Harshraj Shinde, Yikang Hu, Kiflu Tesfamicael, Penny J. Tricker, Ute Baumann, Everard J. Edwards, and Carlos M. Rodriguez Lopez*
*University of Kentucky, 1405 Veterans Dr, 432, Lexington, KY 40506 (cmro267@uky.edu)

Grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) is widely used for winemaking all over the world. Quality and yield is challenged increasingly by environmental stresses. Leaf temperature, stomatal conductance, and stem water potential change rapidly in response to abiotic stress. Our study aimed to screen genes regulating these physiological changes in grapevine. We applied weighted correlation network analysis and clustering to associate changes in physiological parameters with gene expression data. Four significant modules containing 3521 genes and six clusters containing 14,143 genes were identified from transcriptome data. The darkmagenta module showed a strong positive correlation with leaf temperature and significant negative correlation with stem water potential and stomatal conductance. Five hub genes were identified from the darkmagenta module; these genes are involved in reactive oxygen species scavenging, histone methylation, and so on. Gene ontology analyses of modules and clusters highlighted key biological processes as biological regulation, response to stimulus and response to stress. Pathway analyses highlighted key path- ways as thermogenesis, plant hormone signal transduction and protein processing in endoplasmic reticulum. The candidate genes and metabolic pathways identified in this study are valuable genetic resources or targets for future breeding programs.

Funding Support: Australian grape and wine authorities grants, Grant ID: VA1503.