title: Contrasting effects of HC-Pro and 2b viral suppressors from Sugarcane mosaic virus and Tomato aspermy cucumovirus on the accumulation of siRNAs.
abstract: RNA silencing and suppression of silencing are host and virus interactions for defense and counter-defense. Here, we explored the function effect of HC-Pro encoded by Sugarcane mosaic virus (SCMV) on the suppression of RNA silencing. siRNA northern blotting assay indicated that the replication of SCMV was regulated by host RNA silencing machinery. Co-expression assay demonstrated that the HC-Pro encoded by SCMV suppressed the RNA silencing induced by sense RNA and dsRNA. Transitive RNA silencing assay showed that HC-Pro down-regulated the accumulation of 3' secondary siRNA, but not 5' secondary and primary siRNA. Meanwhile, the 2b gene of Tomato aspermy cucumovirus (Tav) evidently down-regulated the accumulation of 5' secondary siRNA. Importantly, we found that HC-Pro and Tav2b down-regulated the accumulation of RDR6 mRNA. Thus, HC-Pro, an RNA silencing suppressor encoded by SCMV, regulates the accumulation of different siRNAs and has more than one target in the RNA silencing pathway.
authors.affiliation: Peking-Yale Joint Center for Plant Molecular Genetics and Agrobiotechnology, National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Du
authors.forename: Lu
authors.initials: L
authors.lastname: Lu
authors.forename: Qi
authors.initials: Q
authors.lastname: Xiao
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Wang
authors.forename: Xuesong
authors.initials: X
authors.lastname: Cao
authors.forename: Bo
authors.initials: B
authors.lastname: Ren
authors.forename: Chunhong
authors.initials: C
authors.lastname: Wei
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D017799:Cucumovirus / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D015536:Down-Regulation; D018551:Solanum lycopersicum / Q000821:virology*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000821:virology; D017800:Potyvirus / Q000378:metabolism / Q000472:pathogenicity*; D034741:RNA, Small Interfering / Q000187:drug effects* / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism; D031786:Saccharum / Q000821:virology*; D013489:Suppression, Genetic; D014026:Nicotiana / Q000821:virology; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*
chemical_list: C404227:2b protein, cucumber mosaic virus; D029681:Arabidopsis Proteins; D034741:RNA, Small Interfering; D014764:Viral Proteins; C514575:RDR6 protein, Arabidopsis; D012324:RNA-Dependent RNA Polymerase; D003546:Cysteine Endopeptidases; C072775:HC-Pro protein, potyvirus