铅、锌胁迫对蕹菜光合色素及活性氧代谢的影响

Effects of Pb,Zn Stress on Photosynthetic Pigments and Active Oxygen Metabolism of Ipomoea aquatic Forsk

研究了铅、锌胁迫对蕹菜叶片的光合色素、活性氧代谢及细胞膜透性变化等的影响。结果表明 ,随着Pb、Zn浓度的增加 ,蕹菜叶片MDA含量和质膜相对透性均显著增大 ,叶绿素、类胡萝卜素含量和叶绿素a/b值均先升后降 ,SOD、POD活性呈现出先升高后降低的趋势 ,它们对Pb、Zn毒害的响应浓度不同 ,分别在 10mg/LPb和 2 5mg/LZn左右时达到峰值。对Pb、Zn毒害作用机制进行了讨论 ,认为活性氧自由基的攻击是其伤害的一个重要原因 ,SOD。

The effects of Pb?Zn on the changes of photosynthetic pigments, active oxygen metabolism and cell membrane permeability were studied. The results showed that, with the increase of Pb?Zn stress concentration, the malondialdehyde (MDA) content and membrane relative permeability of leaves of Ipomoea Aquatic Forsk increased distinctly; the contents of chlorophyll and carotenoid and chlorophyll a/b ratio all first increased and then decreased; the activities of superoxide dismutase(SOD) and peroxide(POD) had the same trend as chlorophyll and carotenoid(CAR), their response concentrations with Pb? Zn toxicity differed and their maximum value were located in concentration of 10 mg/L(Pb) and 25 mg/L(Zn). The medanism of Pb?Zn toxicity was and discussed that active oxygen species was among the important causes of toxicity and SOD? POD and carotenoid had some roles in preventing toxicity of active oxygen species.