title: Replication of a pathogenic non-coding RNA increases DNA methylation in plants associated with a bromodomain-containing viroid-binding protein.
abstract: Viroids are plant-pathogenic molecules made up of single-stranded circular non-coding RNAs. How replicating viroids interfere with host silencing remains largely unknown. In this study, we investigated the effects of a nuclear-replicating Potato spindle tuber viroid (PSTVd) on interference with plant RNA silencing. Using transient induction of silencing in GFP transgenic Nicotiana benthamiana plants (line 16c), we found that PSTVd replication accelerated GFP silencing and increased Virp1 mRNA, which encodes bromodomain-containing viroid-binding protein 1 and is required for PSTVd replication. DNA methylation was increased in the GFP transgene promoter of PSTVd-replicating plants, indicating involvement of transcriptional gene silencing. Consistently, accelerated GFP silencing and increased DNA methylation in the of GFP transgene promoter were detected in plants transiently expressing Virp1. Virp1 mRNA was also increased upon PSTVd infection in natural host potato plants. Reduced transcript levels of certain endogenous genes were also consistent with increases in DNA methylation in related gene promoters in PSTVd-infected potato plants. Together, our data demonstrate that PSTVd replication interferes with the nuclear silencing pathway in that host plant, and this is at least partially attributable to Virp1. This study provides new insights into the plant-viroid interaction on viroid pathogenicity by subverting the plant cell silencing machinery.
authors: Virus-free Seedling Research Institute, Heilongjiang Academy of Agricultural Sciences, Harbin, China.|Heilongjiang Academy of Agricultural Sciences Postdoctoral Programme, Harbin, China.
authors: Dian-Qiu
authors: DQ
authors: Lv
authors: Virus-free Seedling Research Institute, Heilongjiang Academy of Agricultural Sciences, Harbin, China.|State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors: Shang-Wu
authors: SW
authors: Liu
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors: Jian-Hua
authors: JH
authors: Zhao
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors: Bang-Jun
authors: BJ
authors: Zhou
authors: Virus-free Seedling Research Institute, Heilongjiang Academy of Agricultural Sciences, Harbin, China.
authors: Shao-Peng
authors: SP
authors: Wang
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors: Hui-Shan
authors: HS
authors: Guo
authors: State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
authors: Yuan-Yuan
authors: YY
authors: Fang
mesh_terms: D019175:DNA Methylation; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics; D010935:Plant Diseases / Q000235:genetics / Q000821:virology; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D022661:RNA, Untranslated / Q000096:biosynthesis*; D012367:RNA, Viral / Q000096:biosynthesis*; D016601:RNA-Binding Proteins / Q000378:metabolism*; D011198:Solanum tuberosum / Q000378:metabolism / Q000821:virology; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism* / Q000821:virology*; D014772:Viroids / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D014779:Virus Replication / Q000235:genetics / Q000502:physiology
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D022661:RNA, Untranslated; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D049452:Green Fluorescent Proteins