If all else fails: Impact of silicon accumulation in maize leaves on volatile emissions and oviposition site selection of Spodoptera exigua Hübner

If all else fails: Impact of silicon accumulation in maize leaves on volatile emissions and oviposition site selection of Spodoptera exigua Hübner | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article If all else fails: Impact of silicon accumulation in maize leaves on volatile emissions and oviposition site selection of Spodoptera exigua Hübner Nicolas Leroy, Clément Martin, Anthony Arguelles Arias, Jean-Thomas Cornélis, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1862920/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Silicon (Si) fertilization alleviates biotic stresses in plants. Silicon enhances plant resistance against phytophagous insects through physical and biochemical mechanisms. In particular, Si modifies jasmonic acid levels and the emissions of herbivore-induced plant volatiles (HIPVs). Here, we investigated whether Si accumulation in the tissues of maize leaves modifies the emissions of constitutive and herbivore-induced plant volatiles, with cascade deterrent effects on oviposition site selection by Spodoptera exigua Hübner (Lepidoptera: Noctuidae). Maize plants were cultivated in a hydroponic system under three Si concentrations, resulting in three groups of plants expressing different Si concentrations in their tissues (0.31 ± 0.04, 4.69 ± 0.49, and 9.56 ± 0.30 g Si. Kg − 1 DW). We collected volatiles from undamaged and caterpillar-infested plants, and found that Si concentration in plant tissues had no significant impact. Jasmonic acid content was high in insect-infested plants, but was similar across all Si treatments. Oviposition site selection bioassays using fertilized S. exigua females showed that Si concentration in plant tissues did not affect the number of eggs laid on Si-treated plant. In conclusion, our study shows that the Si content in maize tissues does not impact the semiochemical interactions with S. exigua . Silica HIPVs beet armyworm semiochemical interaction Figures Figure 1 Figure 2 Introduction Silicon (Si) is a ubiquitous element and one of the most abundant elements in soil. For instance, Si concentrations in soil solution as uncharged monomeric silicic acid (H 4 SiO 4 ) range from 0.1 to 0.6 mM (Epstein 1994 ), depending on soil physiochemical properties (Cornélis and Delvaux, 2016 ). A wide diversity of plant species accumulates from 0.1 to 10% Si (on dry weight basis) in their tissues (Hodson et al. 2005 ; Epstein 2009 ). Under certain environmental conditions, Si fertilization enhances the performance, yield and fruit quality of plants (Verma et al. 2021 ). Si also reduces the impact of abiotic and biotic stressors (Reynolds et al. 2016 ). For instance, Si enhances plant resistance against pathogens and insects through physical barriers and biochemical mechanisms (Bakhat et al. 2018 ; Acevedo et al. 2021 ). Si accumulates in leaves as amorphous silica (SiO 2 .nH 2 O), also called phytoliths, and provides mechanical resistance against herbivory (Frew et al. 2018 ). Grasses accumulate Si in specialized cells or in silicified external structures, like trichomes or prickle cells (Hall et al. 2020 ; Acevedo et al. 2021 ). These structures reduce the palatability of plant tissues by increasing their hardness and abrasiveness. In turn, this phenomenon negatively impacts the feeding and growth of insects (Massey and Hartley 2009 ; Hartley and DeGabriel 2016 ), and interferes with the digestion capacities (Andama et al. 2020 ). In addition to Si contributing to the mechanical defenses of plants, it activates plant biochemical pathways stimulated by pest infestation (Alhousari and Greger 2018 ). Chemical defenses are regulated by different phytohormones, including jasmonic acid (JA), salicylic acid (SA), and ethylene (ET) (Howe and Jander 2008 ). Among these plant hormones, JA is strongly linked with plant defenses against insect pests, activating both direct and indirect defenses (Mithöfer and Boland 2012 ). There is general consensus that Si accumulation in plant tissues affects phytohormone signaling during herbivory. For instance, Si interferes with the JA response in Oryza sativa (rice) and Brachypodium distachyon (stiff brome) (Ye et al. 2013 ; Kim et al. 2014 ; Hall et al. 2019 ; Johnson et al. 2021 ). However, some authors report that JA levels rise in Si-enriched insect-infested plants (Ye et al., 2013 ), while others report the opposite (Kim et al., 2014 and Hall et al., 2019 ). Hall et al. ( 2019 ) proposed a conceptual model of how Si acts as stimulating element for plant mechanical defense based on existing studies describing Si interactions with JA and taking into account the fact that Si chemical reactivity within plants is limited (Coskun et al. 2019 ). This effect could reduce the JA response, as well as the production of defensive metabolites. Plant chemical defenses include secondary metabolites that have either direct(e.g. terpenes, alkaloids, and phenols) or indirect (e.g. emission of herbivore-induced plant volatiles; HIPVs) effects on phytophagous insects (War et al. 2012 ). The jasmonate-pathway leads to the synthesis and release of HIPVs (Wei et al. 2011 ). These compounds are exploited by the natural enemies of phytophagous insects, and by other herbivorous insects, to locate and select host plants (Bruce et al. 2005 ; Schnee et al. 2006 ; Turlings and Erb 2018 ). In particular, Spodoptera females (Lepidoptera) select their oviposition site using plant volatile organic compounds (VOCs), avoiding plants releasing HIPVs (De Moraes et al. 2001 ; Signoretti et al. 2012 ; Block et al. 2020 ). The production of defensive compounds by plant species that accumulate Si is altered when Si concentrations in plant tissues are elevated. Si could trigger the synthesis of HIPVs, in addition to modifying their composition and emission rates (Callis-duehl et al. 2017 ; Liu et al. 2017 ; Leroy et al. 2019 ). While Spodoptera frugiperda females select their host using chemical cues, Pereira et al. ( 2021 ) showed that they lay half as many eggs on Si-enriched plants compared to non-enriched ones. Abbasi et al. ( 2020 ) obtained similar results for Bemisia tabaci and Si-enriched cotton plants ( Gossypium hirsutum ). Si impacts the chemical defenses of plants under insect infestations; however, the involved mechanisms remain poorly defined (Leroy et al. 2019 ). Here, we investigated whether Si accumulation in maize leaves alters VOC emissions by healthy and insect-infested plants, indirectly impacting oviposition site selection by Spodoptera exigua Hübner. We hypothesized that higher silicon levels in maize tissues lead to reduced VOC emissions and decreased number of eggs laid by S. exigua females. Specifically, we: (i) collected VOCs from maize plants cultivated under three Si concentrations; (ii) quantified JA in healthy and infested plants; and (iii) assessed oviposition choice with S. exigua gravid females on plants cultivated under three Si concentrations. Our results are expected to demonstrate how Si disrupts the ability of insects to identify hosts by modifying VOC emissions, which could be used to reduce herbivory in sustainable pest control management. Methods And Materials Plant Production. Corn plants ( Z. mays L. var. Delprim) were cultivated and used in all experiments (Delley Seeds and Plants, Delley, Switzerland). Seeds were germinated on paper towels moistened with distilled water in Petri dishes, which were kept for three days under dark conditions at 23°C. Then, the seedlings were placed on a rockwool substrate introduced to small hydroponic pots. Seedlings (eight per pot) were cultivated inside a 20-l plastic bucket containing water, and were placed in a temperate chamber. The conditions in the chamber were set to: 24 ± 2°C (day), 20 ± 2°C (night), 55–70% relative humidity, 300 µmol.m − 2 .s − 1 light intensity. After four days, water was replaced with a commercial nutritive solution (HY-PRO®, A&B, Bladel, Netherlands) [46.29 mg.l − 1 N; 23.94 mg.l − 1 P; 227.81 mg.l − 1 K; 115.12 mg.l − 1 Ca; 0.09 mg.l − 1 Cu; 38.79 mg.l − 1 Mg; 1.48 mg.l − 1 Fe; 0.15 mg.l − 1 Mn; 0.13 mg.l − 1 Zn; 3.71 mg.l − 1 Na]. Air pumps in each plastic bucket were used to maintain continuous aeration in the nutritive solution. Seedlings were grown grew in quarter strength nutrient solution (i.e., diluted four times) for, two days. Then, the concentration of the nutritive solution was gradually raised to full strength over one week to avoid osmotic shock. The nutritive solution was renewed every three days during the growing period. Every time the nutritive solution was changed, the pH of the medium was corrected to 5.5 ± 0.5 by adding 0.5 M MgSO 4 , which also corrected the Mg/K ratio in the solution, and prevented Mg deficiency in maize plants. One week after plants were introduced in the 20-l plastic buckets, they were separated into one of the three Si concentrations. These concentrations were: (i) control solution with no Si addition, named Si- [0.05 mM Si]; (ii) medium level of Si, named Si+ [0.6 mM Si]; (iii) highly-enriched solution, named Si++ [2.0 mM Si]. The nutritive solution was enriched with Si in the form of monosilicic acid (H 4 SiO 4 ). The concentration of the Si + solution was chosen according to the average concentration of Si found in soil (Epstein 1994 ). The concentration in the Si + + solution was set according to the limit of solubility of Si (> 2 mM), at which point it may precipitate as amorphous silica (Exley 2015 ). The monosilicic acid solution was freshly prepared by dissolving sodium silicate in demineralized water, and the solution was passed through cation-exchange resin (Amberlite® IR-120) (Cornelis et al. 2010). Insect Rearing. Beet armyworm S. exigua eggs were purchased from Entocare Biological Control (Wageningen, Netherlands). After three days of incubation at 24°C, first instars were fed an artificial diet (General purpose Lepidoptera, Frontier Scientific Services Agriculture, Newark, USA). The insects were reared at 24 ± 2°C and 40–50% relative humidity, under a 18:6 (light: dark; L: D) photoperiod. The moths were kept in flight cages supplied with 10% sugar solution and paper tissue as oviposition substrate. Silicon Quantification in Plant Tissue. Foliar Si content was quantified on maize plants that were grown for 30 to 35 days in the hydroponic system (17–18 BBCH growth stage). All leaves were collected from one plant, dried at 50°C for 72 h. The leaves were then ground (plant shredder) and left for 24 h at 450°C for calcination. One hundred milligrams of ash was melted with 0.4 g Li-tetraborate and 1.6 g Li-tetraborate at 1000°C for five minutes in a graphite crucible (Chaos & Sanzolone, 1992). The fusion bead was then dissolved in 10% HNO 3 before quantifying Si concentrations using inductively coupled plasma optical emission spectroscopy (ICP-OES) (De Tombeur et al. 2020 ). Plant Volatile Collection and Analysis. Volatile blend collection was performed using a dynamic headspace sampling system on undamaged and S. exigua infested maize plants (17–18 BBCH growth stage) cultivated in the hydroponic system under the three Si conditions. Oven PET plastic bags (Roasting bags, 35 x 43 cm, WRAPOK®, China) were placed on the 5th and 6th leaves to collect volatile organic compounds. Beforehand, the bags were cleaned by heating them for 2 h in an oven at 120°C. Before the experiments, the bags were inflated and deflated three times to eject any contamination (Stewart-Jones and Poppy 2006 ). Five fifth instars were introduced to each bags to infest maize plants just before collection. A dynamic “push-pull” system was used for 2h in order to collect volatiles. Specifically, the pushed air flow (charcoal filtered) was set at 0.4 L.min − 1 and the pulled air flow was set at 0.3 L.min − 1 . VOCs were trapped on a dual sorbent sampling thermal desorption cartridge (Tenax® TA-Carbograph, Markes Int., CA, USA) placed at the bag opening. VOCs were collected from healthy and infested plants. Five replicates per Si condition were used. Two infestation durations were assessed: 18 and 54 h after insect infestation. Controls (empty bags only and bags containing caterpillars only) were simultaneously performed during the collection of plant volatiles. n-Butylbenzene (86 ng) was added to each cartridge as the internal standard. Immediately after VOCs collection, cartridges were analyzed using a gas chromatograph (QX-220, Shimadzu®, Japan) coupled with an automatic thermal desorber (TD30R, Shimadzu®, Japan). After desorption, VOCs were cryo-focused at -30°C at linear velocity (35 cm.s − 1 ) (Helium gas, column flow: 0.94 ml.min − 1 ) in a glass liner by the Peltier effect before being injected in the column (HP5-ms 30 mx 0.2 mmx 0.2 µm, Agilent). The oven temperature was set at 40°C, and was held for 1 min before being heated to 300°C via several ramps. The first temperature ramp was set at 5°C.s − 1 to 210°C, the second ramp was set at 20°C.s − 1 to 250°C and the third temperature ramp was set at 50°C.s − 1 to reach the final temperature (300°C), at which point it was held for 5 min. VOCs were detected with a mass spectrometer (Acquisition mode: Scan, from 30 m.z − 1 to 300 m.z − 1 ). Compounds were identified by comparing mass spectra with spectra libraries (NIST, FFNSC), as well as by calculating retention indexes and comparison with those from the libraries. Jasmonic Acid Quantification. Jasmonic acid was extracted following the procedure described in Nguyen et al. (2019). JA was extracted from plants subjected to similar treatments as those used for VOC analyses. All of the leaves of one plant were collected, and approximately 100 to 200 mg fresh leaf material was crushed with liquid nitrogen. JA was extracted from freeze-dried powder with 1 ml of 80% methanol. Each sample was placed in dark conditions and incubated on a shaker for 2h and centrifuged for 10 min at 12.000 x g. The supernatant was collected, and 1 ml of 100% methanol was added to the remaining samples for a second extraction for 1h under the same conditions. Samples were centrifuged again, and the supernatants were combined. A speed vacuum was used to dry samples, and residues were solubilized with 1 ml of 100% methanol. Samples were then passed through 0.2 µm PTFE filters before LC-MS based quantification. The analysis was performed using an Agilent 1290 Infinity II HPLC system (Agilent) coupled to accurate mass detector (Jet Stream ESI-qTOF 6530, Agilent) in negative mode. The MS parameters were set up as follows: capillary voltage: 3 kV; nebulizer pressure: 35 psi; drying gas:8 l min-1; drying gas temperature: 250°C; flow rate of sheath gas: 8 l min-1; sheath gas temperature: 300°C; Nozzle voltage : 200V; fragmentor voltage: 100 V; skimmer voltage: 65 V; octopole RF: 750 V. Accurate mass spectra was recorded in the range of m/z = 50–500. Separation was performed using a C18 Acquity UPLC BEH column (2.1 × 50 mm × 1.7 µm; Waters) and 0.1% formic acid (solvent A)/acetonitrile acidified with 0.1% formic acid (solvent B) as the mobile phase with a constant flow rate at 0.3 ml min-1 and column temperature set at 40°C. First, solvent B gradient from 5–30% B in 0.5 min was applied, followed by an increase from 30–80% solvent B at 2.7 min. Then, 100% solvent B was applied for 3 min, before returning to the initial conditions, which were kept for 5 min before the next analysis. Masshunter Qualitative Analysis software (Agilent) was used for the data analysis. Quantification was performed by comparing the JA peak area in 10 µL of samples with a calibration curve constructed after the injection of different concentrations of pure JA standard (Sigma-Aldrich). JA was quantified four times for each Si condition at each stage of healthy and infested plants. Oviposition Assay. Spodoptera exigua pupae were reared in the laboratory, and males and females were separated. Directly after emergence, each female was placed in a plastic container with two males for 48h to induce mating. The experimental setup consisted of three cages, attached to each other and communicating via 7 cm diameter openings. Five mated S. exigua females were introduced to the central cage (h:32cm, w:32cm, d:32cm). These females were allowed to choose between two side cages (h:76 cm, w:32 cm, d:32 cm) placed on the left and right of the central cage. The aerial parts of maize plants were enclosed in each side cage. Female moths were left in the system for 48 h (18:6 photoperiod). Then the number of eggs laid was counted on each plant. We tested the oviposition preference for three combinations of plants: Si- vs Si+; Si- vs Si++; and Si + vs Si++. The assay was performed using healthy maize plants and plants infested with S. exigua for 54 h (five caterpillars at the fifth instar). Each combination was replicated 15 times. New sets of plants and insects were used for each replicate. Statistical Analyses. Data on Si content were transformed to rank-based INTs using (rn)transform function (GenAbel package). Data on JA levels were be rank transformed (Art package) to reach normal distributions. Two-way analyses of variance and Tukey’s post-hoc tests were applied on Si content and JA levels (α = 0.05). Data on S. exigua oviposition were tested using a Wald test applied on a generalized linear mixed model (GLMM) with a quasi-binomial error distribution (function glmmPQL, package “MASS”) because of an overdispersion effect. To highlight differences in VOC profiles among the various Si and infestation treatments, a permutational multivariate analysis of variance (perMANOVA, adonis package) was performed on the mean abundance of VOCs using a Bray distance matrix and 999 permutations to respect data normality and homoscedasticity. If P -values were significant, a pairwise comparison was performed, allowing cross-interactions between Si treatments and S. exigua infestations to be assessed. To support this multivariate analysis, the mean abundance of individual compounds of each Si treatment and infestation were compared using analysis of variance (ANOVA) or the non-parametric equivalent, a Kruskal-Wallis test and Dunn’s all-pairs test (α = 0.05) if the normal distribution was not reached. Results Si Quantification in Foliar Tissues. Si foliar content significantly increased with Si concentration in the nutritive solution (F 2,12 = 28.52; P < 0.001) (0.31 ± 0.04 g Si. Kg − 1 DW (Si-) ; 4.69 ± 0.49 g Si. Kg − 1 DW (Si+) ; 9.56 ± 0.30 g Si. Kg − 1 DW (Si++); mean ± SD). Si leaf content was significantly different among the three Si treatments (Tukey Post-Hoc test, P < 0.05). Si Accumulation in Maize Leaves and Plant Volatile Emissions. No cross-interaction between Si treatment (Si-; Si+; Si++) and time of infestation (healthy, 18 h; 54 h) was detected (F 4,44 = 0.052, P = 0.420). Si accumulation had no impact on plant (healthy and insect-infested) VOC emissions (F 2,44 = 0.021, P = 0.521). Comparing the mean abundance of each VOC showed one single difference among the Si treatments after 18 h of infestation. Specifically, ( E )-hept-2-enal was emitted at higher quantities from Si + + plants compared to Si- plants (χ 2 = 6.755, df = 2, P = 0.034). Compound-by-compound comparisons revealed no other significant differences. Eleven compounds were collected and identified in the headspace of non-infested maize plants, whereas 38 VOCs were identified from S. exigua -infested maize plants (Table 1 ). Infestation of S. exigua led to modifications in the release of VOCs over time in all Si-treatments (F 2,44 = 0.453, P = 0.001). Pairwise comparisons (P < 0.05) showed significant differences in the volatilome of undamaged plants and plants infested with S. exigua for 18 h. No difference in VOC profile was identified between plants infested for 18 h versus 54 h. Si Accumulation in Plants and Jasmonic Acid Levels. We found no cross interaction on JA levels between Si content and time of infestation (F 4,27 = 0.712, P = 0.590). As expected, herbivory significantly affected JA content in leaves (F 2,27 = 7.893, P = 0.002) (Fig. 1 ). However, Si accumulation in plant tissues did not significantly affect JA levels (F 2 , 27 = 1.421, P = 0.259). Table 1 Emissions of volatile organic compounds from undamaged and S. exigua infested maize plants (18 and 54 hours) in ng. gDW -1 . 2h -1 (Mean ± SD) Compounds KI a (c) Undamaged Plants infested for 18 hours Plants infested for 54 hours Si- Si+ Si++ Si- Si+ Si++ Si- Si+ Si++ ( E )-hex-3-enal 598 19.54 ± 17.33 7.22 ± 4.39 8.78 ± 8.05 48.70 ± 25.13 42.95 ± 35.61 18.09 ± 5.86 16.55 ± 10.51 10.32 ± 8.89 7.16 ± 3.58 Hexanal 600 - - - - - - 5.26 ± 2.07 4.43 ± 2.72 3.44 ± 1.35 ( E )-hex-2-enal 676 1.53 ± 0.69 0.88 ± 0.22 1.84 ± 0.92 13.78 ± 6.08 11.10 ± 4.79 5.84 ± 2.72 6.31 ± 3.39 14.91 ± 11.76 3.60 ± 1.50 ( Z )-hex-3-en-1-ol 679 - - - 27.02 ± 12.22 17.09 ± 7.89 9.69 ± 4.94 9.76 ± 5.84 13.88 ± 6.01 7.80 ± 4.87 Heptanal 802 - - - - - - 0.60 ± 0.21 0.48 ± 0.17 0.39 ± 0.10 [( Z )-pent-2-enyl] acetate 811 - - - 2.59 ± 1.78 3.23 ± 1.86 2.31 ± 0.99 3.92 ± 2.38 2.83 ± 2.05 0.59 ± 0.39 ( E )-hept-2-enal 856 - - - 0.00 a 1.18 ± 0.60 ab 1.25 ± 0.45 b 0.14 ± 0.14 0.60 ± 0.35 0.61 ± 0.34 β-myrcene 889 2.70 ± 2.02 1.41 ± 0.31 1.24 ± 0.46 14.43 ± 5.12 9.11 ± 1.79 9.76 ± 3.37 35.54 ± 9.98 17.88 ± 9.62 5.91 ± 1.36 [( Z )-hex-3-enyl] acetate 908 45.23 ± 11.01 20.26 ± 7.49 7.31 ± 2.32 94.75 ± 26.10 59.13 ± 20.25 49.23 ± 13.11 80.30 ± 24.24 42.08 ± 16.18 30.34 ± 13.91 [( Z )-hex-2-enyl] acetate 925 - - - 2.38 ± 0.95 - 0.68 ± 0.50 10.58 ± 9.63 6.61 ± 6.04 0.53 ± 0.37 ρ-cymene 944 - - - - - - 2.64 ± 1.31 3.89 ± 3.18 0.15 ± 0.15 ( D )-limonene 952 - - - 0.47 ± 0.47 1.48 ± 0.90 1.59 ± 0.77 2.13 ± 0.93 3.08 ± 2.38 0.34 ± 0.22 α-pinene 964 - - - - - - 1.42 ± 0.60 1.48 ± 1.11 - β-ocimene 984 - - - 2.15 ± 0.76 1.76 ± 0.65 1.89 ± 0.66 4.35 ± 1.55 2.57 ± 1.81 0.67 ± 0.25 Linalool 1098 - - - 47.79 ± 19.77 31.97 ± 6.91 50.77 ± 18.28 54.48 ± 24.65 42.15 ± 25.66 11.71 ± 3.63 Nonanal 1104 27.64 ± 5.43 8.46 ± 3.25 9.39 ± 2.37 12.44 ± 2.51 12.34 ± 3.44 8.31 ± 1.08 10.66 ± 2.08 8.00 ± 3.13 5.38 ± 1.47 DMNT 1113 - - - 73.34 ± 28.14 46.20 ± 11.50 70.71 ± 21.38 85.19 ± 31.96 37.85 ± 20.47 25.45 ± 11.37 Decanal 1205 18.55 ± 6.71 6.60 ± 1.66 5.56 ± 1.27 8.81 ± 1.73 7.21 ± 1.14 6.25 ± 1.03 6.75 ± 1.49 3.97 ± 1.04 3.36 ± 1.10 Indole 1294 - - - 112.11 ± 44.67 93.65 ± 26.47 92.81 ± 32.83 135.74 ± 31.13 78.52 ± 16.88 58.59 ± 29.18 Methyl anthranilate 1341 - - - 9.06 ± 4.18 5.27 ± 1.79 12.36 ± 5.02 10.09 ± 4.55 6.23 ± 3.42 0.81 ± 0.57 Geranyl acetate 1377 - - - 8.61 ± 3.74 7.79 ± 2.35 17.44 ± 7.54 28.09 ± 16.66 18.12 ± 13.24 5.09 ± 2.36 Zingiberene 1388 - - - 1.50 ± 0.96 1.70 ± 0.55 3.40 ± 1.27 15.93 ± 6.46 6.16 ± 3.27 2.38 ± 1.03 ( Z )-jasmone 1394 - - - 1.10 ± 0.41 1.02 ± 0.49 0.89 ± 0.32 - - - α-funebrene 1402 0.74 ± 0.74 2.55 ± 1.64 0.57 ± 0.37 4.09 ± 2.17 11.12 ± 4.52 15.79 ± 6.91 29.35 ± 12.60 26.03 ± 13.65 10.09 ± 5.30 β-caryophyllene 1421 - 0.95 ± 0.79 0.26 ± 0.26 4.90 ± 2.96 2.92 ± 0.89 7.27 ± 2.88 39.52 ± 15.42 11.22 ± 4.12 5.02 ± 1.45 ( E )-α-bergamotene 1435 - 6.68 ± 5.38 1.38 ± 1.38 71.95 ± 36.53 70.78 ± 15.89 105.80 ± 32.75 223.03 ± 83.46 58.05 ± 16.95 57.33 ± 20.86 Sesquisabinene 1441 - - - 3.51 ± 1.95 2.28 ± 0.52 6.45 ± 2.63 21.92 ± 10.93 7.09 ± 4.00 2.76 ± 1.36 ( E )-β-farnesene 1455 - 10.82 ± 8.59 1.68 ± 1.35 117.20 ± 49.42 116.59 ± 20.91 168.04 ± 48.96 95.69 ± 48.14 49.58 ± 29.17 138.28 ± 67.41 Dodecan-1-ol 1474 1.42 ± 0.46 0.41 ± 0.21 0.16 ± 0.16 0.45 ± 0.22 0.80 ± 0.31 0.26 ± 0.16 - - - β-himalachene 1480 - - - - - - 4.69 ± 2.60 1.85 ± 1.02 0.70 ± 0.49 α-curcumene 1484 - - - 0.58 ± 0.38 1.18 ± 0.73 1.67 ± 0.73 10.56 ± 4.01 6.31 ± 4.19 2.31 ± 1.34 Sesquithujene 1496 - - - 1.95 ± 1.43 1.47 ± 0.45 5.01 ± 2.25 22.73 ± 10.51 7.50 ± 4.66 4.00 ± 1.89 β-bisabolene 1509 - - - 2.63 ± 1.34 3.85 ± 1.01 6.76 ± 2.59 29.81 ± 12.01 11.86 ± 7.57 5.68 ± 2.37 β-sesquiphellandrene 1527 - - - 7.91 ± 4.37 8.11 ± 1.63 6.76 ± 2.59 82.30 ± 30.91 28.65 ± 16.21 17.30 ± 6.70 ( E )-nerolidol 1560 - - - - - - 1.70 ± 0.83 0.55 ± 0.30 0.08 ± 0.08 TMTT 1573 - - - 4.69 ± 3.35 7.60 ± 3.44 8.19 ± 2.43 42.30 ± 18.06 14.69 ± 6.00 14.13 ± 4.00 a KI (c) : Calculated Kovats Index DMNT: (3 E )-4,8-dimethylnona-1,3,7-triene TMTT: (3 E ,7 E )-4,8,12-trimethyltrideca-1,3,7,11-tetraene Si Accumulation in Plants and S. exigua Oviposition Behavior. The number of eggs laid by S. exigua females did not significantly differ among the three Si treatments (χ 2 = 0.287, df = 2, P = 0.866) (Fig. 2 ), whether on undamaged or S. exigua infested plants. The total number of eggs observed on non-infested plants was: Si- vs Si+ (185 ± 22; 165 ± 28); Si- vs Si++ (152 ± 27; 140 ± 30); Si + vs Si++ (164 ± 25; 170 ± 17) (mean ± SD). The total number of eggs observed on infested plants was: Si- vs Si+ (150 ± 32; 140 ± 21); Si- vs Si++ (118 ± 23; 142 ± 24); Si + vs Si++ (155 ± 31; 148 ± 21)] (mean ± SD). Discussion Previous experiments demonstrated the beneficial effect of high Si concentrations in plant tissues in alleviating pest damage (Keeping et al. 2013 ; Johnson et al. 2020 ; Nagaratna et al. 2021 ). However, whether Si actually modifies the emissions of volatile organic compounds, and indirectly impacts insect pest behavior, remains subject to debate (Kvedaras et al. 2010 ; Callis-Duehl et al. 2017 ; Liu et al. 2017 ). The present study specifically aimed to established the impact of Si accumulation on the emissions of constitutive and herbivore-induced plant volatiles, and to evaluate the cascade deterrent effect on the oviposition behavior of a phytophagous insect. We demonstrated that there is no effect of Si accumulation in maize leaves on constitutive and induced VOC emissions, neither on JA levels nor oviposition site selection by S. exigua females. To the best of our knowledge, this study presents the first evaluation of how Si accumulation in maize leaves affects maize VOC emissions. Most other biological models on this phenomenon found that Si modifies the plant volatile profile. For instance, Si-enriched cucumber plants infested by a chewing herbivore ( Diabrotica balteata LeConte) produced more indole compared to non-enriched plants (Callis-Duehl et al. 2017 ). The volatile profile of rice plants enriched with Si and infested with Cnaphalocris medinalis Guenée was also impacted, resulting in a stronger attraction of natural enemies (Liu et al. 2017 ). Si accumulation also changed the volatile profile of grapevine ( Vitis vinifera L.), with caterpillar-infested plants releasing higher levels of n-heptadecane compared to uninfested plants (Connick 2011 ). Islam et al. ( 2022 ) showed that the volatile profile of Si-enriched French bean ( Phaseolus vulgaris L.) infested by spider mites ( Tetranychus urticae Koch) was impacted, with the concentrations of some VOCs rising, whereas others decreased. In contrast, we observed no significant effect of Si content in maize leaves on HIPVs emission. Similar to previous studies, damage caused by phytophagous insects increased JA levels in the current study. In non-stressed plants, JA levels were not significantly different among Si treatments, supporting the findings of some previous studies (Ye et al. 2013 ; Johnson et al. 2020 ). However, our result contrasted with that of Kim et al. ( 2014 ), who showed that JA levels significantly increased in Si-enriched undamaged rice plants. Concerning insect-infested plants, JA levels were higher for Si-enriched plants after infestation, supporting Ye et al. ( 2013 ). However, we did not find any significant differences between Si treatments. Thus, the “apoplastic obstruction hypothesis did not apply in our case study” ((Coskun et al. 2019 ). This hypothesis predicts that the amorphous portion of Si accumulated in the apoplast interferes with the specificity of the recognition process between the plant and biotic stressors (here, the insect pest). This phenomenon alters the flow of molecular compounds, -such as effectors. However, in the current study, accumulated Si in maize tissues did not interfere with the recognition process and effectors produced by S. exigua caterpillars. Consequently, infestation did not affect Si-enriched maize plants less than non-enriched maize plants, resulting in similar responses. Following herbivory, JA levels rose in a similar manner across all three Si treatments, explaining most of the similarity in HIPVs profiles across all Si-treated plants. When considering Si content in plant tissues, Si concentrations in tested plants (0.95%) were relatively low compared to most previous studies (Ma et al. 2001 ; Liang et al. 2015 ). Thus, the Si content of the current study might not have been sufficient to reach a putative effect of Si fertilization on HIPV emissions by maize plants. Further studies are required to evaluate how different Si concentrations impact maize plant volatile emissions throughout development. We predict that older plants would accumulate larger concentrations of Si in tissue, resulting in a significant impact on semiochemical-based plant-insect interactions. We also expect plant genotype to contribute to responses, as Si concentrations vary within species (Ma and Yamaji 2008 ). Thus, the effects of Si amendment should be evaluated for a wide diversity of maize varieties, especially where potential IPM applications exist. Si accumulation in plant leaves potentially has trophic effects on the pest herbivore. Pereira et al. ( 2021 ) observed that S. frugiperda females avoid laying eggs on Si-enriched maize plants, and lay twice as many eggs on leaves with lower Si concentrations. In contrast,, Brown ( 2019 ) recorded S. frugiperda females laying more eggs on Si-enriched maize plants (whether undamaged or insect-infested); however, these differences were not statistically supported. In the present study, we did not observe any significant effect of Si on oviposition site selection by S. exigua . The differences obtained across these three studies could be explained by the ability of the pests to repress HIPV emissions. For instance, S. frugiperda caterpillars are able to repress HIPV emission by maize plants, whereas S. exigua caterpillar s strongly induce HIPV release (De Lange et al. 2020 ). The involved mechanisms are associated to the diversity of elicitors present in insect saliva. Furthermore, different maize varieties produce different HIPV profiles (Block et al. 2018 ). Thus, the effect of silicon supplies should be evaluated on different (maize) varieties infested by related-insect species (including Spodoptera spp or Helicoverpa zea ). Given the lack of studies and divergent findings, whether Si concentration in leaves impacts the behavior of female moths remains unclear. Si effects differ depending on the stage of maize plant development and the concentration of Si in leaves. The latter is probably a key factor requiring focused study. We hypothesize that plant-specific Si concentration thresholds would triggers defensive pathways. HIPVs are important chemical molecules that allow recruiting natural enemies of insect pests, but their role is not restricted to the mediation with the third trophic level (Halitschke et al. 2008 ). Host selection by female is crucial for offspring survival and HIPVs have also been shown to be either attractive or repellent for herbivores (De Moraes et al. 2001 ). In this work, we have tested the hypothesis that HIPVs impact S. exigua oviposition preference. In their study, Yactayo-Chang et al. ( 2021 ) found that some maize HIPV compounds attract S. frugiperda (methyl salicylate and ( E )-α-bergamotene) whereas others act as oviposition deterrents (DMNT). In our study, Si concentration in the leaves did not impact the emissions of these compounds, which could explain why we found that gravid females showed no preference to any of the Si treatments. Because herbivore responses towards HIPVs depends on multiple parameters, including herbivore species (Szendrei & Rodriguez-Saona 2010 ), S. exigua females might not necessarily reactive to the same compounds. Electrophysiology could provide new insights on the ability of S. exigua females to respond to maize HIPVs. In conclusion, this study demonstrated that Si accumulation in maize leaves did not affect constitutive and induced VOC emissions with respect to, JA levels and the oviposition preference of by S. exigua females. Future studies are required to advance our understanding on whether and how Si is involved in plant chemical defenses against herbivores. Declarations Funding Nicolas Leroy is supported by a FRIA-FNRS grant. Competing Interests The authors have no relevant financial or non-financial interests to disclose. Author Contributions N Leroy, J-T Cornelis and F Verheggen contributed to the study conception and design. Material preparation, data collection and analysis were performed by N. Leroy, A Arguelles Arias and C Martin. The first draft of the manuscript was written by N Leroy and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. References Abbasi A, Sufyan M, Arif MJ, Sahi ST (2020) Effect of silicon on oviposition preference and biology of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) feeding on Gossypium hirsutum (Linnaeus). Int J Pest Manag 1:11. https://doi.org/10.1080/09670874.2020.1802084 Acevedo FE, Peiffer M, Ray S, Tan C-W, Felton GW (2021) Silicon-mediated enhancement of herbivore resistance in agricultural crops. 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Proc Natl Acad Sci 110:E3631–E3639. https://doi.org/10.1073/pnas.1305848110 Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 19 Jul, 2022 Reviewers invited by journal 19 Jul, 2022 Editor assigned by journal 18 Jul, 2022 First submitted to journal 15 Jul, 2022 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 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-1862920","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":122376236,"identity":"82bb65f3-89e7-4379-9704-387adfcb5c95","order_by":0,"name":"Nicolas Leroy","email":"","orcid":"","institution":"Liege University: Universite de Liege","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Nicolas","middleName":"","lastName":"Leroy","suffix":""},{"id":122376237,"identity":"ee5f1300-6f45-4e88-982e-5c80e3d5fe40","order_by":1,"name":"Clément Martin","email":"","orcid":"","institution":"Liege University: Universite de Liege","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Clément","middleName":"","lastName":"Martin","suffix":""},{"id":122376238,"identity":"df35e8dc-c363-49f0-8e1a-d5175cc32109","order_by":2,"name":"Anthony Arguelles Arias","email":"","orcid":"","institution":"Liege University: Universite de Liege","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Anthony","middleName":"Arguelles","lastName":"Arias","suffix":""},{"id":122376239,"identity":"33f230bb-cf52-48c2-b42b-01fbf98b2451","order_by":3,"name":"Jean-Thomas Cornélis","email":"","orcid":"","institution":"Liege University: Universite de Liege","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Jean-Thomas","middleName":"","lastName":"Cornélis","suffix":""},{"id":122376240,"identity":"bd035cff-bd9d-4fc4-9a06-1242d9412ffe","order_by":4,"name":"François Jean Verheggen","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIie3OsUoDQRDG8YGBpJlL2gVfYuAgWsjuq2wYuCpCSosYtopNJG2CPof1hoOzidheGRGsAwGxEPVC1HKIneD+q6/YH7MAqdQfrB0AcD8xwpp3g3RC8Ye0PPhfEmLwcAgxUm2H5xd2djR9MX54ameQLdc6KeR6vrqTxc39rfFcyCJ0hDXiaJVjNqmE67MdKYUj9Yx6hR62mL1X4urBc0M+xEU6flVJe4qYhZFlM2g1JFoG6mmiIZMcqYre1EV+4lm8KTuifwzxCWk0dt25PNabN+u6l1fLjXpmX9kPX6sf8ID3TWP3vZz2LJVKpf5nn8geRhtLrT/KAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-5849-1661","institution":"Universite de Liege Gembloux Agro-Bio Tech","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"François","middleName":"Jean","lastName":"Verheggen","suffix":""}],"badges":[],"createdAt":"2022-07-15 20:16:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1862920/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1862920/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":24158423,"identity":"7759188f-1077-4236-b0e4-6bc0c2ef83d3","added_by":"auto","created_at":"2022-07-21 17:37:03","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":66044,"visible":true,"origin":"","legend":"\u003cp\u003eFoliar concentration of JA in maize plants cultivated at three\u0026nbsp;Si concentrations and at different infestation stages (Undamaged, 18-h S. exigua infestation [I18], 54-h S. exigua infestation [I54]) (Mean ± SD). Different letters on bars indicate significant differences by Tukey’s test (p \u0026lt; 0.05)\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-1862920/v1/8f1ad012901ef2bec7afe4a4.jpeg"},{"id":24158422,"identity":"28e12bb3-84b3-4dd2-81cd-4fbf057d97ca","added_by":"auto","created_at":"2022-07-21 17:37:03","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":96692,"visible":true,"origin":"","legend":"\u003cp\u003eOviposition choice of S. exigua moths exposed to maize plants cultivated in the three Si treatments (Si-, Si+, Si++). Bars represent the proportion of the number of eggs laid. The pie chart (right) represents the proportion of eggs laid in the neutral zone\u003c/p\u003e","description":"","filename":"floatimage2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-1862920/v1/701fc733d436a87e4de07038.jpeg"},{"id":24158424,"identity":"94b40bc0-a589-4684-bb03-de61707946d1","added_by":"auto","created_at":"2022-07-21 17:37:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":396644,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1862920/v1/b05e34b5-64fb-4196-b45c-a236a835a472.pdf"}],"financialInterests":"","formattedTitle":"If all else fails: Impact of silicon accumulation in maize leaves on volatile emissions and oviposition site selection of Spodoptera exigua Hübner","fulltext":[{"header":"Introduction","content":"\u003cp\u003eSilicon (Si) is a ubiquitous element and one of the most abundant elements in soil. For instance, Si concentrations in soil solution as uncharged monomeric silicic acid (H\u003csub\u003e4\u003c/sub\u003eSiO\u003csub\u003e4\u003c/sub\u003e) range from 0.1 to 0.6 mM (Epstein \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e1994\u003c/span\u003e), depending on soil physiochemical properties (Corn\u0026eacute;lis and Delvaux, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). A wide diversity of plant species accumulates from 0.1 to 10% Si (on dry weight basis) in their tissues (Hodson et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Epstein \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). Under certain environmental conditions, Si fertilization enhances the performance, yield and fruit quality of plants (Verma et al. \u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Si also reduces the impact of abiotic and biotic stressors (Reynolds et al. \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). For instance, Si enhances plant resistance against pathogens and insects through physical barriers and biochemical mechanisms (Bakhat et al. \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Acevedo et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Si accumulates in leaves as amorphous silica (SiO\u003csub\u003e2\u003c/sub\u003e.nH\u003csub\u003e2\u003c/sub\u003eO), also called phytoliths, and provides mechanical resistance against herbivory (Frew et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Grasses accumulate Si in specialized cells or in silicified external structures, like trichomes or prickle cells (Hall et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Acevedo et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). These structures reduce the palatability of plant tissues by increasing their hardness and abrasiveness. In turn, this phenomenon negatively impacts the feeding and growth of insects (Massey and Hartley \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2009\u003c/span\u003e; Hartley and DeGabriel \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), and interferes with the digestion capacities (Andama et al. \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn addition to Si contributing to the mechanical defenses of plants, it activates plant biochemical pathways stimulated by pest infestation (Alhousari and Greger \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Chemical defenses are regulated by different phytohormones, including jasmonic acid (JA), salicylic acid (SA), and ethylene (ET) (Howe and Jander \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). Among these plant hormones, JA is strongly linked with plant defenses against insect pests, activating both direct and indirect defenses (Mith\u0026ouml;fer and Boland \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). There is general consensus that Si accumulation in plant tissues affects phytohormone signaling during herbivory. For instance, Si interferes with the JA response in \u003cem\u003eOryza sativa\u003c/em\u003e (rice) and \u003cem\u003eBrachypodium distachyon\u003c/em\u003e (stiff brome) (Ye et al. \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Kim et al. \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Hall et al. \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Johnson et al. \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). However, some authors report that JA levels rise in Si-enriched insect-infested plants (Ye et al., \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2013\u003c/span\u003e), while others report the opposite (Kim et al., \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2014\u003c/span\u003e and Hall et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Hall et al. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) proposed a conceptual model of how Si acts as stimulating element for plant mechanical defense based on existing studies describing Si interactions with JA and taking into account the fact that Si chemical reactivity within plants is limited (Coskun et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). This effect could reduce the JA response, as well as the production of defensive metabolites.\u003c/p\u003e \u003cp\u003ePlant chemical defenses include secondary metabolites that have either direct(e.g. terpenes, alkaloids, and phenols) or indirect (e.g. emission of herbivore-induced plant volatiles; HIPVs) effects on phytophagous insects (War et al. \u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). The jasmonate-pathway leads to the synthesis and release of HIPVs (Wei et al. \u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). These compounds are exploited by the natural enemies of phytophagous insects, and by other herbivorous insects, to locate and select host plants (Bruce et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2005\u003c/span\u003e; Schnee et al. \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Turlings and Erb \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). In particular, \u003cem\u003eSpodoptera\u003c/em\u003e females (Lepidoptera) select their oviposition site using plant volatile organic compounds (VOCs), avoiding plants releasing HIPVs (De Moraes et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Signoretti et al. \u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Block et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The production of defensive compounds by plant species that accumulate Si is altered when Si concentrations in plant tissues are elevated. Si could trigger the synthesis of HIPVs, in addition to modifying their composition and emission rates (Callis-duehl et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Liu et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Leroy et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). While \u003cem\u003eSpodoptera frugiperda\u003c/em\u003e females select their host using chemical cues, Pereira et al. (\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) showed that they lay half as many eggs on Si-enriched plants compared to non-enriched ones. Abbasi et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2020\u003c/span\u003e) obtained similar results for \u003cem\u003eBemisia tabaci\u003c/em\u003e and Si-enriched cotton plants (\u003cem\u003eGossypium hirsutum\u003c/em\u003e).\u003c/p\u003e \u003cp\u003eSi impacts the chemical defenses of plants under insect infestations; however, the involved mechanisms remain poorly defined (Leroy et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Here, we investigated whether Si accumulation in maize leaves alters VOC emissions by healthy and insect-infested plants, indirectly impacting oviposition site selection by \u003cem\u003eSpodoptera exigua\u003c/em\u003e H\u0026uuml;bner. We hypothesized that higher silicon levels in maize tissues lead to reduced VOC emissions and decreased number of eggs laid by \u003cem\u003eS. exigua\u003c/em\u003e females. Specifically, we: (i) collected VOCs from maize plants cultivated under three Si concentrations; (ii) quantified JA in healthy and infested plants; and (iii) assessed oviposition choice with \u003cem\u003eS. exigua\u003c/em\u003e gravid females on plants cultivated under three Si concentrations. Our results are expected to demonstrate how Si disrupts the ability of insects to identify hosts by modifying VOC emissions, which could be used to reduce herbivory in sustainable pest control management.\u003c/p\u003e"},{"header":"Methods And Materials","content":"\u003cp\u003e \u003cem\u003ePlant Production.\u003c/em\u003e Corn plants (\u003cem\u003eZ. mays\u003c/em\u003e L. var. Delprim) were cultivated and used in all experiments (Delley Seeds and Plants, Delley, Switzerland). Seeds were germinated on paper towels moistened with distilled water in Petri dishes, which were kept for three days under dark conditions at 23\u0026deg;C. Then, the seedlings were placed on a rockwool substrate introduced to small hydroponic pots. Seedlings (eight per pot) were cultivated inside a 20-l plastic bucket containing water, and were placed in a temperate chamber. The conditions in the chamber were set to: 24\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u0026deg;C (day), 20\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u0026deg;C (night), 55\u0026ndash;70% relative humidity, 300 \u0026micro;mol.m\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e.s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e light intensity. After four days, water was replaced with a commercial nutritive solution (HY-PRO\u0026reg;, A\u0026amp;B, Bladel, Netherlands) [46.29 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e N; 23.94 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e P; 227.81 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e K; 115.12 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Ca; 0.09 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Cu; 38.79 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Mg; 1.48 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Fe; 0.15 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Mn; 0.13 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Zn; 3.71 mg.l\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e Na]. Air pumps in each plastic bucket were used to maintain continuous aeration in the nutritive solution. Seedlings were grown grew in quarter strength nutrient solution (i.e., diluted four times) for, two days. Then, the concentration of the nutritive solution was gradually raised to full strength over one week to avoid osmotic shock. The nutritive solution was renewed every three days during the growing period. Every time the nutritive solution was changed, the pH of the medium was corrected to 5.5\u0026thinsp;\u0026plusmn;\u0026thinsp;0.5 by adding 0.5 M MgSO\u003csub\u003e4\u003c/sub\u003e, which also corrected the Mg/K ratio in the solution, and prevented Mg deficiency in maize plants. One week after plants were introduced in the 20-l plastic buckets, they were separated into one of the three Si concentrations. These concentrations were: (i) control solution with no Si addition, named Si- [0.05 mM Si]; (ii) medium level of Si, named Si+ [0.6 mM Si]; (iii) highly-enriched solution, named Si++ [2.0 mM Si]. The nutritive solution was enriched with Si in the form of monosilicic acid (H\u003csub\u003e4\u003c/sub\u003eSiO\u003csub\u003e4\u003c/sub\u003e). The concentration of the Si\u0026thinsp;+\u0026thinsp;solution was chosen according to the average concentration of Si found in soil (Epstein \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e1994\u003c/span\u003e). The concentration in the Si\u0026thinsp;+\u0026thinsp;+\u0026thinsp;solution was set according to the limit of solubility of Si (\u0026gt;\u0026thinsp;2 mM), at which point it may precipitate as amorphous silica (Exley \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). The monosilicic acid solution was freshly prepared by dissolving sodium silicate in demineralized water, and the solution was passed through cation-exchange resin (Amberlite\u0026reg; IR-120) (Cornelis et al. 2010).\u003c/p\u003e \u003cp\u003e \u003cem\u003eInsect Rearing.\u003c/em\u003e Beet armyworm \u003cem\u003eS. exigua\u003c/em\u003e eggs were purchased from Entocare Biological Control (Wageningen, Netherlands). After three days of incubation at 24\u0026deg;C, first instars were fed an artificial diet (General purpose Lepidoptera, Frontier Scientific Services Agriculture, Newark, USA). The insects were reared at 24\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u0026deg;C and 40\u0026ndash;50% relative humidity, under a 18:6 (light: dark; L: D) photoperiod. The moths were kept in flight cages supplied with 10% sugar solution and paper tissue as oviposition substrate.\u003c/p\u003e \u003cp\u003e \u003cem\u003eSilicon Quantification in Plant Tissue.\u003c/em\u003e Foliar Si content was quantified on maize plants that were grown for 30 to 35 days in the hydroponic system (17\u0026ndash;18 BBCH growth stage). All leaves were collected from one plant, dried at 50\u0026deg;C for 72 h. The leaves were then ground (plant shredder) and left for 24 h at 450\u0026deg;C for calcination. One hundred milligrams of ash was melted with 0.4 g Li-tetraborate and 1.6 g Li-tetraborate at 1000\u0026deg;C for five minutes in a graphite crucible (Chaos \u0026amp; Sanzolone, 1992). The fusion bead was then dissolved in 10% HNO\u003csub\u003e3\u003c/sub\u003e before quantifying Si concentrations using inductively coupled plasma optical emission spectroscopy (ICP-OES) (De Tombeur et al. \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cem\u003ePlant Volatile Collection and Analysis.\u003c/em\u003e Volatile blend collection was performed using a dynamic headspace sampling system on undamaged and \u003cem\u003eS. exigua\u003c/em\u003e infested maize plants (17\u0026ndash;18 BBCH growth stage) cultivated in the hydroponic system under the three Si conditions. Oven PET plastic bags (Roasting bags, 35 x 43 cm, WRAPOK\u0026reg;, China) were placed on the 5th and 6th leaves to collect volatile organic compounds. Beforehand, the bags were cleaned by heating them for 2 h in an oven at 120\u0026deg;C. Before the experiments, the bags were inflated and deflated three times to eject any contamination (Stewart-Jones and Poppy \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Five fifth instars were introduced to each bags to infest maize plants just before collection. A dynamic \u0026ldquo;push-pull\u0026rdquo; system was used for 2h in order to collect volatiles. Specifically, the pushed air flow (charcoal filtered) was set at 0.4 L.min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and the pulled air flow was set at 0.3 L.min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. VOCs were trapped on a dual sorbent sampling thermal desorption cartridge (Tenax\u0026reg; TA-Carbograph, Markes Int., CA, USA) placed at the bag opening. VOCs were collected from healthy and infested plants. Five replicates per Si condition were used. Two infestation durations were assessed: 18 and 54 h after insect infestation. Controls (empty bags only and bags containing caterpillars only) were simultaneously performed during the collection of plant volatiles. n-Butylbenzene (86 ng) was added to each cartridge as the internal standard. Immediately after VOCs collection, cartridges were analyzed using a gas chromatograph (QX-220, Shimadzu\u0026reg;, Japan) coupled with an automatic thermal desorber (TD30R, Shimadzu\u0026reg;, Japan). After desorption, VOCs were cryo-focused at -30\u0026deg;C at linear velocity (35 cm.s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) (Helium gas, column flow: 0.94 ml.min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) in a glass liner by the Peltier effect before being injected in the column (HP5-ms 30 mx 0.2 mmx 0.2 \u0026micro;m, Agilent). The oven temperature was set at 40\u0026deg;C, and was held for 1 min before being heated to 300\u0026deg;C via several ramps. The first temperature ramp was set at 5\u0026deg;C.s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 210\u0026deg;C, the second ramp was set at 20\u0026deg;C.s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 250\u0026deg;C and the third temperature ramp was set at 50\u0026deg;C.s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to reach the final temperature (300\u0026deg;C), at which point it was held for 5 min. VOCs were detected with a mass spectrometer (Acquisition mode: Scan, from 30 m.z\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 300 m.z\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e). Compounds were identified by comparing mass spectra with spectra libraries (NIST, FFNSC), as well as by calculating retention indexes and comparison with those from the libraries.\u003c/p\u003e \u003cp\u003e \u003cem\u003eJasmonic Acid Quantification.\u003c/em\u003e Jasmonic acid was extracted following the procedure described in Nguyen et al. (2019). JA was extracted from plants subjected to similar treatments as those used for VOC analyses. All of the leaves of one plant were collected, and approximately 100 to 200 mg fresh leaf material was crushed with liquid nitrogen. JA was extracted from freeze-dried powder with 1 ml of 80% methanol. Each sample was placed in dark conditions and incubated on a shaker for 2h and centrifuged for 10 min at 12.000 x g. The supernatant was collected, and 1 ml of 100% methanol was added to the remaining samples for a second extraction for 1h under the same conditions. Samples were centrifuged again, and the supernatants were combined. A speed vacuum was used to dry samples, and residues were solubilized with 1 ml of 100% methanol. Samples were then passed through 0.2 \u0026micro;m PTFE filters before LC-MS based quantification. The analysis was performed using an Agilent 1290 Infinity II HPLC system (Agilent) coupled to accurate mass detector (Jet Stream ESI-qTOF 6530, Agilent) in negative mode. The MS parameters were set up as follows: capillary voltage: 3 kV; nebulizer pressure: 35 psi; drying gas:8 l min-1; drying gas temperature: 250\u0026deg;C; flow rate of sheath gas: 8 l min-1; sheath gas temperature: 300\u0026deg;C; Nozzle voltage : 200V; fragmentor voltage: 100 V; skimmer voltage: 65 V; octopole RF: 750 V. Accurate mass spectra was recorded in the range of m/z\u0026thinsp;=\u0026thinsp;50\u0026ndash;500. Separation was performed using a C18 Acquity UPLC BEH column (2.1 \u0026times; 50 mm \u0026times; 1.7 \u0026micro;m; Waters) and 0.1% formic acid (solvent A)/acetonitrile acidified with 0.1% formic acid (solvent B) as the mobile phase with a constant flow rate at 0.3 ml min-1 and column temperature set at 40\u0026deg;C. First, solvent B gradient from 5\u0026ndash;30% B in 0.5 min was applied, followed by an increase from 30\u0026ndash;80% solvent B at 2.7 min. Then, 100% solvent B was applied for 3 min, before returning to the initial conditions, which were kept for 5 min before the next analysis. Masshunter Qualitative Analysis software (Agilent) was used for the data analysis. Quantification was performed by comparing the JA peak area in 10 \u0026micro;L of samples with a calibration curve constructed after the injection of different concentrations of pure JA standard (Sigma-Aldrich). JA was quantified four times for each Si condition at each stage of healthy and infested plants.\u003c/p\u003e \u003cp\u003e \u003cem\u003eOviposition Assay. Spodoptera exigua\u003c/em\u003e pupae were reared in the laboratory, and males and females were separated. Directly after emergence, each female was placed in a plastic container with two males for 48h to induce mating. The experimental setup consisted of three cages, attached to each other and communicating via 7 cm diameter openings. Five mated \u003cem\u003eS. exigua\u003c/em\u003e females were introduced to the central cage (h:32cm, w:32cm, d:32cm). These females were allowed to choose between two side cages (h:76 cm, w:32 cm, d:32 cm) placed on the left and right of the central cage. The aerial parts of maize plants were enclosed in each side cage. Female moths were left in the system for 48 h (18:6 photoperiod). Then the number of eggs laid was counted on each plant. We tested the oviposition preference for three combinations of plants: Si- \u003cem\u003evs\u003c/em\u003e Si+; Si- \u003cem\u003evs\u003c/em\u003e Si++; and Si\u0026thinsp;+\u0026thinsp;\u003cem\u003evs\u003c/em\u003e Si++. The assay was performed using healthy maize plants and plants infested with \u003cem\u003eS. exigua\u003c/em\u003e for 54 h (five caterpillars at the fifth instar). Each combination was replicated 15 times. New sets of plants and insects were used for each replicate.\u003c/p\u003e \u003cp\u003e \u003cem\u003eStatistical Analyses.\u003c/em\u003e Data on Si content were transformed to rank-based INTs using (rn)transform function (GenAbel package). Data on JA levels were be rank transformed (Art package) to reach normal distributions. Two-way analyses of variance and Tukey\u0026rsquo;s post-hoc tests were applied on Si content and JA levels (α\u0026thinsp;=\u0026thinsp;0.05). Data on \u003cem\u003eS. exigua\u003c/em\u003e oviposition were tested using a Wald test applied on a generalized linear mixed model (GLMM) with a quasi-binomial error distribution (function glmmPQL, package \u0026ldquo;MASS\u0026rdquo;) because of an overdispersion effect.\u003c/p\u003e \u003cp\u003eTo highlight differences in VOC profiles among the various Si and infestation treatments, a permutational multivariate analysis of variance (perMANOVA, adonis package) was performed on the mean abundance of VOCs using a Bray distance matrix and 999 permutations to respect data normality and homoscedasticity. If \u003cem\u003eP\u003c/em\u003e-values were significant, a pairwise comparison was performed, allowing cross-interactions between Si treatments and \u003cem\u003eS. exigua\u003c/em\u003e infestations to be assessed. To support this multivariate analysis, the mean abundance of individual compounds of each Si treatment and infestation were compared using analysis of variance (ANOVA) or the non-parametric equivalent, a Kruskal-Wallis test and Dunn\u0026rsquo;s all-pairs test (α\u0026thinsp;=\u0026thinsp;0.05) if the normal distribution was not reached.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e \u003cem\u003eSi Quantification in Foliar Tissues.\u003c/em\u003e Si foliar content significantly increased with Si concentration in the nutritive solution (F\u003csub\u003e2,12\u003c/sub\u003e = 28.52; P\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (0.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04 g Si. Kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DW (Si-) ; 4.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49 g Si. Kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DW (Si+) ; 9.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30 g Si. Kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DW (Si++); mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD). Si leaf content was significantly different among the three Si treatments (Tukey Post-Hoc test, P\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003cp\u003e \u003cem\u003eSi Accumulation in Maize Leaves and Plant Volatile Emissions.\u003c/em\u003e No cross-interaction between Si treatment (Si-; Si+; Si++) and time of infestation (healthy, 18 h; 54 h) was detected (F\u003csub\u003e4,44\u003c/sub\u003e = 0.052, P\u0026thinsp;=\u0026thinsp;0.420). Si accumulation had no impact on plant (healthy and insect-infested) VOC emissions (F\u003csub\u003e2,44\u003c/sub\u003e = 0.021, P\u0026thinsp;=\u0026thinsp;0.521). Comparing the mean abundance of each VOC showed one single difference among the Si treatments after 18 h of infestation. Specifically, (\u003cem\u003eE\u003c/em\u003e)-hept-2-enal was emitted at higher quantities from Si\u0026thinsp;+\u0026thinsp;+\u0026thinsp;plants compared to Si- plants (χ\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;6.755, df\u0026thinsp;=\u0026thinsp;2, P\u0026thinsp;=\u0026thinsp;0.034). Compound-by-compound comparisons revealed no other significant differences. Eleven compounds were collected and identified in the headspace of non-infested maize plants, whereas 38 VOCs were identified from \u003cem\u003eS. exigua\u003c/em\u003e-infested maize plants (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Infestation of \u003cem\u003eS. exigua\u003c/em\u003e led to modifications in the release of VOCs over time in all Si-treatments (F\u003csub\u003e2,44\u003c/sub\u003e = 0.453, P\u0026thinsp;=\u0026thinsp;0.001). Pairwise comparisons (P\u0026thinsp;\u0026lt;\u0026thinsp;0.05) showed significant differences in the volatilome of undamaged plants and plants infested with \u003cem\u003eS. exigua\u003c/em\u003e for 18 h. No difference in VOC profile was identified between plants infested for 18 h versus 54 h.\u003c/p\u003e \u003cp\u003e \u003cem\u003eSi Accumulation in Plants and Jasmonic Acid Levels.\u003c/em\u003e We found no cross interaction on JA levels between Si content and time of infestation (F\u003csub\u003e4,27\u003c/sub\u003e = 0.712, P\u0026thinsp;=\u0026thinsp;0.590). As expected, herbivory significantly affected JA content in leaves (F\u003csub\u003e2,27\u003c/sub\u003e = 7.893, P\u0026thinsp;=\u0026thinsp;0.002) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). However, Si accumulation in plant tissues did not significantly affect JA levels (F\u003csub\u003e2\u003c/sub\u003e,\u003csub\u003e27\u003c/sub\u003e = 1.421, P\u0026thinsp;=\u0026thinsp;0.259).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eEmissions of volatile organic compounds from undamaged and S. exigua infested maize plants (18 and 54 hours) in ng. gDW\u003csup\u003e-1\u003c/sup\u003e. 2h\u003csup\u003e-1\u003c/sup\u003e (Mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD)\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"11\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" 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 \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCompounds\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eKI\u003csup\u003ea\u003c/sup\u003e\u003csub\u003e(c)\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c5\" namest=\"c3\"\u003e \u003cp\u003eUndamaged\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c8\" namest=\"c6\"\u003e \u003cp\u003ePlants infested for 18 hours\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"3\" nameend=\"c11\" namest=\"c9\"\u003e \u003cp\u003ePlants infested for 54 hours\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\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\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003eSi-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cb\u003eSi+\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cb\u003eSi++\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003cb\u003eSi-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003cb\u003eSi+\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e\u003cb\u003eSi++\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e\u003cb\u003eSi-\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e\u003cb\u003eSi+\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e\u003cb\u003eSi++\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eE\u003c/em\u003e)-hex-3-enal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e598\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.54\u0026thinsp;\u0026plusmn;\u0026thinsp;17.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.22\u0026thinsp;\u0026plusmn;\u0026thinsp;4.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e8.78\u0026thinsp;\u0026plusmn;\u0026thinsp;8.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e48.70\u0026thinsp;\u0026plusmn;\u0026thinsp;25.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e42.95\u0026thinsp;\u0026plusmn;\u0026thinsp;35.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e18.09\u0026thinsp;\u0026plusmn;\u0026thinsp;5.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e16.55\u0026thinsp;\u0026plusmn;\u0026thinsp;10.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e10.32\u0026thinsp;\u0026plusmn;\u0026thinsp;8.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e7.16\u0026thinsp;\u0026plusmn;\u0026thinsp;3.58\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHexanal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e5.26\u0026thinsp;\u0026plusmn;\u0026thinsp;2.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e4.43\u0026thinsp;\u0026plusmn;\u0026thinsp;2.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e3.44\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eE\u003c/em\u003e)-hex-2-enal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e676\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.69\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.88\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e13.78\u0026thinsp;\u0026plusmn;\u0026thinsp;6.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e11.10\u0026thinsp;\u0026plusmn;\u0026thinsp;4.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e5.84\u0026thinsp;\u0026plusmn;\u0026thinsp;2.72\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e6.31\u0026thinsp;\u0026plusmn;\u0026thinsp;3.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e14.91\u0026thinsp;\u0026plusmn;\u0026thinsp;11.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e3.60\u0026thinsp;\u0026plusmn;\u0026thinsp;1.50\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eZ\u003c/em\u003e)-hex-3-en-1-ol\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e679\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e27.02\u0026thinsp;\u0026plusmn;\u0026thinsp;12.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e17.09\u0026thinsp;\u0026plusmn;\u0026thinsp;7.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e9.69\u0026thinsp;\u0026plusmn;\u0026thinsp;4.94\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e9.76\u0026thinsp;\u0026plusmn;\u0026thinsp;5.84\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e13.88\u0026thinsp;\u0026plusmn;\u0026thinsp;6.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e7.80\u0026thinsp;\u0026plusmn;\u0026thinsp;4.87\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHeptanal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e802\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e[(\u003cem\u003eZ\u003c/em\u003e)-pent-2-enyl] acetate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e811\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.59\u0026thinsp;\u0026plusmn;\u0026thinsp;1.78\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.23\u0026thinsp;\u0026plusmn;\u0026thinsp;1.86\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e3.92\u0026thinsp;\u0026plusmn;\u0026thinsp;2.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2.83\u0026thinsp;\u0026plusmn;\u0026thinsp;2.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.39\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eE\u003c/em\u003e)-hept-2-enal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e856\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.00\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.60\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.25\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.14\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.61\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eβ-myrcene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e889\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.70\u0026thinsp;\u0026plusmn;\u0026thinsp;2.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e14.43\u0026thinsp;\u0026plusmn;\u0026thinsp;5.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e9.11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e9.76\u0026thinsp;\u0026plusmn;\u0026thinsp;3.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e35.54\u0026thinsp;\u0026plusmn;\u0026thinsp;9.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e17.88\u0026thinsp;\u0026plusmn;\u0026thinsp;9.62\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e5.91\u0026thinsp;\u0026plusmn;\u0026thinsp;1.36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e[(\u003cem\u003eZ\u003c/em\u003e)-hex-3-enyl] acetate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e908\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e45.23\u0026thinsp;\u0026plusmn;\u0026thinsp;11.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e20.26\u0026thinsp;\u0026plusmn;\u0026thinsp;7.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.31\u0026thinsp;\u0026plusmn;\u0026thinsp;2.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e94.75\u0026thinsp;\u0026plusmn;\u0026thinsp;26.10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e59.13\u0026thinsp;\u0026plusmn;\u0026thinsp;20.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e49.23\u0026thinsp;\u0026plusmn;\u0026thinsp;13.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e80.30\u0026thinsp;\u0026plusmn;\u0026thinsp;24.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e42.08\u0026thinsp;\u0026plusmn;\u0026thinsp;16.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e30.34\u0026thinsp;\u0026plusmn;\u0026thinsp;13.91\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e[(\u003cem\u003eZ\u003c/em\u003e)-hex-2-enyl] acetate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e925\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e10.58\u0026thinsp;\u0026plusmn;\u0026thinsp;9.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e6.61\u0026thinsp;\u0026plusmn;\u0026thinsp;6.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eρ-cymene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e944\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2.64\u0026thinsp;\u0026plusmn;\u0026thinsp;1.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e3.89\u0026thinsp;\u0026plusmn;\u0026thinsp;3.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eD\u003c/em\u003e)-limonene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e952\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.48\u0026thinsp;\u0026plusmn;\u0026thinsp;0.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.59\u0026thinsp;\u0026plusmn;\u0026thinsp;0.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e3.08\u0026thinsp;\u0026plusmn;\u0026thinsp;2.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eα-pinene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e964\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e1.48\u0026thinsp;\u0026plusmn;\u0026thinsp;1.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eβ-ocimene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e984\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.15\u0026thinsp;\u0026plusmn;\u0026thinsp;0.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.76\u0026thinsp;\u0026plusmn;\u0026thinsp;0.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.89\u0026thinsp;\u0026plusmn;\u0026thinsp;0.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e4.35\u0026thinsp;\u0026plusmn;\u0026thinsp;1.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e2.57\u0026thinsp;\u0026plusmn;\u0026thinsp;1.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLinalool\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1098\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e47.79\u0026thinsp;\u0026plusmn;\u0026thinsp;19.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e31.97\u0026thinsp;\u0026plusmn;\u0026thinsp;6.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e50.77\u0026thinsp;\u0026plusmn;\u0026thinsp;18.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e54.48\u0026thinsp;\u0026plusmn;\u0026thinsp;24.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e42.15\u0026thinsp;\u0026plusmn;\u0026thinsp;25.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e11.71\u0026thinsp;\u0026plusmn;\u0026thinsp;3.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNonanal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1104\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e27.64\u0026thinsp;\u0026plusmn;\u0026thinsp;5.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e8.46\u0026thinsp;\u0026plusmn;\u0026thinsp;3.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e9.39\u0026thinsp;\u0026plusmn;\u0026thinsp;2.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e12.44\u0026thinsp;\u0026plusmn;\u0026thinsp;2.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e12.34\u0026thinsp;\u0026plusmn;\u0026thinsp;3.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e8.31\u0026thinsp;\u0026plusmn;\u0026thinsp;1.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e10.66\u0026thinsp;\u0026plusmn;\u0026thinsp;2.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e8.00\u0026thinsp;\u0026plusmn;\u0026thinsp;3.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e5.38\u0026thinsp;\u0026plusmn;\u0026thinsp;1.47\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDMNT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1113\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e73.34\u0026thinsp;\u0026plusmn;\u0026thinsp;28.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e46.20\u0026thinsp;\u0026plusmn;\u0026thinsp;11.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e70.71\u0026thinsp;\u0026plusmn;\u0026thinsp;21.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e85.19\u0026thinsp;\u0026plusmn;\u0026thinsp;31.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e37.85\u0026thinsp;\u0026plusmn;\u0026thinsp;20.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e25.45\u0026thinsp;\u0026plusmn;\u0026thinsp;11.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDecanal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1205\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18.55\u0026thinsp;\u0026plusmn;\u0026thinsp;6.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.60\u0026thinsp;\u0026plusmn;\u0026thinsp;1.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5.56\u0026thinsp;\u0026plusmn;\u0026thinsp;1.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8.81\u0026thinsp;\u0026plusmn;\u0026thinsp;1.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e7.21\u0026thinsp;\u0026plusmn;\u0026thinsp;1.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e6.25\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e6.75\u0026thinsp;\u0026plusmn;\u0026thinsp;1.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e3.97\u0026thinsp;\u0026plusmn;\u0026thinsp;1.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e3.36\u0026thinsp;\u0026plusmn;\u0026thinsp;1.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIndole\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1294\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e112.11\u0026thinsp;\u0026plusmn;\u0026thinsp;44.67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e93.65\u0026thinsp;\u0026plusmn;\u0026thinsp;26.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e92.81\u0026thinsp;\u0026plusmn;\u0026thinsp;32.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e135.74\u0026thinsp;\u0026plusmn;\u0026thinsp;31.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e78.52\u0026thinsp;\u0026plusmn;\u0026thinsp;16.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e58.59\u0026thinsp;\u0026plusmn;\u0026thinsp;29.18\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMethyl anthranilate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1341\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e9.06\u0026thinsp;\u0026plusmn;\u0026thinsp;4.18\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5.27\u0026thinsp;\u0026plusmn;\u0026thinsp;1.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e12.36\u0026thinsp;\u0026plusmn;\u0026thinsp;5.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e10.09\u0026thinsp;\u0026plusmn;\u0026thinsp;4.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e6.23\u0026thinsp;\u0026plusmn;\u0026thinsp;3.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.81\u0026thinsp;\u0026plusmn;\u0026thinsp;0.57\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGeranyl acetate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1377\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e8.61\u0026thinsp;\u0026plusmn;\u0026thinsp;3.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e7.79\u0026thinsp;\u0026plusmn;\u0026thinsp;2.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e17.44\u0026thinsp;\u0026plusmn;\u0026thinsp;7.54\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e28.09\u0026thinsp;\u0026plusmn;\u0026thinsp;16.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e18.12\u0026thinsp;\u0026plusmn;\u0026thinsp;13.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e5.09\u0026thinsp;\u0026plusmn;\u0026thinsp;2.36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eZingiberene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1388\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e3.40\u0026thinsp;\u0026plusmn;\u0026thinsp;1.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e15.93\u0026thinsp;\u0026plusmn;\u0026thinsp;6.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e6.16\u0026thinsp;\u0026plusmn;\u0026thinsp;3.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e2.38\u0026thinsp;\u0026plusmn;\u0026thinsp;1.03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eZ\u003c/em\u003e)-jasmone\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1394\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.10\u0026thinsp;\u0026plusmn;\u0026thinsp;0.41\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.02\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.89\u0026thinsp;\u0026plusmn;\u0026thinsp;0.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eα-funebrene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1402\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.74\u0026thinsp;\u0026plusmn;\u0026thinsp;0.74\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2.55\u0026thinsp;\u0026plusmn;\u0026thinsp;1.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.57\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.09\u0026thinsp;\u0026plusmn;\u0026thinsp;2.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e11.12\u0026thinsp;\u0026plusmn;\u0026thinsp;4.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e15.79\u0026thinsp;\u0026plusmn;\u0026thinsp;6.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e29.35\u0026thinsp;\u0026plusmn;\u0026thinsp;12.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e26.03\u0026thinsp;\u0026plusmn;\u0026thinsp;13.65\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e10.09\u0026thinsp;\u0026plusmn;\u0026thinsp;5.30\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eβ-caryophyllene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1421\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.95\u0026thinsp;\u0026plusmn;\u0026thinsp;0.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.90\u0026thinsp;\u0026plusmn;\u0026thinsp;2.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.92\u0026thinsp;\u0026plusmn;\u0026thinsp;0.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e7.27\u0026thinsp;\u0026plusmn;\u0026thinsp;2.88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e39.52\u0026thinsp;\u0026plusmn;\u0026thinsp;15.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e11.22\u0026thinsp;\u0026plusmn;\u0026thinsp;4.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e5.02\u0026thinsp;\u0026plusmn;\u0026thinsp;1.45\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eE\u003c/em\u003e)-α-bergamotene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1435\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e6.68\u0026thinsp;\u0026plusmn;\u0026thinsp;5.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.38\u0026thinsp;\u0026plusmn;\u0026thinsp;1.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e71.95\u0026thinsp;\u0026plusmn;\u0026thinsp;36.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e70.78\u0026thinsp;\u0026plusmn;\u0026thinsp;15.89\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e105.80\u0026thinsp;\u0026plusmn;\u0026thinsp;32.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e223.03\u0026thinsp;\u0026plusmn;\u0026thinsp;83.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e58.05\u0026thinsp;\u0026plusmn;\u0026thinsp;16.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e57.33\u0026thinsp;\u0026plusmn;\u0026thinsp;20.86\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSesquisabinene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1441\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e3.51\u0026thinsp;\u0026plusmn;\u0026thinsp;1.95\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2.28\u0026thinsp;\u0026plusmn;\u0026thinsp;0.52\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e6.45\u0026thinsp;\u0026plusmn;\u0026thinsp;2.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e21.92\u0026thinsp;\u0026plusmn;\u0026thinsp;10.93\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e7.09\u0026thinsp;\u0026plusmn;\u0026thinsp;4.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e2.76\u0026thinsp;\u0026plusmn;\u0026thinsp;1.36\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eE\u003c/em\u003e)-β-farnesene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1455\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e10.82\u0026thinsp;\u0026plusmn;\u0026thinsp;8.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1.68\u0026thinsp;\u0026plusmn;\u0026thinsp;1.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e117.20\u0026thinsp;\u0026plusmn;\u0026thinsp;49.42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e116.59\u0026thinsp;\u0026plusmn;\u0026thinsp;20.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e168.04\u0026thinsp;\u0026plusmn;\u0026thinsp;48.96\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e95.69\u0026thinsp;\u0026plusmn;\u0026thinsp;48.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e49.58\u0026thinsp;\u0026plusmn;\u0026thinsp;29.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e138.28\u0026thinsp;\u0026plusmn;\u0026thinsp;67.41\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDodecan-1-ol\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1474\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.42\u0026thinsp;\u0026plusmn;\u0026thinsp;0.46\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.41\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.45\u0026thinsp;\u0026plusmn;\u0026thinsp;0.22\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e0.26\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eβ-himalachene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1480\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e4.69\u0026thinsp;\u0026plusmn;\u0026thinsp;2.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e1.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eα-curcumene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1484\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.58\u0026thinsp;\u0026plusmn;\u0026thinsp;0.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.18\u0026thinsp;\u0026plusmn;\u0026thinsp;0.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e1.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e10.56\u0026thinsp;\u0026plusmn;\u0026thinsp;4.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e6.31\u0026thinsp;\u0026plusmn;\u0026thinsp;4.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e2.31\u0026thinsp;\u0026plusmn;\u0026thinsp;1.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSesquithujene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1496\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e1.95\u0026thinsp;\u0026plusmn;\u0026thinsp;1.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1.47\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e5.01\u0026thinsp;\u0026plusmn;\u0026thinsp;2.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e22.73\u0026thinsp;\u0026plusmn;\u0026thinsp;10.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e7.50\u0026thinsp;\u0026plusmn;\u0026thinsp;4.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e4.00\u0026thinsp;\u0026plusmn;\u0026thinsp;1.89\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eβ-bisabolene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1509\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e2.63\u0026thinsp;\u0026plusmn;\u0026thinsp;1.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3.85\u0026thinsp;\u0026plusmn;\u0026thinsp;1.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e6.76\u0026thinsp;\u0026plusmn;\u0026thinsp;2.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e29.81\u0026thinsp;\u0026plusmn;\u0026thinsp;12.01\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e11.86\u0026thinsp;\u0026plusmn;\u0026thinsp;7.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e5.68\u0026thinsp;\u0026plusmn;\u0026thinsp;2.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eβ-sesquiphellandrene\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1527\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e7.91\u0026thinsp;\u0026plusmn;\u0026thinsp;4.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e8.11\u0026thinsp;\u0026plusmn;\u0026thinsp;1.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e6.76\u0026thinsp;\u0026plusmn;\u0026thinsp;2.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e82.30\u0026thinsp;\u0026plusmn;\u0026thinsp;30.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e28.65\u0026thinsp;\u0026plusmn;\u0026thinsp;16.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e17.30\u0026thinsp;\u0026plusmn;\u0026thinsp;6.70\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e(\u003cem\u003eE\u003c/em\u003e)-nerolidol\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1560\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.70\u0026thinsp;\u0026plusmn;\u0026thinsp;0.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.55\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.08\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTMTT\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1573\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e4.69\u0026thinsp;\u0026plusmn;\u0026thinsp;3.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e7.60\u0026thinsp;\u0026plusmn;\u0026thinsp;3.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e8.19\u0026thinsp;\u0026plusmn;\u0026thinsp;2.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e42.30\u0026thinsp;\u0026plusmn;\u0026thinsp;18.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e14.69\u0026thinsp;\u0026plusmn;\u0026thinsp;6.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e14.13\u0026thinsp;\u0026plusmn;\u0026thinsp;4.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"11\"\u003e\u003csup\u003e\u003cb\u003ea\u003c/b\u003e\u003c/sup\u003e KI\u003csub\u003e(c)\u003c/sub\u003e: Calculated Kovats Index\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eDMNT: (3\u003cem\u003eE\u003c/em\u003e)-4,8-dimethylnona-1,3,7-triene\u003c/p\u003e \u003cp\u003eTMTT: (3\u003cem\u003eE\u003c/em\u003e,7\u003cem\u003eE\u003c/em\u003e)-4,8,12-trimethyltrideca-1,3,7,11-tetraene\u003c/p\u003e \u003cp\u003e \u003cem\u003eSi Accumulation in Plants and S. exigua Oviposition Behavior.\u003c/em\u003e The number of eggs laid by \u003cem\u003eS. exigua\u003c/em\u003e females did not significantly differ among the three Si treatments (χ\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;=\u0026thinsp;0.287, df\u0026thinsp;=\u0026thinsp;2, P\u0026thinsp;=\u0026thinsp;0.866) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e), whether on undamaged or \u003cem\u003eS. exigua\u003c/em\u003e infested plants. The total number of eggs observed on non-infested plants was: Si- \u003cem\u003evs\u003c/em\u003e Si+ (185\u0026thinsp;\u0026plusmn;\u0026thinsp;22; 165\u0026thinsp;\u0026plusmn;\u0026thinsp;28); Si- \u003cem\u003evs\u003c/em\u003e Si++ (152\u0026thinsp;\u0026plusmn;\u0026thinsp;27; 140\u0026thinsp;\u0026plusmn;\u0026thinsp;30); Si\u0026thinsp;+\u0026thinsp;\u003cem\u003evs\u003c/em\u003e Si++ (164\u0026thinsp;\u0026plusmn;\u0026thinsp;25; 170\u0026thinsp;\u0026plusmn;\u0026thinsp;17) (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD). The total number of eggs observed on infested plants was: Si- \u003cem\u003evs\u003c/em\u003e Si+ (150\u0026thinsp;\u0026plusmn;\u0026thinsp;32; 140\u0026thinsp;\u0026plusmn;\u0026thinsp;21); Si- \u003cem\u003evs\u003c/em\u003e Si++ (118\u0026thinsp;\u0026plusmn;\u0026thinsp;23; 142\u0026thinsp;\u0026plusmn;\u0026thinsp;24); Si\u0026thinsp;+\u0026thinsp;\u003cem\u003evs\u003c/em\u003e Si++ (155\u0026thinsp;\u0026plusmn;\u0026thinsp;31; 148\u0026thinsp;\u0026plusmn;\u0026thinsp;21)] (mean\u0026thinsp;\u0026plusmn;\u0026thinsp;SD).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003ePrevious experiments demonstrated the beneficial effect of high Si concentrations in plant tissues in alleviating pest damage (Keeping et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Johnson et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Nagaratna et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). However, whether Si actually modifies the emissions of volatile organic compounds, and indirectly impacts insect pest behavior, remains subject to debate (Kvedaras et al. \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2010\u003c/span\u003e; Callis-Duehl et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Liu et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). The present study specifically aimed to established the impact of Si accumulation on the emissions of constitutive and herbivore-induced plant volatiles, and to evaluate the cascade deterrent effect on the oviposition behavior of a phytophagous insect. We demonstrated that there is no effect of Si accumulation in maize leaves on constitutive and induced VOC emissions, neither on JA levels nor oviposition site selection by \u003cem\u003eS. exigua\u003c/em\u003e females.\u003c/p\u003e \u003cp\u003eTo the best of our knowledge, this study presents the first evaluation of how Si accumulation in maize leaves affects maize VOC emissions. Most other biological models on this phenomenon found that Si modifies the plant volatile profile. For instance, Si-enriched cucumber plants infested by a chewing herbivore (\u003cem\u003eDiabrotica balteata\u003c/em\u003e LeConte) produced more indole compared to non-enriched plants (Callis-Duehl et al. \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). The volatile profile of rice plants enriched with Si and infested with \u003cem\u003eCnaphalocris medinalis\u003c/em\u003e Guen\u0026eacute;e was also impacted, resulting in a stronger attraction of natural enemies (Liu et al. \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Si accumulation also changed the volatile profile of grapevine (\u003cem\u003eVitis vinifera\u003c/em\u003e L.), with caterpillar-infested plants releasing higher levels of n-heptadecane compared to uninfested plants (Connick \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2011\u003c/span\u003e). Islam et al. (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) showed that the volatile profile of Si-enriched French bean (\u003cem\u003ePhaseolus vulgaris\u003c/em\u003e L.) infested by spider mites (\u003cem\u003eTetranychus urticae\u003c/em\u003e Koch) was impacted, with the concentrations of some VOCs rising, whereas others decreased. In contrast, we observed no significant effect of Si content in maize leaves on HIPVs emission.\u003c/p\u003e \u003cp\u003eSimilar to previous studies, damage caused by phytophagous insects increased JA levels in the current study. In non-stressed plants, JA levels were not significantly different among Si treatments, supporting the findings of some previous studies (Ye et al. \u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Johnson et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). However, our result contrasted with that of Kim et al. (\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), who showed that JA levels significantly increased in Si-enriched undamaged rice plants. Concerning insect-infested plants, JA levels were higher for Si-enriched plants after infestation, supporting Ye et al. (\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). However, we did not find any significant differences between Si treatments. Thus, the \u0026ldquo;apoplastic obstruction hypothesis did not apply in our case study\u0026rdquo; ((Coskun et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). This hypothesis predicts that the amorphous portion of Si accumulated in the apoplast interferes with the specificity of the recognition process between the plant and biotic stressors (here, the insect pest). This phenomenon alters the flow of molecular compounds, -such as effectors. However, in the current study, accumulated Si in maize tissues did not interfere with the recognition process and effectors produced by \u003cem\u003eS. exigua\u003c/em\u003e caterpillars. Consequently, infestation did not affect Si-enriched maize plants less than non-enriched maize plants, resulting in similar responses.\u003c/p\u003e \u003cp\u003eFollowing herbivory, JA levels rose in a similar manner across all three Si treatments, explaining most of the similarity in HIPVs profiles across all Si-treated plants. When considering Si content in plant tissues, Si concentrations in tested plants (0.95%) were relatively low compared to most previous studies (Ma et al. \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2001\u003c/span\u003e; Liang et al. \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e2015\u003c/span\u003e). Thus, the Si content of the current study might not have been sufficient to reach a putative effect of Si fertilization on HIPV emissions by maize plants. Further studies are required to evaluate how different Si concentrations impact maize plant volatile emissions throughout development. We predict that older plants would accumulate larger concentrations of Si in tissue, resulting in a significant impact on semiochemical-based plant-insect interactions. We also expect plant genotype to contribute to responses, as Si concentrations vary within species (Ma and Yamaji \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). Thus, the effects of Si amendment should be evaluated for a wide diversity of maize varieties, especially where potential IPM applications exist.\u003c/p\u003e \u003cp\u003eSi accumulation in plant leaves potentially has trophic effects on the pest herbivore. Pereira et al. (\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) observed that \u003cem\u003eS. frugiperda\u003c/em\u003e females avoid laying eggs on Si-enriched maize plants, and lay twice as many eggs on leaves with lower Si concentrations. In contrast,, Brown (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) recorded \u003cem\u003eS. frugiperda\u003c/em\u003e females laying more eggs on Si-enriched maize plants (whether undamaged or insect-infested); however, these differences were not statistically supported. In the present study, we did not observe any significant effect of Si on oviposition site selection by \u003cem\u003eS. exigua\u003c/em\u003e. The differences obtained across these three studies could be explained by the ability of the pests to repress HIPV emissions. For instance, \u003cem\u003eS. frugiperda\u003c/em\u003e caterpillars are able to repress HIPV emission by maize plants, whereas \u003cem\u003eS. exigua\u003c/em\u003e caterpillar\u003cem\u003es\u003c/em\u003e strongly induce HIPV release (De Lange et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). The involved mechanisms are associated to the diversity of elicitors present in insect saliva.\u003c/p\u003e \u003cp\u003eFurthermore, different maize varieties produce different HIPV profiles (Block et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Thus, the effect of silicon supplies should be evaluated on different (maize) varieties infested by related-insect species (including Spodoptera spp or \u003cem\u003eHelicoverpa zea\u003c/em\u003e). Given the lack of studies and divergent findings, whether Si concentration in leaves impacts the behavior of female moths remains unclear. Si effects differ depending on the stage of maize plant development and the concentration of Si in leaves. The latter is probably a key factor requiring focused study. We hypothesize that plant-specific Si concentration thresholds would triggers defensive pathways.\u003c/p\u003e \u003cp\u003eHIPVs are important chemical molecules that allow recruiting natural enemies of insect pests, but their role is not restricted to the mediation with the third trophic level (Halitschke et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2008\u003c/span\u003e). Host selection by female is crucial for offspring survival and HIPVs have also been shown to be either attractive or repellent for herbivores (De Moraes et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2001\u003c/span\u003e). In this work, we have tested the hypothesis that HIPVs impact \u003cem\u003eS. exigua\u003c/em\u003e oviposition preference. In their study, Yactayo-Chang et al. (\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) found that some maize HIPV compounds attract \u003cem\u003eS. frugiperda\u003c/em\u003e (methyl salicylate and (\u003cem\u003eE\u003c/em\u003e)-α-bergamotene) whereas others act as oviposition deterrents (DMNT). In our study, Si concentration in the leaves did not impact the emissions of these compounds, which could explain why we found that gravid females showed no preference to any of the Si treatments. Because herbivore responses towards HIPVs depends on multiple parameters, including herbivore species (Szendrei \u0026amp; Rodriguez-Saona \u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e2010\u003c/span\u003e), \u003cem\u003eS. exigua\u003c/em\u003e females might not necessarily reactive to the same compounds. Electrophysiology could provide new insights on the ability of \u003cem\u003eS. exigua\u003c/em\u003e females to respond to maize HIPVs.\u003c/p\u003e \u003cp\u003eIn conclusion, this study demonstrated that Si accumulation in maize leaves did not affect constitutive and induced VOC emissions with respect to, JA levels and the oviposition preference of by \u003cem\u003eS. exigua\u003c/em\u003e females. Future studies are required to advance our understanding on whether and how Si is involved in plant chemical defenses against herbivores.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNicolas Leroy is supported by a FRIA-FNRS grant.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have\u0026nbsp;no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eN Leroy, J-T Cornelis and F Verheggen contributed to the study conception and design. Material preparation, data collection and analysis were performed by N. Leroy, A Arguelles Arias and C Martin. The first draft of the manuscript was written by N Leroy and all authors commented on previous versions of the manuscript. 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J Chem Ecol 47:799\u0026ndash;809. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10886-021-01302-w\u003c/span\u003e\u003cspan address=\"10.1007/s10886-021-01302-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYe M, Song Y, Long J, Wang R, Baerson SR, Pan Z, Zhu-Salzman K, Xie J, Cai K, Luo S, Zeng R (2013) Priming of jasmonate-mediated antiherbivore defense responses in rice by silicon. Proc Natl Acad Sci 110:E3631\u0026ndash;E3639. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1073/pnas.1305848110\u003c/span\u003e\u003cspan address=\"10.1073/pnas.1305848110\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-chemical-ecology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"joce","sideBox":"Learn more about [Journal of Chemical Ecology](https://www.springer.com/journal/10886)","snPcode":"10886","submissionUrl":"https://submission.nature.com/new-submission/10886/3","title":"Journal of Chemical Ecology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Silica, HIPVs, beet armyworm, semiochemical, interaction","lastPublishedDoi":"10.21203/rs.3.rs-1862920/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1862920/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSilicon (Si) fertilization alleviates biotic stresses in plants. Silicon enhances plant resistance against phytophagous insects through physical and biochemical mechanisms. In particular, Si modifies jasmonic acid levels and the emissions of herbivore-induced plant volatiles (HIPVs). Here, we investigated whether Si accumulation in the tissues of maize leaves modifies the emissions of constitutive and herbivore-induced plant volatiles, with cascade deterrent effects on oviposition site selection by \u003cem\u003eSpodoptera exigua\u003c/em\u003e H\u0026uuml;bner (Lepidoptera: Noctuidae). Maize plants were cultivated in a hydroponic system under three Si concentrations, resulting in three groups of plants expressing different Si concentrations in their tissues (0.31\u0026thinsp;\u0026plusmn;\u0026thinsp;0.04, 4.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.49, and 9.56\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30 g Si. Kg\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e DW). We collected volatiles from undamaged and caterpillar-infested plants, and found that Si concentration in plant tissues had no significant impact. Jasmonic acid content was high in insect-infested plants, but was similar across all Si treatments. Oviposition site selection bioassays using fertilized \u003cem\u003eS. exigua\u003c/em\u003e females showed that Si concentration in plant tissues did not affect the number of eggs laid on Si-treated plant. In conclusion, our study shows that the Si content in maize tissues does not impact the semiochemical interactions with \u003cem\u003eS. exigua\u003c/em\u003e.\u003c/p\u003e","manuscriptTitle":"If all else fails: Impact of silicon accumulation in maize leaves on volatile emissions and oviposition site selection of Spodoptera exigua Hübner","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-07-21 17:37:01","doi":"10.21203/rs.3.rs-1862920/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2022-07-20T02:16:56+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2022-07-19T17:07:08+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2022-07-18T22:18:56+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Chemical Ecology","date":"2022-07-15T16:14:59+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-chemical-ecology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"joce","sideBox":"Learn more about [Journal of Chemical Ecology](https://www.springer.com/journal/10886)","snPcode":"10886","submissionUrl":"https://submission.nature.com/new-submission/10886/3","title":"Journal of Chemical Ecology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"e6a85af7-6677-4b86-945a-15e3252f7c6f","owner":[],"postedDate":"July 21st, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2022-09-18T16:25:52+00:00","versionOfRecord":[],"versionCreatedAt":"2022-07-21 17:37:01","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1862920","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1862920","identity":"rs-1862920","version":["v1"]},"buildId":"omnImTCwR2MFx8CMYfrG7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}