Silicon-Mediated Improvement in Maize (Zea mays L.) Resilience: Unrevealing Morpho-Physiological, Biochemical, and Root Attributes Against Cadmium and Drought Stress

Abiotic stress is the major restricting factor for agricultural growth and productivity worldwide particularly drought and cadmium stress in maize. The primary goal of the current research was to determine the role of silicon in reducing the adverse effects of drought and cadmium stress on Maize (Zea mays L.)

The treatments of the current experiment were i) T₀ = Control (100% FC) T₁ = Drought stress (50% FC), T₂ = Cd toxicity (25 mg kg⁻¹), T₃ = Cd + Drought stress ii) and Silicon applications, S₀: No Silicon application, S₁: Silicon soil application (50 mg kg⁻¹).

The results revealed that soil application of Si had significant impacts on growth parameters, including Plant height, LA, SFW, and SDW. Drought and Cd stress decreased SL up to 12% and 22% respectively. Soil application of Si ameliorated the negative impacts of drought and Cd stress and improved the SL by 12%. The turgor potential of leaf was reduced by 29% under drought stress, 26% under Cd stress, and 53% reduction was observed in drought + Cd stress treatment, in comparison with control but soil application of silicon considerably enhanced the leaf turgor potential by 63%. Gas Exchange attributes and photosynthetic pigments significantly declined under drought and Cd stress and a statistically highly significant reduction was observed in combined stress treatment (drought + Cd stress) as compared to control (no stress). Soil application of silicon (50 mg/kg) enhanced the gas exchange attributes, contents of protein, gas exchange attributes, and photosynthetic pigments under drought and cadmium stress alone and also in combined stress (drought + Cd stress) treatment as compared to control. Chlorophyll contents (a and b) improved up to 18% and 26% respectively in comparison with control. The H₂O₂ concentration increased under drought and Cd stress and reduced under control conditions. Cadmium and drought stress reduced the concentrations of peroxidase, superoxide dismutase, and catalase. Soil application of silicon @ 50 mg/kg increased the concentrations of superoxide dismutase, catalase, and peroxidase by 26, 28, and 31% respectively as compared to control.

In crux, soil applications of silicon @ 50 mg kg⁻¹ improved plant growth of maize by improving physiological and biochemical attributes under drought and cadmium stresses.