A Novel Plant Growth–Promoting Agent Mitigates Salt Toxicity in Barley (Hordeum vulgare L.) by Activating Photosynthetic, Antioxidant Defense, and Methylglyoxal Detoxification Machineries

Abstract Developing and applying a novel plant growth–promoting agent (PGPA; micronutrient-amino acid chelated compound developed from autolysis yeast cells) in alleviating salt stress toxicity can be the best alternative option environmentally economically. High-performance liquid chromatography (HPLC) showed that assembled PGPA is rich nucleobases than extract (> 56-fold). This study, as first investigation, was aimed to evaluate PGPA’s potential role reducing oxidative injury induced by stress. Barley ( Hordeum vulgare L. cv. Giza 123) plants were grown under non-saline or saline conditions (6.0 12.0 dS m −1 ) with without foliar application. The application mitigated salt-induced enhancing activity of superoxide dismutase, catalase, guaiacol peroxidase, ascorbate monodehydroascorbate reductase, dehydroascorbate glutathione S-transferase, well content ascorbate, glutathione, proline, glycinebetaine. Moreover, protected salt-stressed deleterious effects methylglyoxal up-regulating glyoxalase enzymes activity. alleviated membrane damage decreasing reactive oxygen species (ROS) accumulation, lipid peroxidation, protein oxidation, electrolyte leakage, NADP + content. protection photosynthesis closely associated improved chlorophyll fluorescence parameters, leaf water content, stability index, NADPH PGPA-treated also exhibited higher stomatal conductivity together transpiration photosynthetic rates conditions. Overall, regulated antioxidant machinery, system, capacity, implying it plays critical mitigation. Therefore, could useful alleviate harmful salinity