Shi Xiaoli, Cui Fa, Han Xinyin, He Yilin, Zhao Long, Zhang Na, Zhang Hao, Zhu Haidong, Liu Zhexin, Ma Bin, Zheng Shusong, Zhang Wei, Liu Jiajia, Fan Xiaoli, Si Yaoqi, Tian Shuiquan, Niu Jianqing, Wu Huilan, Liu Xuemei, Chen Zhuo, Meng Deyuan, Wang Xiaoyan, Song Liqiang, Sun Lijing, Han Jie, Zhao Hui, Ji Jun, Wang Zhiguo, He Xiaoyu, Li Ruilin, Chi Xuebin, Liang Chengzhi, Niu Beifang, Xiao Jun, Li Junming, Ling Hong-Qing
State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing 100101, China.
Key Laboratory of Molecular Module-Based Breeding of High Yield and Abiotic Resistant Plants in Universities of Shandong, College of Agriculture, Ludong University, Yantai 264025, China.
Mol Plant. 2022 Sep 5;15(9):1440-1456. doi: 10.1016/j.molp.2022.07.008. Epub 2022 Jul 21.
Studying the regulatory mechanisms that drive nitrogen-use efficiency (NUE) in crops is important for sustainable agriculture and environmental protection. In this study, we generated a high-quality genome assembly for the high-NUE wheat cultivar Kenong 9204 and systematically analyzed genes related to nitrogen uptake and metabolism. By comparative analyses, we found that the high-affinity nitrate transporter gene family had expanded in Triticeae. Further studies showed that subsequent functional differentiation endowed the expanded family members with saline inducibility, providing a genetic basis for improving the adaptability of wheat to nitrogen deficiency in various habitats. To explore the genetic and molecular mechanisms of high NUE, we compared genomic and transcriptomic data from the high-NUE cultivar Kenong 9204 (KN9204) and the low-NUE cultivar Jing 411 and quantified their nitrogen accumulation under high- and low-nitrogen conditions. Compared with Jing 411, KN9204 absorbed significantly more nitrogen at the reproductive stage after shooting and accumulated it in the shoots and seeds. Transcriptome data analysis revealed that nitrogen deficiency clearly suppressed the expression of genes related to cell division in the young spike of Jing 411, whereas this suppression of gene expression was much lower in KN9204. In addition, KN9204 maintained relatively high expression of NPF genes for a longer time than Jing 411 during seed maturity. Physiological and transcriptome data revealed that KN9204 was more tolerant of nitrogen deficiency than Jing 411, especially at the reproductive stage. The high NUE of KN9204 is an integrated effect controlled at different levels. Taken together, our data provide new insights into the molecular mechanisms of NUE and important gene resources for improving wheat cultivars with a higher NUE trait.
研究驱动作物氮利用效率（NUE）的调控机制对可持续农业和环境保护至关重要。在本研究中，我们为高氮利用效率小麦品种科农9204生成了高质量的基因组组装，并系统分析了与氮吸收和代谢相关的基因。通过比较分析，我们发现高亲和力硝酸盐转运蛋白基因家族在小麦族中发生了扩张。进一步研究表明，随后的功能分化使扩张的家族成员具有盐诱导性，为提高小麦在各种生境中对氮缺乏的适应性提供了遗传基础。为了探究高氮利用效率的遗传和分子机制，我们比较了高氮利用效率品种科农9204（KN9204）和低氮利用效率品种京411的基因组和转录组数据，并量化了它们在高氮和低氮条件下的氮积累。与京411相比，KN9204在拔节后的生殖阶段吸收了显著更多的氮，并将其积累在地上部和种子中。转录组数据分析显示，氮缺乏明显抑制了京411幼穗中与细胞分裂相关基因的表达，而在KN9204中这种基因表达的抑制程度要低得多。此外，在种子成熟过程中，KN9204中NPF基因的表达维持相对较高水平的时间比京411更长。生理和转录组数据表明，KN9204比京411更耐氮缺乏，尤其是在生殖阶段。KN9204的高氮利用效率是不同水平控制的综合效应。综上所述，我们的数据为氮利用效率的分子机制提供了新见解，并为培育具有更高氮利用效率性状的小麦品种提供了重要的基因资源。
