Genome-wide associated study identifies NAC42-activated nitrate transporter conferring high nitrogen use efficiency in rice

First author: Weijie Tang; Affiliations: Nanjing Agricultural University (南京农业大学): Nanjing, China

Corresponding author: Jianmin Wan 

Over-application of nitrogen fertilizer in fields has had a negative impact on both environment and human health. Domesticated rice varieties with high nitrogen use efficiency (NUE) reduce fertilizer for sustainable agriculture. Here, we perform genome-wide association analysis of a diverse rice population displaying extreme nitrogen-related phenotypes over three successive years in the field, and identify an elite haplotype of nitrate transporter OsNPF6.1HapB that enhances nitrate uptake and confers high NUE by increasing yield under low nitrogen supply. OsNPF6.1HapB differs in both the protein and promoter element with natural variations, which are differentially trans-activated by OsNAC42, a NUE-related transcription factor. The rare natural allele OsNPF6.1HapB, derived from variation in wild rice and selected for enhancing both NUE and yield, has been lost in 90.3% of rice varieties due to the increased application of fertilizer. Our discovery highlights this NAC42-NPF6.1 signaling cascade as a strategy for high NUE and yield breeding in rice.

田间过度施用氮肥对于环境和人类健康都有着负面的影响。具有高的氮使用效率的驯化水稻品种能够帮助可持续农业降低肥料的使用。本文中，作者对一个连续三年在大田条件下显示出极端氮相关表型的多样化水稻群体进行了全基因组关联分析，鉴定了一个优质单倍型氮转运蛋白OsNPF6.1HapB，该蛋白不仅能够能够增强氮的吸收，并且能够在低氮条件下通过增加产量从而赋予水稻高的氮使用效率。OsNPF6.1HapB 基因在蛋白和启动子元件上都带有自然变异，会受到一个高氮使用效率相关转录因子OsNAC42差异的反式激活。来自野生水稻的罕见自然OsNPF6.1HapB等位基因受到了选择，同时增强了水稻的高氮使用效率和产量，但是由于肥料施用的增加在90.3%的水稻栽培品种中都已丢失。本文的发现突出了NAC42-NPF6.1信号级联对于水稻高氮使用效率和产量育种的重要意义。

通讯：Guo-Liang Wang (https://slab.njau.edu.cn/info/1064/2284.htm)

个人简介：1982年，南京农业大学，学士；1985年，南京农业大学，硕士；1995年，日本京都大学，博士。

研究方向：高效的农杆菌介导的水稻转化系统建立。

doi: https://doi.org/10.1038/s41467-019-13187-1

Journal: Nature Communications

First Published: November 21, 2019