College of Grassland Agriculture, Northwest A&F University, Yangling, 712100, Shaanxi Province, China.
BMC Plant Biol. 2022 Jul 5;22(1):323. doi: 10.1186/s12870-022-03692-9.
The application of nanotechnology in agriculture can remarkably improve the cultivation and growth of crop plants. Many studies showed that nanoparticles (NPs) made plants grow more vigorously. Light can make NPs aggregated, leading to the reduction of the NPs toxicity. In addition, treatment with NPs had a "hormesis effect" on plants. In this study, light-induced silver nanoparticles (AgNPs) were synthesized by using the alfalfa (Medicago sativa L.) extracts, and then the optimal synthetic condition was determined. Light-induced AgNPs were aggregated, spherical and pink, and they were coated with esters, phenols, acids, terpenes, amino acids and sugars, which were the compositions of alfalfa extracts. The concentration of free Ag was less than 2 % of the AgNPs concentration. Through nanopriming, Ag got into the seedlings and caused the impact of AgNPs on alfalfa. Compared with the control group, low concentration of light-induced AgNPs had a positive effect on the photosynthesis. It was also harmless to the leaf cells, and there was no elongation effect on shoots. Although high concentration of AgNPs was especially beneficial to root elongation, it had a slight toxic effect on seedlings due to the accumulation of silver. With the increase of AgNPs concentration, the content of silver in the seedlings increased and the silver enriched in plants was at the mg/kg level. Just as available research reported the toxicity of NPs can be reduced by using suitable synthesis and application methods, the present light induction, active material encapsulation and nanopriming minimized the toxicity of AgNPs to plants, enhancing the antioxidant enzyme system.
纳米技术在农业中的应用可以显著改善作物的种植和生长。许多研究表明，纳米颗粒（NPs）使植物生长得更加旺盛。光可以使 NPs 聚集，从而降低 NPs 的毒性。此外，NPs 对植物具有“兴奋效应”。在这项研究中，利用紫花苜蓿（Medicago sativa L.）提取物合成了光诱导银纳米颗粒（AgNPs），并确定了最佳的合成条件。光诱导的 AgNPs 聚集，呈球形和粉红色，表面覆盖着酯类、酚类、酸类、萜类、氨基酸和糖类，这些都是紫花苜蓿提取物的成分。游离银的浓度低于 AgNPs 浓度的 2%。通过纳米引发，Ag 进入幼苗并对紫花苜蓿产生影响。与对照组相比，低浓度的光诱导 AgNPs 对光合作用有积极影响。对叶片细胞也无害，对芽的伸长没有影响。虽然高浓度的 AgNPs 特别有利于根的伸长，但由于银的积累，对幼苗有轻微的毒性。随着 AgNPs 浓度的增加，幼苗中银的含量增加，植物中富集的银达到 mg/kg 水平。正如现有研究报道的那样，通过使用合适的合成和应用方法可以降低 NPs 的毒性，本研究中的光诱导、活性物质包封和纳米引发最大限度地降低了 AgNPs 对植物的毒性，增强了抗氧化酶系统。
