Ameliorative Role of Ascorbic acid to Drought Stress in Hordeum Vulgare L. through Modulation of the polyamines, osmolytes and Antioxidant Defense System

Abstract

Drought is a severe environmental condition that negatively impacts the metabolic processes of plants, making it one of the most devastating stressors they face. Drought has a significant detrimental impact on grain crops, such as barley. Exogenous application (foliar) of ascorbic acid has been shown to confer tolerance against biotic and abiotic stresses. In the present research, the ability of ascorbic acid to increase drought stress tolerance was investigated in barley (Hordeum vulgare L.). Three barley genotypes, a drought-resistant genotype (V3 = Jau-Haider 93) and two drought-sensitive genotypes (V1 = 92044 and V2 = 92112) were grown in plastic pots under soil conditions. There were two levels of water, control i.e., with adequate irrigation and drought stress with 60% of field capacity. Ascorbic acid was applied as a foliar spray (1 mM). Overall, the plant growth of all genotypes was inhibited by drought stress. However, the drought-tolerant variety (V3 = Jau-Haider 93) showed higher growth rates under drought stress. Ascorbic acid as foliar spray supported the barley plant growth under drought stress to ameliorate the adverse effects of stress by maintaining growth, relative water contents, and osmotic adjustment by enhancing antioxidant enzymes, polyamines, proline and phenolics contents.