Physiological and transcriptional variations inducing complex adaptive mechanisms in grapevine by salt stress

Abstract

Salinity is an omnipresent stressor, depleting osmotic potential and affecting the vineyard development and productivity. It is indispensable to screen the grapevine genetic resources for possibilities to mitigate and adapt to the stress conditions. This paper describes the distinct response of the grapevine under progressive salt stress duration (0, 24, 48, and 72 h). Intriguingly, besides the adverse effect of salt stress on grapevine growth, the findings exhibit significant levels of stress responses to diminish the impact of salinity. Discerned are the accumulation of glycine betaine (GB) and trehalose, which can be supposed as distinct grapevine responses associated with the maintenance of high K+ level and, consequently, lower K+/Na+ ratios, with an excellent performance of cell water status and photosynthetic activity as compared to the controls. Moreover, an alleviated level of the oxidative stress marker (MDA) gives rise to superoxide radicals (O2−) and hydrogen peroxide (H2O2), while the antioxidative scavenging system is activated to counter the synthesis of reactive oxygen species (ROS). Principal component analysis (PCA) distinguished several salt prediction candidate markers based on physiological and transcriptional indexes in four different clusters. Current findings have elucidated new and fascinating responses of the grapevine to lengthy salt-stress period and provide a list of intended enzymatic targets for candidate gene selection to uplift the abiotic stress tolerance in horticultural crops.