Abstract:

Abstract: Abstract: In order to study is to reveal the influence of Pb2+ resulted in the environmental toxicity and the mechanisms of resistance and victims of mangrove plants, and provide a theoretical basis for the management of heavy metal pollution in marine estuaries. The aegiceras carniculatum seedlings were cultured in a series of seawater which contained 0.1-3 mmol/L Pb2+, Studying the changes of malondialdehyde, hydrogen peroxide，POD and SOD in the seedling roots and the changes of peroxidase in the seedling roots and leaves. The results of experiments showed that both improving the concentration of Pb2+ and extending stressing time increased the MDA contents in seedling roots. The hydrogen peroxide in seedling roots increased with the extending stressing time, but did not change with the strength of Pb2+. It was mainly because of the complex factors impacting the hydrogen peroxide in plant. The activity of POD and SOD increased when the strength of Pb2+ were less than 1mmol/L, and decreased when the strength greater than 1mmol/L With stressing time becoming longer, the activity of glutathione peroxidase in seedling roots had a trend of increasing first and then decreasing, while the activity of glutathione peroxidase in leaves decreasing. Both the activity of glutathione peroxidase in seedling roots and leaves decreased with the increasing strength of Pb2+.