title: Silencing suppressor activity of a begomovirus DNA β encoded protein and its effect on heterologous helper virus replication.
abstract: DNA β satellites are circular single-stranded molecules associated with some monopartite begomoviruses in the family Geminiviridae. They co-infect with their helper viruses to induce severe disease in economically important crops. The βC1 protein encoded by DNA β is a pathogenicity determinant and has been reported to suppress post-transcriptional gene silencing (PTGS). The βC1 proteins from various DNA β molecules show low levels of amino acid sequence conservation. We show here that the βC1 from DNA β associated with Cotton leaf curl Multan virus (CLCuMV) is a suppressor of systemic PTGS. When this DNA β satellite co-inoculated with a heterologous helper virus, Tomato leaf curl virus (ToLCV), reduced the level of ToLCV siRNA and this was associated with a higher level of virus accumulation in infected tobacco plants. This may be a mechanism by which βC1 protects a heterologous virus from host gene silencing.
authors.affiliation: School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, SA 5064, Australia. eini o@yahoo.com
authors.forename: Omid
authors.initials: O
authors.lastname: Eini
authors.forename: Satish C
authors.initials: SC
authors.lastname: Dogra
authors.forename: Ian B
authors.initials: IB
authors.lastname: Dry
authors.forename: John W
authors.initials: JW
authors.lastname: Randles
mesh_terms: D053839:Begomovirus / Q000235:genetics / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism*; D006378:Helper Viruses / Q000235:genetics / Q000502:physiology*; D010935:Plant Diseases / Q000235:genetics* / Q000821:virology; D034622:RNA Interference; D012526:Satellite Viruses / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000235:genetics / Q000821:virology; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins