Rice stripe virus NS3 protein regulates primary miRNA processing through association with the miRNA biogenesis factor OsDRB1 and facilitates virus infection in rice

PLoS Pathogens

Feng Sun¹  Hong Wang¹  Chunhong Wei²  Lijia Zheng²  Shanshan Zhao²  Chaonan Shi²  Zhirui Yang²  Jianguo Wu²  Yi Li²  Qingqing Qin³  Zuomei Ding³  Rui Qiao³  Chao Zhang³  Tong Zhou³  Yu Wang³  Lianhui Xie³ 

[1] Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China;State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China;The State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China

关键词: MicroRNAs;    Rice;    Arabidopsis thaliana;    Genetically modified plants;    Northern blot;    Biosynthesis;    Small interfering RNAs;    Double str;    ed RNA;   

DOI  :  10.1371/journal.ppat.1006662

学科分类：生物科学（综合）

来源: Public Library of Science

【 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.

【 授权许可】

CC BY