title: Identification of an RNA silencing suppressor encoded by a mastrevirus.
abstract: Wheat dwarf virus (WDV) is a DNA virus belonging to the genus Mastrevirus of the family Geminiviridae. In this study, we report that the Rep protein encoded by WDV is a RNA silencing supressor as determined by co-infiltration assays using transgenic Nicotiana benthamiana line 16c carrying the GFP reporter gene. The Rep protein was shown to inhibit both local and systemic RNA silencing of the GFP gene as well as the spread of systemic GFP RNA silencing signals. Gel mobility shift assays showed that the Rep protein binds 21 nt and 24 nt small interfering RNA (siRNA) duplexes and single-stranded (ss)-siRNA. To our knowledge, this is the first identification of an RNA silencing suppressor encoded by mastreviruses. Furthermore, deletion mutagenesis indicates that both the N- and C-terminal regions of the Rep protein are not critical for silencing suppression and self-interaction, but the N terminus of Rep is necessary for its pathogenicity.
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China.
authors.forename: Mingqing
authors.initials: M
authors.lastname: Dang
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China.
authors.forename: Huwei
authors.initials: H
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China.
authors.forename: Yuzhen
authors.initials: Y
authors.lastname: Mei
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China.
authors.forename: Yajuan
authors.initials: Y
authors.lastname: Qian
authors.affiliation: State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou, PR China.
authors.forename: Xueping
authors.initials: X
authors.lastname: Zhou
mesh_terms: D017791:Geminiviridae / Q000235:genetics*; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics*; D010935:Plant Diseases / Q000821:virology; D030821:Plants, Genetically Modified / Q000821:virology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D017384:Sequence Deletion / Q000235:genetics; D014026:Nicotiana / Q000235:genetics*; D014908:Triticum / Q000821:virology; D014764:Viral Proteins / Q000235:genetics
chemical_list: D034741:RNA, Small Interfering; D014764:Viral Proteins; D049452:Green Fluorescent Proteins