, & Tobita S (1998). Antioxidant responses of rice seedlings to salinity stress. Plant Sci. 135(1), 1-9. Ebrahimi A, Galavi M, Ramroudi M, Moaveni P (2016). Study of agronomic traits of pinto bean (Phaseolus vulgaris L.) under nano TiO 2 spraying at various growth stages. International Journal of Pharmaceutical Research and Allied Science, 5(2), 458-471. Faiz S, Yasin NA, Khan WU, Shah AA, Akram W, Ahmad A, Ali A, Naveed NH, Riaz L (2022). Role of magnesium oxide nanoparticles in the mitigation of lead-induced stress in Daucus carota: modulation in polyamines and antioxidant enzymes. Int. J. Phytoremediation. 4(4): 364–372. Faizan M, Hayat S, Pichtel J (2020). Effects of zinc oxide nanoparticles on crop plants: A perspective analysis. Sustainable Agriculture Reviews 41: Nanotechnology for Plant Growth and Development, 83-99. Faraz A, Faizan M, Fariduddin Q, Hayat S (2020). Response of titanium nanoparticles to plant growth: agricultural perspectives. Sustainable Agriculture Reviews 41: Nanotechnology for Plant Growth and Development, 101-110. Fatemi H, Pour BE, Rizwan M (2020). Isolation and characterization of lead (Pb) resistant microbes and their combined use with silicon nanoparticles improved the growth, photosynthesis and antioxidant capacity of coriander ( Coriandrum sativum L.) under Pb stress. Environ. Pollut. 266, 114982. Gao J, Xu G, Qian H, Liu P, Zhao P, Hu Y (2013). Effects of nano-TiO 2 on photosynthetic characteristics of Ulmus elongata seedlings. Environ. Pollut. 176, 63–70. Gaschler MM, & Stockwell BR (2017). Lipid peroxidation in cell death. Biochemical and biophysical research communications, 482(3), 419-425. Gatasheh MK, Shah A A, Ali S, Ramzan M, Javad S, Waseem L, Wahid A (2023). Synergistic application of melatonin and silicon alleviates chromium stress in Brassica napus through regulation of antioxidative defense system and ethylene metabolism. Sci. Hortic. 321, 112280. Heath RL, & Packer L (1968). Photoperoxidation in isolated chloroplasts: I. Kinetics and stoichiometry of fatty acid peroxidation. Arch. Biochem. Biophys. 125(1), 189-198. Hidalgo J, Epelde L, Anza M, Becerril J M, Garbisu C (2023). Mycoremediation with Agaricus bisporus and Pleurotus ostreatus growth substrates versus phytoremediation with Festuca rubra and Brassica sp. for the recovery of a Pb and γ-HCH contaminated soil. Chemosphere. 327, 138538. Hong F, Si W, Zhao X, Wang L, Zhou Y, Chen M, Zhang J (2015). TiO 2 nanoparticle exposure decreases spermatogenesis via biochemical dysfunctions in the testis of male mice. J. Agric. Food Chem. 63(31), 7084-7092. Irshad MA, ur Rehman MZ, Anwar-ul-Haq M, Rizwan M, Nawaz R, Shakoor MB, Ali S (2021). Effect of green and chemically synthesized titanium dioxide nanoparticles on cadmium accumulation in wheat grains and potential dietary health risk: A field investigation. J. Hazard. Mater. 415, 125585. Irshad MK, Noman A, Alhaithloul HA, Adeel M, Rui Y, Shah T, Shang J (2020). Goethite-modified biochar ameliorates the growth of rice ( Oryza sativa L.) plants by suppressing Cd and As-induced oxidative stress in Cd and As co-contaminated paddy soil. Sci. Total Environ. 717, 137086. Islam E, Liu D, Li T., Yang X, Jin X, Mahmood Q, Li J, (2008). Effect of Pb toxicity on leaf growth, physiology and ultrastructure in the two ecotypes of Elsholtzia argyi. J. Hazard. Mater. 154(1-3), 914-926. Jalil S, Alghanem SM, Al-Huqail AA, Nazir MM, Zulfiqar F, Ahmed T, Jin X (2023). Zinc oxide nanoparticles mitigated the arsenic induced oxidative stress through modulation of physio-biochemical aspects and nutritional ions homeostasis in rice ( Oryza sativa L.). Chemosphere. 338, 139566. Kingston‐Smith AH, Harbinson J, Foyer CH (1999). Acclimation of photosynthesis, H 2 O 2 content and antioxidants in maize (Zea mays) grown at sub‐optimal temperatures. Plant Cell Environ. 22(9), 1071-1083. Kolenčík M, Ernst D, Komár M, Urík M, Šebesta M, Dobročka E, Kratošová G (2019). Effect of foliar spray application of zinc oxide nanoparticles on quantitative, nutritional, and physiological parameters of foxtail millet ( Setaria italica L.) under field conditions. Nanomaterials, 9(11), 1559. Kolenčík M, Nemček L, Šebesta M, Urík M, Ernst D, Kratošová G, Konvičková Z (2021). Effect of TiO 2 as plant growth-stimulating nanomaterial on crop production. Plant Responses to Nanomaterials: Recent Interventions, and Physiological and Biochemical Responses, 129-144. Kumar D, Dhankher OP, Tripathi RD, Seth CS (2023). Titanium dioxide nanoparticles potentially regulate the mechanism (s) for photosynthetic attributes, genotoxicity, antioxidants defense machinery, and phytochelatins synthesis in relation to hexavalent chromium toxicity in Helianthus annuus L. J. Hazard. Mater. 454, 131418. Kumar P, Alamri SA, Alrumman SA, Eid EM, Adelodun B, Goala M, Kumar V (2022). Foliar use of TiO 2 -nanoparticles for okra (Abelmoschus esculentus L. Moench) cultivation on sewage sludge–amended soils: biochemical response and heavy metal accumulation. Environ. Sci. Pollut. Res. 29(44), 66507-66518. Kumari S, Khanna RR, Nazir F, Albaqami M, Chhillar H, Wahid I, Khan, MIR (2022). Bio-synthesized nanoparticles in developing plant abiotic stress resilience: A new boon for sustainable approach. Int. J. Mol. Sci. 23(8), 4452. Kurtinová S, & Šebesta M (2023). Heavy metal stress alleviation in plants by ZnO and TiO 2 nanoparticles. In Nanotechnology in Agriculture and Agroecosystems (pp. 347-365). Elsevier. Lei Z, Mingyu S, Xiao W, Chao L, Chunxiang Q, Liang C, Fashui H (2008). Antioxidant stress is promoted by nano-anatase in spinach chloroplasts under UV-B radiation. Biol. Trace Elem. Res. 121, 69-79. Lian J, Zhao L, Wu J, Xiong H, Bao Y, Zeb A, Liu W (2020). Foliar spray of TiO 2 nanoparticles prevails over root application in reducing Cd accumulation and mitigating Cd-induced phytotoxicity in maize (Zea mays L.). Chemosphere. 239, 124794. Liao Y, Li Z, Yang Z, Wang J, Li B, Zu Y (2023). Response of Cd, Zn Translocation and Distribution to Organic Acids Heterogeneity in Brassica juncea L. Plants. 12(3), 479. Lichtenthaler, HK, (1987). [34] Chlorophylls and carotenoids: pigments of photosynthetic biomembranes. In Methods in enzymology (Vol. 148, pp. 350-382). Academic Press. Mahamood MN, Zhu S, Noman A, Mahmood A, Ashraf S, Aqeel M, Irshad MK (2023). An assessment of the efficacy of biochar and zero-valent iron nanoparticles in reducing lead toxicity in wheat ( Triticum aestivum L.). Environ. Pollut. 319, 120979. Manzoor N, Ali L, Al-Huqail A A, Alghanem SMS, Al-Haithloul HA, S Abbas, T Wang G (2023). Comparative efficacy of silicon and iron oxide nanoparticles towards improving the plant growth and mitigating arsenic toxicity in wheat ( Triticum aestivum L.). Ecotoxicol. Environ. Saf. 264, 115382. Mishra V, Mishra RK, Dikshit A, Pandey AC (2014). Interactions of nanoparticles with plants: an emerging prospective in the agriculture industry. In Emerging technologies and management of crop stress tolerance (pp. 159-180). Academic press. Mitra A, Chatterjee S, Voronina AV, Walther C, Gupta DK (2020). Lead toxicity in plants: a review. Lead in Plants and the Environment, 99-116. Nag R & Cummins E (2022). Human health risk assessment of lead (Pb) through the environmental-food pathway. Sci. Total Environ. 810, 151168. Naheed R, Aslam H, Kanwal H, Farhat F, Gamar MIA, Al-Mushhin AA, Hessini K (2021). Growth attributes, biochemical modulations, antioxidant enzymatic metabolism and yield in Brassica napus varieties for salinity tolerance. Saudi J. Biol. Sci. 28(10), 5469-5479. Nakano Y, & Asada K (1981). Hydrogen peroxide is scavenged by ascorbate-specific peroxidase in spinach chloroplasts. Plant Cell Physiol. 22(5), 867-880. Ogunkunle C O, Odulaja DA, Akande FO, Varun M, VishwakarmaV, Fatoba P O (2020). Cadmium toxicity in cowpea plant: Effect of foliar intervention of nano-TiO 2 on tissue Cd bioaccumulation, stress enzymes and potential dietary health risk. J. Biotechnol. 310, 54-61. Pishkar L, Yousefi S, Iranbakhsh A, (2022). Foliar application of Zinc oxide nanoparticles alleviates cadmium toxicity in purslane by maintaining nutrients homeostasis and improving the activity of antioxidant enzymes and glyoxalase system. Ecotoxicol. 31(4), 667-678. Pošćić F, Mattiello A, Fellet G, Miceli F, Marchiol L (2016). Effects of cerium and titanium oxide nanoparticles in soil on the nutrient composition of barley ( Hordeum vulgare L.) kernels. Int. J. Environ. Res. Public Health, 13(6), 577. Poursani AS, Nilchi A, Hassani A, Shariat SM, Nouri J (2016). The synthesis of nano TiO 2 and its use for removal of lead ions from aqueous solution. J. Water Resource Prot. 8(04), 438. Qiao X, Wang P, Shi G, Yang H, (2015). Zinc conferred cadmium tolerance in Lemna minor L. via modulating polyamines and proline metabolism. Plant Growth Regul. 77, 1-9. Raghib F, Naikoo MI, Khan FA, Alyemeni MN, Ahmad P (2020). Interaction of ZnO nanoparticle and AM fungi mitigates Pb toxicity in wheat by upregulating antioxidants and restricted uptake of Pb. J. Biotechnol. 323, 254-263. Rahman A, Nahar K, Hasanuzzaman M, Fujita M (2016). Calcium supplementation improves Na + /K + ratio, antioxidant defense and glyoxalase systems in salt-stressed rice seedlings. Front. Plant Sci. 7, 609. Rai PK, Lee SS, Zhang M, Tsang YF, Kim KH (2019). Heavy metals in food crops: Health risks, fate, mechanisms, and management. Environ. Int. 125, 365-385. Rashid A, Schutte BJ, Ulery A, Deyholos MK, Sanogo S, Lehnhoff EA, Beck L (2023). Heavy Metal Contamination in Agricultural Soil: Environmental Pollutants Affecting Crop Health. Agronomy. 13(6), 1521. Rehman MZU, Rizwan M, Ghafoor A, Naeem A, Ali S, Sabir M, Qayyum MF (2015). Effect of inorganic amendments for in situ stabilization of cadmium in contaminated soils and its phyto-availability to wheat and rice under rotation. Environ. Sci. Pollut. Res. 22, 16897-16906. Rizwan M, Ali S, Ali, Adrees M, Arshad M, Hussain A, ur Rehman MZ, Waris AA (2019). Zinc and iron oxide nanoparticles improved the plant growth and reduced the oxidative stress and cadmium concentration in wheat. Chemosphere 214:269-277. Rizwan M, Ali S, Rehman MZU, Javed MR, Bashir A (2018). Lead toxicity in cereals and its management strategies: a critical review. Water, Air, & Soil Pollut. 229, 1-16. Rizwan M, Ali S, Adrees M, Rizvi H, Zia-ur-Rehman M, Hannan F, Ok YS (2016). Cadmium stress in rice: toxic effects, tolerance mechanisms, and management: a critical review. Environ. Sci. Pollut. Res. 23, 17859-17879. Safdar ME, Qamar R, Javed A, Nadeem, MA, Javeed HMR, Farooq S, Ahmed MA (2023). Combined application of boron and zinc improves seed and oil yields and oil quality of oilseed rape ( Brassica napus L.). Agronomy 13(8), 2020. Sardar R, Ahmed S, Yasin NA (2022). Titanium dioxide nanoparticles mitigate cadmium toxicity in Coriandrum sativum L. through modulating antioxidant system, stress markers and reducing cadmium uptake. Environ. Pollut. 292, 118373. Shakoor MB, Ali S, Hameed A, Farid M, Hussain S, Yasmeen T, Abbasi GH (2014). Citric acid improves lead (Pb) phytoextraction in Brassica napus L. by mitigating Pb-induced morphological and biochemical damages. Ecotoxicol. Environ. Saf. 109, 38-47. Silva S, Dias MC, Silva AM (2022). Titanium and zinc based nanomaterials in agriculture: A promising approach to deal with (a) biotic stresses?. Toxics. 10(4), 172. Song G, Gao Y, Wu H, Hou W, Zhang C, Ma H, (2012). Physiological effect of anatase TiO 2 nanoparticles on Lemna minor. Environ. Toxicol. Chem. 31(9), 2147-2152. Song U, Jun H, Waldman B, Roh J, Kim Y, Yi J, Lee EJ, (2013). Functional analyses of nanoparticle toxicity: a comparative study of the effects of TiO 2 and Ag on tomatoes (Lycopersicon esculentum). Ecotoxicol. Environ. Saf. 93, 60-67. Srivastava D, Tiwari M, Dutta P, Singh P, Chawda K, Kumari M, Chakrabarty D (2021). Chromium stress in plants: toxicity, tolerance and phytoremediation. Sustainability. 13(9), 4629. Tran QT, Tran TH, Nguyen QD, Nguyen TT, Nguyen TD, Nguyen VK, Ha XL (2023). Combination of Superabsorbent Polymer and Vetiver Grass as A Remedy for Lead-Polluted Soil. Geogr. Environ. Sustain. 16(1), 181-188. Tripathi DK, Mishra RK, Singh S, Singh S, Vishwakarma K, Sharma S, Chauhan DK (2017). Nitric oxide ameliorates zinc oxide nanoparticles phytotoxicity in wheat seedlings: implication of the ascorbate–glutathione cycle. Front. Plant Sci. 8, 1. Nations, U (2015). Department of Economic and Social Affairs. Population Division. Vishwakarma A & Singh SP (2020). Synthesis of zinc oxide nanoparticle by sol-gel method and study its characterization. Int. J. Res. Appl. Sci. Eng. Technol. 8(4), 1625-7. Wang Y, Peng C, Fang H, Sun L, Zhang H, Feng J, Shi J (2015). Mitigation of Cu (II) phytotoxicity to rice (Oryza sativa) in the presence of TiO 2 and CeO 2 nanoparticles combined with humic acid. Environ. Toxicol. Chem. 34(7), 1588-1596. Wang Y, Deng C, Cota-Ruiz K, Tan W, Reyes A, Peralta-Videa, JR, Gardea-Torresdey JL (2021). Effects of different surface-coated nTiO 2 on full-grown carrot plants: Impacts on root splitting, essential elements, and Ti uptake. J. Hazard. Mater. 402, 123768. Zhang XZ (1992). The measurement and mechanism of lipid peroxidation and SOD, POD and CAT activities in biological system. Res. Method. Crop Physiol. 208-211. Zhou P, Adeel M, Shakoor N, Guo M, Hao Y, Azeem I, Rui Y (2020). Application of nanoparticles alleviates heavy metals stress and promotes plant growth: An overview. Nanomater. 11(1), 26. Supplementary Files GraphicalAbstract.pptx Highlights.docx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {\"props\":{\"pageProps\":{\"initialData\":{\"identity\":\"rs-3684389\",\"acceptedTermsAndConditions\":true,\"allowDirectSubmit\":true,\"archivedVersions\":[],\"articleType\":\"Research Article\",\"associatedPublications\":[],\"authors\":[{\"id\":267037893,\"identity\":\"a7f5e95f-f761-40e4-9163-9f53fb3afd5b\",\"order_by\":0,\"name\":\"Adiba Khan Sehrish\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nanjing University School of the Environment\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Adiba\",\"middleName\":\"Khan\",\"lastName\":\"Sehrish\",\"suffix\":\"\"},{\"id\":267037894,\"identity\":\"3f2bc67c-6909-486e-8aad-91f73b64b5c0\",\"order_by\":1,\"name\":\"Shoaib Ahmad\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nanjing University School of the Environment\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Shoaib\",\"middleName\":\"\",\"lastName\":\"Ahmad\",\"suffix\":\"\"},{\"id\":267037895,\"identity\":\"f83cb2c4-eba4-41aa-9d62-9de2723c88ac\",\"order_by\":2,\"name\":\"Sarah Owdah Alomrani\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Najran University College of Science and Arts\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Sarah\",\"middleName\":\"Owdah\",\"lastName\":\"Alomrani\",\"suffix\":\"\"},{\"id\":267037896,\"identity\":\"e8c7c432-6efa-4876-930c-e01c1f0f640c\",\"order_by\":3,\"name\":\"Rohina Tabassam\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nanjing University School of the Environment\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Rohina\",\"middleName\":\"\",\"lastName\":\"Tabassam\",\"suffix\":\"\"},{\"id\":267037897,\"identity\":\"ad481266-cf0a-48c9-b701-bfad974a1f6d\",\"order_by\":4,\"name\":\"Hafeez Ur Rahim\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"University of Ferrara Department of Chemical and Pharmaceutical Sciences: Universita degli Studi di Ferrara Dipartimento di Scienze Chimiche e Farmaceutiche\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Hafeez\",\"middleName\":\"Ur\",\"lastName\":\"Rahim\",\"suffix\":\"\"},{\"id\":267037898,\"identity\":\"017c54bd-9b5d-45e0-901f-f35cc32e95dd\",\"order_by\":5,\"name\":\"Azeem Ahmad\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"University of Agriculture Faisalabad\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Azeem\",\"middleName\":\"\",\"lastName\":\"Ahmad\",\"suffix\":\"\"},{\"id\":267037899,\"identity\":\"3fd231b3-e813-48e4-8ef5-f7cb28edd76a\",\"order_by\":6,\"name\":\"Arslan Tauqeer\",\"email\":\"\",\"orcid\":\"\",\"institution\":\"Nanjing University\",\"correspondingAuthor\":false,\"prefix\":\"\",\"firstName\":\"Arslan\",\"middleName\":\"\",\"lastName\":\"Tauqeer\",\"suffix\":\"\"},{\"id\":267037900,\"identity\":\"1e4e6455-dcd8-4577-888f-000bea6d724a\",\"order_by\":7,\"name\":\"Shafaqat Ali\",\"email\":\"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABD0lEQVRIiWNgGAWjYDACCQaGD2AGO2MDQ0KBhRwDAw9BLYwzwBQzSIuBhDEpWkA8A4nEBkJa5Gc3P2z4UWZXx9/M3PzigYFE+objZw8++MBgJ6fbgF2LwZ1jho0955IlJA4ztlkAHZa74UxesuEMhmRjswM4tEgkmD/gbWOWYABqMQBrOZBjJs3DcCBxGw4t8jPSPzb+bauXkIdqSTc4/wa/FoYbOYbNvG2HJQwOMzY/AGpJMLhBwBaggsJmmXPHJTcCbQEFsuHMG2+MDWcY4PYL0GEbG9+UVfPLHW9//PFHhY083/kcwwcfKuzkcGmBADYIKQEiFcAqDfApR2hhBqcc+QZCqkfBKBgFo2CkAQCYiV9D4jGtJwAAAABJRU5ErkJggg==\",\"orcid\":\"https://orcid.org/0000-0002-3773-5196\",\"institution\":\"Government College University Faisalabad\",\"correspondingAuthor\":true,\"prefix\":\"\",\"firstName\":\"Shafaqat\",\"middleName\":\"\",\"lastName\":\"Ali\",\"suffix\":\"\"}],\"badges\":[],\"createdAt\":\"2023-11-30 02:01:56\",\"currentVersionCode\":1,\"declarations\":\"\",\"doi\":\"10.21203/rs.3.rs-3684389/v1\",\"doiUrl\":\"https://doi.org/10.21203/rs.3.rs-3684389/v1\",\"draftVersion\":[],\"editorialEvents\":[],\"editorialNote\":\"\",\"failedWorkflow\":false,\"files\":[{\"id\":49681624,\"identity\":\"9e1e9087-5a04-4676-93c0-83f523ec0c87\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:39:20\",\"extension\":\"png\",\"order_by\":1,\"title\":\"Figure 1\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":1801544,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eCharacterization of ZnO-NPs (a-b) SEM (c) XRD\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"1.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/613a3417b71c4441d2031a6d.png\"},{\"id\":49681620,\"identity\":\"78b40bca-4155-4e81-bab1-3e9137433e7d\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:39:19\",\"extension\":\"png\",\"order_by\":2,\"title\":\"Figure 2\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":450831,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eCharacterization of TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs (a-b) SEM (c) XRD\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"2.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/8c9bbcf51363d03f8f3a6847.png\"},{\"id\":49681273,\"identity\":\"557e4817-6827-4413-9669-55864ae3db19\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:31:19\",\"extension\":\"png\",\"order_by\":3,\"title\":\"Figure 3\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":305072,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eEffect of ZnO-NPs and TiO\\u003csub\\u003e2 \\u003c/sub\\u003e-NPs on root length (A), shoot length (B), root fresh weight (C) and root dry weight (D) of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under lead contaminated soil. The vertical bar on the graph demonstrates the standard deviation among three replicates. Different letters on the bars indicate significate difference among treatment at p ≤ 0.05.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"3.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/0ffea41b53519f2ec35231c7.png\"},{\"id\":49681278,\"identity\":\"914f47fb-7ce5-495e-b492-4e60c767f9b2\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:31:20\",\"extension\":\"png\",\"order_by\":4,\"title\":\"Figure 4\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":225839,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eEffect of ZnO-NPs and TiO\\u003csub\\u003e2 \\u003c/sub\\u003e-\\u003csub\\u003e \\u003c/sub\\u003eNPs on shoot fresh weight (A), shoot dry weight (B) and number of leaves (C) of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under lead contaminated soil.\\u003cstrong\\u003e \\u003c/strong\\u003eThe vertical bar on the graph demonstrates the standard deviation among three replicates. Different letters on the bars indicate significate difference among treatment at p ≤ 0.05.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"4.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/b7f110b6fef7688de5bb6773.png\"},{\"id\":49681623,\"identity\":\"6b3a1fdc-e431-422c-bfd1-1e27d47f389d\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:39:19\",\"extension\":\"png\",\"order_by\":5,\"title\":\"Figure 5\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":356716,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eEffect of ZnO-NPs and TiO\\u003csub\\u003e2 \\u003c/sub\\u003e-NPs on chlorophyll a (A), chlorophyll b (B), total chlorophyll (C), carotenoids (D) and SPAD values (E) of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under lead contaminated soil. The vertical bar on the graph demonstrates the standard deviation among three replicates. Different letters on the bars indicate significate difference among treatment at p ≤ 0.05.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"5.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/a5da892895c2621892b9b251.png\"},{\"id\":49681622,\"identity\":\"ce16d4a5-613a-43ed-b9b8-affa86c344e0\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:39:19\",\"extension\":\"png\",\"order_by\":6,\"title\":\"Figure 6\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":353716,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eEffect of ZnO-NPs and TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs on catalase (A), peroxidase (B), super oxide dismutase (C) and ascorbate peroxidase activities (D) in leaves of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under lead contaminated soil. The vertical bar on the graph demonstrates the standard deviation among three replicates. Different letters on the bars indicate significate difference among treatment at p ≤ 0.05.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"6.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/39ae1e47a963b0a56545be3a.png\"},{\"id\":49681280,\"identity\":\"0ff89d97-f30c-417c-8167-7199e4afcb5a\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:31:20\",\"extension\":\"png\",\"order_by\":7,\"title\":\"Figure 7\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":221747,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eEffect of ZnO -NPs and TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs on the accumulation of malondialdehyde (A), hydrogen peroxide (B) and electrolyte leakage (C) in leaves of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under lead contaminated soil. The vertical bar on the graph demonstrates the standard deviation among three replicates. Different letters on the bars indicate significate difference among treatment at p ≤ 0.05.\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"7.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/68e631712be2ffe0f4c46ea5.png\"},{\"id\":49681282,\"identity\":\"73123ec4-fae6-4f43-8715-baa051b1ef40\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:31:20\",\"extension\":\"png\",\"order_by\":8,\"title\":\"Figure 8\",\"display\":\"\",\"copyAsset\":false,\"role\":\"figure\",\"size\":185508,\"visible\":true,\"origin\":\"\",\"legend\":\"\\u003cp\\u003eEffect of ZnO-NPs and TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs on Lead (Pb) content in root (A), and Pb in shoot (B) of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under lead contaminated soil. The vertical bar on the graph demonstrates the standard deviation among three replicates. Different letters on the bars indicate significate difference among treatment at p ≤ 0.05.\\u0026nbsp;\\u003c/p\\u003e\",\"description\":\"\",\"filename\":\"8.png\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/58c4e0da1739990dbe8c584f.png\"},{\"id\":51308615,\"identity\":\"8280ae23-f54c-44ff-8405-ac146d0a1074\",\"added_by\":\"auto\",\"created_at\":\"2024-02-19 10:08:05\",\"extension\":\"pdf\",\"order_by\":0,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"manuscript-pdf\",\"size\":2558910,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"manuscript.pdf\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/ff0847e2-80c2-4d9b-9483-5bd129e7b1a3.pdf\"},{\"id\":49682093,\"identity\":\"c37356f7-eb0b-4dfe-91ac-d6965bb152a1\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:47:19\",\"extension\":\"pptx\",\"order_by\":1,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":1081101,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"GraphicalAbstract.pptx\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/0f25cb46c6a9de07364f9dd8.pptx\"},{\"id\":49681275,\"identity\":\"1c417368-5899-442f-9dc1-ced2b7170bcb\",\"added_by\":\"auto\",\"created_at\":\"2024-01-16 11:31:19\",\"extension\":\"docx\",\"order_by\":2,\"title\":\"\",\"display\":\"\",\"copyAsset\":false,\"role\":\"supplement\",\"size\":15596,\"visible\":true,\"origin\":\"\",\"legend\":\"\",\"description\":\"\",\"filename\":\"Highlights.docx\",\"url\":\"https://assets-eu.researchsquare.com/files/rs-3684389/v1/2b7421e376285e8d862318b7.docx\"}],\"financialInterests\":\"\",\"formattedTitle\":\"\\u003cp\\u003eComparative efficacy of titanium oxide nanoparticles and zinc oxide nanoparticles against lead tolerance, growth performance and nutrient profiling of Brassica Napus L. grown under Lead contaminated soil\\u003c/p\\u003e\",\"fulltext\":[{\"header\":\"1. Introduction\",\"content\":\"\\u003cp\\u003eHeavy metals have emerged as a prominent class of environmental toxins among abiotic stresses (Rizwan et al. \\u003cspan citationid=\\\"CR66\\\" class=\\\"CitationRef\\\"\\u003e2016\\u003c/span\\u003e; Aborisade et al. \\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). The presence of heavy metals in soil seriously exacerbated food security due to their adverse effects crop productivity on and food quality. Additionally, Heavy metals (HMs) buildup in plant parts including seeds, shoots, and roots can cause agricultural toxicity and reduce plant productivity (Adrees et al. \\u003cspan citationid=\\\"CR2\\\" class=\\\"CitationRef\\\"\\u003e2015\\u003c/span\\u003e; Rai et al. \\u003cspan citationid=\\\"CR61\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Manzoor et al. \\u003cspan citationid=\\\"CR48\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). The accumulation of HMs in plant tissues through the food chain can pose a significant risk to both human and animal populations. The molecular, physiological and biochemical processes with in the plant impacted, when concentration of heavy metals in exceeds specific thresholds level (De Caroli et al. 2020; Rashid et al. \\u003cspan citationid=\\\"CR62\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Lead (Pb) is the second most harmful heavy metal due to its non-degradability in nature and has been classified as carcinogenic (Nag and Cummins, \\u003cspan citationid=\\\"CR51\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e; Mahamood et al. \\u003cspan citationid=\\\"CR47\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Pb contamination in soil from natural and anthropogenic sources harms soil biota and environment. Both stable and isotopic form of Pb, naturally found in the environment can accumulate in vegetation, affecting plant development and food safety (Mitra et al. \\u003cspan citationid=\\\"CR50\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003eExcessive level of Pb in soil have a deleterious impact on plant biomass, lead to restricted photosynthetic activity, chlorosis, cell and chromosomal damage, increased oxidative stress and disruption of the water cycle (Debnath et al. \\u003cspan citationid=\\\"CR18\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Mahamood et al. \\u003cspan citationid=\\\"CR47\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e, Fatemi et al. 2023). Pb accumulation retards plant growth by affecting reactive oxygen species (ROS) balance such as hydrogen peroxide (H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e) and superoxide(O\\u003csub\\u003e2\\u003c/sub\\u003e\\u003csup\\u003e\\u0026minus;\\u003c/sup\\u003e), that are very crucial to plant physiology and morphology. It also affects biochemical molecules and involved in disrupting ionic homeostasis and cellular integrity of plants. Consequently, the availability of nutrients by plants is hindered (Ma et al. 2020; Rashid et al. \\u003cspan citationid=\\\"CR62\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Furthermore, Pb can enter the body through the food chain and its accumulation can disturbs numerous body functions, including the reproductive systems, neurological system, bone fractures, anemia and neurotoxicity (Amos-Kroohs et al. \\u003cspan citationid=\\\"CR11\\\" class=\\\"CitationRef\\\"\\u003e2016\\u003c/span\\u003e; Tran et al. \\u003cspan citationid=\\\"CR74\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Therefore, it is imperative to develop novel and efficient strategies for mitigating environmental health concerns and ensuring global food security. Nanotechnology is an emerging tool for the development of sustainable agriculture with its potentials uses in agroecosystems (Ahmad et al. \\u003cspan citationid=\\\"CR5\\\" class=\\\"CitationRef\\\"\\u003e2018\\u003c/span\\u003e; Diao et al. \\u003cspan citationid=\\\"CR19\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e; Faraz et al. \\u003cspan citationid=\\\"CR24\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). Many studies have shown that heavy metal uptake by crops can be reduced through nanoparticles (NPs). Titanium oxide nanoparticles (TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs) and Zinc oxide nanoparticles (ZnO-NPs) are two examples of different nanomaterials with unique characteristics and modes of action. ZnO-NPs have been recognized for their substantial role in mitigating HMs stress in plants due to their significant involvement in many metabolic pathways, stimulating certain genes and increasing the availability of essential nutrients and amino acids to plants (Faizan et al. \\u003cspan citationid=\\\"CR23\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e; Silva et al. \\u003cspan citationid=\\\"CR70\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e; Huang et al. 2022). Both TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO NPs were applied foliar or in the soil to increase plant tolerance to heavy metals (Kurtinov\\u0026aacute; and Šebesta, \\u003cspan citationid=\\\"CR42\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Numerous studies have demonstrated that ZnO-NPs can effectively diminish metal accumulation by increasing zinc concentrations and oxidative stress tolerance (Ali et al. \\u003cspan citationid=\\\"CR10\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Wu et al. 2020; Chen et al. \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). ZnO-NPs foliar application increased wheat growth and metabolism by decreasing Pb uptake (Raghib et al. \\u003cspan citationid=\\\"CR59\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). Additionally, the application of ZnO-NPs markedly improved the enzymatic activity i.e., CAT, SOD, APX and POD under metal stress, demonstrating the defensive role of NPs in the metal stress environment (Ahmad et al. \\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs are a growth promoter and enhance plant defense mechanism and physiology (Lei et al., \\u003cspan citationid=\\\"CR43\\\" class=\\\"CitationRef\\\"\\u003e2008\\u003c/span\\u003e; Kolenč\\u0026iacute;k et al. \\u003cspan citationid=\\\"CR38\\\" class=\\\"CitationRef\\\"\\u003e2021\\u003c/span\\u003e). Recent studies observed that TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs interact with the \\u003cem\\u003eBrassica juncea\\u003c/em\\u003e L. root system and effectively remove Cd from the soil as a hyperaccumulator (Liao et al. \\u003cspan citationid=\\\"CR45\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles greatly increased the growth, photosynthetic activity and Cd tolerance in Brassica plants under 10 mg/kg Cd contaminated soil (Bakshi and Kumar, \\u003cspan citationid=\\\"CR12\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs reduce rice Pb bioaccumulation to varying degrees, but high exposure levels significantly decrease it (Cai et al. \\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e2017\\u003c/span\\u003e) There is a lack of comprehensive understanding regarding ZnO-NPs and TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs role in alleviating Pb toxicity in \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. and overall effect on plant growth performance.\\u003c/p\\u003e \\u003cp\\u003eAgriculture is the foundation of developing nations' economy and the food source for the world's expanding population (Manzoor et al. \\u003cspan citationid=\\\"CR48\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Around 42.2 hectares of land are used to cultivate Brassica napus, a crop used for food and fodder worldwide (Naheed et al. \\u003cspan citationid=\\\"CR52\\\" class=\\\"CitationRef\\\"\\u003e2021\\u003c/span\\u003e, Rahman et al. \\u003cspan citationid=\\\"CR60\\\" class=\\\"CitationRef\\\"\\u003e2016\\u003c/span\\u003e). The \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. family is often ranked third in terms of food provision, behind pulses and cereals, and is the second-highest-yielding crop in terms of oil production (Safdar et al. \\u003cspan citationid=\\\"CR67\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e, Naheed et al. \\u003cspan citationid=\\\"CR52\\\" class=\\\"CitationRef\\\"\\u003e2021\\u003c/span\\u003e; Borges et al. \\u003cspan citationid=\\\"CR13\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. is an important oilseed crop in Pakistan because of its contribution to current edible oil production. The Brassicaceae family of plants, which includes canola (\\u003cem\\u003eBrassica napus\\u003c/em\\u003e L.) and Indian mustard (\\u003cem\\u003eBrassica juncea\\u003c/em\\u003e L.), has been widely used in phytoextraction and as a hyperaccumulator due to metal accumulation in shoots and high metal tolerance, and also their rapid growth, high biomass production (Hidalgo et al. \\u003cspan citationid=\\\"CR30\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Hence, efforts were made to enhance its agronomic and economic significance by several means, such as enhancing disease resistance, optimizing oil extraction, and improving seed size and reducing metal stress (Srivastava et al. \\u003cspan citationid=\\\"CR73\\\" class=\\\"CitationRef\\\"\\u003e2021\\u003c/span\\u003e; Gatasheh et al. \\u003cspan citationid=\\\"CR28\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). The current study aimed to evaluate and compare the efficacy of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs role in alleviating Pb toxicity in \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. plants via modulation antioxidant enzymes. Furthermore, effects of NPs on \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. morphological and physiological parameters under Pb stress was examined under Pb stress with ultimate goal of exploring TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO NPs as highly efficient, non-toxic, and sustainable strategy for Pb mitigation in agricultural crops.\\u003c/p\\u003e\"},{\"header\":\"2. Material and Methods\",\"content\":\"\\u003cdiv id=\\\"Sec3\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.1. ZnO and TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles preparation and characterization\\u003c/h2\\u003e \\u003cdiv id=\\\"Sec4\\\" class=\\\"Section3\\\"\\u003e \\u003ch2\\u003e2.1.1 Regents\\u003c/h2\\u003e \\u003cp\\u003eZinc acetate dihydrate (Zn (CH\\u003csub\\u003e3\\u003c/sub\\u003eCOO)\\u003csub\\u003e2\\u003c/sub\\u003e.2H\\u003csub\\u003e2\\u003c/sub\\u003eO)\\u0026thinsp;\\u0026ge;\\u0026thinsp;99%, methanol (CH\\u003csub\\u003e3\\u003c/sub\\u003eOH), and Sodium Hydroxide (NaOH) 117\\u0026thinsp;\\u0026ge;\\u0026thinsp;99% and Nitride Chloride TiCl\\u003csub\\u003e4\\u003c/sub\\u003e (\\u0026ge;\\u0026thinsp;99.0%), NH\\u003csub\\u003e3\\u003c/sub\\u003e (Ammonia) were purchased from Alfa Aesar, Karlsruhe, Germany.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec5\\\" class=\\\"Section3\\\"\\u003e \\u003ch2\\u003e2.1.2. ZnO and TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles preparation\\u003c/h2\\u003e \\u003cp\\u003eThe synthesis of zinc nanoparticles (Zn NPs) was carried out using a sol-gel method with minor modifications, as described by Vishwakarma and Sing in 2020. In order to prepare a sol, zinc Acetate dihydrate was dissolved with methanol at room temperature. Subsequently, the solution was subjected to ultrasonication at 25℃ for a duration of 120 minutes. Then, clear transparent sol was obtained with no precipitate and turbidity. Sodium Hydroxide (NaOH) 0.02 M solution, was added and ultrasonically stirred for duration of 60 mins. Filter and wash precipitate with excess methanol to eliminate any impurity. Precipitates were dried on a hot plate at 80℃ temperature for 15 minutes. Following that, the precipitates were annealed at 400℃ for 30 minutes.\\u003c/p\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs were prepared by a sol-gel method slight modification (Poursani et al., \\u003cspan citationid=\\\"CR57\\\" class=\\\"CitationRef\\\"\\u003e2016\\u003c/span\\u003e). In brief, Titanium tetra chloride (TiCl\\u003csub\\u003e4\\u003c/sub\\u003e) was added to deionized water with stirring at 1000 rpm. Ammonia (NH3) solution was added gradually (dropwise) to adjust PH (7.8) of the solution with continuous stirring until gel was formed. After formation of TiOH\\u003csub\\u003e2\\u003c/sub\\u003e colloids, the sediment was separated by filtration and dried at 70˚C for 24 hours. Then, calcination was done at 400˚C in furnace for 4 hours in the Environmental Toxicology \\u0026amp; Chemistry lab, Government College University (GCU), Faisalabad, Punjab, Pakistan.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec6\\\" class=\\\"Section3\\\"\\u003e \\u003ch2\\u003e2.1.3 Instrumental analysis\\u003c/h2\\u003e \\u003cp\\u003eScanning electron microscope (SEM) (German ZEISS Sigma 300) was performed to analyze nanoparticles surface morphology. The X-ray diffraction (XRD) data for ZnO and TiO\\u003csub\\u003e2\\u003c/sub\\u003e was obtained using a Bruker D8 Advance X-ray diffractometer, which was equipped with radiation and operated in the 2-theta range of 25\\u0026ndash;65\\u0026deg;.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec7\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.2. Soil sample collection and analysis\\u003c/h2\\u003e \\u003cp\\u003eThe soil used in this experiment was collected from the agriculture field Faisalabad, Punjab, Pakistan. Sample of the soil were collected from the surface (0\\u0026ndash;200 mm) using scoop shovel, dried in the air, and sifted through 2mm sift for analysis and pot culturing. Soil chemical and physical properties were determined such as soil texture (silt clay), pH (7.80), Zn (0.453 mg kg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e), electrical conductivity (6.71 dS m\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e), SAR (22 mmol L\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e), Ca\\u003csup\\u003e2+\\u003c/sup\\u003e + Mg\\u003csup\\u003e+\\u0026thinsp;2\\u003c/sup\\u003e (18 meq L\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e), available phosphorous (2.78 mg kg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e), and available Pb (21.23 mg kg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e).\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec8\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.3. Plant materials and growth conditions\\u003c/h2\\u003e \\u003cp\\u003eA pot experiment was conducted in a natural environment (day/night 23.3/16\\u0026deg;C, relative humidity 39\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3%) in a botanical garden GC University, Faisalabad, Punjab, Pakistan. The pots used for experiment were cylindrical plastic pots (130 g, 7.8 cm diameter, 8.7 cm height). The experiment was carried under complete randomized designed (CRD) with three replicates. Each pot was filled with five kg soil and spiked with Pb (300 mg Kg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e) using Lead acetate Pb (C\\u003csub\\u003e2\\u003c/sub\\u003eH\\u003csub\\u003e3\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e)\\u003csub\\u003e2\\u003c/sub\\u003e and incubated for two months for Pb stabilization (Ahmed et al. \\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Seeds of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. (\\u003cem\\u003ecv.\\u003c/em\\u003e Super Canola) disinfected with hydrogen peroxide (H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e) 2.5% v/v solution for 20 mins followed by distilled water wash to eliminate any contaminant. Seeds were incubated in darkness at 25 ℃ for three days before sowing in the pots (Farooq et al. 2016). After germination, the recommended dose of NPK (120:80:40 kg ha\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e) was applied in order to avoid any nutritional deficiency. Before, foliar application of nanoparticles (NPs) was ultra-sonicated for 30 min with distilled to disperse properly. Foliar application of ZnO and TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs at 25,50 \\u0026amp; 100mg L\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e concentration was applied according to the treatment plan. Simultaneously, controlled plants were sprayed with the distilled water. In total, five sprays were applied to each treatment after one week of interval. During the growing period, the plants were irrigated using tap water with a pH value of 7.42, as measured by a pH meter (Portable Meter Hanna HI-9812-51).\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec9\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.4. Measurement of growth parameters\\u003c/h2\\u003e \\u003cp\\u003eGrowth parameters including height (cm) of the plant were determined by stainless steel meter rod and then dry weight were determined by electrical weigh balance (OHAUS-PR224) subsequent to the drying process the oven (72 hours at 70\\u0026deg;C) (Model: 101-OAB Digital Lab Thermostatic Electric Incubator). Plants were grinded with the help of grinder into fine powder for further analysis.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec10\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.5. Measurement of chlorophyll pigment and SPAD values\\u003c/h2\\u003e \\u003cp\\u003eTo determine the concentration of chlorophyll, plant leaves weighing 0.15 g, were crushed. The resulting crushed leaves were then placed into a testing tube (10 mL) containing 4 mL of a buffer solution (1:1 ratio) containing ethanol and acetone. Subsequently, the tube was incubated in darkness for a period of 5 hours. The centrifugation was performed at 3000 rpm for a duration of 10 minutes in order to collect the supernatant and measured by spectrophotometer (Labman LMSPUV1900 Double Beam UV-VIS Spectrophotometer). (Lichtenthaler, \\u003cspan citationid=\\\"CR46\\\" class=\\\"CitationRef\\\"\\u003e1987\\u003c/span\\u003e). The SPAD value of leaves was determined with portable SPAD meter (atLEAF CHL STD chlorophyll meter 502).\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec11\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.6. Gas exchange parameters\\u003c/h2\\u003e \\u003cp\\u003eInfrared Gas Analyzer (3051c Plant Photosynthesis meter) was used to examine the parameters of gas exchange on a shiny day (12:00\\u0026ndash;13:00). Fully extended leaves were taken from each pot to measure the water use efficacy, stomatal conductance, transpiration rate, and photosynthetic rate.\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec12\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.7. determination of antioxidant enzymes and oxidants\\u003c/h2\\u003e \\u003cp\\u003eTo prepare antioxidant enzyme extract leaf samples were ground using a pestle and mortar in a phosphate buffer solution with a pH of 7.8. The mixture was centrifuged for 10 min duration at 13,000 rpm to obtain supernatant (enzyme extract) antioxidant enzyme activity analysis. Enzyme extract 0.10 (mL)was added in 50 (mM) PBS phosphate buffer solution 0.3 (mL) at pH (6.0) and 300 (mM) of hydrogen peroxide (H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e) to measure peroxidase activity (POD). The spectrophotometer (Labman LMSPUV1900 Double Beam UV-VIS) was used to measure the reaction mixture at 240 nm after 30s of incubation at room temperature. Superoxidase (SOD) activity was measured according to Zhang (\\u003cspan citationid=\\\"CR80\\\" class=\\\"CitationRef\\\"\\u003e1992\\u003c/span\\u003e). The reaction 3 (mL) was prepared 1.5 (mL) 0.05 M Na\\u003csub\\u003e3\\u003c/sub\\u003ePO\\u003csub\\u003e4\\u003c/sub\\u003e, 0.01 (mL) enzyme extract, 130 (mM) methionine, 20 \\u0026micro;M riboflavin, 750 \\u0026micro;M NBT, with 0.1 mM EDTA-NA\\u003csub\\u003e2\\u003c/sub\\u003e and quantified using a spectrophotometer. Catalase (CAT) activity was measured by Aebi (\\u003cspan citationid=\\\"CR3\\\" class=\\\"CitationRef\\\"\\u003e1984\\u003c/span\\u003e). The reaction solution for APX contained 0.2 (mL) enzyme extract, 50 (mM) 100 nmol of phosphate buffer and 300 nmol of 10 mM H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e. The spectrophotometer was set at 240 nm to record absorbance Nakano and Asda, (1981). The analysis of malondialdehyde (MDA) in plant tissues was conducted in regard to the approaches described by Heath and Packer, \\u003cspan citationid=\\\"CR29\\\" class=\\\"CitationRef\\\"\\u003e1968\\u003c/span\\u003e. In brief, leaf sample 0.5g was homogenized in a solution containing 0.5% thiobarbituric acid (TBA) and centrifuged for 15 mins at 3000 rpm). Subsequently the obtained supernatant was added with 20% TCA solution and allow it to boil at 95 ℃ temperature. After this the mixture was cooled on ice before measurement. The absorbance at 532 nanometer (nm) was measured using a spectrophotometer (Labman LMSPUV1900 Double Beam UV-VIS Spectrophotometer). To determine H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e content, leaf sample was pulverized in 10 mL of 0.1% TCA solution, and then the supernatant (enzyme extract) was obtained after 15 minutes of centrifugation at 12,000 rpm. A mixture consisting of 5 (mL) by 0.5% TBA and 5 (mL) 20% TCA were added to 1(ml) of enzyme extract was prepared and subjected boiling at 95\\u0026deg;C for a period of 30 minutes. After cooling the mixture naturally, it was centrifuged at 12,000 rpm for a period of 15 minutes. The of absorbance for the supernatant was measured at 410 nanometers (nm) using UV\\u0026ndash;vis spectrophotometer (Labman LMSPUV1900 Double Beam UV-VIS Spectrophotometer) The electrolyte leakage (EL) in the leaves was determined according to modified method described by Dionisio-Sese and Tobita, (\\u003cspan citationid=\\\"CR20\\\" class=\\\"CitationRef\\\"\\u003e1998\\u003c/span\\u003e). In brief, leaf samples were soaked in a deionized water at a temperature of 30℃ for a period of 4 hours and allow to cool until room temperature. The value of the EC was measured quickly and labelled as EC\\u003csub\\u003e1\\u003c/sub\\u003e. After incubating the treated samples at 121\\u0026deg;C for a further thirty minutes, the second EC calculation, labelled as EC\\u003csub\\u003e2\\u003c/sub\\u003e, was performed. The EL was calculated by the ratio of the percentage of EC\\u003csub\\u003e1\\u003c/sub\\u003e to EC\\u003csub\\u003e2\\u003c/sub\\u003e as follows:\\u003c/p\\u003e \\u003cp\\u003eElectrolyte Leakage % = (EC\\u003csub\\u003e1\\u003c/sub\\u003e/ EC\\u003csub\\u003e2\\u003c/sub\\u003e) *100 (1)\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec13\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.9. Metal estimation\\u003c/h2\\u003e \\u003cp\\u003ePb and micro and macro nutrients concentration was measured in root and shoot samples. HNO\\u003csub\\u003e3\\u003c/sub\\u003e: HClO\\u003csub\\u003e4\\u003c/sub\\u003e (3:1 v/v) solution was used to digest the plant sample (0.5 g) and left it overnight under fume hood. The mixture was than digested using method described by (Rehman et al. \\u003cspan citationid=\\\"CR63\\\" class=\\\"CitationRef\\\"\\u003e2015\\u003c/span\\u003e) and filtered through 0.22 \\u0026micro;m filters. The filtered samples were subsequently used to measure metal nutrients concentrations in the samples using ICP-OES (Optima 7000DV ICP-OES, Perkin Elmer)\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec14\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e2.10. Statistical analyses\\u003c/h2\\u003e \\u003cp\\u003eData analysis using SPSS Statistix 8.1 (ANOVA) with a 5% probability level was analyzed. Tukey's HSD post hoc test was employed to analyze the significance among the triplicates and OriginPro2023b (Origin Lab Cooperation, Northampton, MA, USA) was used for plotting figure.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"3. Results\",\"content\":\"\\u003cdiv id=\\\"Sec16\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.1. TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO nanoparticles characterization\\u003c/h2\\u003e \\u003cp\\u003eSEM analyses showed the size, shape, and structure of the synthesized ZnO-NPs. ZnO-NPs hexagonal shape, uniform distribution, and nanoscale range were demonstrated by their micrographs. ZnO-NPs showed phases in all XRD patterns. All of peaks observed at 2 theta positions were 31.732\\u0026deg;, 34.364\\u0026deg;, 36.207\\u0026deg;, 47.469\\u0026deg;, 56.526\\u0026deg;, 62.754\\u0026deg;, 67.851\\u0026deg;, 68.995\\u0026deg; along with their corresponding reflected planes (100), (002), (101), (102), (110), (103), (112), (201) respectively with JCPDS No. 01-080-0074.The XRD pattern of prepared ZnO-NPs is shown in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig1\\\" class=\\\"InternalRef\\\"\\u003e1\\u003c/span\\u003e. Under scanning electron microscopy, TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles has predominantly spherical shaped clusters with adequate dispersion at 100nm. (Fig a). These nanoparticles showed clean shape and evenly distributed particles at 200nm magnification. (Fig. b). The XRD pattern of TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs peaks observed at 2 theta positions were 25.335\\u0026deg;, 38.611\\u0026deg;, 48.104\\u0026deg;, 53.921\\u0026deg;, 55.138 along with their corresponding reflected planes (101), (112), (200), (105), (211) respectively with JCPDS No. 01-083-2243. The crystal system of prepared TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanostructure is tetragonal given in Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec17\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.2. The effect of ZnO and TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles on growth\\u003c/h2\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO -NPs foliar application in dose additive manner enhanced growth rate of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under Pb contaminated soil. The lowest shoot length of plant was observed in plants without any supplementation of NPs (control). Specifically, shoot and root length grown in Pb contaminated soil significantly enhanced with increasing level of NPs by 82.31% and 74.01% for 100mg/L for TiO\\u003csub\\u003e2\\u003c/sub\\u003e and 75.41% and 63.44% for 100mg/L ZnO -NPs respectively. When compared with the control without NPs, the application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO -NPs lead to significant enhancement in root fresh weight and root dry weight which was increased by 77.72%, 85.37% for 100mg/L for TiO\\u003csub\\u003e2\\u003c/sub\\u003e and 61.13%, 76.56% for 100mg/L ZnO -NPs treatment respectively(Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e).Similarly shoot fresh weight and shoot dry weight dramatically increased up to 68.93% and 89.31% by foliar spray of 100 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e and up to 57.89% and 78.77% by application of ZnO -NPs as compared to control treatment without NPs, respectively. The highest increase in number of leaves were observed with 100mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e by 90.43% as compared to control (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec18\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.3. The Effect of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO nanoparticles on photosynthetic pigment\\u003c/h2\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO -NPs foliar application showed significant influence on physiological attributes of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown in Pb contaminated soil. Under 100mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs treatment, the chlorophyll a content was about 66.35% and 62.89% higher as compared to respective control without NPs .Chlorophyll b content was about 86.43% and 77.23% at higher application rate of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs (100mg/L) that of control .Similarly, a prominent increase in carotenoid content was observed at 100mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs followed by 100 mg/L ZnO -NPs with increasing value of 89.73% and 76.80% respectively, as compared to control with foliar application of nanoparticles (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e). The imperative role of role of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs was also observed in improving SPAD values. The highest SPAD value was found as 52.09 at 100 mg /L TiO\\u003csub\\u003e2\\u003c/sub\\u003e followed by 100 mg /L ZnO-NPs 49.14 and 50 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e (45.49) and 50 mg /L ZnO-NPs (43.96), which was 79.11%, 68.97%, 56.28%, 44.29% higher than control without NPs, respectively (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e). However, a slight increase was observed statically at 25mg/L in both TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec19\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.4. Effect of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO nanoparticles gas exchange parameters\\u003c/h2\\u003e \\u003cp\\u003eThe resulted depicted that plants treated with TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs substantially increased gas exchange parameters. When compared with control (without Nps) all treatments with Nps boosted gas exchange metrics (Table.1). At 50 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs concentration, the percent increase of the photosynthetic rate (\\u003cem\\u003ePn\\u003c/em\\u003e), transpiration rate (\\u003cem\\u003eTr\\u003c/em\\u003e), water use efficiency (\\u003cem\\u003eWUE\\u003c/em\\u003e) and stomatal conductance \\u003cem\\u003e(Sc)\\u003c/em\\u003e in plant under Pb stress was 70.78%, 75.40%, 71.55%, 69.23% and 50.27%, 63.41, 66.89%, 65.86%, 59.43% respectively, as compared to control without nanoparticles. However, the maximum increase in photosynthetic rate, transpiration rate, water use efficiency, and stomatal conductance, in plants was observed at 100mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs followed by 100mg/L ZnO-NPs which was 86.78, 89.32%, 84.79%, 74.65% and 77.67% 79.65%, 72.65%, 68% respectively, as compared to control with nanoparticles. All measured gas exchange parameters showed non-significant increase at 25 mg/L concentration in both nanoparticles\\u0026rsquo; treatment (TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs).\\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec20\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.5. Effect of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO nanoparticles on oxidant and antioxidant activities\\u003c/h2\\u003e \\u003cp\\u003eThe results of indicated that plant grown under Pb contaminated soil without any nanoparticle\\u0026rsquo;s treatment depicted oxidative stress as compared to NPs treatment. The foliar application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs significantly increased antioxidant enzymatic activities superoxidase (SOD), peroxidase (POD), catalase (CAT), Ascorbate peroxidase (APX) in leaves as shown in (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig6\\\" class=\\\"InternalRef\\\"\\u003e6\\u003c/span\\u003e) while simultaneously reduced the oxidant malondialdehyde (MDA), hydrogen peroxide (H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2)\\u003c/sub\\u003e and electrolyte leakage (EL) with increasing concentration of NPs (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig7\\\" class=\\\"InternalRef\\\"\\u003e7\\u003c/span\\u003e).The application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs at 100 mg/L significantly increased CAT (87.74%), SOD (85.88%), POD (87.86%), APX (79.91%) activities and CAT (74.19%), SOD (73.58%), POD (76.98%), APX (73.58%) respectively. In addition, the antioxidant activities at 100 mg/L ZnO-NPs were significantly lower than that of 100 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e treatment. Likewise, the maximum decrease in oxidant enzymatic activity of MDA (52.37%), H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e (59.91%) and EL (74.82%) was observed at 100 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e compared with control without nanoparticles, with the values dropped to MDA (46.98%), H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e (53.19%) and EL (68.37%) at 100 mg/L ZnO-NPs.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec21\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.6. Pb accumulation and fractions in plant parts\\u003c/h2\\u003e \\u003cp\\u003eThe results depicted that Pb accumulation in plant parts diminished with increasing concentration of both Nps (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig8\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003e). The highest shoot and root Pb concentrations were estimated to be higher at control without NPs. In contrast, the lowest Pb concentration were found where higher level of NPs (TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs) was applied. Specifically, TiO\\u003csub\\u003e2\\u003c/sub\\u003e 100 mg/L significantly diminished the shoot Pb in plant which was decreased by 84.16% followed by 100 mg/L ZnO-NPs (76.77%) and 50 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e Nps (69.58%) as compared to control without NPs. Application of 50 mg/L ZnO-NPs and 25 mg/L or 25 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs also significantly reduced Pb accumulation but slight as compared to above mentioned treatments. A similar trend was also observed in root Pb accumulation as inhibition of Pb was observed with increasing concentration of both NPs (TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs and ZnO-NPs) with the highest reduction in root Pb was found at 100 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs by 45.77% and 42.33% respectively, as compared to control without Nps. The application at 50 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs and ZnO-NPs also showed promising results when compared with control.\\u003c/p\\u003e \\u003cp\\u003e \\u003c/p\\u003e \\u003c/div\\u003e \\u003cdiv id=\\\"Sec22\\\" class=\\\"Section2\\\"\\u003e \\u003ch2\\u003e3.7. Effect TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs and ZnO-NPs on nutrient Profiling under Pb Stress\\u003c/h2\\u003e \\u003cp\\u003eThe lowest micro and macro nutrients were recorded in root and shoot of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under Pb stress (without NPs treatment). While, the foliar application TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs significantly enhanced root and shoot zinc (Zn), iron (Fe), calcium (Ca), manganese (Mn), magnesium (Mg) and Potassium (K) concentrations as compared to control without nanoparticles treatment (Table.2). Our results revealed that 100 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs significantly increased Mg, Fe, K, Mn, Zn and Ca concentrations of root by 53.37% ,68.34%, 70.78%, 28.74%, 63.37%, 71.86% and shoot by 72.13% ,79.43%, 81.25%, 62.78%, 58.45% respectively as compared to control. Interestingly root Ca (81.65%), Zn (75.76%) and Mn (35.99%) and shoot Ca (69.89%), Zn (78.76%) and Mn (68.76%) were found to be higher at 100 mg/L ZnO-NPs followed by 100mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs.\\u003c/p\\u003e \\u003c/div\\u003e\"},{\"header\":\"4. Discussion\",\"content\":\"\\u003cp\\u003eHeavy metal pollution in soil limit crop growth and production, consequently threatens food security (United Nations, 2019). Nanoparticles in agriculture can increase crop quantity and quality with improving heavy metal tolerance (Zhou et al. 2021). ZnO and TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs have great unique and disparate properties among different nanoparticles. The foliar application of these nanoparticles considered to be effective than soil application (Lian et al. \\u003cspan citationid=\\\"CR44\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). Our results showed that foliar application of NPs improved growth parameters in brassica plant and reduced Pb induced toxicity which was evidenced by an increment in shoot and root fresh weight, shoot and root length and number of leaves over the control treatment without NPs (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig3\\\" class=\\\"InternalRef\\\"\\u003e3\\u003c/span\\u003e\\u0026ndash;\\u003cspan refid=\\\"Fig4\\\" class=\\\"InternalRef\\\"\\u003e4\\u003c/span\\u003e). The plant grown under Lead (Pb) stress showed poor growth which is consistent with many previous studies (Islam et al. \\u003cspan citationid=\\\"CR34\\\" class=\\\"CitationRef\\\"\\u003e2008\\u003c/span\\u003e; Shakoor et al. \\u003cspan citationid=\\\"CR69\\\" class=\\\"CitationRef\\\"\\u003e2014\\u003c/span\\u003e; Fatemi et al. \\u003cspan citationid=\\\"CR25\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003ea). Pb accumulation resulted in retarded germination and low biomass in brassica plant (Faiz et al. \\u003cspan citationid=\\\"CR22\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e; Ahmed et al. \\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). The decrease in biomass under control treatment without nanoparticles might be due to the accumulation of toxic metals led to excessive ROS generation, which can damage plant cell membrane (Aborisade et al. \\u003cspan citationid=\\\"CR1\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). The foliar application of NPs especially at 100 mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs significantly ameliorated the Pb toxicity and showed high biomass increment suggesting that TiO\\u003csub\\u003e2\\u003c/sub\\u003e was more efficient in promoting plant growth and positively affected \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. biomass which is consistent with previous studies (Rizwan et al. \\u003cspan citationid=\\\"CR64\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Lian et al. 2019; Ogunkunle et al. \\u003cspan citationid=\\\"CR54\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). The improvement of biomass could potentially be attributed to the reduction Pb concentration and higher mineral nutrients in NPs-treated plants (Rizwan et al. \\u003cspan citationid=\\\"CR64\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e). Increased leaf chlorophyll concentration boosts photosynthesis, making it an important measure for estimating plant photosynthetic efficiency (Ahmed et al. \\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Many studies have documented that the existence of Pb in soil has a detrimental effect on the production of chlorophyll and carotenoid pigments in several agricultural plants. The current study demonstrated that foliar application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs significantly boosted leaf chlorophyll and carotenoid levels (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig5\\\" class=\\\"InternalRef\\\"\\u003e5\\u003c/span\\u003e). Increased photosynthetic content has been observed to promotes growth, photosynthesis and alleviation of metal toxicity. (Sardar et al. \\u003cspan citationid=\\\"CR68\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e). The current results are coherence with the work of many previous studies (Ebrahimi et al., \\u003cspan citationid=\\\"CR21\\\" class=\\\"CitationRef\\\"\\u003e2016\\u003c/span\\u003e; Ahmed et al. \\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). The foliar application TiO\\u003csub\\u003e2\\u003c/sub\\u003e resulted in a substantial increase in the photosynthetic pigment in wheat and maize crop (Irshad et al. \\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e2021\\u003c/span\\u003e; Lian et al. \\u003cspan citationid=\\\"CR44\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). Cowpea plants showed increased chlorophyll concentrations after 100 mg/L foliar sprays of TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs (Ogunkunle et al. \\u003cspan citationid=\\\"CR54\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). The increase in chlorophyll content can potentially be attributed to the beneficial impact of TiO\\u003csub\\u003e2\\u003c/sub\\u003e on enzymatic activities associated with nitrogen metabolism. This, in turn, facilitates the uptake of nitrate by plants and favors the production of organic nitrogen, such as proteins (Song et al. \\u003cspan citationid=\\\"CR72\\\" class=\\\"CitationRef\\\"\\u003e2013\\u003c/span\\u003e; Mishra et al. \\u003cspan citationid=\\\"CR49\\\" class=\\\"CitationRef\\\"\\u003e2014\\u003c/span\\u003e; Ahmed et al. \\u003cspan citationid=\\\"CR6\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs have also been shown to improve leaf PSII electron donation by attaching to the PSII reaction center complex that may lead to better photosynthetic rate (Hong et al. \\u003cspan citationid=\\\"CR31\\\" class=\\\"CitationRef\\\"\\u003e2015\\u003c/span\\u003e). The current study improved concentration of chlorophyll content with ZnO- NPs is consistent with the previous studies. It has been observed that that ZnO NPs can boost plant Zn concentration, which regulates various physiological and biochemical activities (Qiao et al. \\u003cspan citationid=\\\"CR58\\\" class=\\\"CitationRef\\\"\\u003e2015\\u003c/span\\u003e; Rizwan et al. \\u003cspan citationid=\\\"CR64\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Raghib et al. \\u003cspan citationid=\\\"CR59\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e; Ahmad et al. \\u003cspan citationid=\\\"CR8\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003eGas exchange parameters act as stress biomarker of metal stress in plant. The results of our study showed that Pb stress negatively affecting the photosynthetic rate, Transpiration rate, stomatal conductance and intracellular CO\\u003csub\\u003e2\\u003c/sub\\u003e concentration. Higher Pb concentrations in plant leaves impede photosynthesis, hinder electron transport and close stomata to reduce CO\\u003csub\\u003e2\\u003c/sub\\u003e assimilation (Akinci et al. \\u003cspan citationid=\\\"CR7\\\" class=\\\"CitationRef\\\"\\u003e2010\\u003c/span\\u003e). However, foliar application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs and ZnO-NPs significantly enhance \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. gas exchange parameters (Table.1). It is estimated that application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs increased activity of RuBisCO activase, a key enzyme in the Calvin cycle. Higher activity of this enzyme facilitates the process of carbon dioxide fixation and augments photosynthetic activity in plants (Gao et al. \\u003cspan citationid=\\\"CR26\\\" class=\\\"CitationRef\\\"\\u003e2013\\u003c/span\\u003e). TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs enhanced chlorophyll production, plant quantum yield, and photosynthetic system chemical energy (Sardar et al. \\u003cspan citationid=\\\"CR68\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e). ZnO-NPs potentially enhanced the gas exchange parameters in our study. It is well evident that ZnO-NPs can improve photosynthetic rates in rice and soybean plant grown in metal contaminated soil (Fiazan et al. 2018; Ahmad et al. \\u003cspan citationid=\\\"CR4\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). ZnO-NPs 50 mg/L foliar application significantly increase photosynthetic rate, stomatal conductance in Pb stressed soil (Alhammad et al. \\u003cspan citationid=\\\"CR9\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003eEnvironmental stress including heavy metal induce generation ROS such as H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e and O\\u003csub\\u003e2\\u003c/sub\\u003e\\u003csup\\u003e\\u0026minus;\\u003c/sup\\u003e. This oxidative stress can result in detrimental effects, including the degradation of cellular membranes, biomolecules and structural damage (Irshad et al. \\u003cspan citationid=\\\"CR33\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e). MDA is generated during the lipid peroxidation and triggered by ROS production (Gaschler et al. 2017; Tripathi et al. \\u003cspan citationid=\\\"CR75\\\" class=\\\"CitationRef\\\"\\u003e2017\\u003c/span\\u003e). Conversely, it is possible that increased levels of antioxidant activity could reduce the oxidative stress induced by heavy metal by scavenging excessive reactive oxygen species (ROS). The result of the present study portrayed that foliar application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs and ZnO-NPs reduced oxidative stress by decreasing H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e, MDA and EL content in plant and improved the SOD, POD and CAT activities in plant over the control (Pb contaminated soil). SOD scavenges O\\u003csup\\u003e2\\u0026minus;\\u003c/sup\\u003e to H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e, while CAT decomposes H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e into water and oxygen molecule (Rizwan et al. \\u003cspan citationid=\\\"CR64\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e).\\u003c/p\\u003e \\u003cp\\u003eOur results are confirmed by several studies that TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs reduce the indicators of ROS (MDA, H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2,\\u003c/sub\\u003e EL) in different plants and can boost resistance to oxidative stress (Song et al. \\u003cspan citationid=\\\"CR71\\\" class=\\\"CitationRef\\\"\\u003e2012\\u003c/span\\u003e; Rizwan et al. \\u003cspan citationid=\\\"CR64\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Chen et al. \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). The application of zinc oxide nanoparticles (ZnO-NPs) at concentrations of 50 and 100 mg/L on the leaves of soybean plants for a duration of two weeks resulted in a decrease in the levels of H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e and MDA by increasing CAT, SOD, APX, boosting soybean tolerance under metal stress (Ahmed et al. 2020). ZnO-NPs improved antioxidant enzymes capacity in Oryza sativa by scavenging ROS. The ZnO-NPs nanoparticles have the ability to interact with the plasma membrane of cells, leading to the scavenging of ROS and providing protection to the cell membrane against oxidative damage (Jalil et al. \\u003cspan citationid=\\\"CR35\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). In our results the growth of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. showed decrease growth under Pb stress without any NPs treatment. Pb primarily enters the root through the apoplastic pathway or calcium ion channels. Other studies have also demonstrated that there is a higher accumulation of Pb in the roots compared to the shoot depending on the concentration of Pb (Rizwan et al. \\u003cspan citationid=\\\"CR65\\\" class=\\\"CitationRef\\\"\\u003e2018\\u003c/span\\u003e; Fatemi et al. 2021). Our results showed significant decrease in Pb concentrations by the foliar application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs and ZnO-NPs at highest concentrations (100mg/L) (Fig.\\u0026nbsp;\\u003cspan refid=\\\"Fig8\\\" class=\\\"InternalRef\\\"\\u003e8\\u003c/span\\u003e). The lower level of these NPs did not significantly affect Pb concentration in shoot. Decreasing metal accumulation in plants via TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs by was confirmed by several studies (Wang et al. \\u003cspan citationid=\\\"CR78\\\" class=\\\"CitationRef\\\"\\u003e2015\\u003c/span\\u003e; Ji et al. 2017; Rizwan et al. \\u003cspan citationid=\\\"CR64\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Kumari et al. \\u003cspan citationid=\\\"CR41\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e). The application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs resulted in positive effects on the physiological attributes of wheat and maize plants. Additionally, the application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs led to a reduction in the levels of Cd in the biomass, roots, and shoots of cowpea wheat and plants (Irshad et al. \\u003cspan citationid=\\\"CR32\\\" class=\\\"CitationRef\\\"\\u003e2021\\u003c/span\\u003e; Chen et al. \\u003cspan citationid=\\\"CR15\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e). Kumar et al. \\u003cspan citationid=\\\"CR39\\\" class=\\\"CitationRef\\\"\\u003e2023\\u003c/span\\u003e and reported that exogenous application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs created hinderance in the translocation and accumulation of metal might be ascribed to the binding of Cr transporter ions, such as sulphate or iron, with TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles. TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs exposure to rice plants decreased Pb bioaccumulation\\u0026thinsp;\\u0026ge;\\u0026thinsp;80% in dose additive manner (Cai et al. \\u003cspan citationid=\\\"CR14\\\" class=\\\"CitationRef\\\"\\u003e2017\\u003c/span\\u003e). The efficacy of ZnO-NPs in significantly reducing metal concentration has been reported by my studies (Sharifan et al. 2020; Pishkar et al. \\u003cspan citationid=\\\"CR55\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e; Ghori et al. 2023). One of the recent types of research observed that ZnO-NPs can enter through stomatal channels to leaf epidermis and release Zn ions into the apoplast and by taken up by mesophyll cells. Therefore, ZnO-NPs leads to reduction of metal stress in plants (Rizwan et al. \\u003cspan citationid=\\\"CR64\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Zhu et al. 2020). The observed reduction in Pb concentration in plants treated with nanoparticles (NPs) may also be attributed to the augmentation of antioxidant activities and biomass in the treated plants, thus resulting in an overall reduction in metal concentration in the plant.\\u003c/p\\u003e \\u003cp\\u003eIt is recognized that an excess of lead significantly hinders the entry of various ions to their respective absorption sites on the roots. The process of depolarization of the plasma membrane in different cells of the root leads to a decrease in the electromotive force required for the uptake of mineral nutrients (Sardar et al. 2021). In present study it is evident that plants with Pb stress showed lower concentration of nutrients. However, it has been observed that TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs and ZnO-NPs significantly transformed the mineral balance by change in micro nutrients (Zn, Fe, Mn) and macro nutrients (Ca, Mg, K). Foliar application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs significantly enhanced Fe, Zn, K, Mg in (Table\\u0026nbsp;\\u003cspan refid=\\\"Tab2\\\" class=\\\"InternalRef\\\"\\u003e2\\u003c/span\\u003e) while decreased in Ca and Mn was observed in \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. as compared to ZnO-NPs. In a study by Dağhan et al. (\\u003cspan citationid=\\\"CR17\\\" class=\\\"CitationRef\\\"\\u003e2020\\u003c/span\\u003e) TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs were found to decrease K and Mn levels and increase Fe and Cu absorption in \\u003cem\\u003eTriticum vulgare\\u003c/em\\u003e L. TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs enhances the absorption of Fe via stimulating the up-regulation of genes associated with Fe acquisition (Lyu et al. 2017). Additionally, it was shown that the presence of titanium dioxide nanoparticles (at a concentration of 500 mg kg\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e) resulted in increased zinc levels in barley kernels (Pošćić et al. \\u003cspan citationid=\\\"CR56\\\" class=\\\"CitationRef\\\"\\u003e2016\\u003c/span\\u003e). The decrease in Ca as compared to ZnO-NPs may be because of decrease in mobility and absorption of calcium as a result of the formation of complexes between negatively charged pure TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs and calcium ions (Ca\\u003csup\\u003e2+\\u003c/sup\\u003e) at the interface between roots and soil Wang et al. (\\u003cspan citationid=\\\"CR79\\\" class=\\\"CitationRef\\\"\\u003e2021\\u003c/span\\u003e). Application of ZnO-NPs foliar application increased the leaf concentration of macro and micro nutrients and enhanced plant stress tolerance. The positive effect of ZnO-NPs on nutrients has been documented by many studies (Kolenč\\u0026iacute;k et al. \\u003cspan citationid=\\\"CR37\\\" class=\\\"CitationRef\\\"\\u003e2019\\u003c/span\\u003e; Pishkar et al. \\u003cspan citationid=\\\"CR55\\\" class=\\\"CitationRef\\\"\\u003e2022\\u003c/span\\u003e). The finding of the current study suggested that TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs and ZnO-NPs could be very effective strategy to mitigate Pb toxicity however, more pronounced impact on \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. was observed in scenario of TiO\\u003csub\\u003e2\\u003c/sub\\u003e NPs.\\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab1\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 1\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eEffect of ZnO-NPs and TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs on gas exchange parameters of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under lead contaminated soil. Values are the means\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;Standard deviation (n\\u0026thinsp;=\\u0026thinsp;3) different letters indicate significate difference among treatment at p\\u0026thinsp;\\u0026le;\\u0026thinsp;0.05.\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"5\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTreatment\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003ePhotosynthetic rate\\u003c/p\\u003e \\u003cp\\u003e(\\u0026micro; mol CO\\u003csub\\u003e2\\u003c/sub\\u003e m\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e s\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eTranspiration rate\\u003c/p\\u003e \\u003cp\\u003e(mol H\\u003csub\\u003e2\\u003c/sub\\u003eO m\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e s\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eWater Use Efficiency\\u003c/p\\u003e \\u003cp\\u003e(%)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003eStomatal Conductance\\u003c/p\\u003e \\u003cp\\u003e(mol m\\u003csup\\u003e\\u0026minus;\\u0026thinsp;2\\u003c/sup\\u003e s\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e)\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003e(Ck) Pb\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e5.42\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.31d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e0.909\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.040d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e60.48\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.13 e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.0106\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.0011c\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 25 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e6.74\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.65cd\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.214\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.78c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e109.27\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;10.5 cd\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.0255\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.0012bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs 25 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e7.46\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.79bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.394\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.149bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e114.21\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;10.83 c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.0266\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.0037b\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 50 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e8.14\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.15abc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.486\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.019bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e118.43\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;28.01 bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.0383\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.0210ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u0026minus;\\u003c/sub\\u003eNPs 50 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e9.25\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.01bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.595\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.159 ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e121.28\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;25.77 b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.0393\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.0064ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 100 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e10.31\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.94 ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.788\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.056a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e125.24\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;28.41 ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.0404\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.0010a\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs 100 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e10.76\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.26a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1.812\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.0174a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e128.0\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;16.08 a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e0.0411\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.0009a\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e \\u003cp\\u003e \\u003cdiv class=\\\"gridtable\\\"\\u003e\\u003ctable float=\\\"Yes\\\" id=\\\"Tab2\\\" border=\\\"1\\\"\\u003e \\u003ccaption language=\\\"En\\\"\\u003e \\u003cdiv class=\\\"CaptionNumber\\\"\\u003eTable 2\\u003c/div\\u003e \\u003cdiv class=\\\"CaptionContent\\\"\\u003e \\u003cp\\u003eEffect of ZnO-NPs and TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs on nutritional profile in root and shoot of \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. grown under lead contaminated soil. Different letters indicate significate difference among treatment at p\\u0026thinsp;\\u0026le;\\u0026thinsp;0.05. Values are the means\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;Standard deviation (n\\u0026thinsp;=\\u0026thinsp;3).\\u003c/p\\u003e \\u003c/div\\u003e \\u003c/caption\\u003e \\u003ccolgroup cols=\\\"7\\\"\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c1\\\" colnum=\\\"1\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c2\\\" colnum=\\\"2\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c3\\\" colnum=\\\"3\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c4\\\" colnum=\\\"4\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c5\\\" colnum=\\\"5\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c6\\\" colnum=\\\"6\\\"\\u003e\\u003c/div\\u003e \\u003cdiv align=\\\"left\\\" class=\\\"colspec\\\" colname=\\\"c7\\\" colnum=\\\"7\\\"\\u003e\\u003c/div\\u003e \\u003cthead\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003eTreatments\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"6\\\" nameend=\\\"c7\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003eShoots\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"3\\\" nameend=\\\"c4\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003eMacronutrients (mg g\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e DW)\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colspan=\\\"3\\\" nameend=\\\"c7\\\" namest=\\\"c5\\\"\\u003e \\u003cp\\u003eMicronutrients (\\u0026micro;g g\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e DW)\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eCa\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eK\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eMg\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003eMn\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003eFe\\u003c/p\\u003e \\u003c/th\\u003e \\u003cth align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003eZn\\u003c/p\\u003e \\u003c/th\\u003e \\u003c/tr\\u003e \\u003c/thead\\u003e \\u003ctbody\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePb (Ck)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e15573.53\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;303.97f\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e21319.47\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;214.31f\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e13609.80\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;349.20 e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e19.44\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.97e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e184.97\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;9.31e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e14.15\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.07e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 25 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e21617.40\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;390.62d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e344229.0\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;285.73e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e22378.07\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;418.20d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e25.67\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.29d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e224.43\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;15.77d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e18.55\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.07de\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs 25 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e18540.03\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;554.95e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e30105.20\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;446.17e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e22666.43\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;916.29d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e21.10\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.71e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e273.0\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;12.62c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e16.21\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.52de\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 50 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e23435.77\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;258.88c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e38635.60\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;310.56c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e24582.13\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;334.06c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e31.53\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.32bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e309.13\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;15.66b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e36.43\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.87b\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs 50 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e22341.90\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;75.55d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e36240.37\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;588.77d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e25217.73\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;224.71bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e28.61\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.84cd\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e337.33\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.84ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e20.91\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.03d\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 100 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e26296.0\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;852.41a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e42469.60\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;224.57a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e2689.33\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;341.26ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e35.75\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.80a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e361.97\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.82a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e64.98\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.74a\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs 100 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e24650.57\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;465.95b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e40774.40\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;211.53b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e27121.03\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;688.30 a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e33.35\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.67ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e367.57\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;18.01a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e28.03\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.33c\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\" morerows=\\\"2\\\" rowspan=\\\"3\\\"\\u003e \\u003cp\\u003e\\u003cb\\u003eTreatments\\u003c/b\\u003e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"6\\\" nameend=\\\"c7\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003eRoots\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"3\\\" nameend=\\\"c4\\\" namest=\\\"c2\\\"\\u003e \\u003cp\\u003eMacronutrients (mg g\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e DW)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colspan=\\\"3\\\" nameend=\\\"c7\\\" namest=\\\"c5\\\"\\u003e \\u003cp\\u003eMicronutrients (\\u0026micro;g g\\u003csup\\u003e\\u0026minus;\\u0026thinsp;1\\u003c/sup\\u003e DW)\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003eCa\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003eK\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003eMg\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003eMn\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003eFe\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003eZn\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003ePb (Ck)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e763.73\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;21.72f\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1060.07\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;36.77g\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e9492.34\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;319.69f\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e92.28\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.54e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e63.29\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;10.55d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e5.12\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.53e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 25 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1243.50\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;20.07d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1351.10\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;27.70f\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e11285.80\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;152.09e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e108.48\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.28 c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e114.43\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;6.23c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e7.99\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.52de\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e \\u0026ndash;NPs 25 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1153.53\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;31.57e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1470.27\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;17.06e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e11855.43\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;237.16e\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e102.59\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;3.83d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e115.92\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;8.91c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e5.60\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.24e\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 50 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1407.47\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;12.20bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1560.17\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;36.52d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e12621.47\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;215.69d\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e115.95\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.58b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e119.33\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;6.35b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e21.80\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.91b\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs 50 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1357.70\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;30.77c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1670.27\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;43.51c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e13508.40\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;271.60c\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e113.41\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.01bc\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e121.28\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.91b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e9.67\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;0.65d\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eZnO-NPs 100 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1516.50\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;20.62a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1797.90\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;45.20b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e14233.70\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;298.66b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e122.73\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.50 a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e125.28\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;5.91ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e32.31\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.32a\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003ctr\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c1\\\"\\u003e \\u003cp\\u003eTiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs 100 (mg/L)\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c2\\\"\\u003e \\u003cp\\u003e1446.37\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;11.95b\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c3\\\"\\u003e \\u003cp\\u003e1894.40\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;28.56a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c4\\\"\\u003e \\u003cp\\u003e15508.03\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;328.92a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c5\\\"\\u003e \\u003cp\\u003e118.81\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;2.21ab\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c6\\\"\\u003e \\u003cp\\u003e129.26\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;4.46a\\u003c/p\\u003e \\u003c/td\\u003e \\u003ctd align=\\\"left\\\" colname=\\\"c7\\\"\\u003e \\u003cp\\u003e15.27\\u0026thinsp;\\u0026plusmn;\\u0026thinsp;1.51c\\u003c/p\\u003e \\u003c/td\\u003e \\u003c/tr\\u003e \\u003c/tbody\\u003e \\u003c/colgroup\\u003e \\u003c/table\\u003e\\u003c/div\\u003e \\u003c/p\\u003e\"},{\"header\":\"5. Conclusion\",\"content\":\"\\u003cp\\u003eThe present study has highlighted that potential impact of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs on \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. under Pb stress. The foliar application of 100 TiO\\u003csub\\u003e2\\u003c/sub\\u003e-Nps significantly enhanced \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. growth and physiology. TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs reduced oxidative stress by upregulation of leaf antioxidant enzyme activity. The foliar application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs significantly reduced Pb uptake with increasing the rate of NPs by improving plant defensive mechanism. Our study also demonstrated that application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs enhanced Zn, Fe, Mg, Mn, Ca and K in \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. root and shoot by reducing Pb concentration in plant parts and by maintaining the ionic balance. Overall study concluded that both TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs could be affective strategy to reduce Pb bioavailability with more pronounced effect found with TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs.Furthur studies needed to focus on gene expression related to Pb uptake in plant by TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs under different conditions.\\u003c/p\\u003e\"},{\"header\":\"Declarations\",\"content\":\"\\u003cp\\u003e\\u003cstrong\\u003eAcknowledgements\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors wish to acknowledge the State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University and Environmental Toxicology \\u0026amp; Chemistry laboratory, Government College University, Faisalabad.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003cstrong\\u003eAuthors contribution \\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eAdiba Khan Sehrish:\\u003c/strong\\u003e Performed the design of experiment, Formal analysis, carried out the experiment and original drafted the manuscript. \\u003cstrong\\u003eShoaib Ahmad:\\u003c/strong\\u003e writing \\u0026ndash; review and editing. \\u003cstrong\\u003eSarah Owdah Alomrani:\\u0026nbsp;\\u003c/strong\\u003eFormal analysis.\\u003cstrong\\u003e\\u0026nbsp;Rohina Tabassam:\\u003c/strong\\u003e data visualization. \\u003cstrong\\u003eHafeez Ur Rahim:\\u003c/strong\\u003e Methodology. \\u003cstrong\\u003eAzeem Ahmad:\\u003c/strong\\u003e Revising it critically for intellectual content. \\u003cstrong\\u003eArslan Tauqeer:\\u0026nbsp;\\u003c/strong\\u003ewriting \\u0026ndash; review. \\u003cstrong\\u003eShafaqat Ali:\\u003c/strong\\u003e Supervision, Experiment design, Resources, Funding acquisition, Investigation. \\u0026nbsp;\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003e\\u0026nbsp;\\u003c/strong\\u003e\\u003cstrong\\u003eFunding\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThis work was financial supported under project No. 5634/Punjab/NRPU/R\\u0026amp;D/HEC/2016.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eData Availability\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eAll data generated or analyzed during the study are included in this article.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eEthics approval and consent to participate\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe current study didn\\u0026rsquo;t involve human and human data.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eConsent for publication\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThis study does not human subjects. The authors have not submitted to a preprint server before submitting it to \\u003cem\\u003eEnvironmental Science and Pollution Research\\u003c/em\\u003e.\\u0026nbsp;\\u003c/p\\u003e\\n\\u003cp\\u003e\\u003cstrong\\u003eCompeting interests\\u0026nbsp;\\u003c/strong\\u003e\\u003c/p\\u003e\\n\\u003cp\\u003eThe authors declare that they have no known competing interests.\\u003c/p\\u003e\\n\\u003cp\\u003e\\u0026nbsp;\\u003c/p\\u003e\"},{\"header\":\"References\",\"content\":\"\\u003col\\u003e\\n\\u003cli\\u003eAborisade MA, Geng H, Oba BT, Kumar A, Ndudi EA, Battamo A Y, Zhao L (2023). Remediation of soil polluted with Pb and Cd and alleviation of oxidative stress in Brassica rapa plant using nanoscale zerovalent iron supported with coconut-husk biochar. J. Plant Physiol. 154023. \\u003c/li\\u003e\\n\\u003cli\\u003eAdrees M, Ali S, Rizwan M, Zia-ur-Rehman M, Ibrahim M, Abbas F, Irshad M K (2015). Mechanisms of silicon-mediated alleviation of heavy metal toxicity in plants: a review. Ecotoxicol. Environ. Saf. 119, 186-197. \\u003c/li\\u003e\\n\\u003cli\\u003eAebi H, (1984). [13] Catalase in vitro. In Methods in enzymology (Vol. 105, pp. 121-126). Academic press. \\u003c/li\\u003e\\n\\u003cli\\u003eAhmad P, Alyemeni M N, Al-Huqail A A, Alqahtani M A, Wijaya L, Ashraf M, Bajguz A (2020). Zinc oxide nanoparticles application alleviates arsenic (As) toxicity in soybean plants by restricting the uptake of as and modulating key biochemical attributes, antioxidant enzymes, ascorbate-glutathione cycle and glyoxalase system. Plants. 9(7), 825. \\u003c/li\\u003e\\n\\u003cli\\u003eAhmad B, Shabbir A, Jaleel H, Khan MMA, Sadiq Y, (2018). Efficacy of titanium dioxide nanoparticles in modulating photosynthesis, peltate glandular trichomes and essential oil production and quality in Mentha piperita L. Curr. Plant Biol. 13, 6-15. \\u003c/li\\u003e\\n\\u003cli\\u003eAhmed KBM, Khan MMA, Shabbir A, Ahmad B, Uddin M, Azam A (2023). Comparative effect of foliar application of silicon, titanium and zinc nanoparticles on the performance of vetiver-a medicinal and aromatic plant. Silicon. 15(1), 153-166. \\u003c/li\\u003e\\n\\u003cli\\u003eAkinci IE, Akinci S, Yilmaz K (2010). Response of tomato (\\u003cem\\u003eSolanum lycopersicum\\u003c/em\\u003e L.) to lead toxicity: Growth, element uptake, chlorophyll and water content. Afr. J. Agric. Res. 5(6), 416-423. \\u003c/li\\u003e\\n\\u003cli\\u003eAhmad S, Mfarrej MFB, El-Esawi MA, Waseem M, Alatawi A, Nafees M, Ali S (2022). Chromium-resistant Staphylococcus aureus alleviates chromium toxicity by developing synergistic relationships with zinc oxide nanoparticles in wheat. Ecotoxicol. Environ. Saf. 230, 113142. \\u003c/li\\u003e\\n\\u003cli\\u003eAlhammad BA, Ahmad A, Seleiman MF, (2023). Nano-Hydroxyapatite and ZnO-NPs Mitigate Pb Stress in Maize. Agronomy. 13(4), 1174. \\u003c/li\\u003e\\n\\u003cli\\u003eAli S, Rizwan M, Noureen S, Anwar S, Ali B, Naveed M, Ahmad P (2019). Combined use of biochar and zinc oxide nanoparticle foliar spray improved the plant growth and decreased the cadmium accumulation in rice (\\u003cem\\u003eOryza sativa\\u003c/em\\u003e L.) plant. Environ. Sci. Pollut. Res. 26, 11288-11299. \\u003c/li\\u003e\\n\\u003cli\\u003eAmos-Kroohs RM, Graham DL, Grace CE, Braun A A, Schaefer TL, Skelton MR, Williams MT (2016). Developmental stress and lead (Pb): Effects of maternal separation and/or Pb on corticosterone, monoamines, and blood Pb in rats. Neurotoxicology. 54, 22-33. \\u003c/li\\u003e\\n\\u003cli\\u003eBakshi M, \\u0026amp; Kumar A (2023). Co-application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles and hyperaccumulator Brassica juncea L. for effective Cd removal from soil: Assessing the feasibility of using nano-phytoremediation. J. Environ. Manage. 341, 118005. \\u003c/li\\u003e\\n\\u003cli\\u003eBorges CE, Vo dos Santos Veloso R, da Concei\\u0026ccedil;\\u0026atilde;o CA, Mendes DS, Ramirez-Cabral NY, Shabani F, da Silva RS (2023). Forecasting Brassica napus production under climate change with a mechanistic species distribution model. Sci. Rep. 13(1), 12656. \\u003c/li\\u003e\\n\\u003cli\\u003eCai F, Wu X, Zhang H, Shen X, Zhang M, Chen W, Wang X (2017). Impact of TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles on lead uptake and bioaccumulation in rice (\\u003cem\\u003eOryza sativa\\u003c/em\\u003e L.). NanoImpact. 5, 101-108. \\u003c/li\\u003e\\n\\u003cli\\u003eChen F, Li Y, Irshad MA, Hussain A, Nawaz R, Qayyum MF, Ali S (2023). Effect of titanium dioxide nanoparticles and co-composted biochar on growth and Cd uptake by wheat plants: A field study. Environ. Res. 231, 116057. \\u003c/li\\u003e\\n\\u003cli\\u003eChen F, Li Y, Zia-ur-Rehman M, Hussain SM, Qayyum MF, Rizwan M, Ali S (2023). Combined effects of zinc oxide nanoparticles and melatonin on wheat growth, chlorophyll contents, cadmium (Cd) and zinc uptake under Cd stress. Sci. Total Environ. 864, 161061. \\u003c/li\\u003e\\n\\u003cli\\u003eDağhan H, G\\u0026uuml;lmezoğlu N, K\\u0026ouml;leli N, Karakaya B (2020). Impact of titanium dioxide nanoparticles (TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs) on growth and mineral nutrient uptake of wheat (\\u003cem\\u003eTriticum vulgare\\u003c/em\\u003e L.). Biotech. Studies, 29(2), 69-76. \\u003c/li\\u003e\\n\\u003cli\\u003eDebnath B, Singh WS, Manna K (2019). Sources and toxicological effects of lead on human health. India J Med specialities. 10(2), 66-71. \\u003c/li\\u003e\\n\\u003cli\\u003eDiao ZH, Yan L, Dong FX, Qian W, Deng Q H, Kong LJ, Chu W (2020). Degradation of 2, 4-dichlorophenol by a novel iron based system and its synergism with Cd (II) immobilization in a contaminated soil. J. Chem. Eng. 379, 122313. \\u003c/li\\u003e\\n\\u003cli\\u003eDionisio-Sese ML, \\u0026amp; Tobita S (1998). Antioxidant responses of rice seedlings to salinity stress. Plant Sci. 135(1), 1-9. \\u003c/li\\u003e\\n\\u003cli\\u003eEbrahimi A, Galavi M, Ramroudi M, Moaveni P (2016). Study of agronomic traits of pinto bean (Phaseolus vulgaris L.) under nano TiO\\u003csub\\u003e2\\u003c/sub\\u003e spraying at various growth stages. International Journal of Pharmaceutical Research and Allied Science, 5(2), 458-471.\\u003c/li\\u003e\\n\\u003cli\\u003eFaiz S, Yasin NA, Khan WU, Shah AA, Akram W, Ahmad A, Ali A, Naveed NH, Riaz L (2022). Role of magnesium oxide nanoparticles in the mitigation of lead-induced stress in Daucus carota: modulation in polyamines and antioxidant enzymes. Int. J. Phytoremediation. 4(4): 364\\u0026ndash;372. \\u003c/li\\u003e\\n\\u003cli\\u003eFaizan M, Hayat S, Pichtel J (2020). Effects of zinc oxide nanoparticles on crop plants: A perspective analysis. Sustainable Agriculture Reviews 41: Nanotechnology for Plant Growth and Development, 83-99. \\u003c/li\\u003e\\n\\u003cli\\u003eFaraz A, Faizan M, Fariduddin Q, Hayat S (2020). Response of titanium nanoparticles to plant growth: agricultural perspectives. Sustainable Agriculture Reviews 41: Nanotechnology for Plant Growth and Development, 101-110. \\u003c/li\\u003e\\n\\u003cli\\u003eFatemi H, Pour BE, Rizwan M (2020). Isolation and characterization of lead (Pb) resistant microbes and their combined use with silicon nanoparticles improved the growth, photosynthesis and antioxidant capacity of coriander (\\u003cem\\u003eCoriandrum sativum\\u003c/em\\u003e L.) under Pb stress. Environ. Pollut. 266, 114982. \\u003c/li\\u003e\\n\\u003cli\\u003eGao J, Xu G, Qian H, Liu P, Zhao P, Hu Y (2013). Effects of nano-TiO\\u003csub\\u003e2\\u003c/sub\\u003e on photosynthetic characteristics of Ulmus elongata seedlings. Environ. Pollut. 176, 63\\u0026ndash;70. \\u003c/li\\u003e\\n\\u003cli\\u003eGaschler MM, \\u0026amp; Stockwell BR (2017). Lipid peroxidation in cell death. Biochemical and biophysical research communications, 482(3), 419-425. \\u003c/li\\u003e\\n\\u003cli\\u003eGatasheh MK, Shah A A, Ali S, Ramzan M, Javad S, Waseem L, Wahid A (2023). Synergistic application of melatonin and silicon alleviates chromium stress in Brassica napus through regulation of antioxidative defense system and ethylene metabolism. Sci. Hortic. 321, 112280. \\u003c/li\\u003e\\n\\u003cli\\u003eHeath RL, \\u0026amp; Packer L (1968). Photoperoxidation in isolated chloroplasts: I. Kinetics and stoichiometry of fatty acid peroxidation. Arch. Biochem. Biophys. 125(1), 189-198. \\u003c/li\\u003e\\n\\u003cli\\u003eHidalgo J, Epelde L, Anza M, Becerril J M, Garbisu C (2023). Mycoremediation with Agaricus bisporus and Pleurotus ostreatus growth substrates versus phytoremediation with Festuca rubra and Brassica sp. for the recovery of a Pb and \\u0026gamma;-HCH contaminated soil. Chemosphere. 327, 138538. \\u003c/li\\u003e\\n\\u003cli\\u003eHong F, Si W, Zhao X, Wang L, Zhou Y, Chen M, Zhang J (2015). TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticle exposure decreases spermatogenesis via biochemical dysfunctions in the testis of male mice. J. Agric. Food Chem. 63(31), 7084-7092. \\u003c/li\\u003e\\n\\u003cli\\u003eIrshad MA, ur Rehman MZ, Anwar-ul-Haq M, Rizwan M, Nawaz R, Shakoor MB, Ali S (2021). Effect of green and chemically synthesized titanium dioxide nanoparticles on cadmium accumulation in wheat grains and potential dietary health risk: A field investigation. J. Hazard. Mater. 415, 125585. \\u003c/li\\u003e\\n\\u003cli\\u003eIrshad MK, Noman A, Alhaithloul HA, Adeel M, Rui Y, Shah T, Shang J (2020). Goethite-modified biochar ameliorates the growth of rice (\\u003cem\\u003eOryza sativa\\u003c/em\\u003e L.) plants by suppressing Cd and As-induced oxidative stress in Cd and As co-contaminated paddy soil. Sci. Total Environ. 717, 137086. \\u003c/li\\u003e\\n\\u003cli\\u003eIslam E, Liu D, Li T., Yang X, Jin X, Mahmood Q, Li J, (2008). Effect of Pb toxicity on leaf growth, physiology and ultrastructure in the two ecotypes of Elsholtzia argyi. J. Hazard. Mater. 154(1-3), 914-926. \\u003c/li\\u003e\\n\\u003cli\\u003eJalil S, Alghanem SM, Al-Huqail AA, Nazir MM, Zulfiqar F, Ahmed T, Jin X (2023). Zinc oxide nanoparticles mitigated the arsenic induced oxidative stress through modulation of physio-biochemical aspects and nutritional ions homeostasis in rice (\\u003cem\\u003eOryza sativa\\u003c/em\\u003e L.). Chemosphere. 338, 139566. \\u003c/li\\u003e\\n\\u003cli\\u003eKingston‐Smith AH, Harbinson J, Foyer CH (1999). Acclimation of photosynthesis, H\\u003csub\\u003e2\\u003c/sub\\u003eO\\u003csub\\u003e2\\u003c/sub\\u003e content and antioxidants in maize (Zea mays) grown at sub‐optimal temperatures. Plant Cell Environ. 22(9), 1071-1083. \\u003c/li\\u003e\\n\\u003cli\\u003eKolenč\\u0026iacute;k M, Ernst D, Kom\\u0026aacute;r M, Ur\\u0026iacute;k M, \\u0026Scaron;ebesta M, Dobročka E, Krato\\u0026scaron;ov\\u0026aacute; G (2019). Effect of foliar spray application of zinc oxide nanoparticles on quantitative, nutritional, and physiological parameters of foxtail millet (\\u003cem\\u003eSetaria italica\\u003c/em\\u003e L.) under field conditions. Nanomaterials, 9(11), 1559. \\u003c/li\\u003e\\n\\u003cli\\u003eKolenč\\u0026iacute;k M, Nemček L, \\u0026Scaron;ebesta M, Ur\\u0026iacute;k M, Ernst D, Krato\\u0026scaron;ov\\u0026aacute; G, Konvičkov\\u0026aacute; Z (2021). Effect of TiO\\u003csub\\u003e2\\u003c/sub\\u003e as plant growth-stimulating nanomaterial on crop production. Plant Responses to Nanomaterials: Recent Interventions, and Physiological and Biochemical Responses, 129-144. \\u003c/li\\u003e\\n\\u003cli\\u003eKumar D, Dhankher OP, Tripathi RD, Seth CS (2023). Titanium dioxide nanoparticles potentially regulate the mechanism (s) for photosynthetic attributes, genotoxicity, antioxidants defense machinery, and phytochelatins synthesis in relation to hexavalent chromium toxicity in Helianthus annuus L. J. Hazard. Mater. 454, 131418. \\u003c/li\\u003e\\n\\u003cli\\u003eKumar P, Alamri SA, Alrumman SA, Eid EM, Adelodun B, Goala M, Kumar V (2022). Foliar use of TiO\\u003csub\\u003e2\\u003c/sub\\u003e-nanoparticles for okra (Abelmoschus esculentus L. Moench) cultivation on sewage sludge\\u0026ndash;amended soils: biochemical response and heavy metal accumulation. Environ. Sci. Pollut. Res. 29(44), 66507-66518. \\u003c/li\\u003e\\n\\u003cli\\u003eKumari S, Khanna RR, Nazir F, Albaqami M, Chhillar H, Wahid I, Khan, MIR (2022). Bio-synthesized nanoparticles in developing plant abiotic stress resilience: A new boon for sustainable approach. Int. J. Mol. Sci. 23(8), 4452. \\u003c/li\\u003e\\n\\u003cli\\u003eKurtinov\\u0026aacute; S, \\u0026amp; \\u0026Scaron;ebesta M (2023). Heavy metal stress alleviation in plants by ZnO and TiO\\u003csub\\u003e2 \\u003c/sub\\u003enanoparticles. In Nanotechnology in Agriculture and Agroecosystems (pp. 347-365). Elsevier. \\u003c/li\\u003e\\n\\u003cli\\u003eLei Z, Mingyu S, Xiao W, Chao L, Chunxiang Q, Liang C, Fashui H (2008). Antioxidant stress is promoted by nano-anatase in spinach chloroplasts under UV-B radiation. Biol. Trace Elem. Res. 121, 69-79. \\u003c/li\\u003e\\n\\u003cli\\u003eLian J, Zhao L, Wu J, Xiong H, Bao Y, Zeb A, Liu W (2020). Foliar spray of TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles prevails over root application in reducing Cd accumulation and mitigating Cd-induced phytotoxicity in maize (Zea mays L.). Chemosphere. 239, 124794. \\u003c/li\\u003e\\n\\u003cli\\u003eLiao Y, Li Z, Yang Z, Wang J, Li B, Zu Y (2023). Response of Cd, Zn Translocation and Distribution to Organic Acids Heterogeneity in Brassica juncea L. Plants. 12(3), 479. \\u003c/li\\u003e\\n\\u003cli\\u003eLichtenthaler, HK, (1987). [34] Chlorophylls and carotenoids: pigments of photosynthetic biomembranes. In Methods in enzymology (Vol. 148, pp. 350-382). Academic Press. \\u003c/li\\u003e\\n\\u003cli\\u003eMahamood MN, Zhu S, Noman A, Mahmood A, Ashraf S, Aqeel M, Irshad MK (2023). An assessment of the efficacy of biochar and zero-valent iron nanoparticles in reducing lead toxicity in wheat (\\u003cem\\u003eTriticum aestivum\\u003c/em\\u003e L.). Environ. Pollut. 319, 120979. \\u003c/li\\u003e\\n\\u003cli\\u003eManzoor N, Ali L, Al-Huqail A A, Alghanem SMS, Al-Haithloul HA, S Abbas, T Wang G (2023). Comparative efficacy of silicon and iron oxide nanoparticles towards improving the plant growth and mitigating arsenic toxicity in wheat (\\u003cem\\u003eTriticum aestivum\\u003c/em\\u003e L.). Ecotoxicol. Environ. Saf. 264, 115382. \\u003c/li\\u003e\\n\\u003cli\\u003eMishra V, Mishra RK, Dikshit A, Pandey AC (2014). Interactions of nanoparticles with plants: an emerging prospective in the agriculture industry. In Emerging technologies and management of crop stress tolerance (pp. 159-180). Academic press. \\u003c/li\\u003e\\n\\u003cli\\u003eMitra A, Chatterjee S, Voronina AV, Walther C, Gupta DK (2020). Lead toxicity in plants: a review. Lead in Plants and the Environment, 99-116. \\u003c/li\\u003e\\n\\u003cli\\u003eNag R \\u0026amp; Cummins E (2022). Human health risk assessment of lead (Pb) through the environmental-food pathway. Sci. Total Environ. 810, 151168. \\u003c/li\\u003e\\n\\u003cli\\u003eNaheed R, Aslam H, Kanwal H, Farhat F, Gamar MIA, Al-Mushhin AA, Hessini K (2021). Growth attributes, biochemical modulations, antioxidant enzymatic metabolism and yield in Brassica napus varieties for salinity tolerance. Saudi J. Biol. Sci. 28(10), 5469-5479. \\u003c/li\\u003e\\n\\u003cli\\u003eNakano Y, \\u0026amp; Asada K (1981). Hydrogen peroxide is scavenged by ascorbate-specific peroxidase in spinach chloroplasts. Plant Cell Physiol. 22(5), 867-880. \\u003c/li\\u003e\\n\\u003cli\\u003eOgunkunle C O, Odulaja DA, Akande FO, Varun M, VishwakarmaV, Fatoba P O (2020). Cadmium toxicity in cowpea plant: Effect of foliar intervention of nano-TiO\\u003csub\\u003e2\\u003c/sub\\u003e on tissue Cd bioaccumulation, stress enzymes and potential dietary health risk. J. Biotechnol. 310, 54-61. \\u003c/li\\u003e\\n\\u003cli\\u003ePishkar L, Yousefi S, Iranbakhsh A, (2022). Foliar application of Zinc oxide nanoparticles alleviates cadmium toxicity in purslane by maintaining nutrients homeostasis and improving the activity of antioxidant enzymes and glyoxalase system. Ecotoxicol. 31(4), 667-678. \\u003c/li\\u003e\\n\\u003cli\\u003ePo\\u0026scaron;ćić F, Mattiello A, Fellet G, Miceli F, Marchiol L (2016). Effects of cerium and titanium oxide nanoparticles in soil on the nutrient composition of barley (\\u003cem\\u003eHordeum vulgare\\u003c/em\\u003e L.) kernels. Int. J. Environ. Res. Public Health, 13(6), 577. \\u003c/li\\u003e\\n\\u003cli\\u003ePoursani AS, Nilchi A, Hassani A, Shariat SM, Nouri J (2016). The synthesis of nano TiO\\u003csub\\u003e2\\u003c/sub\\u003e and its use for removal of lead ions from aqueous solution. J. Water Resource Prot. 8(04), 438. \\u003c/li\\u003e\\n\\u003cli\\u003eQiao X, Wang P, Shi G, Yang H, (2015). Zinc conferred cadmium tolerance in Lemna minor L. via modulating polyamines and proline metabolism. Plant Growth Regul. 77, 1-9. \\u003c/li\\u003e\\n\\u003cli\\u003eRaghib F, Naikoo MI, Khan FA, Alyemeni MN, Ahmad P (2020). Interaction of ZnO nanoparticle and AM fungi mitigates Pb toxicity in wheat by upregulating antioxidants and restricted uptake of Pb. J. Biotechnol. 323, 254-263. \\u003c/li\\u003e\\n\\u003cli\\u003eRahman A, Nahar K, Hasanuzzaman M, Fujita M (2016). Calcium supplementation improves Na\\u003csup\\u003e+\\u003c/sup\\u003e/K\\u003csup\\u003e+\\u003c/sup\\u003e ratio, antioxidant defense and glyoxalase systems in salt-stressed rice seedlings. Front. Plant Sci. 7, 609. \\u003c/li\\u003e\\n\\u003cli\\u003eRai PK, Lee SS, Zhang M, Tsang YF, Kim KH (2019). Heavy metals in food crops: Health risks, fate, mechanisms, and management. Environ. Int. 125, 365-385. \\u003c/li\\u003e\\n\\u003cli\\u003eRashid A, Schutte BJ, Ulery A, Deyholos MK, Sanogo S, Lehnhoff EA, Beck L (2023). Heavy Metal Contamination in Agricultural Soil: Environmental Pollutants Affecting Crop Health. Agronomy. 13(6), 1521. \\u003c/li\\u003e\\n\\u003cli\\u003eRehman MZU, Rizwan M, Ghafoor A, Naeem A, Ali S, Sabir M, Qayyum MF (2015). Effect of inorganic amendments for in situ stabilization of cadmium in contaminated soils and its phyto-availability to wheat and rice under rotation. Environ. Sci. Pollut. Res. 22, 16897-16906. \\u003c/li\\u003e\\n\\u003cli\\u003eRizwan M, Ali S, Ali, Adrees M, Arshad M, Hussain A, ur Rehman MZ, Waris AA (2019). Zinc and iron oxide nanoparticles improved the plant growth and reduced the oxidative stress and cadmium concentration in wheat. Chemosphere 214:269-277. \\u003c/li\\u003e\\n\\u003cli\\u003eRizwan M, Ali S, Rehman MZU, Javed MR, Bashir A (2018). Lead toxicity in cereals and its management strategies: a critical review. Water, Air, \\u0026amp; Soil Pollut. 229, 1-16. \\u003c/li\\u003e\\n\\u003cli\\u003eRizwan M, Ali S, Adrees M, Rizvi H, Zia-ur-Rehman M, Hannan F, Ok YS (2016). Cadmium stress in rice: toxic effects, tolerance mechanisms, and management: a critical review. Environ. Sci. Pollut. Res. 23, 17859-17879. \\u003c/li\\u003e\\n\\u003cli\\u003eSafdar ME, Qamar R, Javed A, Nadeem, MA, Javeed HMR, Farooq S, Ahmed MA (2023). Combined application of boron and zinc improves seed and oil yields and oil quality of oilseed rape (\\u003cem\\u003eBrassica napus\\u003c/em\\u003e L.). Agronomy 13(8), 2020. \\u003c/li\\u003e\\n\\u003cli\\u003eSardar R, Ahmed S, Yasin NA (2022). Titanium dioxide nanoparticles mitigate cadmium toxicity in \\u003cem\\u003eCoriandrum sativum\\u003c/em\\u003e L. through modulating antioxidant system, stress markers and reducing cadmium uptake. Environ. Pollut. 292, 118373. \\u003c/li\\u003e\\n\\u003cli\\u003eShakoor MB, Ali S, Hameed A, Farid M, Hussain S, Yasmeen T, Abbasi GH (2014). Citric acid improves lead (Pb) phytoextraction in Brassica napus L. by mitigating Pb-induced morphological and biochemical damages. Ecotoxicol. Environ. Saf. 109, 38-47. \\u003c/li\\u003e\\n\\u003cli\\u003eSilva S, Dias MC, Silva AM (2022). Titanium and zinc based nanomaterials in agriculture: A promising approach to deal with (a) biotic stresses?. Toxics. 10(4), 172. \\u003c/li\\u003e\\n\\u003cli\\u003eSong G, Gao Y, Wu H, Hou W, Zhang C, Ma H, (2012). Physiological effect of anatase TiO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles on Lemna minor. Environ. Toxicol. Chem. 31(9), 2147-2152. \\u003c/li\\u003e\\n\\u003cli\\u003eSong U, Jun H, Waldman B, Roh J, Kim Y, Yi J, Lee EJ, (2013). Functional analyses of nanoparticle toxicity: a comparative study of the effects of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and Ag on tomatoes (Lycopersicon esculentum). Ecotoxicol. Environ. Saf. 93, 60-67. \\u003c/li\\u003e\\n\\u003cli\\u003eSrivastava D, Tiwari M, Dutta P, Singh P, Chawda K, Kumari M, Chakrabarty D (2021). Chromium stress in plants: toxicity, tolerance and phytoremediation. Sustainability. 13(9), 4629. \\u003c/li\\u003e\\n\\u003cli\\u003eTran QT, Tran TH, Nguyen QD, Nguyen TT, Nguyen TD, Nguyen VK, Ha XL (2023). Combination of Superabsorbent Polymer and Vetiver Grass as A Remedy for Lead-Polluted Soil. Geogr. Environ. Sustain. 16(1), 181-188.\\u003c/li\\u003e\\n\\u003cli\\u003eTripathi DK, Mishra RK, Singh S, Singh S, Vishwakarma K, Sharma S, Chauhan DK (2017). Nitric oxide ameliorates zinc oxide nanoparticles phytotoxicity in wheat seedlings: implication of the ascorbate\\u0026ndash;glutathione cycle. Front. Plant Sci. 8, 1. \\u003c/li\\u003e\\n\\u003cli\\u003eNations, U (2015). Department of Economic and Social Affairs. Population Division.\\u003c/li\\u003e\\n\\u003cli\\u003eVishwakarma A \\u0026amp; Singh SP (2020). Synthesis of zinc oxide nanoparticle by sol-gel method and study its characterization. Int. J. Res. Appl. Sci. Eng. Technol. 8(4), 1625-7.\\u003c/li\\u003e\\n\\u003cli\\u003eWang Y, Peng C, Fang H, Sun L, Zhang H, Feng J, Shi J (2015). Mitigation of Cu (II) phytotoxicity to rice (Oryza sativa) in the presence of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and CeO\\u003csub\\u003e2\\u003c/sub\\u003e nanoparticles combined with humic acid. Environ. Toxicol. Chem. 34(7), 1588-1596. \\u003c/li\\u003e\\n\\u003cli\\u003eWang Y, Deng C, Cota-Ruiz K, Tan W, Reyes A, Peralta-Videa, JR, Gardea-Torresdey JL (2021). Effects of different surface-coated nTiO\\u003csub\\u003e2\\u003c/sub\\u003e on full-grown carrot plants: Impacts on root splitting, essential elements, and Ti uptake. J. Hazard. Mater. 402, 123768. \\u003c/li\\u003e\\n\\u003cli\\u003eZhang XZ (1992). The measurement and mechanism of lipid peroxidation and SOD, POD and CAT activities in biological system. Res. Method. Crop Physiol. 208-211.\\u003c/li\\u003e\\n\\u003cli\\u003eZhou P, Adeel M, Shakoor N, Guo M, Hao Y, Azeem I, Rui Y (2020). Application of nanoparticles alleviates heavy metals stress and promotes plant growth: An overview. Nanomater. 11(1), 26. \\u003c/li\\u003e\\n\\u003c/ol\\u003e\"}],\"fulltextSource\":\"\",\"fullText\":\"\",\"funders\":[],\"hasAdminPriorityOnWorkflow\":false,\"hasManuscriptDocX\":true,\"hasOptedInToPreprint\":true,\"hasPassedJournalQc\":\"\",\"hasAnyPriority\":false,\"hideJournal\":true,\"highlight\":\"\",\"institution\":\"\",\"isAcceptedByJournal\":false,\"isAuthorSuppliedPdf\":false,\"isDeskRejected\":\"\",\"isHiddenFromSearch\":false,\"isInQc\":false,\"isInWorkflow\":false,\"isPdf\":false,\"isPdfUpToDate\":true,\"isWithdrawnOrRetracted\":false,\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true},\"keywords\":\"Nanoparticles, Brassica napus L., Lead (Pb), Chlorophyll contents, Antioxidant activities, Nutrient Content\",\"lastPublishedDoi\":\"10.21203/rs.3.rs-3684389/v1\",\"lastPublishedDoiUrl\":\"https://doi.org/10.21203/rs.3.rs-3684389/v1\",\"license\":{\"name\":\"CC BY 4.0\",\"url\":\"https://creativecommons.org/licenses/by/4.0/\"},\"manuscriptAbstract\":\"\\u003cp\\u003eThe lead (Pb) has been regarded as toxic metal that negatively impact both plant growth and human health. Due to limited information available about the application of titanium dioxide (TiO\\u003csub\\u003e2\\u003c/sub\\u003e-NPs) and Zinc oxide nanoparticles (ZnO-NPs) for the alleviation of Pb stress in crop particularly in \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. The current experiment was aimed to investigate the efficacy of foliar application TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs on Pb uptake and growth performance. The results of our study demonstrated that TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs foliar application at (25, 50 and 100 mg/L) significantly decreased Pb uptake and simultaneously improved plant growth attributes, including shoot and root length, shoot and root fresh weight. Additionally, the NPs foliar application significantly augmented plant photosynthetic pigment (chlorophyll a, chlorophyll b, total chlorophyll and carotenoids) and gas exchange parameters compared to control. The biochemical analysis showed increased in plant antioxidative enzymes activities (peroxidase, Catalase, Superoxide dismutase) and reduction in oxidative stress (malondialdehyde, hydrogen peroxide, electrolyte leakage) under Pb stress upon NPs application. Importantly, foliar application of 100mg/L significantly reduced the uptake and translocation of pb in plant root and shoot with 45.7% and 84.1% respectively, as compared to control without nanoparticles. Furthermore, foliar application of TiO\\u003csub\\u003e2\\u003c/sub\\u003e and ZnO-NPs enhance shoot zinc (Zn), iron (Fe), manganese (Mn), magnesium (Mg) calcium (Ca) and Potassium (K) when compared to control without nanoparticles. Interestingly concentrations of macro and micro nutrients with the type and dose of nanoparticles were varied. The highest concentrations of Ca (69.8%), Mn (67.3%) and Zn (78.7%) were found at 100mg/L ZnO-NPs foliar application while, the highest concentrations of Fe (79.4%), Mg (72.1%) and K (81.4%) were observed at 100mg/L TiO\\u003csub\\u003e2\\u003c/sub\\u003e -NPs. Overall, application of nanoparticles especially, TiO\\u003csub\\u003e2\\u003c/sub\\u003e- NPs for \\u003cem\\u003eBrassica napus\\u003c/em\\u003e L. is promising strategy for sustainable agriculture towards alleviating Pb toxicity and ensuring food security.\\u003c/p\\u003e\",\"manuscriptTitle\":\"Comparative efficacy of titanium oxide nanoparticles and zinc oxide nanoparticles against lead tolerance, growth performance and nutrient profiling of Brassica Napus L. grown under Lead contaminated soil\",\"msid\":\"\",\"msnumber\":\"\",\"nonDraftVersions\":[{\"code\":1,\"date\":\"2024-01-16 11:31:15\",\"doi\":\"10.21203/rs.3.rs-3684389/v1\",\"editorialEvents\":[{\"type\":\"communityComments\",\"content\":0}],\"status\":\"published\",\"journal\":{\"display\":true,\"email\":\"info@researchsquare.com\",\"identity\":\"researchsquare\",\"isNatureJournal\":false,\"hasQc\":true,\"allowDirectSubmit\":true,\"externalIdentity\":\"\",\"sideBox\":\"\",\"snPcode\":\"\",\"submissionUrl\":\"/submission\",\"title\":\"Research Square\",\"twitterHandle\":\"researchsquare\",\"acdcEnabled\":true,\"dfaEnabled\":false,\"editorialSystem\":\"\",\"reportingPortfolio\":\"\",\"inReviewEnabled\":false,\"inReviewRevisionsEnabled\":true}}],\"origin\":\"\",\"ownerIdentity\":\"3347214a-6cf8-47a3-b89a-5e70fa1c0746\",\"owner\":[],\"postedDate\":\"January 16th, 2024\",\"published\":true,\"recentEditorialEvents\":[],\"rejectedJournal\":[],\"revision\":\"\",\"amendment\":\"\",\"status\":\"posted\",\"subjectAreas\":[],\"tags\":[],\"updatedAt\":\"2024-02-19T09:59:57+00:00\",\"versionOfRecord\":[],\"versionCreatedAt\":\"2024-01-16 11:31:15\",\"video\":\"\",\"vorDoi\":\"\",\"vorDoiUrl\":\"\",\"workflowStages\":[]},\"version\":\"v1\",\"identity\":\"rs-3684389\",\"journalConfig\":\"researchsquare\"},\"__N_SSP\":true},\"page\":\"/article/[identity]/[[...version]]\",\"query\":{\"redirect\":\"/article/rs-3684389\",\"identity\":\"rs-3684389\",\"version\":[\"v1\"]},\"buildId\":\"qtupq5eGEP_6zYnWcrvyt\",\"isFallback\":false,\"isExperimentalCompile\":false,\"dynamicIds\":[84888],\"gssp\":true,\"scriptLoader\":[]}","source_license":"CC-BY-4.0","license_restricted":false}