Temporal gene expression analysis reveals a synergistic effect of combined drought and heat stress in grapevine (Vitis vinifera L.)

Abstract

Grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) is widely used for winemaking all over the world. Drought and heat stresses are two of the major abiotic stresses reducing grape quality and yield. However, drought and heat tolerance are still poorly characterized in perennial crops such as grapevine. During this study, stomatal conductance, stem water potential and leaf temperature were measured to determine plant physiological status. RNA-seq technology was used for the analysis of differentially expressed genes (DEGs) of leaf samples between the control and three treatments, which were drought, heat and a combined treatment. Gene expression profiles were grouped by treatments and timepoints. The great majority of unique DEGs were found to be induced by the combined drought and heat treatment. 169 up-regulated genes were induced by drought, 85 by heat and 1218 by the combined treatment; 78 down-regulated genes were induced by drought, 72 by heat and 1427 by the combined treatment. Three potential and significant regulation pathways of stress response were identified based on Gene Ontology (GO) analysis i.e. cytokinin-activated signalling pathway, ion transport pathway and Nitric Oxide-mediated pathway. This study provides preliminary insights into the transcriptomic response to drought and heat stress in grapevine.