Response of Nanosilica on Physiological and Leaf Surface Anotomical Characters in Rice under Drought

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Krishna Surendar, R. Karthik Raja, N. Sritharan, V. Ravichandran, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3849684/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 experimentation was carried out during the summer (2021–2022) at the Rice Department, Tamil Nadu Agricultural University, Coimbatore to assess the effects of nanosilica on drought imposed rice plants and to assess the impact of different concentrations of nanosilica (SiO2) on growth, anatomical, physio-biochemical parameters and yield characters of rice under drought conditions. In this experiment, different concentrations of the nanosilica formulation at 200, 400, 600, 800, and 1000 ppm were applied as foliar sprays under drought conditions. Spraying of 400 ppm of nanosilica formulation under drought stress in this field experiment has resulted of increases in leaf area and specific leaf weight of 14.3 and 15.3%, respectively. Application of 400 ppm nanosilica increases up to 12.5% in terms of membrane stability index (MSI), meanwhile in chlorophyll stability index (CSI) was increased up to 20.4%. Proline content was decreased up to 26.9% by application of nanosilica (400 ppm) in drought imposed treated plants. Trichome length and the length of the silica bodies were significantly increase of about 17.4 and 9.1% over the control. Application 400 ppm of nanosilica had maximum of 68.9 and 29.4% increment in terms of trichome and silicon bodies length over the drought. Stomatal structures are reduced significantly with mean reduction of 43.5% than the control in both the rice varieties. Under the drought, the average increase in stomatal size was 65.5% when 400 ppm nanosilica was applied. When exposed to 400 ppm of nanosilica treatments, CO54 showed more responses than the other variety in terms of leaf area, specific leaf weight, MSI, CSI, proline and leaf surface characteristics during drought. Nanosilica rice drought physiology proline catalase activity leaf surface Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Rice ( Oriza sativa L.) is considered as the majority of the world basic food crops. It is grown under irrigated ecosystem and some parts of India and Tamil Nadu cultivated under rainfed ecosystem. Rice is also known as ‘Global grain’ because it is cultivated in more than 100 countries. Asian countries are the toppest in production and consumption of rice (Samal et al. 2018). According to Pandey and Shukla (2015) rice is most important staple food and most of the world population depends for its consumption and also income generation. Climate change is the main factor limiting rice production (drought and flooding). This ultimately impacts on agricultural, mostly in developing nations, and typically influences the amounts of hydrological variation (Turral et al. 2011). The main factor restricting production of rice is drought (Nelson et al. 2014). Therefore, enhancing rice yield with climate change and water limitation is the first approach for enhancing rice production to meet out the food demand in future, expected from the probable increasing in world population. Silicon is considered as non-essential nutrient because, silicon cannot fulfil the “essential criteria for a nutrient” given by Arnon and Stout (1939). So, until 1994 silicon considered as non-essential element. After that, Epstein (1994) given the astonishing review on silicon in ‘The anomaly of silicon in plant biology’ changes the prospects of silicon in the farming field. Several studies reported that beneficial effects of silicon. ‘International Plant Nutrition Institute’ promotes the silicon from non-essential to beneficial element (IPNI 2015). Because small number of plant species requires silicon particularly in rice plant. McLarnon et al. (2017) reported that, silicon requirements increased during stress and silicon actively absorbed in some grass species. In this present study framed with the objectives of enhancing the drought tolerant capacity in rice through foliar application of different concentrations of nanosilica. Materials and Methods Experimental site The experimentation was conducted at Rice Department, Tamil Nadu Agricultural University (TNAU), Coimbatore. Geographically, the experimental site was situated in the zone of western agro- climatic of Tamil Nadu at an altitude of 426.72 meters above mean sea level with 11°N latitude and 77°E longitude. The total duration of the experiment was five months from January to May (2021–2022). During the study period, the average of maximum temperature was 32.2°C and 22.6°C, respectively. The total amount of rainfall received during the crop period was 71.3 mm. However, there is no rainfall received at the time of stress imposition and foliar application of nanosilica. The two rice varieties of CO53 and CO54 having short duration were together from the Rice Department, TNAU (Table 1 ). Nanosilica materials were prepared and collected from the Nano Science and Technology Department, TNAU, Coimbatore. Table 1 Characters of rice varieties Variety Parentage Duration (days) CO 53 PKM(R) x Norungan 115–120 CO 54 CB04110 x CB05501 115–120 Preparation of nanosilica formulation Nanosilica emulsion was prepared from pure nanosilica and it was mixed with tween 80 and water (1:3 ratio). After that, the solution was sonicated for 30 minutes at a rate of 10:10 plus at 50% amplification. Solutions were well homogenized. Based on the requirement of experiment different concentration viz ., 200, 400, 600, 800 and 1000 ppm of nanosilica has been prepared and used for this field study as foliar spray. The drought was imposed by withholding of irrigation for all treatments except T1 (Irrigated) from 12 days before flowering and 10 days after flowering. The total period of the stress was 22 days. The irrigation was controlled by bund and the water leakage was vetoed by placing of plastic sheets. The water drained out by buffer channels in drought imposed plots. The application of nanosilica as foliar spray at 50% flowering stage (mid of the drought period). Totally seven treatments were choocen for this experiment viz., T1 – Irrigated, T2 – Drought, T3 – Drought + Nanosilica (200 ppm), T4 – Drought + Nanosilica (400 ppm), T5 – Drought + Nanosilica (600 ppm), T6 – Drought + Nanosilica (800 ppm) and T7 – Drought + Nanosilica (1000 ppm). Observations recorded Plant sampling The growth anatomical, physiological, biochemical and yield parameters were recorded in each treatment with three plants per replications per treatments were collected at seven days after application of nanosilica in 50% flowering stage and physiological maturity stage for measuring all the observation. Growth attributes Leaf area (cm2) Leaf area was measured from three randomly selected plants from each plot by using leaf area meter (LI-3100 Area Meter) and expressed in cm 2 . Specific leaf weight SLA was calculated from leaf weight of the plant and leaf area of the plant and it was expressed in dry weight per unit leaf surface area. It is an indirect measurement of width and thickness of the leaf and noticed in mg cm -2 . Leaf anatomical characters (SEM measurements) Stomatal characters Leave bits are collected from plants of each treatment at seven days after the application of nanosilica and the length and breadth of the stomata are measure under Scanning Electron Microscope (SEM) available at Nano science and Technology Department, TNAU, Coimbatore. Leaf surface characters Trichomes characters and silicon content of two rice varieties were viewed and measured under the scanning electron microscope (SEM) at seven days after foliar application of nanosilica. Silicon content (%) The silicon content was measured under scanning electron microscope by following the energy dispersive x-ray analysis (EDAX) method. Physiological and biochemical analysis Proline content Proline estimate has been done using the method derived from Bates et al. (1973). Following the weighing of 500 mg of leaf samples, 10 ml of 3% sulpho salicylic acid was macerated. Subsequently, the solution was centrifuged at 3000 rpm for 10 minutes. Two ml of the supernatant was removed and 2 ml each of acid ninhydrin, glacial acetic acid and 6M orthophosporic acid were added to the test tube. The test tube was then placed in a hot water bath for a one hour. Subsequently, the solutions were poured into separate funnels, 4 ml of toluene was added and everything was shaken evenly for 30 seconds. After discarding the colourless solution and gathering the upper pink solution, the optical density was calculated at 520 nm and reported in mg g -1 of fresh weight. Catalase activity We estimated the catalase activity using the method Volk and Feierabend (1989) presented. The Catalase activity determines by the rate of reduction in hydrogen peroxide abortion at 240 nm and expressed in µg of H2O2 g -1 min -1 . Statistical analysis In a factorial randomized block design (FRBD), the data was obtained and statistical analysis was carried out (Gomez et al. 1984). Results and Discussion Leaf area One of the most vital and useful parts of a plant is its leaf. Many physiological and biochemical reaction are carried out inside the leaf and it is the effective in the yield under abiotic stress condition (Wang et al. 2005). It is main source of carbon fixation by photosynthesis and maintains the leaf temperature by transpiration through stomata (Buckley et al. 2015; Yuvaraj et al. 2023). The decline of leaf area surface is the first reaction of drought adoption to reduce the transpiration losses (Larcher 2003). The effect of silica nano formulations in leaf area are described in (Table 2 ). Table 2 Impact of silica nanoformulation on leaf area and SLW in rice under drought condition Treatments Leaf area (cm 2 ) Specific leaf weight (mg cm-2) CO 54 CO 53 CO 54 CO 53 T1 – Control 1744.6 1814.4 5.28 5.58 T2 – Drought 1441.3 1616.5 3.86 4.42 T3 – Drought + 200 ppm 1660.5 1705.2 4.62 4.80 T4 – Drought + 400 ppm 1699.0 1787.8 4.88 5.30 T5 – Drought + 600 ppm 1619.9 1680.4 4.43 4.61 T6 – Drought + 800 ppm 1568.3 1654.7 4.25 4.58 T7 – Drought + 1000 ppm 1550.1 1636.4 4.06 4.52 Mean 1612.0 1699.3 4.48 4.83 SEd CD (0.05) SEd CD(0.05) V (Variety) 35.38 72.71* 0.195 0.400 T (Treatment) 66.18 136.04** 0.364 0.768* V x T 93.59 192.38 0.515 1.059 * Significant at 5% level ** Significant at 1% level The outcome clarified the rising trend in control and declining trend in drought affected plants when silica nano formulation was applied. Among the treatments, control plants had maximum leaf area of 1814.4 cm 2 plant -1 and 1744.6 cm 2 plant -1 in CO53 and CO54, respectively. Comparing the two varieties, CO53 had maximum leaf area of 1616.5 cm 2 plant - 1 than CO54 (1441.3 cm 2 plant -1 ) under drought alone condition. The results revealed that a significant variation could also be observed between drought alone and drought with silica nanoformulation treatments. Among the nanosilica treatments, T4 (Drought + 400 ppm) recorded maximum leaf area of about 1787.8 cm 2 plant -1 and 1699.0 cm 2 plant -1 in CO53 and CO54 under drought condition respectively. Whereas, the treatment T3 (Drought + 200 ppm) registered the leaf area of about 1705.2 cm 2 plant -1 and 1660.5 cm 2 plant -1 under drought conditions. The treatment T4 and T3 are on par with each other. According to Kafi et al. (2021) who stated that the suppression of cell elongation and division due to drought. In this present filed experiment shows, drought minimize the leaf area in both varieties. Comparing the two varieties, maximum reduction of leaf area are observed in CO54 (17.4%) than CO53 (11.0%) under drought. Application 400 ppm of nanosilica in drought affected plants increases the leaf area up to 14.25% in both the rice varieties. This may be due to silicon increases the water use efficiency (Ma et al. 200l) and maintain the higher relative water content in the leaf, it helps leaf expansion (Da Silva Lobato 2020). Present study was agreement with Shen et al. (2010) who opined that silicon improve the growth characters including leaf area. The same kind of results reported by Gong et al. (2008) insisted that silicon improve the leaf growth under drought condition. Specific leaf weight The measurement of leaf thickness is represented by SLW. It has been found to have a substantial positive link with the uptake of carbon from leaves, which raises the photosynthetic index and indirectly indicates the leaf density in rice (Sarkar et al. 1996). Leaf thickness and succulence of the plants had strong connection and improve the drought tolerance (Bussoti et al. 2002). The effect of silica nanoformulation on specific leaf weight in rice displayed in (Table 2 ). Comparing seven treatments, the increasing trend in specific leaf weight were noticed in control plants, besides declining trend was noticed in drought and nanosilica imposed crops. Comparing the two varieties CO53 had maximum specific leaf weight (5.58 mg cm -2 ) over the drought alone treatments (CO53- 4.42 mg cm -2 ; CO54-3.86 mg cm -2 ). Among the different concentration of nanosilica treatments, T4 (Drought + 400 ppm) differed significantly an increasing of specific leaf weight under drought in both varieties (CO53-5.30 mg cm -2 ; CO54-4.15 mg cm -2 ) which was followed by T3 (CO53-4.80 mg cm -2 ; CO54-4.62 mg cm -2 ) treatments. Both are on par with each other. These data support what the current investigation discovered, which was CO54 had maximum specific leaf weight reduction of 26.8% than CO53 (20.7%) under drought alone condition. Reduction of specific leaf weight shows that, CO53 registered more resistance to drought than CO54. Foliar application of 400 ppm of nanosilica on drought induced plants, slightly alleviate the adverse effect of drought; besides higher recovery percent of 26.0 and 20.0% registered by CO54 and CO53 respectively. Drought reduces the leaf mass, thickness and area for minimize the transpiration loss. These outcomes concur with Siddique et al. (2015), opined that application of silica improve the water status, it helps the cells to enlarge and enhance the photosynthesis in the plants also silicon helps to maintaining the turgidity of the cells (Isa et al. 2010). The identical results concurred with Gong et al. (2005) and Wang et al. (2019) insisted that, silicon improving the number of mesophyll cells and mesophyll cell enlargement, which leads to enhance the photosynthetic efficiency in the rice under drought. Leaf surface characters Trichome length Trichomes are unicellular unicellular (or) multi cellular branched hair like structure arises from the single (or) multi cell of protodermal cells (Hulskamp et al. 1994). Trichome contains essential oils, secondary metabolites and act as salt gland under salinity stress. Under drought condition trichomes are very use full trait for resistance against water deficient. Trichomes involved in the production of secondary metabolites like terpenes for drought tolerance (Kennedy 2003). Guntwer et al. (2021) opined that density and length of the trichome are increased under drought conditions. The data on trichome length of different nanosilica application are presented in (Table 3 ). Table 3 Influence of silica nanoformulation on trichome length, stomatal size and silica bodies Trichome length (µm) Stomatal size (µm2) silica bodies (µm) Treatments CO54 CO53 CO54 CO53 CO54 CO53 T1 – Control 186.35 246.53 31.34 25.90 13.02 12.34 T2 – Drought 222.27 284.27 16.39 15.71 13.54 14.10 T3 – Drought + 200 ppm 305.23 497.30 29.69 19.57 16.12 16.12 T4 – Drought + 400 ppm 342.10 522.70 30.25 20.00 17.08 18.70 T5 – Drought + 600 ppm 273.47 424.93 25.28 17.23 15.87 15.43 T6 – Drought + 800 ppm 263.70 418.27 24.87 17.03 15.51 15.26 T7 – Drought + 1000 ppm 260.93 300.43 20.00 16.60 15.20 14.30 Mean 264.86 384.92 25.40 18.86 15.19 15.18 SEd CD(0.05) SEd CD(0.05) SEd CD(0.05) V (Variety) 30.827 63.366** 1.755 3.608** 0.249 0.511 T (Treatment) 57.672 118.548** 3.284 6.750** 0.4654 0.957** V x T 81.561 167.653 4.644 9.546 0.658 1.353 * Significant at 5% level ** Significant at 1% level Plants treated with nanosilica showed an increasing trend, while plants receiving control treatment alone exhibited a reduction in trichome length. Between two varieties, highest trichome length of 284.27 µm registered by CO53 than CO54 (222.27 µm) under drought alone condition. Control alone treatment plants showed lowest trichome length of 184.35 µm in CO54 and CO53 had 246.53 µm. In the present study, silicon treated plants had highest length of trichomes. Among the nanosilica application, Drought + 400 ppm treatment (T4) recorded lesser trichome length of 522.70 µm in CO53 than CO54 (342.10 µm) under drought condition. These results are agreement with present study; drought stress had 19.3% increases of trichome length in CO54 and 15.15% in CO53 over the control (Fig. 2 ). Application of silicon increases the trichome length of 68.85% over the drought. Silicon improves the plant trichome length under drought. The current study's findings concur with those of Rostkowska et al. (2016) who stated that, silicon deposited in the inside the trichomes and it helps to improve the length of the trichomes. Similar outcomes were noted in Mentha piperita by Ahmad et al. (2011). Takeda et al. (2013) reported that silicon deposited in the trichome increases the infra-red light use efficiency in plant. Stomatal size Surface area of the rice leaf covered by cuticle layer. All surface cells are not identical each other same degree of changes were noticed based on the nature specie. Some surface cells differ from the outer epidermal cell they are kidney shaped specialised cell for gas exchange purpose (opening and closing of stomata) that cells called guard cells drought alter the development and differentiation of pore size, stomatal length and breadth, density of the Stomata. Wang et al. (2019) noticed that size of the stomata reduced under drought. The results on stomatal size illustrated in the (Table 3 ). The stomatal size observation indicates a trend towards increase in control and decline in plants treated with silica nanoformulation and drought. The table indicates that control plant had maximum stomatal size (31.34 µm 2 ) and drought plants shows lowest stomatal size of (15.71 µm 2 ). Between the two varieties, CO54 recorded maximum stomatal size of 31.34 µm 2 than the CO53 (25.9 µm 2 ) under control. Drought and drought with plants treated with nanosilica differed significantly. Among the different nanosilica treatments, T4 (Drought + 400 ppm) registered maximum stomatal size of about 30.25 µm 2 and 20.00 µm 2 in CO54 and CO53 respectively, with lesser reduction over control. Which was closely flowed by T3 (Drought + 200 ppm) treatment in both varieties (CO54-29.69 µm 2 ; CO53-19.57 µm 2 ). Drought increases the density of the stomata (stomatal frequency) are increases, while stomata size were reduced which leads rapid stomatal conductance for increasing the photosynthetic rate. The results are agreement with present study, drought stress significantly decreases the stomatal size in both varieties. CO54 had highest present decreases of about 47.7% than CO53 (39.3%) over the control (Fig. 3 ). Application of 400 ppm nanosilica had 68.85% increases in stomatal size in rice over the control. These findings agree with Verma et al. (2020) in sugarcane. Vandegeer et al. (2020) opined that, silicon application helps to maintain the water content of the guard cell and improve the stomatal conductance to increases the photosynthetic rate in tall fescue. Silicon bodies length The data (Table 3 ) represent the silicon bodies present in the leaf surface. Results revealed that nanosilica treatment had increasing trend and drought alone and control plants had declining trend. Comparing the two rice varieties, CO54 had minimum silicon body length of 13.02 µm than the CO53 (12.34 µm) under control alone condition. However, a considerable increment could also register in silicon body length due to drought. Maximum silica bodies length recorded in CO53 (14.10 µm) than CO54 (13.54 µm) under drought alone condition. A significant increasing trend could also be noticed in nanosilica treatment. Among the different silica treatments, T4 had maximum silicon bodies length of 18.70 µm than all the other treatments. In T4 treatment, the varieties CO53 and CO54 both on par with each other. Silicon content (%) (SEM-EDAX) The silicon content were measured under scanning electron microscope by following the energy dispersive x-ray analysis (EDAX) method and tabulated in (Table 4 ). Highest silicon content could notice in CO53 (10.12%) than CO54 (6.82%) under control alone treatment (T1). An increasing trend could also be observed in drought alone and drought with nanosilica applied crops. Among the different concentration of silica nanoformulations treatments under drought, T7 had maximum silicon content of about 16.66% registered by CO53 than CO54 (13.66%), which was followed by T6 (Drought + 200 ppm) (CO53-14.23%; CO54-12.12%) (Fig. 1 ). However, the treatment drought alone registered lesser amount of silica content of 12.1% (CO53) and 8.81% (CO54) respectively than other nanosilica treatments. Besides; this drought alone (T2) treatment had higher silica content than the control (T1) treatment. Table 4 Impact of silica nanoformulation on silica content (%) (SEM-EDAX) in rice under drought condition Treatments Silica content (%) CO 54 CO 53 T1 – Control 6.82 10.12 T2 – Drought 8.81 12.11 T3 – Drought + 200ppm 9.17 12.57 T4 – Drought + 400ppm 10.64 12.94 T5 – Drought + 600ppm 11.05 13.50 T6 – Drought + 800ppm 12.12 14.23 T7 – Drought + 1000ppm 13.66 16.66 Mean 21.1 23.1 SEd CD(0.05) V (Variety) 0.104 0.215** T (Treatment) 0.196 0.402** V x T 0.277 0.568** * Significant at 5% level ** Significant at 1% level Leaf proline Proline is an imino acid (proline) acts as best osmolytes which will help to keep up the more plant tissue Ψw under water deficit conditions. Conferring to Mc Neil et al. ( 1999) stated that, the osmoprotected iminoacid (proline) resides in the cytoplasm and scavenging of free radicals that are produced under drought (Delauney and Verma, 1990). In the present study, drought adversely affects the protein degradation and significantly increases the proline content in both varieties. The proline content data indicated that plants treated with nanosilica during a drought experienced a less significant decline (Table 5 ). CO54 had maximum proline content when compared to the CO53 (291.8 µg g -1 ) under drought alone condition. Comparing the different nanosilica treatments, T4 (Drought + 400 ppm) registered the lesser proline content of about 216.1 µg g -1 to 242.0 µg g -1 , which was followed by T3 (Drought + 200 ppm) treatment (239.86 µg g -1 to 270.51 µg g -1 ) under drought condition. High proline accumulation could be noticed in CO54 (87.0% over the control) than CO53 (54.2% over the control). Application of silicon has the capacity to curtail the influence of water deficit by plummeting the deprivation of protein and also reduces the proline production (Gunes et al. 2008). Among different nanosilica treatments of nanosilica application, 400 ppm of nanosilica had 26.5% decreased proline accumulation over the drought alone treatment. These evidences are in agreement with this present study found that, nanosilica application as foliar spray during mid of the drought period had the capacity to diminish the production of ROS through stir up the proline synthesis. Agarie et al. (1998) showed comparable results in rice during a drought. Table 5 Influence of silica nanoformulation on proline and catalase activity in rice under drought condition Leaf proline (µg g-1) Catalase activity (µg of H2O2 g -1 min -1 ) Treatments CO 54 CO 53 CO 54 CO 53 T1 – Control 177.0 188.2 161.3 190.2 T2 – Drought 331.2 292.3 196.1 234.9 T3 – Drought + 200 ppm 270.5 238.8 242.7 290.7 T4 – Drought + 400 ppm 242.0 216.1 271.7 311.2 T5 – Drought + 600 ppm 285.4 261.8 232.5 275.1 T6 – Drought + 800 ppm 311.3 238.4 218.2 255.4 T7 – Drought + 1000 ppm 317.9 273.9 208.1 245.9 Mean 276.47 244.21 218.66 257.63 SEd CD(0.05) SEd CD(0.05) V (Variety) 7.850 16.136** 2.780 5.714** T (Treatment) 14.685 30.188** 5.200 10.690** V x T 20.769 42.693 7.355 15.118 * Significant at 5% level ** Significant at % level Catalase activity The second most prevalent antioxidant enzyme is called catalase, and it has the capacity to reduce H 2 O 2 production in peroxisomes and its subsequent detoxification into oxygen and water during a drought (Vendemiale et al. 1999). According to Uchida et al. (2012) catalase inhibits lipid peroxidation, damages cell membranes, and prevents chlorophyll from degrading Luna-Lopez et al. (2012) reported that, drought increases the catalase activity to alleviate negative effects of hydrogen peroxide. A rising trend was observed in nanosilica treated plants under drought and reduction of catalase activity in control alone treatment (Table 5 ). More catalase activity of 235.1 µg of H2O2 g -1 min -1 found in CO53 than CO54 (195.4 µg of H2O2 g -1 min -1 ) under drought alone condition. Control alone treatment crops showed lesser catalase activity of 159.6 µg of H2O2 g -1 min -1 registered by CO54; whereas CO53 had (189.3 µg of H2O2 g -1 min -1 ). In the present research, silicon applied plants had highest catalase activity under drought condition. Among the nanosilica application, Drought + 400 ppm treatment (T4) had lower catalase activity of 310.2 µg of H2O2 g -1 min -1 recorded in CO53; CO54 had 272.1 µg of H2O2 g -1 min -1 under drought condition. These findings are in agreement with present study explained that, drought induced plants had highest catalase activity of 24.1% (CO53), whereas CO54 had (22.4%) over the control. Application of nanosilica significantly increases the catalase activity in drought induced plants. Foliar application of 400 ppm nanosilica had maximum increases of catalase activity of about 40.8% in CO54 and 31.9% in CO53 under control. These outcomes accord with the barley study conducted by Liang et al. (2003). Ahmad et al. (2011) who opined that, silicon increases the antioxidant enzymes like catalase (CAT) peroxidise (POX), superoxide dismutase (SOD) under drought condition. By modifying the activity of antioxidant enzymes and stimulating the cell wall ability to bind cations, silicon treatment in rice may improve its ability to withstand drought (Sivaneasan and Park 2014). Conclusion Leaf area had 10.9% reduction under drought condition. Foliar application of 400 ppm nanosilica had increase in leaf area and leaf area index of 14.2% in drought induced plants over the unsprayed nano silica drought stressed rice plant. Among the different nano silica concentrations, 400 ppm of nanosilica concentration had significantly increased in specific leaf weight under drought of about 19.9 to 26.4% over the drought alone conditions. Drought tolerance trait like chlorophyll stability index and membrane stability index, relative water content had significant decline of 15.7, 17.2 and 14.6% over the control in rice under drought condition. These drought tolerant traits are increased by 10.6, 18.6 and 10.7% over the drought in rice varieties due to foliar application of 400 ppm of nano silica under drought over the drought alone condition. Proline content was increased due to drought. Maximum proline accumulations of 87.0% were noticed in CO54; meanwhile, CO53 had 54.2% increment. Application of 400 ppm of nanosilica had mean reduction in proline content of 33.9% in both varieties when compared to drought over the drought alone and control. The length of the trichome and silica bodies were measured under scanning electron microscope (SEM) and a significant increase in terms of length of the trichome and silica content by 17.4 and 9.1% due to application of 400 ppm of nano silica under drought. The same results were observed in stomatal characters where an increment of 27.3% registered by application of 400 ppm nanosilica under drought than the drought alone conditions. Hence, the concentration of 400 ppm nanosilica as foliar spray can be efficiently alleviating the effect of drought at reproductive stage in rice. Declarations All the author read and understood the publishing policy, and submit this manuscript in accordance with this policy. Funding No funding Acknowledgement We thank Department of Nano Science and Technology, TNAU, Coimbatore for nanosilica product and laboratory support. We are grateful to the Department of Rice at TNAU in Coimbatore for supplying the labourers and rice seed material. Author contribution [K. Krishna Surendar1*, R. Karthik Raja2] Methodology: [K. Krishna Surendar1*, R. Karthik Raja2, Dr. N. Sritharan2, Dr. V. Ravichandran2] Formal analysis: [R. Anitha, R. Nageswari, V. Dhanushkodi] Investigation: [K. Krishna Surendar1*, R. Karthik Raja2] Writing–original draft: [K. Krishna Surendar1*, R. Karthik Raja2] Writing review and editing: [Dr. M. Kannan3, Dr. R. Pushpam4, R. Anitha5, R. Sathya Priya6 and M. Yuvaraj7]; Supervision:[K. Krishna Surendar1*, R. Karthik Raja2]. Ethical Approval Not applicable Data availability The authors confirm that the data supporting the findings of this study are available from the corresponding author upon reasonable request. Consent to Participate: Every researcher involved in the experiment gave their consent. Consent for Publication: Permission to publish this research study in the journal has been granted by the authors. Competing Interest: The writers believe they have no conflicting intentions. References Agarie S, Uchida H, Agata W, Kubota F, Kaufman PB (1998) Effects of silicon on transpiration and leaf conductance in rice plants ( Oryza sativa L.). Plant Prod Sci. 1(2):89–95 Ahmed M, Khurshid Y (2011) Does silicon and irrigation have impact on drought tolerance mechanism of sorghum? 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(3):032120 Turral H, Burke J, Faurès JM (2011) Climate change, water and food security: Food and Agriculture Organization of the United Nations (FAO) Watabe-Uchida M, Zhu L, Ogawa SK, Vamanrao A, Uchida N. (2012) Whole-brain mapping of direct inputs to midbrain dopamine neurons. Neuron. 7;74(5):858-73. Vandegeer RK, Zhao C, Stewart XC, Wuhrer R, Hall CR, Hartley SE, Tissue DT, Johnson SN (2021) Silicon deposition on guard cells increases stomatal sensitivity as mediated by K+ efflux and consequently reduces stomatal conductance. Physiol Plant. 171 (3):358–370. doi: 10.1111/ppl.13202. Epub 2020 Sep 16 Vendemiale G, Grattagliano I, Altomare E (1999) An update on the role of free radicals and antioxidant defense in human disease. Int J Clin and Lab Res. 29(2):49–55 Volk S, Feierabend J. (1989) Photoinactivation of catalase at low temperature and its relevance to photosynthetic and peroxide metabolism in leaves. Plant, Cell & Environment. Sep;12(7):701-12. Verma KK, Singh P, Song XP, Malviya MK, Singh RK, Chen GL, Solomon S, Li YR. (2020) Mitigating climate change for sugarcane improvement: role of silicon in alleviating abiotic stresses. Sugar Tech.;22:741-9. Wang Y, Zhang B, Jiang D, Chen G (2019) Silicon improves photosynthetic performance by optimizing thylakoid membrane protein components in rice under drought stress. Env Exp Bot. 158:117-124. https://doi.org/10.1016/j.envexpbot.2018.11.022 Yoshida S, Navasero S, Ramirez E (1969) Effects of silica and nitrogen supply on some leaf characters of the rice plant. Plant Soil. 31(1):48–56 Yuvaraj M , Sathya Priya R, Jagathjothi N, Saranya M, Suganthi N, Sharmila R, Cyriac J, Anitha R, Subramanian KS (2023) Silicon nanoparticles (SiNPs): Challenges and perspectives for sustainable agriculture. Physiol and Mol Plant Pathol. 128: 102161. doi: https://doi.org/10.1016/j.pmpp.2023.102161 Zhu Y, Gong H (2014) Beneficial effects of silicon on salt and drought tolerance in plants. Agron Sustain Dev. 34:455–472 Zhu Z, Wei G, Li J, Qian Q, Yu J (2004) Silicon alleviates salt stress and increases antioxidant enzymes activity in leaves of salt-stressed cucumber ( Cucumis sativus L.). Plant Sci. 167 (3):527–533 Additional Declarations Competing interest reported. The writers believe they have no conflicting intentions. 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-3849684","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":266375759,"identity":"2dc11943-408f-433f-9b44-3d0d29e545fa","order_by":0,"name":"K. Krishna Surendar","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABE0lEQVRIie3OMUvDQBTA8RcO0uUlWRMO7Fe4cHAglOarXAjo4iIuQoUGAjdVnYv1O3R0VALX5XAWBBUEp2yBLgUxXYpCjuLW4f7THfd+3ANwuQ6wGLyS7G4IwKLdjfSBPpKoveT305YwvWex5K6u2vOHccZea/3RXL1x/n791CKMhzAIHvsIDXNF56bIl88np+lCXwihw4IiFGlJQtlHjtBTJFBEMoOCoi9HQiPrCJFAkFlI1QZqmjETrSl+yxFXyDcIUyuh6JU0ULW3NOh3BymYv/0OaitJZp7qJlf53Pgiub+RPNZn4njBVqmykNgMPrvFJlloyFfcrGV6Wxn+0lxOhlFkeomtbtj/z7zL5XK5/vQDZpBNdUxVko8AAAAASUVORK5CYII=","orcid":"","institution":"Tamil Nadu Agricultural University","correspondingAuthor":true,"prefix":"","firstName":"K.","middleName":"Krishna","lastName":"Surendar","suffix":""},{"id":266375760,"identity":"a88b43e4-df42-42a9-9d2a-d0ff4a4ae573","order_by":1,"name":"R. 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Sathya Priya","email":"","orcid":"","institution":"Tamil Nadu Agricultural University","correspondingAuthor":false,"prefix":"","firstName":"R.","middleName":"Sathya","lastName":"Priya","suffix":""},{"id":266375767,"identity":"917e5fe3-3a55-4cdc-83cb-62c2e537d41b","order_by":8,"name":"M Yuvaraj","email":"","orcid":"","institution":"Agricultural College and Research Institute","correspondingAuthor":false,"prefix":"","firstName":"M","middleName":"","lastName":"Yuvaraj","suffix":""}],"badges":[],"createdAt":"2024-01-10 08:18:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3849684/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3849684/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":49452919,"identity":"22aeaa71-6a82-497a-a60e-8fe0dd4e33a8","added_by":"auto","created_at":"2024-01-11 05:37:30","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":339550,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eImpact of silica nanoformulation on silica content in rice under drought condition observed under Scanning Electron Microscope-EDAX method\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3849684/v1/b3ad66bb360dc82214dcb278.png"},{"id":49453362,"identity":"8c2ff541-a8dc-475f-bcd3-6e761b3523f6","added_by":"auto","created_at":"2024-01-11 05:45:29","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":865684,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eImpact of silica nanoformulations on trichome (µm) in CO54 and CO53 in rice under drought condition observed under Scanning Electron Microscope-EDAX method\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3849684/v1/1e9a820124a4b4214e9b3789.png"},{"id":49452917,"identity":"69fda8f2-3c60-42ad-bef2-1e29e5b90a02","added_by":"auto","created_at":"2024-01-11 05:37:29","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":774067,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eEffect of silica nanoformulation on stomatal size (µm\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sup\u003e\u003cstrong\u003e) in CO54 and CO53 in rice under drought condition observed under Scanning Electron Microscope-EDAX method\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-3849684/v1/c88f1b6c67b625824e3b76de.png"},{"id":49453361,"identity":"51dda42a-a481-47e8-b392-5a525162a657","added_by":"auto","created_at":"2024-01-11 05:45:29","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":318639,"visible":true,"origin":"","legend":"\u003cp\u003eUnnumbered image in the Materials and Methods section.\u003c/p\u003e","description":"","filename":"UF1.png","url":"https://assets-eu.researchsquare.com/files/rs-3849684/v1/f12b896d54b6d0aef17815d5.png"},{"id":49452915,"identity":"2472f30e-03fc-4895-9ea3-3e7522de170d","added_by":"auto","created_at":"2024-01-11 05:37:29","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":60053,"visible":true,"origin":"","legend":"\u003cp\u003eUnnumbered image in the Materials and Methods section.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eA flowchart illustrating the period of drought in rice\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"UF2.png","url":"https://assets-eu.researchsquare.com/files/rs-3849684/v1/80ac9bf1556446215b7553da.png"},{"id":49552045,"identity":"39d9436a-b395-4674-839b-9d3a057fe75f","added_by":"auto","created_at":"2024-01-12 21:52:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2726852,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3849684/v1/e0a7ff72-5f4a-43f2-865e-90c7ddf1d090.pdf"}],"financialInterests":"Competing interest reported. The writers believe they have no conflicting intentions.","formattedTitle":"Response of Nanosilica on Physiological and Leaf Surface Anotomical Characters in Rice under Drought","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRice (\u003cem\u003eOriza sativa\u003c/em\u003e L.) is considered as the majority of the world basic food crops. It is grown under irrigated ecosystem and some parts of India and Tamil Nadu cultivated under rainfed ecosystem. Rice is also known as \u0026lsquo;Global grain\u0026rsquo; because it is cultivated in more than 100 countries. Asian countries are the toppest in production and consumption of rice (Samal et al. 2018). According to Pandey and Shukla (2015) rice is most important staple food and most of the world population depends for its consumption and also income generation. Climate change is the main factor limiting rice production (drought and flooding). This ultimately impacts on agricultural, mostly in developing nations, and typically influences the amounts of hydrological variation (Turral et al. 2011). The main factor restricting production of rice is drought (Nelson et al. 2014). Therefore, enhancing rice yield with climate change and water limitation is the first approach for enhancing rice production to meet out the food demand in future, expected from the probable increasing in world population. Silicon is considered as non-essential nutrient because, silicon cannot fulfil the \u0026ldquo;essential criteria for a nutrient\u0026rdquo; given by Arnon and Stout (1939). So, until 1994 silicon considered as non-essential element. After that, Epstein (1994) given the astonishing review on silicon in \u0026lsquo;The anomaly of silicon in plant biology\u0026rsquo; changes the prospects of silicon in the farming field. Several studies reported that beneficial effects of silicon. \u0026lsquo;International Plant Nutrition Institute\u0026rsquo; promotes the silicon from non-essential to beneficial element (IPNI 2015). Because small number of plant species requires silicon particularly in rice plant. McLarnon et al. (2017) reported that, silicon requirements increased during stress and silicon actively absorbed in some grass species. In this present study framed with the objectives of enhancing the drought tolerant capacity in rice through foliar application of different concentrations of nanosilica.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003eExperimental site\u003c/h2\u003e\n \u003cp\u003eThe experimentation was conducted at Rice Department, Tamil Nadu Agricultural University (TNAU), Coimbatore. Geographically, the experimental site was situated in the zone of western agro- climatic of Tamil Nadu at an altitude of 426.72 meters above mean sea level with 11\u0026deg;N latitude and 77\u0026deg;E longitude. The total duration of the experiment was five months from January to May (2021\u0026ndash;2022). During the study period, the average of maximum temperature was 32.2\u0026deg;C and 22.6\u0026deg;C, respectively. The total amount of rainfall received during the crop period was 71.3 mm. However, there is no rainfall received at the time of stress imposition and foliar application of nanosilica. The two rice varieties of CO53 and CO54 having short duration were together from the Rice Department, TNAU (Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). Nanosilica materials were prepared and collected from the Nano Science and Technology Department, TNAU, Coimbatore.\u0026nbsp;\u003c/p\u003e\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eCharacters of rice varieties\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eVariety\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eParentage\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDuration (days)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCO 53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePKM(R) x Norungan\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e115\u0026ndash;120\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCO 54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCB04110 x CB05501\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e115\u0026ndash;120\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003ePreparation of nanosilica formulation\u003c/h2\u003e\n \u003cp\u003eNanosilica emulsion was prepared from pure nanosilica and it was mixed with tween 80 and water (1:3 ratio). After that, the solution was sonicated for 30 minutes at a rate of 10:10 plus at 50% amplification. Solutions were well homogenized. Based on the requirement of experiment different concentration \u003cem\u003eviz\u003c/em\u003e., 200, 400, 600, 800 and 1000 ppm of nanosilica has been prepared and used for this field study as foliar spray.\u003c/p\u003e\n \u003cp\u003eThe drought was imposed by withholding of irrigation for all treatments except T1 (Irrigated) from 12 days before flowering and 10 days after flowering. The total period of the stress was 22 days. The irrigation was controlled by bund and the water leakage was vetoed by placing of plastic sheets. The water drained out by buffer channels in drought imposed plots. The application of nanosilica as foliar spray at 50% flowering stage (mid of the drought period). Totally seven treatments were choocen for this experiment viz., T1 \u0026ndash; Irrigated, T2 \u0026ndash; Drought, T3 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;Nanosilica (200 ppm), T4 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;Nanosilica (400 ppm), T5 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;Nanosilica (600 ppm), T6 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;Nanosilica (800 ppm) and T7 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;Nanosilica (1000 ppm).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\n \u003ch2\u003eObservations recorded\u003c/h2\u003e\n \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\n \u003ch2\u003ePlant sampling\u003c/h2\u003e\n \u003cp\u003eThe growth anatomical, physiological, biochemical and yield parameters were recorded in each treatment with three plants per replications per treatments were collected at seven days after application of nanosilica in 50% flowering stage and physiological maturity stage for measuring all the observation.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\n \u003ch2\u003eGrowth attributes\u003c/h2\u003e\n \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\n \u003ch2\u003eLeaf area (cm2)\u003c/h2\u003e\n \u003cp\u003eLeaf area was measured from three randomly selected plants from each plot by using\u003c/p\u003e\n \u003cp\u003eleaf area meter (LI-3100 Area Meter) and expressed in cm\u003csup\u003e2\u003c/sup\u003e.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\n \u003ch2\u003eSpecific leaf weight\u003c/h2\u003e\n \u003cp\u003eSLA was calculated from leaf weight of the plant and leaf area of the plant and it was expressed in dry weight per unit leaf surface area. It is an indirect measurement of width and thickness of the leaf and noticed in mg cm\u003csup\u003e-2\u003c/sup\u003e.\u003c/p\u003e\n \u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"373\" height=\"71\"\u003e\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003cbr\u003e\u003c/div\u003e\n\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\n \u003ch2\u003eLeaf anatomical characters (SEM measurements)\u003c/h2\u003e\n \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e\n \u003ch2\u003eStomatal characters\u003c/h2\u003e\n \u003cp\u003eLeave bits are collected from plants of each treatment at seven days after the application of nanosilica and the length and breadth of the stomata are measure under Scanning Electron Microscope (SEM) available at Nano science and Technology Department, TNAU, Coimbatore.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\n \u003ch2\u003eLeaf surface characters\u003c/h2\u003e\n \u003cp\u003eTrichomes characters and silicon content of two rice varieties were viewed and measured under the scanning electron microscope (SEM) at seven days after foliar application of nanosilica.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\n \u003ch2\u003eSilicon content (%)\u003c/h2\u003e\n \u003cp\u003eThe silicon content was measured under scanning electron microscope by following the energy dispersive x-ray analysis (EDAX) method.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec15\" class=\"Section2\"\u003e\n \u003ch2\u003ePhysiological and biochemical analysis\u003c/h2\u003e\n \u003cdiv id=\"Sec16\" class=\"Section3\"\u003e\n \u003ch2\u003eProline content\u003c/h2\u003e\n \u003cp\u003eProline estimate has been done using the method derived from Bates et al. (1973). Following the weighing of 500 mg of leaf samples, 10 ml of 3% sulpho salicylic acid was macerated. Subsequently, the solution was centrifuged at 3000 rpm for 10 minutes. Two ml of the supernatant was removed and 2 ml each of acid ninhydrin, glacial acetic acid and 6M orthophosporic acid were added to the test tube. The test tube was then placed in a hot water bath for a one hour. Subsequently, the solutions were poured into separate funnels, 4 ml of toluene was added and everything was shaken evenly for 30 seconds. After discarding the colourless solution and gathering the upper pink solution, the optical density was calculated at 520 nm and reported in mg g\u003csup\u003e-1\u003c/sup\u003e of fresh weight.\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\n \u003ch2\u003eCatalase activity\u003c/h2\u003e\n \u003cp\u003eWe estimated the catalase activity using the method Volk and Feierabend (1989) presented. The Catalase activity determines by the rate of reduction in hydrogen peroxide abortion at 240 nm and expressed in \u0026micro;g of H2O2 g\u003csup\u003e-1\u003c/sup\u003e min\u003csup\u003e-1\u003c/sup\u003e.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\n \u003ch2\u003eStatistical analysis\u003c/h2\u003e\n \u003cp\u003eIn a factorial randomized block design (FRBD), the data was obtained and statistical analysis was carried out (Gomez et al. 1984).\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results and Discussion","content":"\u003cdiv id=\"Sec25\" class=\"Section2\"\u003e \u003ch2\u003eLeaf area\u003c/h2\u003e \u003cp\u003eOne of the most vital and useful parts of a plant is its leaf. Many physiological and biochemical reaction are carried out inside the leaf and it is the effective in the yield under abiotic stress condition (Wang et al. 2005). It is main source of carbon fixation by photosynthesis and maintains the leaf temperature by transpiration through stomata (Buckley et al. 2015; Yuvaraj et al. 2023). The decline of leaf area surface is the first reaction of drought adoption to reduce the transpiration losses (Larcher 2003). The effect of silica nano formulations in leaf area are described in (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\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\u003eImpact of silica nanoformulation on leaf area and SLW in rice under drought condition\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\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eLeaf area (cm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eSpecific leaf weight (mg cm-2)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCO 54\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCO 53\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCO 54\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCO 53\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1 \u0026ndash; Control\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1744.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1814.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.58\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT2 \u0026ndash; Drought\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1441.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1616.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.42\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT3 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;200 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1660.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1705.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.80\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT4 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;400 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1699.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1787.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT5 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;600 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1619.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1680.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.61\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT6 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;800 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1568.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1654.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.58\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT7 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;1000 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1550.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1636.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.52\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e1612.0\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e1699.3\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003e4.48\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003e4.83\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eSEd\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eCD (0.05)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eSEd\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eCD(0.05)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eV (Variety)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e35.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e72.71*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.195\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.400\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eT (Treatment)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e66.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e136.04**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.364\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.768*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eV x T\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e93.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e192.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.515\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.059\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e* Significant at 5% level\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e** Significant at 1% level\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\u003eThe outcome clarified the rising trend in control and declining trend in drought affected plants when silica nano formulation was applied. Among the treatments, control plants had maximum leaf area of 1814.4 cm\u003csup\u003e2\u003c/sup\u003e plant\u003csup\u003e-1\u003c/sup\u003e and 1744.6 cm\u003csup\u003e2\u003c/sup\u003e plant\u003csup\u003e-1\u003c/sup\u003e in CO53 and CO54, respectively. Comparing the two varieties, CO53 had maximum leaf area of 1616.5 cm\u003csup\u003e2\u003c/sup\u003e plant\u003csup\u003e- 1\u003c/sup\u003e than CO54 (1441.3 cm\u003csup\u003e2\u003c/sup\u003e plant\u003csup\u003e-1\u003c/sup\u003e) under drought alone condition. The results revealed that a significant variation could also be observed between drought alone and drought with silica nanoformulation treatments. Among the nanosilica treatments, T4 (Drought\u0026thinsp;+\u0026thinsp;400 ppm) recorded maximum leaf area of about 1787.8 cm\u003csup\u003e2\u003c/sup\u003e plant\u003csup\u003e-1\u003c/sup\u003e and 1699.0 cm\u003csup\u003e2\u003c/sup\u003e plant\u003csup\u003e-1\u003c/sup\u003e in CO53 and CO54 under drought condition respectively. Whereas, the treatment T3 (Drought\u0026thinsp;+\u0026thinsp;200 ppm) registered the leaf area of about 1705.2 cm\u003csup\u003e2\u003c/sup\u003e plant\u003csup\u003e-1\u003c/sup\u003e and 1660.5 cm\u003csup\u003e2\u003c/sup\u003e plant\u003csup\u003e-1\u003c/sup\u003e under drought conditions. The treatment T4 and T3 are on par with each other. According to Kafi et al. (2021) who stated that the suppression of cell elongation and division due to drought. In this present filed experiment shows, drought minimize the leaf area in both varieties. Comparing the two varieties, maximum reduction of leaf area are observed in CO54 (17.4%) than CO53 (11.0%) under drought. Application 400 ppm of nanosilica in drought affected plants increases the leaf area up to 14.25% in both the rice varieties. This may be due to silicon increases the water use efficiency (Ma et al. 200l) and maintain the higher relative water content in the leaf, it helps leaf expansion (Da Silva Lobato 2020). Present study was agreement with Shen et al. (2010) who opined that silicon improve the growth characters including leaf area. The same kind of results reported by Gong et al. (2008) insisted that silicon improve the leaf growth under drought condition.\u003c/p\u003e \u003cdiv id=\"Sec26\" class=\"Section3\"\u003e \u003ch2\u003eSpecific leaf weight\u003c/h2\u003e \u003cp\u003eThe measurement of leaf thickness is represented by SLW. It has been found to have a substantial positive link with the uptake of carbon from leaves, which raises the photosynthetic index and indirectly indicates the leaf density in rice (Sarkar et al. 1996). Leaf thickness and succulence of the plants had strong connection and improve the drought tolerance (Bussoti et al. 2002). The effect of silica nanoformulation on specific leaf weight in rice displayed in (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Comparing seven treatments, the increasing trend in specific leaf weight were noticed in control plants, besides declining trend was noticed in drought and nanosilica imposed crops. Comparing the two varieties CO53 had maximum specific leaf weight (5.58 mg cm\u003csup\u003e-2\u003c/sup\u003e) over the drought alone treatments (CO53- 4.42 mg cm\u003csup\u003e-2\u003c/sup\u003e; CO54-3.86 mg cm\u003csup\u003e-2\u003c/sup\u003e). Among the different concentration of nanosilica treatments, T4 (Drought\u0026thinsp;+\u0026thinsp;400 ppm) differed significantly an increasing of specific leaf weight under drought in both varieties (CO53-5.30 mg cm\u003csup\u003e-2\u003c/sup\u003e; CO54-4.15 mg cm\u003csup\u003e-2\u003c/sup\u003e) which was followed by T3 (CO53-4.80 mg cm\u003csup\u003e-2\u003c/sup\u003e; CO54-4.62 mg cm\u003csup\u003e-2\u003c/sup\u003e) treatments. Both are on par with each other. These data support what the current investigation discovered, which was CO54 had maximum specific leaf weight reduction of 26.8% than CO53 (20.7%) under drought alone condition. Reduction of specific leaf weight shows that, CO53 registered more resistance to drought than CO54. Foliar application of 400 ppm of nanosilica on drought induced plants, slightly alleviate the adverse effect of drought; besides higher recovery percent of 26.0 and 20.0% registered by CO54 and CO53 respectively. Drought reduces the leaf mass, thickness and area for minimize the transpiration loss. These outcomes concur with Siddique et al. (2015), opined that application of silica improve the water status, it helps the cells to enlarge and enhance the photosynthesis in the plants also silicon helps to maintaining the turgidity of the cells (Isa et al. 2010). The identical results concurred with Gong et al. (2005) and Wang et al. (2019) insisted that, silicon improving the number of mesophyll cells and mesophyll cell enlargement, which leads to enhance the photosynthetic efficiency in the rice under drought.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec27\" class=\"Section2\"\u003e \u003ch2\u003eLeaf surface characters\u003c/h2\u003e \u003cdiv id=\"Sec28\" class=\"Section3\"\u003e \u003ch2\u003eTrichome length\u003c/h2\u003e \u003cp\u003eTrichomes are unicellular unicellular (or) multi cellular branched hair like structure arises from the single (or) multi cell of protodermal cells (Hulskamp et al. 1994). Trichome contains essential oils, secondary metabolites and act as salt gland under salinity stress. Under drought condition trichomes are very use full trait for resistance against water deficient. Trichomes involved in the production of secondary metabolites like terpenes for drought tolerance (Kennedy 2003). Guntwer et al. (2021) opined that density and length of the trichome are increased under drought conditions. The data on trichome length of different nanosilica application are presented in (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eInfluence of silica nanoformulation on trichome length, stomatal size and silica bodies\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\" colspan=\"3\" nameend=\"c3\" namest=\"c1\"\u003e \u003cp\u003eTrichome length (\u0026micro;m)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eStomatal size (\u0026micro;m2)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003esilica bodies (\u0026micro;m)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCO54\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCO53\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCO54\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCO53\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eCO54\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eCO53\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1 \u0026ndash; Control\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e186.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e246.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e31.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e25.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e12.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT2 \u0026ndash; Drought\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e222.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e284.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e16.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e15.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e14.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT3 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;200 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e305.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e497.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e29.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e19.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e16.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e16.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT4 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;400 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e342.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e522.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e30.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e20.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e17.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e18.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT5 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;600 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e273.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e424.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e17.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e15.43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT6 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;800 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e263.70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e418.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e24.87\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e17.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e15.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT7 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;1000 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e260.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e300.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e16.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e14.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e264.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e384.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e25.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e18.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e15.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e15.18\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eSEd\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eCD(0.05)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eSEd\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eCD(0.05)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003eSEd\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003eCD(0.05)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eV (Variety)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30.827\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e63.366**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.755\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.608**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.249\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.511\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eT (Treatment)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e57.672\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e118.548**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.284\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.750**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.4654\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.957**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eV x T\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81.561\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e167.653\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.644\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.546\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.658\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.353\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c4\" namest=\"c3\"\u003e \u003cp\u003e* Significant at 5% level\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"3\" nameend=\"c7\" namest=\"c5\"\u003e \u003cp\u003e** Significant at 1% level\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\u003ePlants treated with nanosilica showed an increasing trend, while plants receiving control treatment alone exhibited a reduction in trichome length. Between two varieties, highest trichome length of 284.27 \u0026micro;m registered by CO53 than CO54 (222.27 \u0026micro;m) under drought alone condition. Control alone treatment plants showed lowest trichome length of 184.35 \u0026micro;m in CO54 and CO53 had 246.53 \u0026micro;m. In the present study, silicon treated plants had highest length of trichomes. Among the nanosilica application, Drought\u0026thinsp;+\u0026thinsp;400 ppm treatment (T4) recorded lesser trichome length of 522.70 \u0026micro;m in CO53 than CO54 (342.10 \u0026micro;m) under drought condition. These results are agreement with present study; drought stress had 19.3% increases of trichome length in CO54 and 15.15% in CO53 over the control (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Application of silicon increases the trichome length of 68.85% over the drought. Silicon improves the plant trichome length under drought. The current study's findings concur with those of Rostkowska et al. (2016) who stated that, silicon deposited in the inside the trichomes and it helps to improve the length of the trichomes. Similar outcomes were noted in \u003cem\u003eMentha piperita\u003c/em\u003e by Ahmad et al. (2011). Takeda et al. (2013) reported that silicon deposited in the trichome increases the infra-red light use efficiency in plant.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e\n\u003ch3\u003eStomatal size\u003c/h3\u003e\n\u003cp\u003eSurface area of the rice leaf covered by cuticle layer. All surface cells are not identical each other same degree of changes were noticed based on the nature specie. Some surface cells differ from the outer epidermal cell they are kidney shaped specialised cell for gas exchange purpose (opening and closing of stomata) that cells called guard cells drought alter the development and differentiation of pore size, stomatal length and breadth, density of the Stomata. Wang et al. (2019) noticed that size of the stomata reduced under drought. The results on stomatal size illustrated in the (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The stomatal size observation indicates a trend towards increase in control and decline in plants treated with silica nanoformulation and drought. The table indicates that control plant had maximum stomatal size (31.34 \u0026micro;m\u003csup\u003e2\u003c/sup\u003e) and drought plants shows lowest stomatal size of (15.71 \u0026micro;m\u003csup\u003e2\u003c/sup\u003e). Between the two varieties, CO54 recorded maximum stomatal size of 31.34 \u0026micro;m\u003csup\u003e2\u003c/sup\u003e than the CO53 (25.9 \u0026micro;m\u003csup\u003e2\u003c/sup\u003e) under control. Drought and drought with plants treated with nanosilica differed significantly. Among the different nanosilica treatments, T4 (Drought\u0026thinsp;+\u0026thinsp;400 ppm) registered maximum stomatal size of about 30.25 \u0026micro;m\u003csup\u003e2\u003c/sup\u003eand 20.00 \u0026micro;m\u003csup\u003e2\u003c/sup\u003ein CO54 and CO53 respectively, with lesser reduction over control. Which was closely flowed by T3 (Drought\u0026thinsp;+\u0026thinsp;200 ppm) treatment in both varieties (CO54-29.69 \u0026micro;m\u003csup\u003e2\u003c/sup\u003e; CO53-19.57 \u0026micro;m\u003csup\u003e2\u003c/sup\u003e). Drought increases the density of the stomata (stomatal frequency) are increases, while stomata size were reduced which leads rapid stomatal conductance for increasing the photosynthetic rate. The results are agreement with present study, drought stress significantly decreases the stomatal size in both varieties. CO54 had highest present decreases of about 47.7% than CO53 (39.3%) over the control (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Application of 400 ppm nanosilica had 68.85% increases in stomatal size in rice over the control. These findings agree with Verma et al. (2020) in sugarcane. Vandegeer et al. (2020) opined that, silicon application helps to maintain the water content of the guard cell and improve the stomatal conductance to increases the photosynthetic rate in tall fescue.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec30\" class=\"Section2\"\u003e \u003ch2\u003eSilicon bodies length\u003c/h2\u003e \u003cp\u003eThe data (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) represent the silicon bodies present in the leaf surface. Results revealed that nanosilica treatment had increasing trend and drought alone and control plants had declining trend. Comparing the two rice varieties, CO54 had minimum silicon body length of 13.02 \u0026micro;m than the CO53 (12.34 \u0026micro;m) under control alone condition. However, a considerable increment could also register in silicon body length due to drought. Maximum silica bodies length recorded in CO53 (14.10 \u0026micro;m) than CO54 (13.54 \u0026micro;m) under drought alone condition. A significant increasing trend could also be noticed in nanosilica treatment. Among the different silica treatments, T4 had maximum silicon bodies length of 18.70 \u0026micro;m than all the other treatments. In T4 treatment, the varieties CO53 and CO54 both on par with each other.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec31\" class=\"Section2\"\u003e \u003ch2\u003eSilicon content (%) (SEM-EDAX)\u003c/h2\u003e \u003cp\u003eThe silicon content were measured under scanning electron microscope by following the energy dispersive x-ray analysis (EDAX) method and tabulated in (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Highest silicon content could notice in CO53 (10.12%) than CO54 (6.82%) under control alone treatment (T1). An increasing trend could also be observed in drought alone and drought with nanosilica applied crops. Among the different concentration of silica nanoformulations treatments under drought, T7 had maximum silicon content of about 16.66% registered by CO53 than CO54 (13.66%), which was followed by T6 (Drought\u0026thinsp;+\u0026thinsp;200 ppm) (CO53-14.23%; CO54-12.12%) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e1\u003c/span\u003e). However, the treatment drought alone registered lesser amount of silica content of 12.1% (CO53) and 8.81% (CO54) respectively than other nanosilica treatments. Besides; this drought alone (T2) treatment had higher silica content than the control (T1) treatment.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eImpact of silica nanoformulation on silica content (%) (SEM-EDAX) in rice under drought condition\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\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 \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eSilica content (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCO 54\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCO 53\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1 \u0026ndash; Control\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e6.82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT2 \u0026ndash; Drought\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT3 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;200ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT4 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;400ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12.94\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT5 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;600ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e11.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT6 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;800ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14.23\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT7 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;1000ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16.66\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e21.1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e23.1\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eSEd\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eCD(0.05)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eV (Variety)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.104\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.215**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eT (Treatment)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.196\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.402**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eV x T\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.277\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.568**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e \u003cp\u003e* Significant at 5% level\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e** Significant at 1% level\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 \u003c/p\u003e \u003cdiv id=\"Sec32\" class=\"Section3\"\u003e \u003ch2\u003eLeaf proline\u003c/h2\u003e \u003cp\u003eProline is an imino acid (proline) acts as best osmolytes which will help to keep up the more plant tissue Ψw under water deficit conditions. Conferring to Mc Neil et al. \u003cem\u003e(\u003c/em\u003e1999) stated that, the osmoprotected iminoacid (proline) resides in the cytoplasm and scavenging of free radicals that are produced under drought (Delauney and Verma, 1990). In the present study, drought adversely affects the protein degradation and significantly increases the proline content in both varieties. The proline content data indicated that plants treated with nanosilica during a drought experienced a less significant decline (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). CO54 had maximum proline content when compared to the CO53 (291.8 \u0026micro;g g\u003csup\u003e-1\u003c/sup\u003e) under drought alone condition. Comparing the different nanosilica treatments, T4 (Drought\u0026thinsp;+\u0026thinsp;400 ppm) registered the lesser proline content of about 216.1 \u0026micro;g g\u003csup\u003e-1\u003c/sup\u003e to 242.0 \u0026micro;g g\u003csup\u003e-1\u003c/sup\u003e, which was followed by T3 (Drought\u0026thinsp;+\u0026thinsp;200 ppm) treatment (239.86 \u0026micro;g g\u003csup\u003e-1\u003c/sup\u003e to 270.51 \u0026micro;g g\u003csup\u003e-1\u003c/sup\u003e) under drought condition. High proline accumulation could be noticed in CO54 (87.0% over the control) than CO53 (54.2% over the control). Application of silicon has the capacity to curtail the influence of water deficit by plummeting the deprivation of protein and also reduces the proline production (Gunes et al. 2008). Among different nanosilica treatments of nanosilica application, 400 ppm of nanosilica had 26.5% decreased proline accumulation over the drought alone treatment. These evidences are in agreement with this present study found that, nanosilica application as foliar spray during mid of the drought period had the capacity to diminish the production of ROS through stir up the proline synthesis. Agarie et al. (1998) showed comparable results in rice during a drought.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eInfluence of silica nanoformulation on proline and catalase activity in rice under drought condition\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\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLeaf proline\u003c/p\u003e \u003cp\u003e(\u0026micro;g g-1)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003eCatalase activity\u003c/p\u003e \u003cp\u003e(\u0026micro;g of H2O2 g\u003csup\u003e-1\u003c/sup\u003e min\u003csup\u003e-1\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTreatments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCO 54\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCO 53\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCO 54\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCO 53\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT1 \u0026ndash; Control\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e177.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e188.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e161.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e190.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT2 \u0026ndash; Drought\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e331.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e292.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e196.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e234.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT3 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;200 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e270.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e238.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e242.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e290.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT4 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;400 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e242.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e216.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e271.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e311.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT5 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;600 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e285.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e261.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e232.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e275.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT6 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;800 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e311.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e238.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e218.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e255.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eT7 \u0026ndash; Drought\u0026thinsp;+\u0026thinsp;1000 ppm\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e317.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e273.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e208.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e245.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMean\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e276.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e244.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e218.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e257.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eSEd\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eCD(0.05)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eSEd\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eCD(0.05)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eV (Variety)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7.850\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16.136**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.780\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.714**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eT (Treatment)\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.685\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.188**\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10.690**\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eV x T\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20.769\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e42.693\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.355\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e15.118\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003e* Significant at 5% level\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c5\" namest=\"c4\"\u003e \u003cp\u003e** Significant at % level\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec33\" class=\"Section3\"\u003e \u003ch2\u003eCatalase activity\u003c/h2\u003e \u003cp\u003eThe second most prevalent antioxidant enzyme is called catalase, and it has the capacity to reduce H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e production in peroxisomes and its subsequent detoxification into oxygen and water during a drought (Vendemiale et al. 1999). According to Uchida et al. (2012) catalase inhibits lipid peroxidation, damages cell membranes, and prevents chlorophyll from degrading Luna-Lopez et al. (2012) reported that, drought increases the catalase activity to alleviate negative effects of hydrogen peroxide. A rising trend was observed in nanosilica treated plants under drought and reduction of catalase activity in control alone treatment (Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). More catalase activity of 235.1 \u0026micro;g of H2O2 g\u003csup\u003e-1\u003c/sup\u003e min\u003csup\u003e-1\u003c/sup\u003e found in CO53 than CO54 (195.4 \u0026micro;g of H2O2 g\u003csup\u003e-1\u003c/sup\u003e min\u003csup\u003e-1\u003c/sup\u003e) under drought alone condition. Control alone treatment crops showed lesser catalase activity of 159.6 \u0026micro;g of H2O2 g\u003csup\u003e-1\u003c/sup\u003e min\u003csup\u003e-1\u003c/sup\u003e registered by CO54; whereas CO53 had (189.3 \u0026micro;g of H2O2 g\u003csup\u003e-1\u003c/sup\u003e min\u003csup\u003e-1\u003c/sup\u003e). In the present research, silicon applied plants had highest catalase activity under drought condition. Among the nanosilica application, Drought\u0026thinsp;+\u0026thinsp;400 ppm treatment (T4) had lower catalase activity of 310.2 \u0026micro;g of H2O2 g\u003csup\u003e-1\u003c/sup\u003e min\u003csup\u003e-1\u003c/sup\u003e recorded in CO53; CO54 had 272.1 \u0026micro;g of H2O2 g\u003csup\u003e-1\u003c/sup\u003e min\u003csup\u003e-1\u003c/sup\u003e under drought condition. These findings are in agreement with present study explained that, drought induced plants had highest catalase activity of 24.1% (CO53), whereas CO54 had (22.4%) over the control. Application of nanosilica significantly increases the catalase activity in drought induced plants. Foliar application of 400 ppm nanosilica had maximum increases of catalase activity of about 40.8% in CO54 and 31.9% in CO53 under control. These outcomes accord with the barley study conducted by Liang et al. (2003). Ahmad et al. (2011) who opined that, silicon increases the antioxidant enzymes like catalase (CAT) peroxidise (POX), superoxide dismutase (SOD) under drought condition. By modifying the activity of antioxidant enzymes and stimulating the cell wall ability to bind cations, silicon treatment in rice may improve its ability to withstand drought (Sivaneasan and Park 2014).\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eLeaf area had 10.9% reduction under drought condition. Foliar application of 400 ppm nanosilica had increase in leaf area and leaf area index of 14.2% in drought induced plants over the unsprayed nano silica drought stressed rice plant. Among the different nano silica concentrations, 400 ppm of nanosilica concentration had significantly increased in specific leaf weight under drought of about 19.9 to 26.4% over the drought alone conditions. Drought tolerance trait like chlorophyll stability index and membrane stability index, relative water content had significant decline of 15.7, 17.2 and 14.6% over the control in rice under drought condition. These drought tolerant traits are increased by 10.6, 18.6 and 10.7% over the drought in rice varieties due to foliar application of 400 ppm of nano silica under drought over the drought alone condition. Proline content was increased due to drought. Maximum proline accumulations of 87.0% were noticed in CO54; meanwhile, CO53 had 54.2% increment. Application of 400 ppm of nanosilica had mean reduction in proline content of 33.9% in both varieties when compared to drought over the drought alone and control. The length of the trichome and silica bodies were measured under scanning electron microscope (SEM) and a significant increase in terms of length of the trichome and silica content by 17.4 and 9.1% due to application of 400 ppm of nano silica under drought. The same results were observed in stomatal characters where an increment of 27.3% registered by application of 400 ppm nanosilica under drought than the drought alone conditions. Hence, the concentration of 400 ppm nanosilica as foliar spray can be efficiently alleviating the effect of drought at reproductive stage in rice.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAll the author read and understood the publishing policy, and submit this manuscript in accordance with this policy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo funding\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe thank Department of Nano Science and Technology, TNAU, Coimbatore for nanosilica product and laboratory support. We are grateful to the Department of Rice at TNAU in Coimbatore for supplying the labourers and rice seed material.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contribution\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e[K. Krishna Surendar1*, R. Karthik Raja2] Methodology: [K. Krishna Surendar1*, R. Karthik Raja2, Dr. N. Sritharan2, Dr. V. Ravichandran2] Formal analysis: [R. Anitha, R. Nageswari, V. Dhanushkodi] Investigation: [K. Krishna Surendar1*, R. Karthik Raja2] Writing\u0026ndash;original draft: [K. Krishna Surendar1*, R. Karthik Raja2] Writing review and editing: [Dr. M. Kannan3, Dr. R. Pushpam4, R. Anitha5, R. Sathya Priya6 and M. Yuvaraj7]; Supervision:[K. Krishna Surendar1*, R. Karthik Raja2].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical Approval\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors confirm that the data supporting the findings of this study are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate:\u003c/strong\u003e Every researcher involved in the experiment gave their consent.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for Publication:\u0026nbsp;\u003c/strong\u003ePermission to publish this research study in the journal has been granted by the authors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interest:\u003c/strong\u003e The writers believe they have no conflicting intentions.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAgarie S, Uchida H, Agata W, Kubota F, Kaufman PB (1998) Effects of silicon on transpiration and leaf conductance in rice plants (\u003cem\u003eOryza sativa\u003c/em\u003e L.). 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Env Exp Bot. 158:117-124. https://doi.org/10.1016/j.envexpbot.2018.11.022\u003c/li\u003e\n\u003cli\u003eYoshida S, Navasero S, Ramirez E (1969) Effects of silica and nitrogen supply on some leaf characters of the rice plant. Plant Soil. 31(1):48\u0026ndash;56\u003c/li\u003e\n\u003cli\u003eYuvaraj M , Sathya Priya R, Jagathjothi N, Saranya M, Suganthi N, Sharmila R, Cyriac J, Anitha R, Subramanian KS (2023) Silicon nanoparticles (SiNPs): Challenges and perspectives for sustainable agriculture. Physiol and Mol Plant Pathol. 128: 102161. doi: https://doi.org/10.1016/j.pmpp.2023.102161\u003c/li\u003e\n\u003cli\u003eZhu Y, Gong H (2014) Beneficial effects of silicon on salt and drought tolerance in plants. Agron Sustain Dev. 34:455\u0026ndash;472\u003c/li\u003e\n\u003cli\u003eZhu Z, Wei G, Li J, Qian Q, Yu J (2004) Silicon alleviates salt stress and increases antioxidant enzymes activity in leaves of salt-stressed cucumber (\u003cem\u003eCucumis sativus\u003c/em\u003e L.). Plant Sci. 167 (3):527\u0026ndash;533\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"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":"[email protected]","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":"Nanosilica, rice, drought, physiology, proline, catalase activity, leaf surface","lastPublishedDoi":"10.21203/rs.3.rs-3849684/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3849684/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe experimentation was carried out during the summer (2021\u0026ndash;2022) at the Rice Department, Tamil Nadu Agricultural University, Coimbatore to assess the effects of nanosilica on drought imposed rice plants and to assess the impact of different concentrations of nanosilica (SiO2) on growth, anatomical, physio-biochemical parameters and yield characters of rice under drought conditions. In this experiment, different concentrations of the nanosilica formulation at 200, 400, 600, 800, and 1000 ppm were applied as foliar sprays under drought conditions. Spraying of 400 ppm of nanosilica formulation under drought stress in this field experiment has resulted of increases in leaf area and specific leaf weight of 14.3 and 15.3%, respectively. Application of 400 ppm nanosilica increases up to 12.5% in terms of membrane stability index (MSI), meanwhile in chlorophyll stability index (CSI) was increased up to 20.4%. Proline content was decreased up to 26.9% by application of nanosilica (400 ppm) in drought imposed treated plants. Trichome length and the length of the silica bodies were significantly increase of about 17.4 and 9.1% over the control. Application 400 ppm of nanosilica had maximum of 68.9 and 29.4% increment in terms of trichome and silicon bodies length over the drought. Stomatal structures are reduced significantly with mean reduction of 43.5% than the control in both the rice varieties. Under the drought, the average increase in stomatal size was 65.5% when 400 ppm nanosilica was applied. When exposed to 400 ppm of nanosilica treatments, CO54 showed more responses than the other variety in terms of leaf area, specific leaf weight, MSI, CSI, proline and leaf surface characteristics during drought.\u003c/p\u003e","manuscriptTitle":"Response of Nanosilica on Physiological and Leaf Surface Anotomical Characters in Rice under Drought","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-01-11 05:37:24","doi":"10.21203/rs.3.rs-3849684/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","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":"63a8b851-8b60-46aa-8f12-724c8f1320c3","owner":[],"postedDate":"January 11th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-01-12T21:44:15+00:00","versionOfRecord":[],"versionCreatedAt":"2024-01-11 05:37:24","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-3849684","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3849684","identity":"rs-3849684","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}