Silicic acid seed pre-treatment modulates growth and antioxidant responses in maize under drought stress.

Drought stress is the most vulnerable abiotic factor affecting plant growth and yield. The use of silicic acid as seed priming treatment is emerging as an effective approach to regulate maize plants susceptibility to water stress. The study was formulated for investigating the effect of silicic acid seed priming treatment in modulating the oxidative defense and key physio-biochemical attributes of maize plants under drought stress conditions. Silicic acid (control, 0.3, 0.5, 0.7, and 1 mM) primed seeds of maize cultivars Gohar-19 and Pak Afghoi were sown in soil filled pots at 100% and 60% field capacity. At 60% field capacity, a marked decline in fresh (1.23, 1.03 g) and dry (0.45, 0.38 g) biomass was observed as compared to 100% field capacity (1.34, 1.13 g; 0.53, 0.50 g) in Gohar-19, which exhibited better performance as compared to Pak Afghoi under control and drought stress conditions. Notably, seed priming with 1 mM silicic acid markedly enhanced antioxidant enzyme activities including peroxidase, superoxide dismutase, and catalase, thereby strengthening the antioxidant defense system. Additionally, primed seeds exhibited improved accumulation of primary and secondary metabolites critical for stress adaptation. Principal component analysis confirmed a distinct separation of attributes with respect to silicic acid pretreatment under water stress in maize plants. These findings demonstrate that silicic acid seed priming effectively enhances maize growth and biochemical resilience under drought stress by activating antioxidant defenses and modulating key metabolic pathways. This approach holds a significant potential as a sustainable agronomic practice to mitigate drought effects and to improve crop productivity through nutri-priming.