title: ARGONAUTE2 mediates RNA-silencing antiviral defenses against Potato virus X in Arabidopsis.
abstract: RNA-silencing mechanisms control many aspects of gene regulation including the detection and degradation of viral RNA through the action of, among others, Dicer-like and Argonaute (AGO) proteins. However, the extent to which RNA silencing restricts virus host range has been difficult to separate from other factors that can affect virus-plant compatibility. Here we show that Potato virus X (PVX) can infect Arabidopsis (Arabidopsis thaliana), which is normally a nonhost for PVX, if coinfected with a second virus, Pepper ringspot virus. Here we show that the pepper ringspot virus 12K protein functions as a suppressor of silencing that appears to enable PVX to infect Arabidopsis. We also show that PVX is able to infect Arabidopsis Dicer-like mutants, indicating that RNA silencing is responsible for Arabidopsis nonhost resistance to PVX. Furthermore, we find that restriction of PVX on Arabidopsis also depends on AGO2, suggesting that this AGO protein has evolved to specialize in antiviral defenses.
authors.affiliation: Boyce Thompson Institute for Plant Research, Ithaca, New York 14853, USA.
authors.forename: Marianne
authors.initials: M
authors.lastname: Jaubert
authors.forename: Saikat
authors.initials: S
authors.lastname: Bhattacharjee
authors.forename: Alexandre F S
authors.initials: AF
authors.lastname: Mello
authors.forename: Keith L
authors.initials: KL
authors.lastname: Perry
authors.forename: Peter
authors.initials: P
authors.lastname: Moffett
mesh_terms: D017360:Arabidopsis / Q000276:immunology* / Q000821:virology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D060565:Argonaute Proteins; D016153:Genes, Suppressor; D007113:Immunity, Innate / Q000276:immunology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009154:Mutation / Q000235:genetics; D010935:Plant Diseases / Q000276:immunology / Q000821:virology; D017863:Potexvirus / Q000502:physiology*; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D016601:RNA-Binding Proteins; D014764:Viral Proteins; C559855:argonaute 2 protein, Arabidopsis