Stress response induced by cadmium in soybeans (Glycine max L.) and health risk assessment

Cadmium (Cd) is considered to be a dangerous trace element and environmental pollutant that causes a serious problem to agro ecosystem, and alters the functions of living organisms. For this purpose, this research was to assess the effects of Cd on the ecophysiological responses of Glycine max L. Seeds of soybean were grown in soil with 0, 50, 150, and 300 ppm CdCl2 for 10 days. The growth and physiological parameters of soybean were measured; the potential toxicological risk associated with soybean consumption was evaluated. Roots, stems, and leaves were contaminated by Cd in a concentration-dependent manner. The human health risk caused by Cd is only acceptable at 50 ppm and increases with the concentration of Cd. The results revealed different responses according to Cd concentration. However, to control the level of ROS, soybeans could counteract Cd stress via elevating antioxidant enzyme activities which are upregulated in roots and leaves. The total phenols, flavonoids, proline content and phenylalanine ammonia-lyase activity were increased with Cd concentration. Finally, glutathione, and ascorbate were increased in the leaves, and they were less affected in the roots compared to control.