State Key Laboratory of Crop Genetics and Germplasm Enhancement, Jiangsu Collaborative Innovation Center for Modern Crop Production, Nanjing Agricultural University, Nanjing, 210095, China.
Key Laboratory of Biology, Genetics and Breeding of Japonica Rice in the Mid-lower Yangtze River, Ministry of Agriculture, Jiangsu Plant Gene Engineering Research Centre, Nanjing, 210095, China.
Plant J. 2022 Jun;110(6):1751-1762. doi: 10.1111/tpj.15768. Epub 2022 Apr 28.
Excessive nitrogen fertilizer application is harmful to the environment and reduces the quality of cereal crops. Maintaining crop yields under low nitrogen (LN) conditions and improving quality are important goals for cereal crop breeding. Although the effects of nitrogen assimilation on crop nitrogen-use efficiency (NUE) have been intensively studied, natural variations of the key assimilation genes underlying grain development and quality are largely unclear. Here, we identified an NUE-associated gene, OsGS1;1, encoding glutamine synthase, through genome-wide association analysis, followed by validation experiments and functional analysis. Fifteen single-nucleotide polymorphisms in the OsGS1;1 region led to alternative splicing that generated two functional transcripts: OsGS1;1a and OsGS1;1b. The elite haplotype of OsGS1;1 showed high OsGS1;1b activity, which improved NUE, affected grain development, and reduced amylose content. The results show that OsGS1;1, which is induced under LN conditions, affects grain formation by regulating sugar metabolism and may provide a new avenue for the breeding of high-yield and high-quality rice (Oryza sativa).
过量施用氮肥对环境有害，并降低谷物的质量。在低氮 (LN) 条件下保持作物产量并提高质量是谷物作物培育的重要目标。尽管氮同化对作物氮利用效率 (NUE) 的影响已得到深入研究，但基础谷物发育和品质的关键同化基因的自然变异在很大程度上仍不清楚。在这里，我们通过全基因组关联分析鉴定了一个与 NUE 相关的基因 OsGS1;1，该基因编码谷氨酰胺合成酶，随后进行了验证实验和功能分析。OsGS1;1 区域的 15 个单核苷酸多态性导致了选择性剪接，产生了两种功能转录本：OsGS1;1a 和 OsGS1;1b。OsGS1;1 的优良单倍型表现出高 OsGS1;1b 活性，提高了 NUE，影响了谷物发育，并降低了直链淀粉含量。结果表明，在 LN 条件下诱导的 OsGS1;1 通过调节糖代谢影响谷物形成，可能为培育高产优质水稻 (Oryza sativa) 提供新途径。
