Contrasting tolerance among soybean genotypes subjected to different levels of cadmium stress

The present study investigated the effects of cadmium stress on the growth, physio-biochemical attributes, and enzyme activity of five soybean genotypes. Cadmium stress significantly reduced growth attributes, such as the length of plant shoots and roots and the fresh and dry weight of plant shoots, but enhanced hydrogen peroxide (H₂O₂) production, lipid peroxidation (MDA), and electrolyte leakage, especially in the PK-416 and Pusa-24 genotypes. Cadmium stress also enhanced leaf proline content and the activity of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase, especially in the Pusa-37 and Pusa-16 genotypes. Efficient antioxidant systems determine the stress tolerance potential of specific genotypes. Cadmium accumulated to higher levels in roots than in shoots, which indicated that cadmium was selectively absorbed to upper sensitive plant parts. The present study may provide a sustainable approach for identifying soybean genotypes that can be cultivated at heavy metal-polluted sites.