高等植物GS/GOGAT循环研究进展

Research advances on GS/GOGAT cycle in higher plants

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。

The aims of this article are to review recent studies on ammonium assimilation via the GS/GOGAT cycle in higher plants More than 95% of the ammonium, derived from various metabolisms 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 is to assimilate the ammonium from photorespiration and nitrate reduction in leave, the ammonium from nitrogen fixation in nodule and the ammonium from absorption by roots from soil and nitrate reduction in roots The regulatory mechanisms of the GS/GOGAT cycle are not clear But the advances of gene engineering technology, immunocyto chemistry and modern physiological technology can help us to better understand the regulatory mechanisms of the GS/GOGAT cycle With modern biotechnology held, the plant nutrition studies can expand more To better understand the regulatory mechanisms of the GS/GOGAT cycle is essential to adequately apply nitrogen fertilizer and improve plant nitrogen use efficiency