南京林业大学学报（自然科学版）2016，Vol.40Issue(2)：21-26,6.DOI:10.3969/j.issn.1000-2006.2016.02.004
崇明东滩湿地土壤中Cr3＋、Pb2＋和Cd2＋对硝酸还原酶的Hormesis效应
Hormetic effects of Cr3+, Pb2+and Cd2+on nitrate reductase in soils in Chongming Dongtan wetlands
摘要
Abstract
The objective of this study is to discover the hormetic effects ( a biphasic dose⁃response characterized by a low dose benefit and a high dose inhibition) between heavy metals and soil enzyme in a typical wetland. Soil samples were taken from Chongming Dongtan, a wetland in the Yangtze River Delta of China. The activities of nitrate reductase ( NR) in soils were examined at 0, 6, 12, 24, 48, 72 and 120 hrs incubation in the presence of Cr3+(0.0, 0�5, 5�0, 50�0, 500�0 and 5 000�0 mg/kg), Pb2+(0, 10, 30, 50, 100, 300 and 500 mg/kg) and Cd2+(0�0, 0�1, 1�0, 5�0, 10�0 and 100�00 mg/kg), respectively. Results showed that low dosages of Cr3+(0�5-5�0 mg/kg), Pb2+(10�0 mg/kg) and Cd2+(0�1 mg/kg) significantly enhanced NR activities comparing with that of the control (0�0 mg/kg metal ions added) ( P<0�05) , showing a typical inverted U-shaped dose⁃response curve, respectively, which indicated that a hormetic dose-response relationship existed between the three metals and NR in soils. The hormetic effects occurred at time of 6-72 h ( Cr3+) , 24-120 h ( Pb2+) and 6-48 h ( Cd2+) incubations, respectively, with the maximum stimulatory response of 56�4%-107�4% greater than the control. Therefore, the hormetic effects imply that the enhanced NR activities possi⁃bly affect nitrate reduction in wetland soils. It is very necessary to define and evaluate the effects of low dose heavy met⁃als on soil functions in a wetland in the future.关键词
滨海湿地/重金属/硝酸还原酶/Hormesis效应/崇明岛Key words
coastal wetlands/heavy metals/nitrate reductase/Hormesis/Chongming island分类
资源环境引用本文复制引用
印杰,范弟武,徐莎,韩建刚,朱咏莉,薛建辉..崇明东滩湿地土壤中Cr3＋、Pb2＋和Cd2＋对硝酸还原酶的Hormesis效应[J].南京林业大学学报（自然科学版）,2016,40(2):21-26,6.基金项目
国家自然科学基金项目（41471191，41375149）；国家林业公益性行业科研专项项目（201404305）；江苏高校优势学科建设工程资助项目 （）
