Lead (Pb), like other heavy metals, exerts highly toxic direct and indirect effects on plants, animals, and humans. This hydroponic study investigated the alleviating effects and beneficial role of exogenous silicon (Si) application in Pb-stressed wheat plants (BARI-27). Growth and physiological parameters including chlorophyll content, photosynthesis, morphological traits, Pb uptake and accumulation, lipid peroxidation (LPO), hydrogen peroxide (H₂O₂) content, electrolyte leakage, cell death, soluble protein, glutathione, cysteine, and non-enzymatic antioxidant activities were evaluated. In this study plants were harvested after five days of treatment for physiological and biochemical analyses. Pb stress severely inhibited root and shoot growth, whereas Si supplementation markedly restored plant growth under Pb stress. Si application significantly reduced Pb uptake, electrolyte leakage, H₂O₂ accumulation, LPO content and cell death, while enhancing soluble protein content, Si accumulation, glutathione and cysteine in Pb-stressed wheat plants compared with Pb treatment alone. Overall, Si supplementation protected plant tissues from oxidative membrane damage under Pb stress, thereby alleviating Pb toxicity and improving wheat growth and physiological performance. These findings suggest that Si plays a significant role in mitigating Pb-induced morphological and physiological damage in wheat plants.
