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

ABSTRACT

Grapevine is an important and extensively grown fruit crop, which is severely hampered by drought worldwide. So, comprehending the impact of drought on grapevine genetic resources is necessary. In the present study, RNA-sequencing was executed using cDNA libraries constructed from both drought-stress and control plants. Results generated 12,451 differentially expressed genes (DEGs), out of which 8,021 genes were up-regulated, and 4,430 were down-regulated. Further physiological and biochemical investigations were also performed to validate the biological processes associated with the development of grapevine in response to drought stress. Results also revealed that decline in the rate of stomatal conductance, in turn, decrease the photosynthetic activity and CO2 assimilation in the grapevine leaves. Reactive oxygen species, including stress enzymes and their related proteins, and secondary metabolites were also activated in the present study. Likewise, various hormones also induced in response to drought stress. Overall, the present study concludes that these DEGs play both positive and negative roles in drought tolerance by regulating various biological pathways of grapevine. Nevertheless, our findings have provided valuable gene information for future studies of abiotic stress in grapevine and various other fruit crops.