中文摘要：小RNA (miRNAs)是由最初的miRNA转录而来的小调控RNA，植物miRNAs在植物生长、发育和微生物侵染反应中起着重要的作用。微生物侵染改变了miRNA的生物合成，但是其潜在的机制仍是知之甚少。本文研究报道了水稻条纹病毒（RSV）编码的非结构蛋白3（NS3）与OsDRB1（水稻miRNA加工复合体不可缺少的一个成分）之间的交互作用。研究结果揭示了一个前所未知的新机制：病毒蛋白劫持OsDRB1（加工复合体的重要成分）共同作用于miRNA的生物合成，提高水稻上的病毒侵染和发病机制。
外文摘要：MicroRNAs (miRNAs) are small regulatory RNAs processed from primary miRNA transcripts, and plant miRNAs play important roles in plant growth, development, and response to infection by microbes. Microbial infections broadly alter miRNA biogenesis, but the underlying mechanisms remain poorly understood. In this study, we report that the Rice stripe virus (RSV)-encoded nonstructural protein 3 (NS3) interacts with OsDRB1, an indispensable component of the rice (Oryza sativa) miRNA-processing complex. Moreover, the NS3-OsDRB1 interaction occurs at the sites required for OsDRB1 self-interaction, which is essential for miRNA biogenesis. Further analysis revealed that NS3 acts as a scaffold between OsDRB1 and pri-miRNAs to regulate their association and aids in vivo processing of pri-miRNAs. Genetic evidence in Arabidopsis showed that NS3 can partially substitute for the function of double-stranded RNA binding domain (dsRBD) of AtDRB1/AtHYL1 during miRNA biogenesis. As a result, NS3 induces the accumulation of several miRNAs, most of which target pivotal genes associated with development or pathogen resistance. In contrast, a mutant version of NS3 (mNS3), which still associated with OsDRB1 but has defects in pri-miRNA binding, reduces accumulation of these miRNAs. Transgenic rice lines expressing NS3 exhibited significantly higher susceptibility to RSV infection compared with non-transgenic wild-type plants, whereas the transgenic lines expressing mNS3 showed a less-sensitive response. Our findings revealed a previously unknown mechanism in which a viral protein hijacks OsDRB1, a key component of the processing complex, for miRNA biogenesis and enhances viral infection and pathogenesis in rice.
作者：Zheng, Lijia; Zhang, Chao; Shi, Chaonan; 等
作者单位：福建农林大学
期刊名称：PLOS PATHOGENS
期刊影响因子：6.608
出版年份：2017
出版刊次：10
点击下载：水稻条纹病毒NS3蛋白与miRNA生物合成因子OsDRB1联合调控初级miRNA加工并促进了病毒对水稻的侵染