植物铵态氮同化及其调控机制的研究进展

Advances in Study of Ammonium Assimilation and its Regulatory Mechanism in Plants

氮是维持植物生长发育最重要的矿质营养元素之一,在植物整个生命进程中发挥着重要作用。在植物体内,氮同化既是植物利用氮素的一个中心环节,也是导致植物氮利用效率不高的因素之一。氮同化主要分为硝态氮(NO3–)和铵态氮(NH4+)同化,其中铵态氮同化是氮同化中最为关键的一步。按照不同来源,植物体内铵态氮同化又可分为一次同化和二次同化,但两者都是通过谷氨酰胺/谷氨酸合成酶(GS/GOGAT)途径进行。植物铵态氮同化不仅需要大量的能量,而且需要大量的碳源,所以其在转录、转录后以及翻译后等各个水平上都受到严格调控。该文综述了目前关于植物铵态氮同化及其调控机制的最新研究进展。

Nitrogen is one of the most important mineral nutrient elements for plant growth and development, playing an essential role in the whole process of plant life. Nitrogen assimilation is a central link for plants to utilize nitrogen and also a factor in low nitrogen use efficiency in plants. It includes two types： assimilation of nitrate（NO3^–） and ammonium（NH4^＋）; the latter is the critical step in the process of nitrogen assimilation. The source of NH4^＋ during ammonium assimilation can be divided into 2 types—primary assimilation and secondary assimilation—but both proceed in the glutamine/glutamate（GS/GOGAT） pathway. Ammonium assimilation requires much energy resources but also consumes abundant carbon skeletons, so it is strictly regulated at different levels including transcription, post-transcription, and post-translation. We review the current progress in study of ammonium assimilation and its regulatory mechanism in plants.