Justine Claverie, Freddy Boutrot, Lena Stransfeld, Daphnée Brulé, Lucie Trdá, Marie-Claire Héloir, Pablo Tornero, Laura J. Davies, Clizia Villano, Annick Chiltz, Benoît Darblade, Marielle Adrian, Cyril Zipfel, Benoît Poinssot, Ian B. Dry, University of Zurich, Dry, Ian B, Agroécologie [Dijon], Université de Bourgogne (UB)-Institut National de la Recherche Agronomique (INRA)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Centre National de la Recherche Scientifique (CNRS), University of Naples Federico II, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Elicityl SA, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Norwich Research Park, The Sainsbury Laboratory [Norwich] (TSL), ANR (PATRIC project) [ANR-13-KBBE-0001], Regional Council of Bourgogne Franche-Comte (PARI grant) [2016-9201AAO050S016 36, 2015-9201AAO048502578, 29000907], Regional Council of Bourgogne Franche-Comte (FEDER) [2015-9201AAO048502578, 29000907, BG0005888], INRA [2015-9201AAO048502578, 29000907], Gatsby Charitable Foundation, Biotechnology and Biological Sciences Research Council (BBSRC) [BB/G024936/1], Dry, Ian B., Poinssot, Benoît, Brule, Daphnee, Villano, Clizia, Davies, Laura J., Trda, Lucie, Claverie, Justine, Heloir, Marie-Claire, Chiltz, Annick, Adrian, Marielle, Darblade, Benoıt, Tornero, Pablo, Stransfeld, Lena, Boutrot, Freddy, Zipfel, Cyril, and Poinssot, Benoit
[EN] Chitin, a major component of fungal cell walls, is a well-known pathogen-associated molecular pattern (PAMP) that triggers defense responses in several mammal and plant species. Here, we show that two chitooligosaccharides, chitin and chitosan, act as PAMPs in grapevine (Vitis vinifera) as they elicit immune signalling events, defense gene expression and resistance against fungal diseases. To identify their cognate receptors, the grapevine family of LysM receptor kinases (LysM-RKs) was annotated and their gene expression profiles were characterized. Phylogenetic analysis clearly distinguished three V. vinifera LysM-RKs (VvLYKs) located in the same clade as the Arabidopsis CHITIN ELICITOR RECEPTOR KINASE1 (AtCERK1), which mediates chitin-induced immune responses. The Arabidopsis mutant Atcerk1, impaired in chitin perception, was transformed with these three putative orthologous genes encoding VvLYK1-1, -2, or -3 to determine if they would complement the loss of AtCERK1 function. Our results provide evidence that VvLYK1-1 and VvLYK1-2, but not VvLYK1-3, functionally complement the Atcerk1 mutant by restoring chitooligosaccharide-induced MAPK activation and immune gene expression. Moreover, expression of VvLYK1-1 in Atcerk1 restored penetration resistance to the non-adapted grapevine powdery mildew (Erysiphe necator). On the whole, our results indicate that the grapevine VvLYK1-1 and VvLYK1-2 participate in chitin- and chitosan-triggered immunity and that VvLYK1-1 plays an important role in basal resistance against E. necator., This work has been financially supported by ANR (PATRIC project, grant ANR-13-KBBE-0001) (to BP), the Regional Council of Bourgogne Franche-Comte (PARI grant 2016-9201AAO050S016 36 and FEDER grant BG0005888) and INRA for the funding of Justine Claverie's PhD (grants 2015-9201AAO048502578 and 29000907), by the Gatsby Charitable Foundation (to CZ), and by the Biotechnology and Biological Sciences Research Council (BBSRC) grants BB/G024936/1 (ERA-PG PRR CROP (to CZ).