6533b852fe1ef96bd12ab311

RESEARCH PRODUCT

Role of Lys-M Receptor Kinases in the perception of chitooligosaccharides to trigger signaling events and immune responses in grapevine (Vitis vinifera)

subject

description

The establishment of defense reactions to protectplants against invading pathogens first requires therecognition of Microbe-Associated MolecularPatterns (MAMPs), detected by plasma membrane-bound Pattern Recognition Receptors (PRRs). TheseMAMPs, also termed elicitors, are used in severalbiocontrol products that are gradually developing toreduce the use of chemical pesticides inagriculture. Chitin, the main component of fungalcell walls, as well as its deacetylated derivative,chitosan, are two chitooligosaccharides (COS) thatcan be found in some of these products.Unfortunately, the mechanism allowing theperception of these molecules is still poorlyunderstood in Vitis vinifera, sometimes hamperingthe improvement and the generalization of theseemerging crop protection tools. On the contrary,chitin perception in the model plant Arabidopsisthaliana is well described and relies on a tripartitecomplex formed by three membrane-bound LysMReceptor-Like Kinases named AtLYK1/CERK1, AtLYK4& AtLYK5, the latter having the strongest affinity tochitin. In grapevine, we have demonstrated that COSperception rely on VvLYK1-1 & VvLYK1-2 but not onVvLYK1-3. In this context, we recently performedexperiments to complement the Arabidopsis lyk5simple mutant and the lyk4/5 double mutant, whichshowed altered response to COS, by overexpressingtheir grapevine orthologous genes (VvLYK5-1/2). Ourresults revealed that MAPK activation and defensegene expression were partially restored after chitintreatment by the complementation with VvLYK5-1 butnot with VvLYK5-2. These preliminary results seem toindicate that VvLYK5-1 participates in the chitinrecognition in grapevine, together with VvLYK1-1/2previously identified. Furthermore, as theperception of chitosan does not seem altered in theAtlyk5 mutant, it would also appear that theperception of chitin and chitosan does not involvethe same receptors. FRET-FLIM experimentsinitiated with these co-receptors will soon provideadditional information to better decipher themechanism of COS perception in grapevine.