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.

研究推动作物氮利用效率 (NUE) 的调控机制对于可持续农业和环境保护具有重要意义。在这项研究中，我们为高 NUE 小麦品种 Kenong 9204 生成了高质量的基因组组装，并系统地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科中得到了扩展。. 进一步的研究表明，随后的功能分化赋予了扩大的家族成员盐分诱导能力，为提高小麦对不同生境对氮缺乏的适应性提供了遗传基础。为了探索高 NUE 的遗传和分子机制，我们比较了高 NUE 品种科农 9204 (KN9204) 和低 NUE 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。与荆411相比，KN9204在芽后生殖阶段吸收的氮量明显更多，并在芽和种子中积累。转录组数据分析显示，氮缺乏明显抑制了荆411幼穗细胞分裂相关基因的表达，而这种对基因表达的抑制在 KN9204 中要低得多。此外，KN9204在种子成熟过程中保持NPF基因相对高表达的时间比京411更长。生理和转录组数据显示，KN9204比荆411更能耐受氮缺乏，尤其是在生殖阶段。KN9204的高NUE是不同层次控制的综合效果。总之，我们的数据为 NUE 的分子机制和重要的基因资源提供了新的见解，以改善具有更高 NUE 性状的小麦品种。生理和转录组数据显示，KN9204比荆411更能耐受氮缺乏，尤其是在生殖阶段。KN9204的高NUE是不同层次控制的综合效果。总之，我们的数据为 NUE 的分子机制和重要的基因资源提供了新的见解，以改善具有更高 NUE 性状的小麦品种。生理和转录组数据显示，KN9204比荆411更能耐受氮缺乏，尤其是在生殖阶段。KN9204的高NUE是不同层次控制的综合效果。总之，我们的数据为 NUE 的分子机制和重要的基因资源提供了新的见解，以改善具有更高 NUE 性状的小麦品种。