Selenium Alleviates the Toxic Effects of Cadmium in Lupine (Lupinus Albus L.)

Abstract

This study aimed at investigating the effects of selenium (Se) against cadmium (Cd) toxicity on the plant growth, antioxidative enzyme activity, and Cd and Se content in lupine (Lupinus albus L.) plant and soil. The experiment was carried out under controlled conditions according to the factorial experiment design. Two doses of Cd (Cd1:25 mg kg-1and Cd2:50 mg kg-1) were applied in the soil. Three doses of Se (Se1:2,5 mg kg-1 Se2: 5 mg kg-1, and Se3:10 mg kg-1) were applied to the Cd-treated pots. Two-way analysis of variance was conducted to explore the interactions between Cd and Se doses. The results showed that Cd1 and Cd2 applications alone caused a decrease in plant growth as well as increased oxidative stress due to shoot and root Cd content in plants and soil. Se1 and Se2 applications to Cd-treated pots caused an increase in shoot and root length, fresh and dry shoot weights, fresh and dry root weights. However, Se3(10 mg kg-1) application decreased shoot and root length, fresh and dry shoot weights, fresh and dry root weights. More importantly, application of Se (2,5 mg Se kg-1 and 5 mg Se kg-1) is effective in improving the toxicity of cadmium increasing plant growth and diminishing shoot and root Cd, MDA content and DTPA-Cd content in lupine plant. We concluded that low and medium levels of Se alleviated the toxic effects of Cd in lupine. But high level of Se exerted negative influence on plant growth and oxidative stress under Cd toxicity. Moreover the effectiveness of selenium in reducing cadmium toxicity depends on the dose as well as the form of application.