title: The endopolygalacturonase 1 from Botrytis cinerea activates grapevine defense reactions unrelated to its enzymatic activity.
abstract: A purified glycoprotein from Botrytis cinerea (strain T4), identified as endopolygalacturonase 1 (T4BcPG1) by mass spectrometry analysis, has been shown to activate defense reactions in grapevine (Vitis vinifera cv. Gamay). These reactions include calcium influx, production of active oxygen species, activation of two mitogen-activated protein kinases, defense gene transcript accumulation, and phytoalexin production. Most of these defense reactions were also activated in grapevine in response to purified oligogalacturonides (OGA) with a degree of polymerization of 9 to 20. In vivo, these active OGA might be a part of the released products resulting from endopolygalacturonase activity on plant cell walls. Nevertheless, the intensity and kinetics of events triggered by OGA were very different when compared with T4BcPG1 effects. Moreover, chemical treatments of T4BcPG1 and desensitization assays have allowed us to discriminate enzymatic and elicitor activities, indicating that elicitor activity was not due to released oligogalacturonides. Thus, BcPG1 should be considered as both an avirulence and a virulence factor. The role of the secreted BcPG1 in the pathogenicity of Botrytis cinerea is discussed.
authors.affiliation: Laboratoire de Biochimie, Biologie cellulaire et Ecologie des Interactions Plantes/Micro-Organismes, UMR 1088 INRA/Université de Bourgogne, 17 rue Sully, BP 86510, 21065 Dijon cedex, France.
authors.forename: Benoît
authors.initials: B
authors.lastname: Poinssot
authors.forename: Elodie
authors.initials: E
authors.lastname: Vandelle
authors.forename: Marc
authors.initials: M
authors.lastname: Bentéjac
authors.forename: Marielle
authors.initials: M
authors.lastname: Adrian
authors.forename: Caroline
authors.initials: C
authors.lastname: Levis
authors.forename: Yves
authors.initials: Y
authors.lastname: Brygoo
authors.forename: Jérome
authors.initials: J
authors.lastname: Garin
authors.forename: Francesca
authors.initials: F
authors.lastname: Sicilia
authors.forename: Pierre
authors.initials: P
authors.lastname: Coutos-Thévenot
authors.forename: Alain
authors.initials: A
authors.lastname: Pugin
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D020171:Botrytis / Q000201:enzymology*; D002118:Calcium / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D007113:Immunity, Innate / Q000187:drug effects / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000378:metabolism; D011096:Polygalacturonase / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D027843:Vitis / Q000166:cytology / Q000235:genetics / Q000378:metabolism*
chemical_list: D009844:Oligosaccharides; C412763:oligogalacturonic acid; D006861:Hydrogen Peroxide; D020928:Mitogen-Activated Protein Kinases; D011096:Polygalacturonase; D002118:Calcium