镧缓解镍对水鳖叶片的毒害效应研究

Detoxication of Lanthanum against Nickel in Hydrocharis dubia B L. Backer Leaves

以水鳖叶片为实验材料,研究了重金属Ni毒害下La的缓解效应。La能缓解重金属Ni胁迫导致的水鳖(HydrocharisdubiaBL Backer)叶片叶绿素含量的降低,细胞膜透性(relativemembranepenetrability)的增加和丙二醛(MDA)的积累。加入10mg·L-1La后与同浓度的单一Ni处理相比,超氧化物歧化酶(SOD),过氧化氢酶(CAT)活性有不同程度的增强,过氧化物酶(POD)活性有所减弱,表明它增强了对活性氧的清除能力,缓解了Ni对膜的伤害;可溶性蛋白含量则保持较高的水平,脯氨酸(proline)含量刚好相反,体现出La能增强水鳖对Ni胁迫的抗性,两组不同处理差异显著。而高浓度Ni处理,La则与Ni协同,从而加快细胞死亡进程。因此,La只能缓解一定浓度Ni对水鳖的毒害(Ni<10mg·L-1),而对高浓度Ni缓解效应不明显甚至加剧毒害作用。

The paper briefly dealt with the effects of La on high aquatic plantHydrocharis dubia B L Backer growing in the solution containing different concentration of Ni The results show that La relieves the reduction of chlorophyll content, the accumulation of MDA and the elevation of RMP (relative membrane penetrability) After 10 mg·L-1 La is added to the solution, the activities of SOD and CAT in the leaves of Hydrocharis dubia B L Backer increases compared to the single treatment of Ni, while the activity of POD decreases. This phenomenon reveals that La enhances the abilities of scavenging the activated oxygen in the plant and alleviates the damage to the membranes The soluble protein content of Ni+La compound treatment is higher than that of single Ni does, and proline content is on the contrary compared with the soluble protein So La improves the resistance of Hydrocharis dubia B L Backer to the stress of Ni However, the La can aggravate the damage to the cells under the extremely high concentration of Ni treatment