Co-Overexpression of and Increased Agronomic Nitrogen Use Efficiency in Transgenic Rice Plants.

The NO transporter plays an important role in rice nitrogen acquisition and nitrogen-use efficiency. Our previous studies have shown that the high affinity systems for nitrate uptake in rice is mediated by a two-component NRT2/NAR2 transport system. In this study, transgenic plants were successful developed by overexpression of alone, alone and co-overexpression of and . Our field experiments indicated that transgenic lines expressing or constructs exhibited increased grain yields of approximately 14.1% and 24.6% compared with wild-type (cv. Wuyunjing 7, WT) plants, and the agricultural nitrogen use efficiency increased by 15.8% and 28.6%, respectively. Compared with WT, the N influx in roots of and lines increased 18.9%‑27.8% in response to 0.2 mM, 2.5 mM NO , and 1.25 mM NH NO, while there was no significant difference between and lines; only the N distribution ratio of shoot to root for lines increased significantly. However, there were no significant differences in nitrogen use efficiency, N influx in roots and the yield between the transgenic lines and WT. This study indicated that co-overexpression of and could increase rice yield and nitrogen use efficiency.