摘要
将水生植物菜在含不同浓度 Cd Cl2 的培养液中培养不同的时间 ,分别测定菜的茎叶、根系、培养液中的含镉量 ,植株细胞中超氧阴离子 (O-·2 )、丙二醛 (MDA)的含量、超氧化物歧化酶 (SOD)活性及细胞外渗的量。实验结果表明 ,菜对镉有较强的耐受性 ,5mg/ L镉为其最小致死浓度 ,菜通过根系的吸收和分泌物的吸附作用固定溶液中的镉 ,对含镉污水有较高的净化能力 ,最高可清除污水中 99.5%的镉。在可耐受的范围内 ,菜植株中 SOD活性应激性升高 ,使镉毒害造成的 O-·2 大量生成与清除达到新的平衡 ,有效抑制膜脂过氧化物 MDA的形成 ,认为这是菜在镉胁迫下的防护机制之一。
In an experiment, Nymphoides peltatum (Gmel) O.Kuntze, an aquatic plant, was cultured in solution with varying concentration of CdCl\-2 for a varying period of time. Then samples of its stems and leaves, roots, and the culture solution were collected and determined for content of Cd\+\{2+\} ,O -· 2 and MDA in the plant cell, activity of SOD and exosmosis. The results show that the plant is fairly tolerable to Cd 2+ with 5mg/L being its minimum lethal concentration. It purifies Cd 2+ containing sewage by roots absorbing and exudate adsorbing Cd 2+ in the solution, thus removing about 99.5% of the Cd 2+ in the solution. Within the range of tolerable Cd 2+ concentration, the plant has higher SOD activity to balance the large amount of O -· 2 generated as a result of Cd 2+ poisoning, thus effectively prohibiting the formation of MDA. This is believed to be one of its defensive mechanism under Cd 2+ stress.
出处
《农村生态环境》
CAS
CSSCI
CSCD
2000年第3期9-14,共6页
Rural Eco-Environment
基金
国家自然科学基金!资助项目 (39770 0 46 )
关键词
荇菜
镉
污水净化
SOD
废水处理
水生植物
Cadmium, Nymphoides peltatum (Gmel) O.Kuntze, purifying effect, mechanism, SOD
