Attenuating the adverse aspects of water stress on wheat genotypes by foliar spray of melatonin and indole-3-acetic acid

Melatonin is important due to its involvement in regulation of diverse mechanisms in plants. Its presence in plants is universal and provides primary defense against environmental stresses. In this study the effect of foliarly applied indole-3-Acetic Acid (IAA) and melatonin (control, 100, 150 µg/g each) on wheat seedling growth under water deficit condition was examined. The mitigation of stress was seen in melatonin treated wheat plants facing abiotic stress, with less accumulation of the H2O2, MDA and anthocyanin. A marked decrease in chlorophyll, total soluble proteins, total soluble sugars, ascorbic acid, phenolic contents and yield- related attributes was noticed in stressed condition. Treatment with melatonin and IAA alleviated stress induced decrease in biochemical attributes, and growth of wheat plants in a dose-dependent manner. A significant increase in yield was achieved by melatonin treatments in Ujala-2016 under limited water supply. It is worthy to mention that melatonin spray at 150 µg/g followed by IAA proved to be the most pronounced treatment in the buildup of osmolytes and regulation of antioxidant defense system with increase in yield under water limited environment.