Roles of ascorbic acid on physiological, biochemical and molecular system of Lycopersicon esculentum Mill. against salt stress

Tomato is one of the important plants in the world as a food, medicine etc. it is sensitive to abiotic stresses and its crop is affected by them. Moreover, Ascorbic acid (AsA) is one of the universal of plant defence mechanism against the stresses specially salinity and drought to scavenger’s reactive oxygen species. According to global warming and scarcity of water resources, subsequently drying and salinization of soils; we need to investigation of AsA effects in tomato under salinity stress. In this context, effects of ascorbic acid and salinity stress on some of physiological parameters, key enzymes including SOD, APX and expression of LeNHX1 and SIERF16 genes that involved in antioxidant system were studied in Lycopersicon esculentum Mill. plants in hydroponic conditions. Our results showed that the Ascorbic acid treatments were increased activity of superoxide dismutase (SOD) and Ascorbate peroxidase (APX) and improved physiological parameters such as lipid peroxidation and Na+/K+ contents of tomato under salt stress via increases of LeNHX1 and SIERF16 genes expression.