铅胁迫对凤眼莲氮代谢关键酶的影响

Effect of Pb^(2+) on the Key Enzyme Activities of Nitrogen Metabolism of Eichhornia Crassipes

研究不同浓度Pb2+胁迫凤眼莲0.25,6,20,60 d,其氮代谢关键酶活性的变化.结果表明:在凤眼莲根、叶中均有谷氨酰胺合成酶(GS)和谷氨酰胺α-酮戊二酸氨基转移酶(GOGAT)的分布,无论是否有Pb2+胁迫,凤眼莲的根、叶的GS活性大于NADH-GOGAT活性,且GS活性和NADH-GOGAT活性均表现为叶大于根.0.1~2 mmol.L-1Pb2+胁迫凤眼莲0.25,6,20,60 d,其根和叶的GS活性降低,但在胁迫60 d后随着凤眼莲新生组织的萌生,各处理浓度GS活性均出现不同程度的上升.凤眼莲叶片的GOGAT活性受Pb2+的影响在其处理60 d后极为明显,极显著上升.

The activities of NADH-GOGAT and GS of the roots and the leaves of Eichhornia crassipes under Pb2＋stress with 0.25,6,20,60 days were analyzed.The results show that GS and NADH-GOGAT activity are distributed in the roots and the leaves of Eichhornia crassipes.GS activity is higher than NADH-GOGAT activity in both of the roots and the leaves of Eichhornia crassipes,and GS activity and NADH-GOGAT of leaves are higher than those of roots.GS activity both in the roots and in the leaves decrease with the treatment of 0.1—2 mmol·L-1 Pb2＋,but GS activity increase in varying degrees after treated with 60 days.GOGAT activity of the leaves under Pb2＋ stress with 60 days is significantly increased.