title: The PP2C-type phosphatase AP2C1, which negatively regulates MPK4 and MPK6, modulates innate immunity, jasmonic acid, and ethylene levels in Arabidopsis.
abstract: Wound signaling pathways in plants are mediated by mitogen-activated protein kinases (MAPKs) and stress hormones, such as ethylene and jasmonates. In Arabidopsis thaliana, the transmission of wound signals by MAPKs has been the subject of detailed investigations; however, the involvement of specific phosphatases in wound signaling is not known. Here, we show that AP2C1, an Arabidopsis Ser/Thr phosphatase of type 2C, is a novel stress signal regulator that inactivates the stress-responsive MAPKs MPK4 and MPK6. Mutant ap2c1 plants produce significantly higher amounts of jasmonate upon wounding and are more resistant to phytophagous mites (Tetranychus urticae). Plants with increased AP2C1 levels display lower wound activation of MAPKs, reduced ethylene production, and compromised innate immunity against the necrotrophic pathogen Botrytis cinerea. Our results demonstrate a key role for the AP2C1 phosphatase in regulating stress hormone levels, defense responses, and MAPK activities in Arabidopsis and provide evidence that the activity of AP2C1 might control the plant's response to B. cinerea.
authors.affiliation: Max F. Perutz Laboratories of the University of Viena, 1030 Viena, Austria.
authors.forename: Alois
authors.initials: A
authors.lastname: Schweighofer
authors.forename: Vaiva
authors.initials: V
authors.lastname: Kazanaviciute
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Scheikl
authors.forename: Markus
authors.initials: M
authors.lastname: Teige
authors.forename: Robert
authors.initials: R
authors.lastname: Doczi
authors.forename: Heribert
authors.initials: H
authors.lastname: Hirt
authors.forename: Manfred
authors.initials: M
authors.lastname: Schwanninger
authors.forename: Merijn
authors.initials: M
authors.lastname: Kant
authors.forename: Robert
authors.initials: R
authors.lastname: Schuurink
authors.forename: Felix
authors.initials: F
authors.lastname: Mauch
authors.forename: Antony
authors.initials: A
authors.lastname: Buchala
authors.forename: Francesca
authors.initials: F
authors.lastname: Cardinale
authors.forename: Irute
authors.initials: I
authors.lastname: Meskiene
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000276:immunology / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D015415:Biomarkers; D020171:Botrytis; D003517:Cyclopentanes / Q000378:metabolism*; D015536:Down-Regulation / Q000235:genetics; D004789:Enzyme Activation; D005030:Ethylenes / Q000378:metabolism*; D007113:Immunity, Innate; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics*; D054883:Oxylipins / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology; D011485:Protein Binding; D011523:Protoplasts / Q000201:enzymology; D012441:Saccharomyces cerevisiae / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D015415:Biomarkers; D003517:Cyclopentanes; D005030:Ethylenes; D054883:Oxylipins; C011006:jasmonic acid; C036216:ethylene; C436292:AtMPK4 protein, Arabidopsis; C436293:MPK6 protein, Arabidopsis; D020928:Mitogen-Activated Protein Kinases; C524430:AP2C1 protein, Arabidopsis; D010749:Phosphoprotein Phosphatases