title: Arabidopsis MPK3 and MPK6 play different roles in basal and oligogalacturonide- or flagellin-induced resistance against Botrytis cinerea.
abstract: Mitogen-activated protein kinases (MAPKs) are fundamental components of the plant innate immune system. MPK3 and MPK6 are Arabidopsis (Arabidopsis thaliana) MAPKs activated by pathogens and elicitors such as oligogalacturonides (OGs), which function as damage-associated molecular patterns, and flg22, a well-known microbe-associated molecular pattern. However, the specific contribution of MPK3 and MPK6 to the regulation of elicitor-induced defense responses is not completely defined. In this work we have investigated the roles played by these MAPKs in elicitor-induced resistance against the fungal pathogen Botrytis cinerea. Analysis of single mapk mutants revealed that lack of MPK3 increases basal susceptibility to the fungus, as previously reported, but does not significantly affect elicitor-induced resistance. Instead, lack of MPK6 has no effect on basal resistance but suppresses OG- and flg22-induced resistance to B. cinerea. Overexpression of the AP2C1 phosphatase leads to impaired OG- and flg22-induced phosphorylation of both MPK3 and MPK6, and to phenotypes that recapitulate those of the single mapk mutants. These data indicate that OG- and flg22-induced defense responses effective against B. cinerea are mainly dependent on MAPKs, with a greater contribution of MPK6.
authors.affiliation: Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Biologia e Biotecnologie "Charles Darwin," Sapienza Università di Roma, 00185 Rome, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Galletti
authors.forename: Simone
authors.initials: S
authors.lastname: Ferrari
authors.forename: Giulia
authors.initials: G
authors.lastname: De Lorenzo
mesh_terms: D017360:Arabidopsis / Q000382:microbiology* / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D020171:Botrytis / Q000472:pathogenicity*; D060467:Disease Resistance; D005408:Flagellin / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant; D054884:Host-Pathogen Interactions; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009844:Oligosaccharides / Q000737:chemistry / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology
chemical_list: D029681:Arabidopsis Proteins; D009844:Oligosaccharides; C412763:oligogalacturonic acid; D005408:Flagellin; C458516:AtMPK3 protein, Arabidopsis; C436293:MPK6 protein, Arabidopsis; D020928:Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; C524430:AP2C1 protein, Arabidopsis; D010749:Phosphoprotein Phosphatases