Hg^2＋和Al^3＋单一及复合污染对小白菜生理特性的影响

目的]研究重金属对小白菜的毒害机理。方法]在砂培条件下,研究了Hg^2＋、Al^3＋单一及复合胁迫对小白菜小杂56叶片丙二醛（MDA）含量及过氧化氢酶（CAT）和过氧化物酶（POD）活性的影响。结果]小白菜幼苗叶片MDA含量随Hg^2＋胁迫浓度的增加先升高后下降,随Al^3＋胁迫浓度的增加先降低后升高,复合污染条件下小白菜叶片MDA含量显著增加。各处理小白菜叶片CAT和POD活性明显高于对照,Hg^2＋、Al^3＋单一污染条件下,POD和CAT活性均随处理浓度的增加而升高;而复合污染条件下,CAT活性随处理浓度的增加先升高后降低,POD活性随处理浓度的增加逐渐升高。结论]Hg^2＋、Al^3＋等重金属胁迫对小白菜叶片抗氧化酶活性的影响不同,且重金属之间存在协同作用。

Influences of Single and Compound Pollution of Hg2+ and Al3+ on the Physiological Characteristics of Pakchoi

Objective] The aim was to study the toxicity mechanism of heavy metals on pakchoi. Method] The influences of single and compound pollution of Hg2+ and Al3+ on the MDA content,CAT and POD activities in the leaves of pakchoi Xiaoza56 were studied through sand culture experiments. Result] The MDA content in the leaves of young pakchoi was firstly increased and then decreased along with the increase of stress concn. of Hg2+ and firstly decreased and then increased along with the increase of stress concn. of Al3+. Under compound pollution,the MDA content in pakchoi leaves was increased significantly. In all the treatments,the CAT and POD activities in pakchoi leaves were obviously higher than that in CK. Under single pollution of Hg2+ and Al3+,the POD and CAT activities were increased along with the increase of treating concn. Under compound pollution,the CAT activity was firstly increased and then decreased and the POD activity was increased gradually along with the increase of treating concn. Conclusion] The heavy metal stress,such as Hg2+ and Al3+,had different influences on antioxidase activity in pakchoi leaves and there was synergistic effect among heavy metals.