title: A Signaling Cascade from miR444 to RDR1 in Rice Antiviral RNA Silencing Pathway.
abstract: Plant RNA-DEPENDENT RNA POLYMERASE1 (RDR1) is a key component of the antiviral RNA-silencing pathway, contributing to the biogenesis of virus-derived small interfering RNAs. This enzyme also is responsible for producing virus-activated endogenous small interfering RNAs to stimulate the broad-spectrum antiviral activity through silencing host genes. The expression of RDR1 orthologs in various plants is usually induced by virus infection. However, the molecular mechanisms of activation of RDR1 expression in response to virus infection remain unknown. Here, we show that a monocot-specific microRNA, miR444, is a key factor in relaying the antiviral signaling from virus infection to OsRDR1 expression. The expression of miR444 is enhanced by infection with Rice stripe virus (RSV), and overexpression of miR444 improves rice (Oryza sativa) resistance against RSV infection accompanied by the up-regulation of OsRDR1 expression. We further show that three miR444 targets, the MIKC(C)-type MADS box proteins OsMADS23, OsMADS27a, and OsMADS57, form homodimers and heterodimers between them to repress the expression of OsRDR1 by directly binding to the CArG motifs of its promoter. Consequently, an increased level of miR444 diminishes the repressive roles of OsMADS23, OsMADS27a, and OsMADS57 on OsRDR1 transcription, thus activating the OsRDR1-dependent antiviral RNA-silencing pathway. We also show that overexpression of miR444-resistant OsMADS57 reduced OsRDR1 expression and rice resistance against RSV infection, and knockout of OsRDR1 reduced rice resistance against RSV infection. In conclusion, our results reveal a molecular cascade in the rice antiviral pathway in which miR444 and its MADS box targets directly control OsRDR1 transcription.
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China (H.W., X.J., X.K., Y.W., X.C., R.F., Y.Y.);National Plant Gene Research Center, Beijing 100101, China (H.W., X.J., X.K., X.C., R.F., Y.Y.);University of the Chinese Academy of Sciences, Beijing 100049, China (H.W., X.K.); andDepartment of Biology, Syed Babar Ali (SBA) School of Science and Engineering, Lahore University of Management Sciences, Defence Housing Authority (DHA), Lahore 54792, Pakistan (S.H.).
authors: Huacai
authors: H
authors: Wang
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China (H.W., X.J., X.K., Y.W., X.C., R.F., Y.Y.);National Plant Gene Research Center, Beijing 100101, China (H.W., X.J., X.K., X.C., R.F., Y.Y.);University of the Chinese Academy of Sciences, Beijing 100049, China (H.W., X.K.); andDepartment of Biology, Syed Babar Ali (SBA) School of Science and Engineering, Lahore University of Management Sciences, Defence Housing Authority (DHA), Lahore 54792, Pakistan (S.H.).
authors: Xiaoming
authors: 0000-0003-2391-991X
authors: X
authors: Jiao
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China (H.W., X.J., X.K., Y.W., X.C., R.F., Y.Y.);National Plant Gene Research Center, Beijing 100101, China (H.W., X.J., X.K., X.C., R.F., Y.Y.);University of the Chinese Academy of Sciences, Beijing 100049, China (H.W., X.K.); andDepartment of Biology, Syed Babar Ali (SBA) School of Science and Engineering, Lahore University of Management Sciences, Defence Housing Authority (DHA), Lahore 54792, Pakistan (S.H.).
authors: Xiaoyu
authors: X
authors: Kong
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China (H.W., X.J., X.K., Y.W., X.C., R.F., Y.Y.);National Plant Gene Research Center, Beijing 100101, China (H.W., X.J., X.K., X.C., R.F., Y.Y.);University of the Chinese Academy of Sciences, Beijing 100049, China (H.W., X.K.); andDepartment of Biology, Syed Babar Ali (SBA) School of Science and Engineering, Lahore University of Management Sciences, Defence Housing Authority (DHA), Lahore 54792, Pakistan (S.H.).
authors: Sadia
authors: S
authors: Hamera
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China (H.W., X.J., X.K., Y.W., X.C., R.F., Y.Y.);National Plant Gene Research Center, Beijing 100101, China (H.W., X.J., X.K., X.C., R.F., Y.Y.);University of the Chinese Academy of Sciences, Beijing 100049, China (H.W., X.K.); andDepartment of Biology, Syed Babar Ali (SBA) School of Science and Engineering, Lahore University of Management Sciences, Defence Housing Authority (DHA), Lahore 54792, Pakistan (S.H.).
authors: Yao
authors: Y
authors: Wu
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China (H.W., X.J., X.K., Y.W., X.C., R.F., Y.Y.);National Plant Gene Research Center, Beijing 100101, China (H.W., X.J., X.K., X.C., R.F., Y.Y.);University of the Chinese Academy of Sciences, Beijing 100049, China (H.W., X.K.); andDepartment of Biology, Syed Babar Ali (SBA) School of Science and Engineering, Lahore University of Management Sciences, Defence Housing Authority (DHA), Lahore 54792, Pakistan (S.H.).
authors: Xiaoying
authors: X
authors: Chen
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China (H.W., X.J., X.K., Y.W., X.C., R.F., Y.Y.);National Plant Gene Research Center, Beijing 100101, China (H.W., X.J., X.K., X.C., R.F., Y.Y.);University of the Chinese Academy of Sciences, Beijing 100049, China (H.W., X.K.); andDepartment of Biology, Syed Babar Ali (SBA) School of Science and Engineering, Lahore University of Management Sciences, Defence Housing Authority (DHA), Lahore 54792, Pakistan (S.H.).
authors: Rongxiang
authors: R
authors: Fang
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China (H.W., X.J., X.K., Y.W., X.C., R.F., Y.Y.);National Plant Gene Research Center, Beijing 100101, China (H.W., X.J., X.K., X.C., R.F., Y.Y.);University of the Chinese Academy of Sciences, Beijing 100049, China (H.W., X.K.); andDepartment of Biology, Syed Babar Ali (SBA) School of Science and Engineering, Lahore University of Management Sciences, Defence Housing Authority (DHA), Lahore 54792, Pakistan (S.H.) yanys@im.ac.cn.
authors: Yongsheng
authors: Y
authors: Yan
mesh_terms: D000998:Antiviral Agents / Q000378:metabolism*; D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D059372:Nucleotide Motifs / Q000235:genetics; D012275:Oryza / Q000235:genetics* / Q000821:virology*; D010935:Plant Diseases / Q000821:virology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D055503:Protein Multimerization; D034622:RNA Interference; D015398:Signal Transduction; D029364:Tenuivirus / Q000502:physiology; D015854:Up-Regulation / Q000235:genetics
chemical_list: D000998:Antiviral Agents; D035683:MicroRNAs; D010940:Plant Proteins