中国农科院作科所揭示OsNHX2转录及转录后调控水稻耐寒机制
国家级科研机构在顶刊发表的水稻耐寒关键基因机制研究，方法新颖、结论可靠，对耐冷分子育种具有直接指导价值。
中国农业科学院作物科学研究所最新研究通过GWAS在MAGIC群体中鉴定出OsNHX2,一种液泡膜定位的K+转运体,在苗期增强水稻耐寒性。OsNHX2通过促进地上部钾离子含量增加,刺激脯氨酸积累并降低ROS和MDA水平来增强耐寒性。OsNHX2编码区的自然变异导致K+转运能力差异。其表达受转录因子OsATH1负调控。论文发表于《Molecular Plant》(IF=32.7),为水稻耐寒分子育种提供了重要依据。
Transcriptional and post-transcriptional regulation of OsNHX2 encoding a tonoplast-localized transporter controls intracellular K+ accumulation to regulate cold tolerance in rice
Huimin Shi, Kuitian Shao, Zhihu Ding, Jian Feng, Zhiyuan Zhang, Huimin Cao, Wenyu Zhang, Xiuqin Zhao, Tianqing Zheng, Dapu Liu, Kai Chen, Wensheng Wang, Fan Zhang, Jianlong Xu
Molecular Plant; 2026; IF: 32.7
DOI:10.1016/j.molp.2026.10.002
Abstract
Low-temperature stress significantly reduces rice yield and grain quality. Identifying major cold-tolerance genes and deciphering their regulatory networks is therefore essential for rice molecular breeding for cold tolerance. Here, through a genome-wide association study (GWAS) in a multi-parent advanced generation intercross (MAGIC) population, we identified OsNHX2, a tonoplast-localized K+ transporter that enhances cold tolerance at the seedling stage. OsNHX2 enhances cold tolerance by promoting an increase in potassium ion content in shoots, which stimulates proline accumulation and reduces the levels of reactive oxygen species (ROS) and malondialdehyde (MDA). Natural variation in the coding region of OsNHX2 underlies differences in K+ transport ability. We further demonstrated that OsNHX2 expression is negatively regulated by the transcription factor OsATH1. One natural variant in the OsNHX2 promoter, a 45-bp deletion, elevates OsNHX2 expression by reducing OsATH1 binding. Notably, we found that OsNHX2 physically interacts with OsGAPC3, a cytosolic glyceraldehyde-3-phosphate dehydrogenase known to modulate responses to abiotic stresses via ROS signaling. This interaction masks the tonoplast-targeting signal of OsNHX2, altering its subcellular localization, impairing K+ transport, and promoting cytosolic K+ accumulation. Overexpression of OsNHX2 significantly increased the seed-setting rate under cold stress at the booting stage without compromising grain yield under normal conditions. Haplotype analysis revealed that rice accessions carrying the cold-tolerant OsNHX2 haplotype are predominantly distributed in higher-latitude regions, suggesting adaptive selection. Our findings demonstrate that OsNHX2, which is negatively regulated by OsATH1 and OsGAPC3 at both transcriptional and post-transcriptional levels, modulates intracellular K+ accumulation to control cold tolerance in rice.