Cadmium- and barium-toxicity effects on growth and antioxidant capacity of soybean (Glycine max L.) plants, grown in two soil types with different physicochemical properties

摘要: The pollution of agricultural soils by metals is growing concern worldwide, and increasingly subject to regulatory limits. However, the effect metal pollutants on responses plants can vary with soil types. In this study, we examined growth antioxidant soybean exposed contrasting (Oxisol Entisol), which were artificially contaminated cadmium (Cd) or barium (Ba). Cadmium reduced plant at concentrations higher than 5.2 mg (kg soil)–1, while Ba only affected 600 mg kg–1. Such levels are limits imposed Brazilian environmental legislation. Lipid peroxidation was increased a Cd concentration 10.4 mg kg–1 in Oxisol, after 30 d exposure. Twelve superoxide dismutase (SOD; EC 1.15.1.1) isoenzymes evaluated, most classified as Cu/Zn forms. SOD activity leaves grown Oxisol decreased over time, whilst remaining high Entisol. Catalase (CAT; 1.11.1.6) exhibited little response Ba, but time. Glutathione reductase (GR; 1.6.4.2) time when concentrations, following exposure Oxisol. enzyme-activity changes mainly dependent type, and, lesser extent, soil. Soybean sandy low buffering capacity, such Entisol, suffer greater oxidative stress those clay soil,