Institute of Environmental Processes and Pollution Control, School of Environmental and Civil Engineering, Jiangnan University, Wuxi, 214122, Jiangsu, China.
College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China.
Sci Total Environ. 2021 Jul 15;778:146378. doi: 10.1016/j.scitotenv.2021.146378. Epub 2021 Mar 11.
Silicon, in its nanoscale form, has shown plant-promoting and insecticidal properties. To date, however, we lack mechanistic evidence for how nanoscale silicon influences the regulation of plant chemical defenses against herbivore attacks. To address this gap, we compared the effect of Si nanodots (NDs) and sodium silicate, a conventional silicate fertilizer, on maize (Zea mays L.) chemical defenses against the oriental armyworm (Mythimna separata, Walker) caterpillars. We found that Si NDs and sodium silicate additions, at the dose of 50 mg/L, significantly inhibited the growth of caterpillars by 53.5% and 34.2%, respectively. This increased plant resistance was associated with a 44.2% increase in the production of chlorogenic acid, as well as the expression of PAL, C4H, 4CL, C3H and HCT, core genes involved in the biosynthesis of chlorogenic acid, by 1.7, 2.4, 1.9, 1.8 and 4.5 folds, respectively. Particularly, in the presence of M. separata, physiological changes in maize plants treated with 50 mg/L Si NDs, including changes in shoot biomass, leaf nutrients (e.g., K, P, Si), and chemical defense compounds (e.g., chlorogenic acid, total phenolics), were higher than those of plants added with equivalent concentrations of conventional silicate fertilizer. Taken together, our findings indicate that Si, in nanoscale form, could replace synthetic pesticides, and be implemented for a more effective and ecologically-sound management of insect pests in maize crop farming.
硅在纳米尺度下表现出促进植物生长和杀虫的特性。然而，迄今为止，我们缺乏关于纳米尺度硅如何影响植物化学防御机制以抵御草食性昆虫攻击的机制证据。为了解决这一差距，我们比较了硅纳米点（NDs）和硅酸钠（一种传统的硅酸盐肥料）对玉米（Zea mays L.）化学防御机制抵御东方粘虫（Mythimna separata，Walker）幼虫的影响。我们发现，硅 NDs 和硅酸钠添加剂量为 50mg/L 时，分别显著抑制了 53.5%和 34.2%的幼虫生长。这种增加的植物抗性与绿原酸产量增加 44.2%有关，同时苯丙氨酸解氨酶（PAL）、肉桂酸 4-羟化酶（C4H）、4-香豆酸-CoA 连接酶（4CL）、咖啡酸 3-O-甲基转移酶（C3H）和羟甲基戊二酰辅酶 A 还原酶（HCT）等参与绿原酸生物合成的核心基因的表达分别增加了 1.7、2.4、1.9、1.8 和 4.5 倍。特别是在有东方粘虫存在的情况下，用 50mg/L 硅 NDs 处理的玉米植株的生理变化，包括茎生物量、叶片养分（如 K、P、Si）和化学防御化合物（如绿原酸、总酚）的变化，都高于用等量传统硅酸盐肥料处理的植株。总之，我们的研究结果表明，纳米尺度的硅可以替代合成农药，用于更有效地、生态友好地管理玉米作物中的虫害。
