Response of Different Doses of Zinc Oxide Nanoparticles in Early Growth of Mung Bean Seedlings to Seed Priming under Salinity Stress Condition

Abstract

Background: Salinity impacts physiological processes, including germination, seedling development, ionic balance and water relations, leading to growth inhibition. Mung bean’s early stage is susceptible to salt stress. Our study aimed to mitigate salt stress at early stage using zinc oxide nanoparticles (ZnO-NPs) to enhance mung bean tolerance. Methods: Pot experiment was carried out to incorporate ZnO-NPs into mung bean seedlings. Two mung bean genotypes, TMB-37 (tolerant) and MH-1314 (sensitive), were chosen. Seeds were primed with ZnO-NPs at various concentrations (0.00 ppm, 50 ppm, 100 ppm, 500 ppm and 1000 ppm) and shown in saline soil. Result: ZnO-NP priming notably increased germination percentage, shoot length and shoot dry weight in both genotypes. In 25days-old seedlings, ZnO-NPs elevated antioxidant enzyme activity, proline content, especially superoxide dismutase (SOD) and peroxidase (POX) activity, while reducing lipid peroxidation and membrane injury. 1000 ppm ZnO-NPs had the negative impact on the root trait of sensitive genotype. Lower doses of ZnO-NP (50 ppm) concentrations was very effective in mitigating the adverse effect of salinity stress in both the genotypes offering a key approach for mung bean’s salt stress mitigation.