Insights into grapevine defense response against drought as revealed by biochemical, physiological and RNA-Seq analysis

Abstract

Grapevine is economically important and widely cultivated fruit crop, which is seriously hampered by drought worldwide. It is necessary to understand the impact of glitches incurred by the drought on grapevine genetic resources. Therefore, in the present study RNA-sequencing analysis was performed using cDNA libraries constructed from both drought-stress and control plants. Results yielded, a total of 12,451 differentially expressed genes (DEGs) out of which 8,022 genes were up-regulated and 4,430 were down-regulated. Further physiological and biochemical analyses were carried out to validate the various biological processes involved in the development of grapevine in response to drought stress. Results also showed that decrease in rate of stomatal conductance in-turn decrease the photosynthetic activity and CO₂ assimilation rate in the grapevine leaves and most ROS detoxification systems, including stress enzymes, stress related proteins and secondary metabolites were strongly induced. Moreover, various hormones were known to be induced in the present study in response to drought. Overall the present study concludes that these DEGs play both positive and negative role in drought tolerance by regulating different biological pathways of grapevine. However our findings have provided valuable gene information for future studies of abiotic stress in grapevine and other fruit crops.