title: Interference with jasmonic acid-regulated gene expression is a general property of viral suppressors of RNA silencing but only partly explains virus-induced changes in plant-aphid interactions.
abstract: The cucumber mosaic virus (CMV) 2b viral suppressor of RNA silencing (VSR) inhibits host responses to jasmonic acid (JA), a chemical signal regulating resistance to insects. Previous experiments with a CMV subgroup IA strain and its 2b gene deletion mutant suggested that VSRs might neutralize aphid (Myzus persicae) resistance by inhibiting JA-regulated gene expression. To further investigate this, we examined JA-regulated gene expression and aphid performance in Nicotiana benthamiana infected with Potato virus X, Potato virus Y, Tobacco mosaic virus and a subgroup II CMV strain, as well as in transgenic plants expressing corresponding VSRs (p25, HC-Pro, 126 kDa and 2b). All the viruses or their VSRs inhibited JA-induced gene expression. However, this did not always correlate with enhanced aphid performance. Thus, VSRs are not the sole viral determinants of virus-induced changes in host-aphid interactions and interference with JA-regulated gene expression cannot completely explain enhanced aphid performance on virus-infected plants.
authors.affiliation: Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Jack H
authors.initials: JH
authors.lastname: Westwood
authors.affiliation: Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Mathew G
authors.initials: MG
authors.lastname: Lewsey
authors.affiliation: Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Alex M
authors.initials: AM
authors.lastname: Murphy
authors.affiliation: Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Trisna
authors.initials: T
authors.lastname: Tungadi
authors.affiliation: Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Anne
authors.initials: A
authors.lastname: Bates
authors.affiliation: Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Gilligan
authors.affiliation: Department of Plant Sciences, Downing Street, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: John P
authors.initials: JP
authors.lastname: Carr
mesh_terms: D000818:Animals; D001042:Aphids / Q000502:physiology*; D017799:Cucumovirus / Q000235:genetics* / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism*; D006790:Host-Parasite Interactions; D054883:Oxylipins / Q000378:metabolism*; D010935:Plant Diseases / Q000235:genetics / Q000469:parasitology / Q000821:virology*; D017863:Potexvirus / Q000502:physiology; D012367:RNA, Viral / Q000235:genetics* / Q000378:metabolism; D013489:Suppression, Genetic; D014026:Nicotiana / Q000235:genetics* / Q000469:parasitology / Q000502:physiology / Q000821:virology
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D012367:RNA, Viral; C011006:jasmonic acid