State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agroproducts, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Institute of Plant Virology, Ningbo University, Ningbo 315211, China.
Institute of Agricultural Sciences in Lixiahe District of Jiangsu Province, Yangzhou, Jiangsu 225007, China.
Mol Plant. 2021 Jul 5;14(7):1088-1103. doi: 10.1016/j.molp.2021.03.022. Epub 2021 Mar 30.
Virus-derived small interference RNAs (vsiRNAs) not only suppress virus infection in plants via induction of RNA silencing but also enhance virus infection by regulating host defensive gene expression. However, the underlying mechanisms that control vsiRNA-mediated host immunity or susceptibility remain largely unknown. In this study, we generated several transgenic wheat lines using four artificial microRNA expression vectors carrying vsiRNAs from Wheat yellow mosaic virus (WYMV) RNA1. Laboratory and field tests showed that two transgenic wheat lines expressing amiRNA1 were highly resistant to WYMV infection. Further analyses showed that vsiRNA1 could modulate the expression of a wheat thioredoxin-like gene (TaAAED1), which encodes a negative regulator of reactive oxygen species (ROS) production in the chloroplast. The function of TaAAED1 in ROS scavenging could be suppressed by vsiRNA1 in a dose-dependent manner. Furthermore, transgenic expression of amiRNA1 in wheat resulted in broad-spectrum disease resistance to Chinese wheat mosaic virus, Barley stripe mosaic virus, and Puccinia striiformis f. sp. tritici infection, suggesting that vsiRNA1 is involved in wheat immunity via ROS signaling. Collectively, these findings reveal a previously unidentified mechanism underlying the arms race between viruses and plants.
病毒来源的小干扰 RNA（vsiRNA）不仅通过诱导 RNA 沉默来抑制植物中的病毒感染，还通过调节宿主防御基因表达来增强病毒感染。然而，控制 vsiRNA 介导的宿主免疫或易感性的潜在机制在很大程度上仍然未知。在这项研究中，我们使用四个携带小麦黄花叶病毒（WYMV）RNA1 的人工 microRNA 表达载体生成了几个转基因小麦品系。实验室和田间试验表明，表达 amiRNA1 的两个转基因小麦品系对 WYMV 感染具有高度抗性。进一步的分析表明，vsiRNA1 可以调节小麦硫氧还蛋白样基因（TaAAED1）的表达，该基因编码叶绿体中活性氧（ROS）产生的负调节剂。vsiRNA1 可以以剂量依赖的方式抑制 TaAAED1 在 ROS 清除中的功能。此外，amiRNA1 在小麦中的转基因表达导致对中国小麦花叶病毒、大麦条纹花叶病毒和条锈菌 f. sp. tritici 感染的广谱抗病性，表明 vsiRNA1 通过 ROS 信号参与小麦免疫。总之，这些发现揭示了病毒和植物之间军备竞赛的一个以前未被识别的机制。
