Department of Microbiology & Plant Pathology and Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, USA.
Department of Microbiology & Plant Pathology and Center for Plant Cell Biology, Institute for Integrative Genome Biology, University of California, Riverside, Riverside, CA, USA.
Cell Host Microbe. 2024 Oct 9;32(10):1691-1704.e4. doi: 10.1016/j.chom.2024.08.009. Epub 2024 Sep 6.
Known for over a century, seed transmission of plant viruses promotes trans-continental virus dissemination and provides the source of infection to trigger devastating disease epidemics in crops. However, it remains unknown whether there is a genetically defined immune pathway to suppress virus vertical transmission in plants. Here, we demonstrate potent immunosuppression of cucumber mosaic virus (CMV) seed transmission in its natural host Arabidopsis thaliana by antiviral RNA interference (RNAi) pathway. Immunofluorescence microscopy reveals predominant embryo infection at four stages of embryo development. We show that antiviral RNAi confers resistance to seed infection with different genetic requirements and drastically enhanced potency compared with the inhibition of systemic infection of whole plants. Moreover, we detect efficient seed transmission of a mutant CMV lacking its RNAi suppressor gene in mutant plants defective in antiviral RNAi, providing further support for the immunosuppression of seed transmission by antiviral RNAi.
一个多世纪以来，植物病毒的种子传播促进了跨大陆病毒的传播，并为引发农作物毁灭性疾病流行提供了感染源。然而，目前尚不清楚植物中是否存在一种遗传定义的免疫途径来抑制病毒的垂直传播。在这里，我们证明了抗病毒 RNA 干扰（RNAi）途径在其天然宿主拟南芥中对黄瓜花叶病毒（CMV）种子传播具有强大的抑制作用。免疫荧光显微镜显示，在胚胎发育的四个阶段，胚胎感染占主导地位。我们表明，抗病毒 RNAi 赋予了对不同遗传要求的种子感染的抗性，并且与抑制整个植物的系统感染相比，其效力大大增强。此外，我们在抗病毒 RNAi 缺陷的突变体植物中检测到缺乏 RNAi 抑制剂基因的突变 CMV 的有效种子传播，这为抗病毒 RNAi 对种子传播的免疫抑制提供了进一步的支持。
