中文摘要：

目的：为了探讨水葫芦对富营养化水体中铵态氮吸收的分子机理。方法：采用简并引物克隆了3种水葫芦铵转运蛋白基因（EcAMT1、EcAMT2和EcAMT3）片段,并对这3个基因在不同形态的氮素条件下的表达进行了研究。结果：相比缺氮,铵态氮和硝态氮条件下,EcAMT1基因的表达被抑制,而EcAMT2和EcAMT3的表达刚好相反,铵态氮和硝态氮条件反而能够促进基因表达。结论：说明不同类型的铵转运蛋白基因的表达对外界环境因素的响应各不相同。

英文摘要：

Objective：The objective was in order to explore the molecular mechanism for Eichhornia crassipes to take up the ammonium nitrogen in eutrophication water. Method ：Three ammonium transporter gene fragments were cloned from Eichhornia crassipes using degenerate primers and their expressions were analyzed under three different nitrogen conditions. Result：The result showed that EcAMT1 expression was repressed by both ammonium and nitrate nitrogen compared with nitrogen starvation. Instead, ammonium and nitrate nitrogen could improve the expressions of EcAMT2 and ExAMT3. Conclusion ：All these illustrated different ammonium transporter gene expressions have different response to different environmental factors.