Chongqing Key Laboratory of Plant Disease Biology, College of Plant Protection, Southwest University, Chongqing, China.
National Citrus Engineering Research Center, Southwest University, Chongqing, China.
Mol Plant Pathol. 2023 May;24(5):466-473. doi: 10.1111/mpp.13310. Epub 2023 Feb 16.
Virus-derived small interfering RNAs (vsiRNAs) play important roles in regulating host endogenous gene expression to promote virus infection and induce RNA silencing to suppress virus infection. However, to date, how vsiRNAs affect geminivirus infection in host plants has been less studied. In this study, we found that tobacco curly shoot virus (TbCSV)-derived vsiRNA18 (TvsiRNA18) can regulate TbCSV infection in Nicotiana benthamiana plants. The virus-mediated small RNA expression system and stable transformation technique were used to clarify the molecular role of TvsiRNA18 in TbCSV infection. The results indicate that TvsiRNA18 can aggravate disease symptoms in these plants and enhance viral DNA accumulation. ATP-dependent RNA helicase (ATP-dRH) was proven to be a target of TvsiRNA18, and down-regulation of ATP-dRH in plants was shown to induce virus-like leaf curling symptoms and increase TbCSV infection. These results suggest that TvsiRNA18 is an important regulator of TbCSV infection by suppressing ATP-dRH expression. This is the first report to demonstrate that TbCSV-derived vsiRNA can target host endogenous genes to affect symptom development, which helps to reveal the molecular mechanism of symptom occurrence after the virus infects the host.
病毒来源的小干扰 RNA（vsiRNA）在调节宿主内源性基因表达以促进病毒感染和诱导 RNA 沉默以抑制病毒感染方面发挥重要作用。然而，迄今为止，vsiRNA 如何影响植物中的双生病毒感染还研究较少。在本研究中，我们发现烟草曲茎病毒（TbCSV）衍生的 vsiRNA18（TvsiRNA18）可以调节烟草原生质体中的 TbCSV 感染。利用病毒介导的小 RNA 表达系统和稳定转化技术阐明了 TvsiRNA18 在 TbCSV 感染中的分子作用。结果表明，TvsiRNA18 可加重这些植物的病症并增强病毒 DNA 积累。证明 ATP 依赖性 RNA 解旋酶（ATP-dRH）是 TvsiRNA18 的靶标，并且植物中 ATP-dRH 的下调会诱导类病毒卷曲的叶片症状并增加 TbCSV 感染。这些结果表明 TvsiRNA18 通过抑制 ATP-dRH 表达成为 TbCSV 感染的重要调节剂。这是第一个报道表明 TbCSV 衍生的 vsiRNA 可以靶向宿主内源性基因从而影响症状发育的报告，这有助于揭示病毒感染宿主后症状发生的分子机制。
