VvXYLP02 confers gray mold resistance by amplifying jasmonate signaling pathway in Vitis vinifera

Xylogen-like proteins (XYLPs) are essential for plant growth, development, and stress responses. However, little is known about the XYLP gene family in grape and its protective effects against gray mold a destructive disease caused by Botrytis cinerea. We identified and characterized six common XYLPs in the Vitis vinifera genome (VvXYLPs). VvXYLP expression pattern analyses with B. cinerea infection showed that VvXYLP02 was significantly up-regulated in the resistant genotype but down-regulated or only slightly up-regulated in the susceptible genotype. VvXYLP02 overexpression in Arabidopsis thaliana significantly increased resistance to B. cinerea, indicating that the candidate gene has functional importance. Furthermore, JA treatment significantly up-regulated VvXYLP02 expression in V. vinifera. JA-responsive genes were also up-regulated in VvXYLP02 overexpression lines in A. thaliana under B. cinerea inoculation. These findings suggest that VvXYLP02, which is induced by JA upon the pathogen infection, enhances JA dependent response to enforce plant resistance against gray mold disease.