Ameliorative Effects of Silica on Growth, Antioxidant Response, and Metal Uptake in Chromium-Exposed Wheat
摘要
Chromium (Cr) toxicity adversely affects crop productivity and poses significantly health risks. However, silicon (Si), an inorganic amendment, has potential to mitigate these effects in wheat crop. A pot study was conducted to examine the ameliorative role of Si in enhancing grain yield, reducing metal accumulation and improving overall crop performance by influencing morphological, physiological and biochemical parameters under Cr stress. The experiment followed a completely randomized design with four replications. The pots were irrigated weekly with Cr contaminated water after germination, and two levels of silicon (Si at 50 mg kg−1 and Si at 100 mg kg−1) were applied. Chromium stress reduced wheat growth; however, the application of both levels of silica to Cr stressed plants improved crop growth by reducing the Cr toxicity and enhancing physiological and biochemical attributes. The addition of silicon under Cr stress led to a significant increase in plant height (up to 11%), and improved root and shoot biomass, with fresh biomass increased by 60 and 70%, and dry biomass by 47 and 162%, respectively. Root morphological parameters improved by up to 100%, and membrane stability increased by 67%. Additionally, Si modulated antioxidant enzymatic activity, which provided protection against Cr stress. Silicon application also reduced Cr concentration in plant tissues by up to 35%. Daily intake of Cr and the Health Risk Index were lowered with Si application. Overall, the exogenous application of Si reduced Cr phytoaccumulation, thereby lowering health risks and promoting wheat crop growth and development.