荠菜幼苗对汞胁迫的生理响应

Physiological Response of Shepherd's Purse Seedlings to Mercury Stress

[目的]探讨荠菜幼苗对汞胁迫的生理响应。[方法]采用砂培法研究了不同浓度Hg2+胁迫下荠菜幼苗叶中叶绿素含量以及SOD和POD抗氧化酶活性的变化。[结果]幼苗叶绿素含量在低浓度Hg2+(≤1.0 mg/L)胁迫时略有增加,而在高浓度Hg2+胁迫(20.0mg/L)时降低。丙二醛含量则随Hg2+胁迫浓度的增加而增加。SOD和POD活性均随着Hg2+浓度的增加呈先上升后下降的趋势,其中当Hg2+浓度为1.0 mg/L时SOD和POD活性分别为对照的158.0%和161.0%,而在当Hg2+浓度为20.0 mg/L时分别为对照的27.1%和16.7%,表明酶活性在一定浓度的Hg2+胁迫下能作出应激反应。[结论]为荠菜驯化和栽培提供了理论依据。

[Objective] The aim was to explore the physiological response of shepherd＇s purse seedlings to mercury stress.[Method] Changes of chlorophyll content,SOD and POD activities of shepherd＇s purse seedlings under different concentrations of Hg2＋ stress were studied by sand culture method.[Result] The content of chlorophyll in shepherd＇s purse seedlings increased slightly under lower concentrations of Hg2＋ stress（≤1.0 mg/L） but decreased under high concentrations of Hg2＋ stress（20.0 mg/L）.The content of MDA increased with the increase of Hg2＋ stress concentration.SOD and POD activities gradually increased first and then decreased with the increase of Hg2＋ stress concentration,among them SOD and POD activities accounted for 158.0% and 161.0% of control when Hg2＋ stress concentration was 1.0 mg/L,and accounted for 27.1% and 16.7% of control when Hg2＋ stress concentration was 20.0 mg/L respectively,which suggested that enzyme activities were resulted from the adaptability of shepherd＇s purse seedings stress by Hg2＋.[Conclusion] The research provides theoretical basis for the domestication and cultivation of shepherd＇s purse.