高等植物GS/GOGAT循环研究进展

高等植物体内 95%以上的NH4+通过GS/GOGAT(谷氨酰胺合成酶 /谷氨酸合成酶 )循环同化。GS、GOGAT在植物叶片、根瘤以及根中均有分布 ,但在不同器官中GS/GOGAT循环的作用不尽相同。在绿色组织中 ,GS/GOGAT循环的主要作用是同化光呼吸产生的NH4+以及硝酸盐在叶中还原产生的NH4+,在根瘤中则主要同化根瘤菌固N产生的NH4+,而在根中则是同化吸收到体内的NH4+以及硝酸盐被吸收后在根中还原产生的NH4+。迄今有关植物GS/GOGAT循环的研究还不太深入 ,但是随着基因工程技术、免疫组织化学技术以及现代植物生理学技术的发展 ,GS/GOGAT循环研究展示广阔前景。对该循环及其调控机制的进一步了解 ,可为合理利用氮肥、提高植物N的利用率提供理论依据。本文综述了近年来对GS/GOGAT循环的研究进展情况

Research advances on GS/GOGAT cycle i n higher plants

The aims of this ar ticle are to review recent studies onammonium assimilation via the GS/GOGAT cyc le in higher plants. More than 95% of the ammonium, derived from various metabo l isms and uptake from soil, are thought to be assimilated via GS/GOGAT cycle. GS and GOGAT can be found in leave, nodules and roots. The role of GS/GOGAT cycle i s to assimilate the ammonium from photorespiration and nitrate reduction in leav e, the ammonium from nitrogen fixation in nodule and the ammonium from absorptio n by roots from soil and nitrate reduction in roots. The regulatory mechanisms o f the GS/GOGAT cycle are not clear. But the advances of gene engineering techno l ogy, immunocyto-chemistry and modern physiological technology can help us to be tter understand the regulatory mechanisms of the GS/GOGAT cycle. With modern bi o technology held, the plant nutrition studies can expand more. To better underst a nd the regulatory mechanisms of the GS/GOGAT cycle is essential to adequately ap ply nitrogen fertilizer and improve plant nitrogen use efficiency.