Mitigation of Chromium Toxicity in Wheat (Triticum aestivum L.) Through Silicon

Chromium (Cr) is a toxic metal usually found in soil and water, causing environmental pollution. Silicon (Si), however, has excelled in alleviating the stress caused by toxic elements in plants, and its beneficial role was mainly based on external and internal plant mechanisms. This study investigates whether and how Si influences the alleviation of Cr toxicity in wheat at the physiological and biochemical levels. The addition of Si in Cr-stressed plants significantly improved morpho-physiological characteristics, total protein, and membrane stability compared to Cr-stressed plants, suggesting that Si does have critical roles in Cr detoxification in wheat. Furthermore, Si supplementation in Cr-stressed plants showed a significant increase of Cr in roots but not in shoots compared with the plants grown under Cr stress. The addition of Si in Cr stress the raised the total chlorophyll (a and b) compared to non-treated controls. Beside this, abiotic stress indicators, such as cell death, electrolyte leakage and total soluble protein remarkably improved subjected to Si under Cr stress. These improvements are in accordance with the significant decrease of Cr in both root and shoot due to Si under Cr stress. Furthermore, Si application enhanced non-enzymatic scavenging and proline concentration to reduce Cr-induced oxidative damage in wheat. These findings reveal the role of Si on Cr detoxification in wheat and can be further implemented as a fertilization strategy.