Mitigating the Effect of Salt Toxicity on Growth, Physiological and Biochemical Processes of Wheat by the Application of Ascorbic Acid

Abstract

Salt stress is an important factor which reduces plant growth and yield, it reduces nutrient uptake and water balance which adversely effects on plants health. Higher salt concentrations in growth medium hinder nutrient uptake and can lead to dehydration which results in destruction of plant cells ultimately leading to reduced plant growth and yield. Salt toxicity is a major issue to agriculture land globally. After soil erosion it is second most prominent cause of soil degradation. In winter season 2023 a pot experiment according to complete randomized design (CRD) was conducted to examine effects of exogenous application of antioxidant ascorbic acid (ASA) on growth, biochemical and physiological parameters of wheat under salt stress. Two treatments of ASA 0.2 and 0.8 mM were applied to wheat plants grown under normal and stress conditions. Analysis of data revealed that salt stress significantly reduced all growth parameters like root length, shoot length and their fresh and dry weight. When ASA was applied, it significantly reversed the effects of salinity on growth parameters. Application of ASA also significantly improved biochemical and physiological parameters such as carbonic anhydrase (CA) activity, photosynthetic pigments Chl a, Chl b and total chlorophyll. It also increased accumulation of compatible solutes like proline to alleviate toxic effects of salinity. Exogenous application of ASA also reduced the generation and accumulation of reactive oxygen species (ROS) and harmful free radicals such as H2O2 and malondialdehyde (MDA). Accumulation of MDA and H2O2 can cause deterioration of membrane. So from this study it can be concluded that exogenous application of ASA can enhance wheat plants tolerance to salt toxicity by increasing photosynthetic rate, accumulation of compatible solutes and by reducing the generation and accumulation of ROS.