Effects of Cadmium on Growth, Oxidative Stress and Antioxidant Enzyme Activities in Peanut (Arachis hypogaea L.) Seedlings

摘要

The effects of different cadmium (Cd) concentrations on growth, oxidative stress, and antioxidant enzymes activities in peanut seedlings of five cultivars were investigated in Hoagland’s nutrient solution. The results indicated that the growth of seedlings and the maximal photochemical efficiency of Photosystem II were significantly reduced after treatment with 500 ?M Cd 2+ for 4 days, but no significant difference was detected when exposed to 10 and 100 ?M Cd 2+ , with the exception of FH3 being more sensitive to 100 ?M Cd 2+ . The changes in H 2 O 2 and malondialdehyde contents indicated that Cd 2+ stress caused an accumulation of reactive oxygen species and induced oxidative stress when exposed to 100 and 500 ?M Cd 2+ . The changes in total soluble protein (TSP) content and antioxidant enzyme activities were similar among the five cultivars. However, in the different concentrations of Cd 2+ , TSP content and antioxidant enzyme activities showed different trends when compared with control groups. Exposure to 100 ?M Cd 2+ markedly enhanced activities of four antioxidant enzymes in both shoots and roots of all investigated cultivars. Additionally, cadmium stress had a more severe impact on roots as opposed to shoots of seedlings.