title: Disruption of Ethylene Responses by Turnip mosaic virus Mediates Suppression of Plant Defense against the Green Peach Aphid Vector.
abstract: Plants employ diverse responses mediated by phytohormones to defend themselves against pathogens and herbivores. Adapted pathogens and herbivores often manipulate these responses to their benefit. Previously, we demonstrated that Turnip mosaic virus (TuMV) infection suppresses callose deposition, an important plant defense induced in response to feeding by its aphid vector, the green peach aphid (Myzus persicae), and increases aphid fecundity compared with uninfected control plants. Further, we determined that production of a single TuMV protein, Nuclear Inclusion a-Protease (NIa-Pro) domain, was responsible for changes in host plant physiology and increased green peach aphid reproduction. To characterize the underlying molecular mechanisms of this phenomenon, we examined the role of three phytohormone signaling pathways, jasmonic acid, salicylic acid, and ethylene (ET), in TuMV-infected Arabidopsis (Arabidopsis thaliana), with or without aphid herbivory. Experiments with Arabidopsis mutants ethylene insensitive2 and ethylene response1, and chemical inhibitors of ET synthesis and perception (aminoethoxyvinyl-glycine and 1-methylcyclopropene, respectively), show that the ET signaling pathway is required for TuMV-mediated suppression of Arabidopsis resistance to the green peach aphid. Additionally, transgenic expression of NIa-Pro in Arabidopsis alters ET responses and suppresses aphid-induced callose formation in an ET-dependent manner. Thus, disruption of ET responses in plants is an additional function of NIa-Pro, a highly conserved potyvirus protein. Virus-induced changes in ET responses may mediate vector-plant interactions more broadly and thus represent a conserved mechanism for increasing transmission by insect vectors across generations.
authors.affiliation: Department of Plant Pathology, University of California, Davis, California 95616 (C.L.C., A.B.); Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (M.D.A., G.J.); andDepartment of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011 (H.D., S.A.W.) ccasteel@ucdavis.edu.
authors.forename: Clare L
authors.identifier: http://orcid.org/0000-0003-3678-0187
authors.initials: CL
authors.lastname: Casteel
authors.affiliation: Department of Plant Pathology, University of California, Davis, California 95616 (C.L.C., A.B.); Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (M.D.A., G.J.); andDepartment of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011 (H.D., S.A.W.).
authors.forename: Manori
authors.initials: M
authors.lastname: De Alwis
authors.affiliation: Department of Plant Pathology, University of California, Davis, California 95616 (C.L.C., A.B.); Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (M.D.A., G.J.); andDepartment of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011 (H.D., S.A.W.).
authors.forename: Aurélie
authors.initials: A
authors.lastname: Bak
authors.affiliation: Department of Plant Pathology, University of California, Davis, California 95616 (C.L.C., A.B.); Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (M.D.A., G.J.); andDepartment of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011 (H.D., S.A.W.).
authors.forename: Haili
authors.identifier: http://orcid.org/0000-0002-7860-5611
authors.initials: H
authors.lastname: Dong
authors.affiliation: Department of Plant Pathology, University of California, Davis, California 95616 (C.L.C., A.B.); Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (M.D.A., G.J.); andDepartment of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011 (H.D., S.A.W.).
authors.forename: Steven A
authors.identifier: http://orcid.org/0000-0003-3542-3188
authors.initials: SA
authors.lastname: Whitham
authors.affiliation: Department of Plant Pathology, University of California, Davis, California 95616 (C.L.C., A.B.); Boyce Thompson Institute for Plant Research, Ithaca, New York 14853 (M.D.A., G.J.); andDepartment of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa 50011 (H.D., S.A.W.).
authors.forename: Georg
authors.identifier: http://orcid.org/0000-0002-9675-934X
authors.initials: G
authors.lastname: Jander
mesh_terms: D000818:Animals; D001042:Aphids / Q000502:physiology* / Q000821:virology; D017360:Arabidopsis / Q000235:genetics / Q000276:immunology*; D029688:Brassica napus / Q000235:genetics / Q000276:immunology*; D003517:Cyclopentanes / Q000378:metabolism; D005030:Ethylenes / Q000378:metabolism; D006790:Host-Parasite Interactions; D007303:Insect Vectors / Q000502:physiology* / Q000821:virology; D054883:Oxylipins / Q000378:metabolism; D010935:Plant Diseases / Q000276:immunology*; D010937:Plant Growth Regulators / Q000378:metabolism*; D017800:Potyvirus / Q000502:physiology*; D020156:Salicylic Acid / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; D010937:Plant Growth Regulators; C011006:jasmonic acid; C036216:ethylene; D020156:Salicylic Acid