Responses of the Antioxidant System inNelumbo nuciferaSeedlings to Arsenic Toxicity

To study the antioxidant system of Nelumbo nucifera seedlings in response to arsenic stressꎬ compared the influence of two valences of inorganic arsenicꎬ As (III) and As (V)ꎬ on soluble protein contentꎬ malondialdehyde(MDA)and the antioxidant system. Results showed that: MDA and soluble protein content of N. nucifera seedlings increased and then decreased with increasing concentrationꎻ MDA and protein content were more sensitive to As(III) than to As(V) treatment. The Superoxide Dismutase(SOD)was the most sensitive to arsenic treatmentꎻ when the concentration of As (III)was 2􀆰 5 μmol / L and As(V)was 100 μmol / Lꎬ the activity of SOD increased significantly. When the concentration of As(III) was 10 μmol / Lꎬ the activity of Peroxidase(POD) increased significantly. The Catalase(CAT)was more sensitive to As(V). From the experimental resultsꎬ with the increase in arsenic concentrationꎬ the enzyme activities of SODꎬ CAT and POD increasedꎬ which can be used to eliminate reactive oxygen species (ROS) and maintain cell metabolism stability. This study provides some basic data for further study of N. nucifera physiology and growth changeꎬ cultivation and transplants with arsenic stress.