Author:
Wang Ying,Du Yi-Tong,Tam Nora Fung-Yee
Abstract
Due to close proximity to urban development, mangroves exposed to the contamination of polybrominated diphenyl ethers (PBDEs). Decabromodiphenyl ether (BDE-209) is one of the most predominant PBDE congener. The present study aimed to investigate the toxic effects of BDE-209 on the antioxidative and non-antioxidative responses of Kandelia obovata, a very common mangrove species, under different concentrations of BDE-209, 0.1, 1, 5 and 10 mg l-1. BDE-209 did not exhibit any negative effects on the growth of K. obovata seedlings. The stimulatory effects of BDE-209 on the enzymes including superoxide dismutase, peroxidase and catalase only occurred in weeks 1 and 4 and diminished in week 8. The concentrations of total polyphenols (TP) and extractable condensed tannins (ECT) were not affected by BDE-209. The production of O2·- was induced only at the very high level of BDE-209 (10 mg l-1). H2O2 was induced only in weeks 1 and 4 under BDE-209 treatment. BDE-209 was taken up by the roots of K. obovata, translocated to above-ground tissues, and accumulated in plant tissues with the concentrations declined in the order of root > propagule > stem > leaf. Although BDE-209 has higher molecular weight and higher log Kow than other PBDE congeners, the K. obovata seedlings could absorb, translocate and accumulate BDE-209. These findings suggested that mangrove plants could take up, accumulate PBDEs, and BDE-209 are less toxic than other congeners but more difficult to be removed by mangrove systems.
Funder
Natural Science Foundation of Tianjin City
Subject
Ocean Engineering,Water Science and Technology,Aquatic Science,Global and Planetary Change,Oceanography