Geminivirus Activates ASYMMETRIC LEAVES 2 to Accelerate Cytoplasmic DCP2-Mediated mRNA Turnover and Weakens RNA Silencing in Arabidopsis

PLoS Pathogens

Pingzhi Zhao¹  Nam-Hai Chua²  Yanwei Sun²  Junyi Yang³  Choonkyun Jung³  Jing Qu³  Jian Ye⁴  Rongxiang Fang⁴  Shiqiang Gao⁴ 

[1] Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan;Laboratory of Plant Molecular Biology, Rockefeller University, New York, New York, United States of America;State Key laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China;Temasek Life Sciences Laboratory, National University of Singapore, Singapore

关键词: Small interfering RNAs;    Arabidopsis thaliana;    Genetically modified plants;    Leaves;    Virus effects on host gene expression;    dsRNA viruses;    Messenger RNA;    RNA synthesis;   

DOI  :  10.1371/journal.ppat.1005196

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Aberrant viral RNAs produced in infected plant cells serve as templates for the synthesis of dsRNAs. The derived virus-related small interfering RNAs (siRNA) mediate cleavage of viral RNAs by post-transcriptional gene silencing (PTGS), thus blocking virus multiplication. Here, we identified ASYMMETRIC LEAVES2 (AS2) as a new component of plant P body complex which mediates mRNA decapping and degradation. We found that AS2 promotes DCP2 decapping activity, accelerates mRNA turnover rate, inhibits siRNA accumulation and functions as an endogenous suppressor of PTGS. Consistent with these findings, as2 mutant plants are resistant to virus infection whereas AS2 over-expression plants are hypersensitive. The geminivirus nuclear shuttle protein BV1 protein, which shuttles between nuclei and cytoplasm, induces AS2 expression, causes nuclear exit of AS2 to activate DCP2 decapping activity and renders infected plants more sensitive to viruses. These principles of gene induction and shuttling of induced proteins to promote mRNA decapping in the cytosol may be used by viral pathogens to weaken antiviral defenses in host plants.

【 授权许可】

CC BY