【摘要】 利用不同浓度的Cd2+和不同浓度的Cd2+加5 mg L-1Ce3+分别处理菱植株,对菱叶中的叶绿素、脯氨酸、保护酶———超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性的动态变化进行了研究。实验结果表明:在镉胁迫下,随着镉浓度的上升(0~4 mg L-1)菱叶中叶绿素含量下降,SOD、POD活性和脯氨酸含量在镉低浓度时上升而高浓度时下降,相反,CAT活性在镉低浓度时下降而高浓度时上升。与镉离子单一处理相比,Cd2+-Ce3+复合处理中的Ce3+可提高叶片中叶绿素的含量和SOD、POD的活性,尤其是在1 mg L-1Cd2+加5 mg L-1Ce3+复合处理中,POD活性较对照提高了8.33倍。由此表明,5 mg L-1Ce3+对低浓度镉引起菱叶片的毒害作用有较为明显的缓解效果。更多还原

【Abstract】 Dynamic changes in content of chlorophll and proline,and activity of protective enzymes such as superoxide（SOD）,peroxidase（POD） and chloramphenicol acetyltransferase（CAT） in the leaves of Trapa bispinosa treated,respectively,with Cd²⁺at varying rates and Cd²⁺plus 5 mg L^-1 Ce³⁺ were studied.Results show that chlorophyll contents decreased with increasing Cd²⁺ concentration,while the activity of both SOD and POD,and the content of proline increased when Cd²⁺ concentration was low and decreased when it was high.In contrast,CAT activity decreased when it was low and increased when it was high.Compared with the single ion treatments,the Cd²⁺+Ce³⁺treatments increased cholorophyll contents,and stimulated activity of SOD and POD,especially,that of the latter,which was 8.33 times higher than its control when the combination was(5 mg L^-1 Ce³⁺plus) 1 mg L^-1 Cd²⁺.The results suggest that the addition of (5 mg L^-1 Ce³⁺ can) relieve the toxicity of a low concentration Cd²⁺ on leaves of Trapa bispinosa.更多还原