几种重金属对紫背萍的过氧化氢酶(CAT)活性的影响

THE EFFECTS OF SEVERAL HEAVY METALS ON THE CATALASE (CAT) ACTIVITIES OF SPIRODELA POLYRRHIZA

通过测定试验植物的过氧化氢酶（ＣＡＴ）分解过氧化氢后所放出氧气的量（体积），确定紫背萍（Ｓｐｉｒｏｄｅｌａｐｏｌｙｒｒｈｉｚａ）的过氧化氢酶的活性。结果表明，紫背萍在暴露到镉，锌，铜和铁的不同浓度时，其ＣＡＴ活性明显升高，这表明４种重金属对紫背萍的ＣＡＴ活性均有刺激作用。结果还表明，紫背萍在有铁存在的两种金属的复合作用下（Ｃｄ－Ｆｅ，Ｚｎ－Ｆｅ），其ＣＡＴ活性明显降低。这表明Ｆｅ对Ｃｄ和Ｚｎ均有一定的拮抗效应。在Ｃｕ－Ｆｅ的复合作用下，Ｆｅ对高浓度的ＣＵ有拮抗效应而对低浓度的Ｃｕ有一定的协同作用。

By measuring the volume of O2 whichis released after the CAT of plants exposed to heavy metal solutions decomposes H2O2,the CAT activities of Spirodela polyrrhizare are determined.The results show us that the CAT activities of Spirodela polyrrhiza significantly increase as exposed to various concentrations of Cd, Zn,Cu, and Fe respectively. It illustrates that there are stimulating effects of the four metals on the CAT of Spirodela polyrrhiza. The results also show us that the CAT activities of Spirodela polyrrhiza decrease below the normal values of controlling groups of the plants as exposed to Cd-Fe and Zn-Fe solutions respectively. This is an evidence that there are antagonistic effects of Fe on Cd and Zn respectively.There are antagonistic effects of Fe on Cu with higher concentrations, but synergistic effects on Cu with lower concentrations.