Wang Qing, Su Qingmei, Nian Jinqiang, Zhang Jian, Guo Meng, Dong Guojun, Hu Jiang, Wang Rongsheng, Wei Changshuo, Li Guanwen, Wang Wan, Guo Hui-Shan, Lin Shaoyang, Qian Wenfeng, Xie Xianzhi, Qian Qian, Chen Fan, Zuo Jianru
State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China.
University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China.
Mol Plant. 2021 Jun 7;14(6):1012-1023. doi: 10.1016/j.molp.2021.04.012. Epub 2021 Apr 27.
The genetic improvement of nitrogen use efficiency (NUE) of crops is vital for grain productivity and sustainable agriculture. However, the regulatory mechanism of NUE remains largely elusive. Here, we report that the rice Grain number, plant height, and heading date7 (Ghd7) gene genetically acts upstream of ABC1 REPRESSOR1 (ARE1), a negative regulator of NUE, to positively regulate nitrogen utilization. As a transcriptional repressor, Ghd7 directly binds to two Evening Element-like motifs in the promoter and intron 1 of ARE1, likely in a cooperative manner, to repress its expression. Ghd7 and ARE1 display diurnal expression patterns in an inverse oscillation manner, mirroring a regulatory scheme based on these two loci. Analysis of a panel of 2656 rice varieties suggests that the elite alleles of Ghd7 and ARE1 have undergone diversifying selection during breeding. Moreover, the allelic distribution of Ghd7 and ARE1 is associated with the soil nitrogen deposition rate in East Asia and South Asia. Remarkably, the combination of the Ghd7 and ARE1 elite alleles substantially improves NUE and yield performance under nitrogen-limiting conditions. Collectively, these results define a Ghd7-ARE1-based regulatory mechanism of nitrogen utilization, providing useful targets for genetic improvement of rice NUE.
作物氮素利用效率（NUE）的遗传改良对粮食生产力和可持续农业至关重要。然而，NUE的调控机制在很大程度上仍不清楚。在此，我们报道水稻粒数、株高和抽穗期7（Ghd7）基因在遗传上作用于NUE的负调控因子ABC1抑制因子1（ARE1）的上游，以正向调控氮素利用。作为一种转录抑制因子，Ghd7可能以协同方式直接结合到ARE1启动子和内含子1中的两个类似傍晚元件的基序上，从而抑制其表达。Ghd7和ARE1呈现出相反振荡方式的昼夜表达模式，反映了基于这两个位点的调控机制。对一组2656个水稻品种的分析表明，Ghd7和ARE1的优良等位基因在育种过程中经历了多样化选择。此外，Ghd7和ARE1的等位基因分布与东亚和南亚的土壤氮沉降速率有关。值得注意的是，Ghd7和ARE1优良等位基因的组合在氮素限制条件下显著提高了NUE和产量表现。总之，这些结果定义了一种基于Ghd7-ARE1的氮素利用调控机制，为水稻NUE的遗传改良提供了有用的靶点。
