【摘要】 通过测定被暴露植物分解过氧化氢后放出氧气的体积，确定紫背萍过氧化氢酶（ＣＡＴ）的活性。结果表明，紫背萍暴露在Ｈｇ、Ｐｂ、Ｃｒ、Ｎｉ、Ｆｅ的溶液中，其ＣＡＴ活性除在Ｐｂ作用下明显降低外，在其它４种重金属的作用下都有不同程度的升高。这表明Ｐｂ对紫背萍ＣＡＴ活性有抑制作用，而其它４种重金属对紫背萍ＣＡＴ均有刺激作用。紫背萍对５种重金属所表现出来的这种生态效应，是重金属水污染的植物潜在效应，植物的ＣＡＴ活性可作为这种效应的标志更多还原

【Abstract】 By measuring the Oxygen volume released by exposed plants decomposed hydrogen dioxide,the activity of spirodela polyrrhiza CAT can be defined.The result shows that in different solutions with different conservation,such as Hg,Pb,Cr,Ni,Fe,spirodela polyrrhiz a’s CAT activity increases respectively under the action of the four heavy metals except Pb.That means Pb prohibits CAT activity while the others stmulate.The ecological effect of spirodela polyrrhiza to the five heavy metals is the potential effect of the plants in water polluted by heavy metals.The CAT activity of plants can be regarded as a sign of this effect.更多还原