title: Effects of DICER-like proteins 2, 3 and 4 on cucumber mosaic virus and tobacco mosaic virus infections in salicylic acid-treated plants.
abstract: Salicylic acid (SA)-mediated resistance and RNA silencing are both important plant antiviral defence mechanisms. To investigate overlap between these resistance phenomena, we examined the ability of mutant Arabidopsis thaliana plants lacking DICER-like (DCL) endoribonucleases 2, 3 and 4 to exhibit SA-induced defence. We found that in dcl2/3/4 triple mutant plants, treatment with exogenous SA stimulated resistance to two positive-sense RNA viruses: cucumber mosaic virus and tobacco mosaic virus. We conclude that DCLs 2, 3 and 4, which are the predominant DCL endoribonucleases involved in silencing of positive-sense RNA viruses, are not required for effective SA-induced resistance to these viruses. However, the findings do not exclude RNA silencing from making a contribution to SA-mediated resistance in wild-type plants.
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: Mathew G
authors.initials: MG
authors.lastname: Lewsey
authors.affiliation: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: John P
authors.initials: JP
authors.lastname: Carr
mesh_terms: D017360:Arabidopsis / Q000187:drug effects* / Q000821:virology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D017799:Cucumovirus / Q000472:pathogenicity*; D009154:Mutation; D010935:Plant Diseases / Q000821:virology; D034622:RNA Interference; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism; D020156:Salicylic Acid / Q000494:pharmacology*; D014027:Tobacco Mosaic Virus / Q000472:pathogenicity*
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; C504982:DCL4 protein, Arabidopsis; C511919:DCL2 protein, Arabidopsis; C519654:DCL3 protein, Arabidopsis; D043244:Ribonuclease III; D020156:Salicylic Acid