Cd2+、Cu2+对坛紫菜生化效应研究

研究了不同浓度(0．1、0．5、1．0、10、20mg／L)和不同培养时间(12、24、48、72h)下，重金属(Cd2 和Cu^2 )对坛紫菜(Porphyra haitanensis)核酸(RNA和DNA)含量、过氧化物酶(POD)活性的影响．结果表明：1)10、20mg／L Cd^2 、Cu^2 暴露，POD活性先上升(48h前)后下降(48h后)，其它浓度组POD活性均随污染时间的延长而升高．24、48、72h均出现比较良好的剂量一效应关系．2)Cd^2 和Cu^2 对RNA、DNA含量的影响基本上表现为先上升后下降的时间效应关系，同一污染物浓度越大越早出现下降．同时出现随暴露剂量的增加，RNA、DNA含量先上升后下降或全部下降的剂量一效应关系．

Study on Biochemical Effect of Cu2+ and Cd2+ on Porphyra haitanensis

Effects on nucleic acid (RNA and DNA) content and peroxidase (POD) activity of Porphyra haintanensis exposed to bivalent cadmium (Cd~(2+)) and bivalent copper (Cu~(2+) ) at concentrations of 0.1,0.5,1,10,20 mg/L were studied in experimental conditions.Samples were taken after exposure for 12 h,24 h,48 h and 72 h.Time-effect and dose-effect relationships of the nucleic acids and POD were investigated.The results showed:1)In groups exposed to 10 mg/L or 20 mg/L Cd~(2+) and Cu~(2+),the POD activity increased at first 48 hours,then decreased during the prolonging of the exposure time.In other dealing groups exposed to lower concentration of two heavy metals,POD activity increased throughout the exposing time.2)With the prolonging of exposure time, the effects of Cd~(2+) and Cu~(2+) on RNA and DNA contents in all group showed similar way:the content first increased and then decreased.And the higher the concentrations of the same pollutant,the earlier the decrease turned up.At the same time,there were significant dose-effect relationships between pollutants and RNA and DNA contents.The contents of nucleic acids increased first,then decreased or decreased completely with concentrations of two heavy metals increased.