title: Cocksfoot mottle virus P1 suppresses RNA silencing in Nicotiana benthamiana and Nicotiana tabacum.
abstract: The Sobemovirus genome consists of positive sense, single-stranded polycistronic RNA. The 5'-terminal ORF, encoding the protein P1, is its most variable region. Sobemoviral P1 has been described as dispensable for replication but indispensable for systemic infection. The P1 of Rice yellow mottle virus-Nigerian isolate (RYMV-N) is the only RNA silencing suppressor reported for sobemoviruses until now. Using an agrobacterium-mediated transient assay, we demonstrate here that P1 of Cocksfoot mottle virus-Norwegian isolate (CfMV-NO) suppresses RNA silencing in Nicotiana benthamiana and Nicotiana tabacum, two non-host plants. CfMV-NO P1 was able to suppress the initiation and maintenance of silencing. The suppression of systemic silencing was weaker with CfMV-NO P1 than in the case of RYMV-N P1. In the case of suppression at the local level, the reduction in the amount of 25-nucleotide small interfering RNAs (siRNAs) was less pronounced for CfMV-NO P1 than it was when RYMV-N P1 was used. At the same time, we show that CfMV-NO P1 did not bind siRNAs.
authors.affiliation: Tallinn University of Technology, Department of Gene Technology, Akadeemia tee 15, 19086 Tallinn, Estonia. cecilia.sarmiento@ttu.ee
authors.forename: Cecilia
authors.initials: C
authors.lastname: Sarmiento
authors.forename: Eva
authors.initials: E
authors.lastname: Gomez
authors.forename: Merike
authors.initials: M
authors.lastname: Meier
authors.forename: Tony A
authors.initials: TA
authors.lastname: Kavanagh
authors.forename: Erkki
authors.initials: E
authors.lastname: Truve
mesh_terms: D015536:Down-Regulation; D010935:Plant Diseases / Q000235:genetics / Q000821:virology*; D018515:Plant Leaves / Q000235:genetics / Q000821:virology; D010942:Plant Viruses / Q000737:chemistry* / Q000502:physiology; D034622:RNA Interference; D012328:RNA Viruses / Q000737:chemistry* / Q000502:physiology; D018749:RNA, Plant / Q000235:genetics; D014026:Nicotiana; D014764:Viral Proteins / Q000502:physiology*
chemical_list: D018749:RNA, Plant; D014764:Viral Proteins