Controlling Preharvest Sprouting of Wheat through Nanonetworks

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Controlling pre-harvest sprouting of wheat through nanonetworks Huilan Zhang, Caiguo Tang, Xian Shu, Hao Hu, Minghui Cao, Yuhan Ma, Weiwei Zhao, Zhengyan Wu, Minghao Li, Dongqing Cai, and Lifang Wu ACS Sustainable Chem. Eng., Just Accepted Manuscript • DOI: 10.1021/acssuschemeng.8b02528 • Publication Date (Web): 12 Jul 2018 Downloaded from http://pubs.acs.org on July 23, 2018

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ACS Sustainable Chemistry & Engineering

Controlling pre-harvest sprouting of wheat through nanonetworks

Huilan Zhang||,†,‡, Caiguo Tang||,†,‡, Xian Shu||,†,‡, Hao Hu†,‡, Minghui Cao†,‡, Yuhan Ma†,§, Weiwei Zhao†,§, Zhengyan Wu†,§, Minghao Li*,†,‡,§, Dongqing Cai *,†,§,Lifang Wu*,†,§

†

Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei

Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, People’s Republic of China ‡

University of Science and Technology of China, No. 96 Jinzhai Road, Hefei, Anhui

230026, People’s Republic of China §

Key Laboratory of Environmental Toxicology and Pollution Control Technology of

Anhui Province, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, People’s Republic of China

||

Co-first authors

*Corresponding authors. Email addresses: [email protected] (M.L.), [email protected] (D.C.), [email protected] (L.W.).

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ABSTRACT: To address the severe problem of pre-harvest sprouting of wheat, we fabricated and tested a nanonetwork-structured nanocomposite using palygorskite (Pal) modified by amino silicon oil (ASO). The nanocomposite was used as a nanonet membrane (NNM) on the surface of wheat seeds to effectively inhibit pre-harvest sprouting (PHS). The NNM made the surface of the wheat seeds rougher and formed a hydrophobic nanomembrane on the surface of the wheat ears, effectively preventing the wheat seeds from adsorbing water. The PHS ratio of wheat decreased by 51.4% in the experimental group compared to the control. This study provides a promising approach to prevent wheat pre-harvest sprouting, which has potential value for application to wheat production. KEYWORDS: pre-harvest sprouting, attapulgite, ASO, wheat, hydrophobic

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INTRODUCTION Wheat, as the staple food and feed for most temperate countries in the world, has a global annual output of about 6 billion tons. Maintaining its high yield, stable production, and excellent quality is related to social and economic development and human existence.1,2 Moreover, bread wheat, which includes rich nutrients and biologically active ingredients like vitamin C, vitamin A, niacin, thiamin, and other elements, has high value for human health and function. Therefore, improving wheat yield and quality has always been a focus of effort for scientists. Pre-harvest sprouting (PHS) is defined as the germination of seed within mature ears on the plant before harvest.8 In the last decade, crop yield decline caused by PHS seriously threatened food security in countries throughout the world, such as Canada, Australia, and China.3-6 The amount of wheat affected by PHS in China was reported as approximately 83%.7 PHS in wheat mainly results from the breaking or lack of seed dormancy under rainy or wet conditions, which leads to huge economic losses due to decreased grain production and seed quality.9,10 PHS that mainly occurs in the northern winter wheat area, northeast spring wheat area, and the middle and lower reaches of the Yangtze River in China is a major factor affecting wheat yield and quality reduction in China.8 Therefore, scientists and breeders have to pay more attention to guarantee wheat yield and quality. PHS affects wheat quality by causing seed germination, which leads to a series of physiological changes. Dereran et al.

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reported that hydrolytic enzyme activity

increases (especially proteolytic enzyme activity, which is lacking in dry seeds of wheat), degrading protein into amino acids after grain germination. Additionally, the starch is transformed by amylum hydrolase into oligosaccharides and dextrin leading to difficulty with flour bread shaping and conferring a sticky flour taste to noodles and 3



steamed bread products.15 Moreover, the phenomenon of PHS cannot always be observed from the grain surface; rather, a series of changes, like mildew, have taken place in the grain interior, which reduces the edible value and the economic value of wheat. In recent decades, in order to solve this severe problem, scientists described PHS as a complex trait affected by environmental factors.16,17 Multi-genes or quantitative trait loci (QTLs) that contribute to PHS are distributed on many chromosomes, including 2A, 3A, 3B, 3D, 4A, 4B, 6B, and 7D.18-27 One of the main reason for controlling PHS was related to seed dormancy, which maps on 3A, 3B, 3D, 4A, and 4B by QTLs sharing the same or similar genetic intervals with PHS loci.28-30 Many morphological characteristics and physiological traits are related to PHS; for example, amylase activity, glume inhibition, endogenous hormones GA and ABA,31-34 seed coat color,21,35,36 and structure of spikes.37 Additionally, environmental conditions showed great influence on the germination of grains.38,39 Despite these findings, more research is needed to overcome PHS of wheat. Investigators are applying advanced technologies such as homology-based cloning and map-based cloning to find candidate genes related to PHS, and are successfully applying these genes to breeding and production. In order to advance this urgent work, we provide an innovative, secure, environmentally-friendly, and low-cost technology for inhibiting the PHS of wheat. In this study, we describe a novel nanocomposite, referred to as the nanonet membrane (NNM), using palygorskite (Pal) and amino silicon oil (ASO). Nowadays, nanotechnology is widely used in materials for medicine, environment and energy, and biotechnology and agricultural products. Moreover, innovative nanonetwork technologies have been successfully employed in agriculture for controlling pesticide loss,40 and producing pH-controlled-release ferrous foliar 4


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fertilizer.41 Compared with nanorods, nanonetworks possess favorable properties. Therefore, the design and fabrication of nanonetworks have received more attention recently.42 Linglin Zhou et al.43 reported that ASO can improve Pal dispersibility and modify the microstructure and surface of Pal to increase roughness and amounts of hydrophobic surface groups, producing a hydrophobic agent. Based on this method, we fabricated a NNM to control the PHS of wheat and tested whether the NNM can effectively inhibit wheat PHS, which might have potential applications in wheat production. EXPERIMENTAL SECTION Materials. Raw Pal powder (300 mesh) was provided by Mingmei Co., Ltd. (Anhui, China). Analytical reagent grade ASO was purchased from Silok Chemical Company (Guangzhou, China). Other chemicals of analytical reagent grade were purchased from Sinopharm Chemical Reagent Company (Shanghai, China). Deionized water was used in all experiments. NNM solution preparation. Raw Pal powder (0.1g) was dispersed in 100 mL of deionized water with stirring (3000 rpm) for 5 min. ASO in different amounts (0, 0.1, 0.5, 1.0, 5, and 10 mL) was added to this system which was then stirred (3000 rpm) for 10 min at room temperature to form NNM emulsions referred to as NNM1, NNM2, NNM3, NNM4, NNM5, and NNM6. Hydrophobic performance. The surfaces of glass slides (76 mm X 26 mm) were evenly sprayed with 1 mL of each of the six NNM emulsions and dried at 60oC for 4 h. The contact angle (CA) was detected using the sessile drop method at room temperature. Respiration of treated wheat seeds. The surfaces of 1.5g of wheat seed were covered with 1ml of the optimized NNM emulsion (NNM5) and the seeds were 5



placed in a 280 mL reagent bottle. The CO2 concentration in the bottle was measured using a portable infrared analyzer (GXH-305) every 24 hours. Germination of wheat seeds. 1 mL of each NNM emulsion (NNM1, NNM2, NNM3, NNM4, NNM5, and NNM6) was sprayed on the surface of 30 wheat seeds in a petri dish. Then, the seeds were air-dried at room temperature and maintained at 20oC and 80% moisture for 7 days. The number of germinated seeds was counted every day and the germination ratio (GR) was calculated with the equation: GR (%)=number of germinated seeds/30×100% All tests were carried out in triplicate. Germination of wheat ears. Ears of wheat from the main axis were harvested from the field after the waxy ripe stage and maintained at -20 oC for 7 days after being naturally air-dried. These ears were divided into seven groups with five replicates and immediately sprayed with NNM solutions of different concentrations (from NNM1 to NNM6). Then, the treated wheat ears were air-dried at room temperature, soaked in water for 12 hours, and maintained in boxes at 20oC and 100% moisture for 7 days. The number of germinating seed were recorded daily. After 7 days, to the rate of germinated seed was calculated with the general equation: GR= the number of germinated seeds/total number of seeds Field trial. Bread wheat (Triticum aestivum L. cv. Lianmai 7) in a field (31°54′ N, 117°10′ E) at Hefei Institutes of Physical Science, Chinese Academy of Sciences was sown in plots of 15.0 meters in length and 1 meter in width; the distance between rows was 20 centimeters, and 40 seeds were planted in each row. Fertilizer and weed management were similar to wheat breeding. The ripe individuals of Lianmai 7 which were sown at the greenhouse of the field were divided into seven areas and treated with NNM solution of different concentrations (NNM1 to NNM6). We simulated rain 6


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every two days to guarantee that the seed had sufficiently wet conditions to germinate. After half month, the seeds from the wheat main axis for each group (15 ears with 5 replicates) were harvested and the rate of germinated seed (GR) was calculated using the general equation: GR= the number of germinated seeds/total number of seed Characterization analysis. Sample morphology was observed on a scanning electron microscope (SEM) (Sirion 200, FEI Co., U.S.A.) and a transmission electron microscope (TEM) (JEOL-2010, JE Co., Japan). X-ray spectra of samples were recorded by using a TTR-III X-ray diffractometer (XRD) (Rigaku Co., Japan) with Cu radiation (40 kV, 200 mA, λ =1.541867 Å, 2θ=3° to 70°, scanning speed=8°/min, step size = 0.0200°). The samples were also characterized by Fourier Transform Infrared (FTIR) spectroscopy (iS10, Nicolet Co., U.S.A.) in a KBr pellet at ambient temperature, wherein the sample content in KBr was 0.5%. For each sample, 32 scans were recorded in a 400– 4000 cm−1 spectral range at a resolution of 4 cm−1. The thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) were performed by a thermogravimetric analyzer (Q5000IR, TA Co., U.S.A.) at a scan rate of 10°C/min from room temperature to 800°C in nitrogen. The morphology of PSI emulsion, PSI-shell, and PSI-seed were observed on a scanning electron microscope (SEM) with an energy dispersive X-ray spectrometer (EDX) (Sirion 200, FEI Co., USA). The structure and interaction were analyzed using a TTRIII X-ray diffractometer (XRD) (Rigaku Co., Japan) and FTIR spectrometer (Bruker Co., Germany). Estimation of restoration germination. Seeds that did not demonstrate PHS in the field test were collected from both the group treated with the optimized NNM emulsion (NNM5), referred to as the OAA (optimized ratio of ASO and ATP)-treated 7



group and from the CK (control check) group that did not treated by any NNM emulsion. Then, these seeds were washed with flowing water for three minutes and air-dried for 8 hours. Approximately 150 seeds from both groups were planted in three pots with nutrient soil. These pots were placed at 23oC and adequate amounts of water and illumination (2000lux 10 hours) were given every day. After seven days, the GR was calculated and fresh weight, dry weight, root length, and shoot length were determined. RESULTS AND DISCUSSION Wheat germination in vitro Pal, a type of hydrophobic nanorod-structured clay, does not, alone, adhere tightly to the seed surface. The treatment solutions containing Pal were more effective in inhibiting germination than the solutions without Pal in both the raw seed and field experiments (Figure 1). The dense nanonetwork structure spread on the surface of wheat seeds resulted in rapidly decreased seed respiration. In the absence of ASO and the addition of Pal, the GR of wheat was lower (81.47%) compared to the GR of raw wheat seed in the CK treatment group (85.56%). In the inhibition of wheat ears experiment, the GR of wheat with no Pal (16.4%) was higher than the GR of wheat treated with Pal (15.6%). Field test results were consistent with the in vitro test results; in both experiments, Pal had an inhibitory effect on seed germination compared to CK. When we fixed Pal at the concentration of 0.1g in 1L water solution and added 0.1ml ASO (Pal:ASO=1:1), the GR of wheat in vitro (67.78%) was significantly lower than that of CK (85.56%). With the addition of ASO, the dispersibility of Pal improved. Furthermore, the structure of Pal modified by ASO formed a hydrophobic surface and prevented the adsorption of water. ASO also helped Pal bind more tightly to the surface of wheat spikes to prevent seed respiration more effectively. When the 8


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fixed amount of immobilized Pal was 0.1g, the GR of wheat was with Pal:ASO = 1:5 (64.4%) was significantly lower than that of Pal:ASO = 1:1. When the Pal:ASO was 1:5, the GR of wheat was lowest (33.3% in raw wheat seed). This ratio had the best inhibitory effect in field testing; GR was reduced by approximately 50% compared to CK. Furthermore, in the wheat ears germination experiment, GR in the group treated with a Pal:ASO of 1:5 was 0% after 7 days; in other words, it completely inhibited the occurrence of pre-harvest sprouting of wheat. Therefore, we identified this 1:5 ratio as the optimal proportion of Pal and ASO, and refer to the optimized Pal-ASO composite as the OAA. As shown, the germination of CK is good and the roots and shoots grow well (Figure 2A). The most suitable Pal concentration treated alone did not significantly inhibit the effect of germination compared to CK. However, the optimum concentration of ASO treatment has a measurable effect on the inhibition of germination compared to CK, probably because ASO spreads more evenly across the surface of the seed than Pal alone. However, like Pal, ASO alone cannot adhere to the seed surface tightly; therefore, Pal alone or ASO alone cannot achieve the best inhibition of seed germination. OAA treatment results in the lowest GR (Figure 2B). The OAA composite may form a hydrophobic structure on the seed surface, and OAA can adhere more tightly to the seed surface than Pal or ASO alone. Therefore, the optimized Pal and ASO ratio of the OAA composite has a strong inhibitory effect on wheat germination in raw seed; after treatment of raw wheat seeds, the GR can be reduced to 33.33%. From these results, we conclude that the optimized ASO and Pal composite forms the most dense and uniform network structure on the seed surface, potentially inhibiting PHS most effectively. Investigation of GR of wheat ears The CK group germinated significantly after seven days (Figure 3A), with a calculated GR of 16.4%. In addition, the wheat 9



malt grew well. The wheat of the Pal treatment group also germinated and grew well (Figure 3A). Pal treatment did not significantly inhibit the effect of germination compared to CK and also had high GR (15.6%). Probably because Pal was a hydrophobic agent with many nanorods on the surface of wheat ears, it affected the wheat seed Figure 3A. However, Pal alone cannot adhere to the wheat seed surface tightly, and Pal can be wash away by rainwater easily. Therefore, Pal treatment alone may not inhibit the occurrence of the PHS. In contrast, the effect of ASO was the opposite. After ASO treatment alone, the wheat GR reduced to 2.4%. It had a marked inhibitory effect on wheat compared to the CK group. These results demonstrate that ASO inhibits the germination of wheat in vitro. In addition, the growth of wheat of roots and shoots with ASO treatment alone was clearly not as good as CK treatment. This result may demonstrate that ASO spreads on the surface of wheat seeds more evenly and densely, effectively preventing water adsorption and respiration, resulting in reduced PHS. OAA treatment significantly reduced the GR 24-fold after seven days compared to CK (Figure 3B). This result demonstrated that OAA could effectively inhibit the germination of the wheat in vitro, which was favorable for the effect of the inhibition of the germination of the wheat in fields. Evidently, the optimal ASO and Pal ratio results in the most dense and uniform network structure on the wheat seed surface, preventing water adsorption and breathability of the wheat seed most effectively so as to inhibit PHS. Wheat germination in vivo As shown in Figure 4A, The percentage of pre-harvest sprouting in the CK group (95%) and the Pal treatment group (90.56%) were both high; therefore, Pal did not significantly inhibit the effect of germination in vivo. Probably because Pal is a hydrophobic agent with many nanorods spread on the surface of the wheat seed, it influences the wheat seed respiration. However, Pal alone 10


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cannot adhere to the wheat seed surface tightly, and Pal can be washed away by rainwater easily. Therefore, Pal treatment alone may not inhibit the occurrence of PHS. However, after ASO treatment, the germination phenomenon of PHS substantially decreased (Figure 4A). In vivo, the effect of ASO treatment alone is greater than Pal treatment alone. This result also demonstrates that ASO spreads over the surface of wheat seed more evenly and densely, preventing the water adsorption and respiration of wheat seeds and inhibiting PHS. The percentage of pre-harvest sprouting of the ASO treatment group decreased by 20% compared to the CK group, and the nature percentage of the pre-harvest sprouting was 57.7%. In addition, the growth of wheat roots and shoots with ASO treatment alone was clearly not as robust as in the CK group. OAA treatment decreased the GR by 50% after 7 days compared to CK (Figure 4B). After OAA treatment, the percentage of pre-harvest sprouting was 49.98%. Thus, OAA treatment can inhibit the phenomenon of PHS effectively, possibly because the OAA structure can adhere more tightly to the surface of wheat seed, effectively preventing water adsorption and wheat seed respiration. Evidently, OAA can inhibit the phenomenon of PHS. Hydrophobic performance of PSI emulsion The modification effect of ASO and Pal was investigated (Figures 5A and 5B). The CA varied with the amounts of ASO added to Pal, indicating that ASO substantially affects the hydrophobic property of Pal. After Pal treatment, the surface CA was 0 degrees, which was the same as the results with CK treatment (Figures 5Aa and 5Ab). The surface CA increased to 50-60 degrees with ASO treatment (Figure 5B). However, after OAA treatment, the surface CA increased to 90 degrees. These results indicate that OAA possesses higher hydrophobic capacity compared to Pal. 11



Additionally, the morphologies of the OAA complex were observed. The kernels and glumes of wheat are porous; this structure provides access to water transport and makes water more easily absorbed by seeds, thereby promoting germination (Figure 6a,d) . After coating the surfaces of seeds and glumes by Pal, we could clearly see that Pal consists of many nanorods joined together to form numerous woodpile-like bunches (Figure 6b,e). Therefore, Pal has low dispersibility. However, after modification by ASO with its low surface free energy, these bunches became loose and most of the rods in a bunch were oriented in the same direction (Figure 6 c,f). This was in accordance with the XRD result. The transformation of the Pal microstructure is probably driven by the H-bonds between Pal and ASO (described below). Consequently, this Pal-ASO complex displayed greater roughness, which is favorable for conferring hydrophobic properties. In addition, the ASO adsorbed on the Pal surface could also significantly increase the proportion of hydrophobic groups, converting Pal from hydrophilic to hydrophobic. Additionally, more ASO molecules were exposed on the surface of the highly dispersed Pal (Figure 6c). Evidently, Pal-ASO possesses higher roughness, more hydrophobic surface groups, and thus greater hydrophobicity compared to Pal alone. Investigation of seed respiration Seed germination begins with water adsorption, and a series of physiological and biochemical changes begin to occur in the cells. The smooth progress of this series of changes requires sufficient energy. Respiratory metabolism in plant cells includes the glycolytic pathway (EMP), pentose phosphate pathway (HMP), tricarboxylic acid cycle (TCA), and glyoxylate cycle, which together regulate seed germination through material transformation and energy metabolism. Therefore, whether seeds can successfully complete the germination process is closely related to the respiration that generates energy. The respiration rate 12


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of wheat seeds after OAA treatment and under normal conditions was measured. As can be seen from Fig. 7, the wheat seeds in the treated ( red line ) and CK ( black line ) groups prolonged with the time of imbibition germination, and their respiration rates increased significantly; the same treatment at different stages of the germination stage. Compared to the CK group, the respiration rate of the wheat seeds in the treatment group was lower than that of the CK group. We conclude that the OAA treatment limits the respiration rate of germinating seeds to a certain extent; possibly because the OAA nanonetworks prevent gas entry and reduce wheat seed respiration. Morphology and Microstructure Modification In order to better understand the interaction between Pal and ASO, FTIR measurement of the Pal-ASO system was performed (Figure 8A). The main adsorption peaks at 3556 and 3385 cm−1 were ascribed to the stretching vibrations of zeolitic water (–OH2) and adsorbed water (H2O) of Pal. The peaks at 984 and 1028 cm −1 were ascribed to the stretching vibrations of Si–O-Si of Pal. After being modified by ASO, these main characteristic peaks of Pal can also be seen clearly in the spectrum of Pal-ASO. Also, we found that both the peak Si–C stretching vibration and the peak C-N bending in the plane of ASO were weakened and red-shifted from 804 to 801 cm−1 and 1263 to 1260 cm-1, respectively; the peak ascribed to –CH3 stretching vibration was weakened and blue-shifted from 2961 to 2963 cm−1. These results demonstrate that hydrogen bonds (H-bonds) probably exist between ASO (–NH2 , C–O and –CH3 ) and Pal (–OH2 , H2O, and – OH). The XRD pattern of Pal-ASO is consistent with that of Pal (Figure 8B), demonstrating that ASO does not change the crystal structure of Pal. Several reflections (d=3.14, 1.82, and 1.12Å) of Pal-ASO were intensified compared to Pal,

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probably because ASO promotes Pal nanorods to form large bunches via the H-bonds between ASO and Pal, increasing the number of rods oriented in the same direction. The stability of OAA was also investigated. After being stored at room temperature for four months, OAA still displayed marked hydrophobicity, indicating that OAA is stable for sufficiently long periods to fulfill the requirements for practical application. Further, the thermal stability of SP was also investigated. The mass loss between 38.04°C and 269.91°C (5.489%) is attributed to the removal of free water and –OH2 (Figure 8C). The mass loss between 269.91°C and 664.42°C (38.33%) corresponds to the desorption of –OH2, and the decomposition of ASO into small molecules. The mass loss between 664.42°C and 725.72°C (approximately 0.8940%) reflects the pyrolysis of small molecules of ASO. From this thermal analysis, we conclude that the OAA coating is stable below 269.91 °C. Investigation of ability of repeated seed germination Pal alone cannot increase the resistance to PHS effectively, mainly because Pal cannot adhere tightly to the wheat surface, it could easily be washed away by rain. Pal modified by ASO, however, has improved dispersibility and forms a dense nanonetwork covering the wheat seed surface. A rougher and more hydrophobic wheat seed surface is favorable for the prevention of water adsorption and seed respiration. After seven days in culture, the non-sprouting grains from the OAA and CK groups had the same growth status (Figure 9). On repeated field germination, there was no significant difference in germination and growth index for OAA-treated and CK seeds that did not have PHS. The OAA treatment group GR (95%) is similar to the CK group GR (96%) (Figure 9), probably because the OAA nanonetwork structure may be washed away, allowing the seed to absorb water and respire normally, resulting in radicle and germ breaking through the seed coat and germinating naturally. 14


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The growth index of wheat seed, root and shoot lengths, and fresh and dry weights were measured to determine the function of the OAA nanonetwork. After seven days in culture, the shoot length, root length, fresh weight, and dry weight are similar between the OAA-treatment and CK groups (Figure 9), indicating that the OAA nanonetwork can be washed away by sufficient amounts of water, and that OAA treatment has no influence on the quality and vitality of wheat seed. In other words, OAA solution can inhibit PHS, and repeated germination of recovered seeds is feasible. CONCLUSIONS In this study, an approach for preventing PHS was developed using Pal modified by ASO to form OAA. ASO improves Pal dispersibility, and the resulting nanocomposite possesses a nanonetwork structure. This nanocomposite could endow wheat seeds and ears hydrophobic surfaces, reducing water adsorption and thus inhibiting PHS. This technology may be beneficial for improving the efficiency of wheat cultivation through inhibition of PHS. AUTHOR INFORMATION Corresponding Authors *M.L. Tel: +86-551-65595012. Fax: +86-551-65595672. Email: [email protected] *D.C. Tel.: +86-551-65595143. Fax: +86-551-65595012. Email: [email protected]. *L.W. Tel: +86-551-65591413. Fax: +86-551-65591413. Email: [email protected]. Author Contributions H.Z, C.T and X.S. are co-first authors. Notes The authors declare no competing financial interest.

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Acknowledgements This work was supported by the Science and Technology Service program of the Chinese Academy of Sciences (KFJ-STS-ZDTP-002), the major special project of Anhui Province (16030701103), and the key program of the 13th five-year plan, CASHIPS (No. kp-2017-21).

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Figure captions: Figure 1. (A) GR of raw seed with different concentrations of ASO, (B) GR of raw wheat ears with different concentrations of ASO and germination percentage in vivo with different concentrations of ASO (C). Without Pal added (a), and with 0.1 g Pal added (b). Figure 2. (A) Digital photos and (B) GR of (a) raw wheat seeds and seeds treated by (b) Pal, (c) ASO, and (d) OAA. Figure 3. (A) Digital photos and (B) GR of (a) raw wheat ears and wheat ears treated by (b) Pal, (c) ASO, and (d) OAA. Figure 4. (A) Digital photos and (B) GR in a field of (a) raw naturally-mature seed and seed treated by (b) Pal, (c) ASO, and (d) OAA. Figure 5. (A) Digital photos of the water droplets on the coatings and (B) water CAs of different samples (a) no something coatings, (b) Pal, (c) ASO, (d) OAA. Figure 6. SEM images of (a) glume, (b) Pal on glume, (c) OAA on glume, (d) seed surface, (e) Pal on the seed surface, (f) OAA on seed. Figure 7. Respiratory rate with different germination time Figure 8. (A) FTIR spectra of OAA and Pal, (B) XRD spectra of OAA and Pal, (C) TGA curves of OAA Figure 9. Digital photos of repeated germination of non-sprouted grains and growth index of non-sprouted grains.

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Figure 1

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Figure 2

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Figure 9

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TOC

Controlling pre-harvest sprouting of wheat through nanonetworks Huilan Zhang, Caiguo Tang, Xian Shu, Hao Hu, Minghui Cao, Yuhan Ma, Weiwei Zhao, Zhengyan Wu, Minghao Li*, Dongqing Cai*, Lifang Wu*

This work fabricates a nanonetwork-structured nanocomposite which can effectively prevent pre-harvest sprouting of wheat and may be beneficial for improving the efficiency of wheat cultivation.

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Controlling Preharvest Sprouting of Wheat through Nanonetworks

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