低浓度重金属Cr^(6+)对紫狼尾草生理生化特性的影响

Effects of low concentrations of heavy metal Cr^(6+) on physiological and biochemical characteristics of Pennisetum purpureum Schum.

为探讨污水中Cr6+对紫狼尾草(Pennisetum purpureum Schum.)生理生化特性的影响,将其幼苗置于含不同浓度Cr6(+0、1、10、20、30、40、50 mg/L K2Cr2O7)生活污水中培养。分别在不同时期测定植株叶片Pro、MDA、可溶性糖、SOD、POD活性及植株总铬含量。结果表明:经不同时期处理后,叶片Pro含量、可溶性糖含量、POD活性均随Cr6+处理浓度的增大而先上升后下降;SOD活性没有受到明显的抑制;MDA含量随着铬处理浓度的升高、时间延长而逐渐升高。20mg/L Cr6+处理14d后植株生长速率最快,1～40mg/L Cr6+能有效促进紫狼尾草对铬的吸收与积累;而50mg/L Cr6+则对根系有毒害效应,抑制植株生长。这些结果显示,低浓度Cr6+能有效促进紫狼尾草生长,从而使其在受Cr6+污染环境中的植物修复方面具有一定的应用前景。

To discuss the effects of Cr in sewage on physiological and biochemical characteristics of Pennisetum purpureum Schum., the seedlings of Pennisetum purpureum Schum. were cultured in polluted water with different concentrations of Cr^6＋ （0, 1, 10, 20, 30, 40, 50 mg/L K2Cr2O7）. The contents of Pro, MDA, soluble sugar, the activities of SOD and POD, and the content of total chromium in plant were determined at different stages. The results showed that the contents of Pro, soluble sugar, and the activity of POD were increased at first and then decreased with the increasing Cr^6＋ concentration at different stages. The activity of SOD was not restrained obviously, and the MDA content was increased slowly with the increasing Cr^6＋ concentrations and pollution time. Moreover, the growth rate of plant was the fastest when treated with 20 mg/L Cr^6＋ on 14th day, and the absorption and accumulation of heavy metal in Pennisetum purpureum Schum. were improved remarkably when treated with 1-40 mg/L Cr^6＋, while the root of plant was poisoned by 50 mg/L Cr^6＋ and the growth was inhibited. Therefore, low concentrations of Cr^6＋ could promote the growth of plant, and Pennisetum purpureum Schum. would be utilized well in plant remedy of Cr^6＋ polluted environment in the future.