Improvement of nitrogen-use-efficiency based on molecular mechanisms of ammonium assimilation and nitrogen recycling system in rice

对基因组测序完成后发现的与水稻氨离子初级同化相关的两种新酶GS1；3和NADH-GOGAT进行了功能研究。反向遗传学方法成功地表明，GS1；3在种子萌发过程中起重要作用，而NADH-GOGAT2在叶片衰老过程中起着氮素再动员的作用。利用正向遗传方法发现了一个与氮素利用效率相关的新基因，该基因对水稻根系伸长和氮素吸收有一定的促进作用。

Two new enzymes, GS1;3 and NADH-GOGAT, related to the primary assimilation of ammonium ions in rice discovered after the complete sequencing of genome were focused to understand their functions. Reverse genetics approaches successfully showed that GS1;3 is important during the seed germination, while NADH-GOGAT2 is functioning during nitrogen remobilization during leaf senescence. A new gene related to the nitrogen use efficiency was identified with the forward genetics and it contributed the increase in root-elongation as well as nitrogen uptake in rice.