Biogenic ZnO nanoparticles synthesized using Halimeda opuntia seaweed extract: A sustainable approach for promoting horse gram seed germination

Rapid and uniform seed germination is crucial for optimizing crop productivity and economic returns in commercial agriculture, thereby contributing to global food security. Hence, this study explored the effect of impact of ZnO nanoparticles (ZnO NPs) synthesized using Halimeda opuntia (L.) Lam. extract on the seed germination of horse gram, Macrotyloma uniflorum (Lam.) Verdc. When compared to the control, the ZnO NPs significantly improved seed germination, shoot length, root length, dry matter, and vigor index of the seeds of horse gram, M. uniflorum. The optimal concentration of the ZnO NPs for these improvements was 75 ppm, resulting in a 94% germination rate, 11.88 cm shoot length,19.77 cm root length, 374.8 mg dry matter, and 2876.4 vigor index. Biochemical analysis revealed that ZnO NPs stimulated the activities of antioxidant enzymes, catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) in germinated seeds while reducing malondialdehyde (MDA) content, a marker of oxidative stress. These findings suggest that ZnO NPs enhance horse gram seed germination through improved antioxidant defense and reduced oxidative stress. Overall, this study validates the potential of ZnO NPs as a promising eco-friendly approach for promoting horse gram seed germination and potentially improving crop yield.