Application of Silicon Improves Rhizosheath Formation, Morpho-Physiological and Biochemical Responses of Wheat under Drought Stress

Rhizosheath, a mixture of soil and mucilage that remains attached to the root system after being removed from the soil and shaken, plays a prominent role in the resistance of plants to drought stress. This study aims to investigate the effect of silicon (Si) on rhizosheath formation and mitigate the effects of drought stress in wheat. It was hypothesized that Si positively enhances root hair formation and rhizosheath formation under soil drying conditions, improving plant access to water under soil drying conditions. Wheat seeds were grown under different levels of Si (control, 150 and 300 mg kg−1 monosilicic acid, and 150 and 300 mg kg−1 nano-silicon) and irrigation (0.4 field capacity (FC) and 0.8 FC) under greenhouse conditions. Under drought stress, the application of Si significantly increased root hair length, density, rhizosheath formation, and transpiration rate. Applying Si increased the length of root hairs by 45–107