抗氧化系统在海州香薷耐铜机制中的作用

Antioxidative Defence Systems in a Copper Tolerant Plant, Elsholtzia haichowensis, under Copper Stress

利用溶液培养的方法研究了铜胁迫下海州香薷根系和地上部分MDA含量，各种抗氧化酶及非酶抗氧化系统的变化。结果表明，不同浓度铜处理8d后，海州香薷根系中MDA含量显著增加，叶片中则无显著变化；根系中SOD、POD、CAT、APX、GR活性和叶片中POD、SOD的活性随铜处理浓度的增加而显著增加，而50-200μmol·L^-1。铜处理条件下叶片中CAT、APX、GR活性与对照相比无明显差异。除CAT外，根系中这些抗氧化酶的活性都远远大于叶片中的活力。另外，实验结果表明，50μmol·L^-1 Cu^2＋对海州香薷的生物量并没有显著影响，当铜浓度达到100和200μmol·L^-1。时，铜则可显著降低海州香薷根系的生物量，对地上部生物量仍无显著影响。

Hydroponic cultures were conducted to study the concentrations of MDA, activities of antioxidative enzymes and non-enzymatic antioxidant enzymes system in the roots and leaves of Elsholtzia haichowensis under copper stress. The results showed that copper treatments caused significant increases of malondialdehyde （MDA） concentrations in the roots of Elsholtzia haichowensis, while had no significant effect on those in the leaves. The activities of SOD, POD, CAT, APX and GR in the roots, as well as the activities of POD and SOD in the leaves of E. haichowensis increased with the increasing Cu concentrations in the culture solution. The activities of the antioxidative enzymes in the roots were much higher than those in the leaves with exception of CAT. The results also showed there is no significant difference in the shoots dry weights of E. haichowensis under 50-200 μmol·L^-1 copper stress when compared to the control. Copper with concentrations of 100 and 200 μmol·L^-1 significantly decreased the root dry weight ofE. haichowensis.