College of Plant Protection, Southwest University, Chongqing, 400715, China.
Guizhou Academy of Tobacco Science, Guiyang, 550081, China.
J Hazard Mater. 2020 Jul 5;393:122415. doi: 10.1016/j.jhazmat.2020.122415. Epub 2020 Feb 26.
Nanoparticles are recently employed as a new strategy to directly kill pathogens (e.g., bacteria and fungus) and acted as nanofertilizers. However, the influences of this foliar deposition of nanoparticles on plant physiology particularly plant immunity are poorly understood. The uptake and physiological effects of FeO nanoparticles (FeONPs), and plant resistance response against Tobacco mosaic virus (TMV) after foliar spraying were studied. Specifically, FeONPs entered leaf cells and were transported and accumulated throughout the whole Nicotiana benthamiana plant, and increased plant dry and fresh weights, activated plant antioxidants, and upregulated SA synthesis and the expression of SA-responsive PR genes (i.e., PR1 and PR2), thereby enhancing plant resistance against TMV. Conversely, the viral infection was not inhibited in the NahG transgenic plants treated by FeONPs, suggesting the involvement of salicylic acid (SA) induced by FeONPs in the production of plant resistance. Moreover, no inhibition was observed of the infection after inoculating with the pretreated TMV mixtures. Thus, the deposition of FeONPs induced the accumulation of endogenous SA, which was correlated with the plant resistance against TMV infection. Such information is vital for valuing the risk of FeONPs products and broadens the researching and applying nanoparticles in the fight against plant diseases meantime.
纳米颗粒最近被用作一种直接杀死病原体（如细菌和真菌）并充当纳米肥料的新策略。然而，这种叶面沉积纳米颗粒对植物生理学特别是植物免疫的影响还知之甚少。本研究研究了叶面喷施 FeO 纳米颗粒（FeONPs）后，FeONPs 的吸收和生理效应以及对烟草花叶病毒（TMV）的植物抗性反应。具体来说，FeONPs 进入叶片细胞，并在整个 Nicotiana benthamiana 植物中被运输和积累，增加了植物的干重和鲜重，激活了植物抗氧化剂，上调了 SA 的合成和 SA 响应的 PR 基因（即 PR1 和 PR2）的表达，从而增强了植物对 TMV 的抗性。相反，在用 FeONPs 处理的 NahG 转基因植物中，病毒感染并没有被抑制，这表明 FeONPs 诱导的水杨酸（SA）参与了植物抗性的产生。此外，在用预处理的 TMV 混合物接种后，感染也没有被抑制。因此，FeONPs 的沉积诱导了内源性 SA 的积累，这与植物对 TMV 感染的抗性有关。这些信息对于评估 FeONPs 产品的风险至关重要，同时拓宽了研究和应用纳米颗粒防治植物病害的范围。
