Mitigation of cadmium toxicity stress by magnetopriming during germination of soybean

Abstract

Cadmium (Cd) is a highly toxic heavy metal that poses a significant threat to food safety and agricultural production worldwide. Its solubility enables easy entry into plants, leading to reductions in seed germination, growth and crop yield. Thus, it is crucial to discover methods to alleviate the harmful impact of Cd on plant growth. Magnetopriming (MP) is a non-invasive and cost-effective technique that has been proposed to improve plant growth under abiotic stress conditions. The current study investigated the potential of MP to improve the seed germination, early seedling growth and biochemical responses of soybean under Cd toxicity. Soybean seeds were magnetoprimed with static magnetic field (SMF) strength of 200 mT for 1 hour before germination. The unprimed and magnetoprimed seeds were grown under different concentrations of cadmium chloride (0, 25, 50, 75, 100, 200 and 300 μM CdCl2) in Petri plates for five days in the dark at 25 + 1°C. The results revealed that Cd toxicity significantly reduced the germination percentage and inhibited the seedling growth parameters and increased oxidative stress, as determined by malondialdehyde (MDA) content in soybean seedlings from unprimed seeds. The inhibitory effect was increased with increasing concentration of Cd. However, MP remarkably increased the germination percentage, seedling growth parameters, activities of total amylase and protease, and hydrogen peroxide (H2O2) content and decreased MDA and proline content in germinating soybean seedlings at all concentrations of Cd. These findings suggest that MP can alleviate the adverse effects of Cd stress in soybean seedlings and increase the tolerance index towards Cd toxicity by enhancing the activity of amylotic and proteolytic enzymes and reducing oxidative stress.