Physiological and biochemical analysis of barley (Hordeum vulgare) genotypes with contrasting salt tolerance

Salt stress tolerance is a complex trait reducing drastically barley production. The present study assessed variability among two salt-tolerant contrasting barley genotypes on ROS-scavenging enzymes, osmorptectants, growth, water status and photosynthetic activity. The screening was released at the early vegetative stage under 200 mM NaCl during 0, 2 and 9 days. The results showed a significant earlier and higher increase in enzyme activities and transcript abundances of SOD and APX, in the salt-tolerant compared to the salt-sensitive genotype, In addition, the salt-tolerant barley genotype had better osmoprotection ability with higher accumulation of proline and soluble sugars contents. Hence conferring a differential growth performance among barley salt stress contrasting genotypes. Furthermore, High positive significant correlations have been detected between the antioxidative response (assessed by antioxidant enzymes activities and the expression profiles of their respective genes) and the osmotic response (evaluated by both proline and soluble sugars contents) under salt stress. Hence emphasizing the involvement of oxidative and osmotic homeostasis adjustment on averting ROS accumulation and resulting in significant growth rate sustain, water use efficiency and photosynthetic potential maintenance under salt stress.