The endopolygalacturonase 1 from Botrytis cinerea activates grapevine defense reactions unrelated to its enzymatic activity.
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.
Poinssot
Benoît
B
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.
Vandelle
Elodie
E
Bentéjac
Marc
M
Adrian
Marielle
M
Levis
Caroline
C
Brygoo
Yves
Y
Garin
Jérome
J
Sicilia
Francesca
F
Coutos-Thévenot
Pierre
P
Pugin
Alain
A
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*
D009844:Oligosaccharides; C412763:oligogalacturonic acid; D006861:Hydrogen Peroxide; D020928:Mitogen-Activated Protein Kinases; D011096:Polygalacturonase; D002118:Calcium