镉胁迫对水浮莲幼苗生理功能的影响

Effects of Cd on Physiological Function of Pistia Stratiotes L.Seedlings

采用水培实验,研究镉胁迫对水浮莲(Pistia stratiotes L.)幼苗生理功能的影响,包括叶绿素含量、叶片和根系中可溶性蛋白质含量、POD和SOD酶活的变化情况。结果表明,镉胁迫明显抑制水浮莲幼苗叶绿素和蛋白质合成,且随着镉浓度增加和胁迫时间延长,其抑制作用增强;在抗氧化酶活性方面,根和地上部分对镉胁迫的反应存在显著差异,重金属镉对水浮莲幼苗根系的损伤较叶片强。根系POD酶活在重金属胁迫下显著下降,且根中酶活对高浓度镉胁迫比低浓度条件下反应敏感。叶片POD、SOD酶活能够被诱导而升高。综合分析水浮莲幼苗在镉胁迫下的生理特性,其适用于低浓度镉污染水体的生态修复。

A solution culture experiment is carried out to explore effects of Cd on physiological and ecological of Pistia stratiotes L.seedlings,which include： the changes in SOD and POD activities and soluble protein content in the leaves and roots of Pistia stratiotes as well as chlorophyll content in the leaves influenced by Cd.The results show that Cd stress obviously inhibites chlorophyll content and protein biosynthesis and its inhibition increases with the increase of Cd concentrations and time.Roots and shoots of Pistia stratiotes responds differently to Cd stress in terms of antioxidant enzyme activity,and the damages to the roots by Cd are stronger than to the leaves.The activities of POD in shoots decreases significantly with Cd stress,which demonstrates the shoots are more sensitive in high concentration of Cd employed than in low concentration treatment.The POD and SOD activities in the leaves would be induced to increase under the stress of Cd.Through comprehensive analyses on the physiological properties of Pistia stratiotes L.under Cd stress,it is suitable for phytopurification and phytoremediation of wastewater with low concentration of Cd.