title: Interference in plant defense and development by non-structural protein NSs of Groundnut bud necrosis virus.
abstract: Groundnut bud necrosis virus (GBNV) infects a large number of leguminous and solanaceous plants. To elucidate the biological function of the non-structural protein encoded by the S RNA of GBNV (NSs), we studied its role in RNA silencing suppression and in viral pathogenesis. Our results demonstrated that GBNV NSs functions as a suppressor of RNA silencing using the agroinfiltration patch assay. An in silico analysis suggested the presence of pro-apoptotic protein Reaper-like sequences in the GBNV NSs, which were known to be present in animal infecting bunyaviruses. Utilizing NSs mutants, we demonstrated that a Leu-rich domain was required for RNA silencing suppression activity, but not the non-overlapping Trp/GH3 motif of the Reaper-like sequence. To investigate the role of NSs in symptom development we generated transgenic tomato expressing the GBNV NSs and showed that the expression of NSs in tomato mimics symptoms induced by infection with GBNV, such as leaf senescence and necrosis. As leaf senescence is controlled by miR319 regulation of the transcription factor TCP1, we assessed the accumulation of both RNAs in transgenic NSs-expressing and GBNV-infected tomato plants. In both types of plants the levels of miR319 decreased, while the levels of TCP1 transcripts increased. We propose that GBNV-NSs affects miRNA biogenesis through its RNA silencing suppressor activity and interferes with TCP1-regulated leaf developmental pathways.
authors.affiliation: Division of Biochemistry, Indian Agricultural Research Institute, New Delhi-110012, India.
authors.forename: Suneha
authors.initials: S
authors.lastname: Goswami
authors.forename: Nandita
authors.initials: N
authors.lastname: Sahana
authors.forename: Vanita
authors.initials: V
authors.lastname: Pandey
authors.forename: Paula
authors.initials: P
authors.lastname: Doblas
authors.forename: R K
authors.initials: RK
authors.lastname: Jain
authors.forename: Peter
authors.initials: P
authors.lastname: Palukaitis
authors.forename: Tomas
authors.initials: T
authors.lastname: Canto
authors.forename: Shelly
authors.initials: S
authors.lastname: Praveen
mesh_terms: D010367:Arachis / Q000821:virology; D020868:Gene Silencing; D018551:Solanum lycopersicum / Q000254:growth & development / Q000276:immunology / Q000502:physiology* / Q000821:virology*; D035683:MicroRNAs / Q000378:metabolism; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000821:virology; D010940:Plant Proteins / Q000037:antagonists & inhibitors; D030821:Plants, Genetically Modified / Q000821:virology; D017865:Tospovirus / Q000472:pathogenicity*; D014157:Transcription Factors / Q000037:antagonists & inhibitors; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism*; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D035683:MicroRNAs; D050505:Mutant Proteins; D010940:Plant Proteins; D014157:Transcription Factors; D017361:Viral Nonstructural Proteins; D037521:Virulence Factors