Unlocking Triticum aestivum L. resilience: Exogenous proline's remarkable role in mitigating lead stress, and delving into the secrets of TaGSK1 gene expression

The application of proline as foliar spraying has emerged as a promising solution to combat lead-induced crop stress. This study highlights the effectiveness of external proline in enhancing wheat crop health under lead stress. We reveal how lead stress negatively impacts key factors like biomass, chlorophyll levels, and crop yield, particularly in 100-grain weight. Gas exchange parameters, including stomatal conductance, CO2 levels, photosynthesis, water-use efficiency, and transpiration, also suffer under lead stress. Significantly, exposure to lead stress triggers the activation of antioxidant enzymes and elevates levels of proline, calcium, and protein. Nonetheless, the application of foliar proline proves highly effective in alleviating these detrimental effects by reducing reactive oxygen species and enhancing proline and protein levels in wheat. Additionally, our findings demonstrate a significant upregulation of TaGSK1 gene expression at different proline concentrations. Compared to controls, TaGSK1 expression increases by 1.7-fold under 50 mM proline stress and an impressive 4.7-fold under 200 mM proline stress in wheat. This finding holds promise in alleviating the adverse effects of lead stress and strengthening crop resilience for a more secure and sustainable future in wheat cultivation amid various stressors. (c) 2024 SAAB. Published by Elsevier B.V. All rights reserved.