Short-term Effects of Exogenous Application of Ascorbic Acid on Barley (Hordeum vulgare L.) Seedlings under Salinity Stress

Ascorbic acid (AA) is one of the most important and abundant water-soluble antioxidants in plants, and plays important role in adaptation of plants to stress conditions including salt stress. Salt stress is first perceived by the plant roots and inhibits plant growth in the short-term by inducing osmotic stres caused by decreased water availability. The study focused on determination of alleviating effects of exogenous application of ascorbic acid (AA) on barley seedlings exposed to salt stress for short term. In hydroponic conditions, three-leaf-stage barley cv. Marti treated with 160 mM NaCl with or without 0.5 mM AA for 0, 2, and 26 h. The exogenous AA has been found to increase the accumulation of osmolytes by 10 and 25% in leaf and root, respectively, at 26 h after treatment compared to salinity conditions. Besides, AA decreased the enhanced levels of electrolyte leakage due to salt stress of root and leaf tissues from 88.6 to 78.2% and 37.5 to 32.9%, respectively. Furthermore, addition of 0.5 mM AA into root medium led to rapidly differentiation in expression of salt-stress responsive genes including HvDRF2, HvWRKY12, HvBAS1, HvDHN3, and HvNHX1 in root and leaf of barley seedlings under salt stress.