β-ketoacyl-CoA synthase improves the drought tolerance of root restricted grown grapevines by regulating the cuticular wax biosynthesis

Abstract

• Twenty-five VvKCS genes were identified in grapevine ( Vitis vinifera L.). • VvKCS12 and VvKCS14 were induced by root restriction and drought stress. • Overexpression of VvKCS12 and VvKCS14 improved wax biosynthesis in Arabidopsis. • Overexpression of VvKCS12 and VvKCS14 enhanced drought tolerance in Arabidopsis. Drought stress limits fruit ripening and quality of grape cultivar, particularly with the use of root restriction. However, the mechanism involved in the molecular response to water deficit concomitant to agriculture adjustment remains poorly understood. In the present study, the regulation of two grape β-ketoacyl-CoA synthase ( KCS ) genes obtained with transcriptome analysis whose expression is significantly up-regulated under root restriction. Twenty-five KCS coding genes were identified and analyzed from grapevine genome. Two VvKCSs ( VvKCS12 and VvKCS14 ) had one major transcript expressed at a significantly higher level and up-regulated by drought stress in grape leaves. Subcellular localization analysis demonstrated that VvKCS12 and VvKCS14 were located on endoplasmic reticulum (ER). Heterologous overexpression of VvKCS12 and VvKCS14 promoted leaves cuticular wax biosynthesis and deposition, and enhanced drought tolerance in Arabidopsis. These findings underscore the roles of VvKCS12 and VvKCS14 in the drought response of grapes due to root restriction and pave the way for advanced study of other different functions.