Regulation of the non-selective Na+ importer capacity of NRT1.2/NPF4.6/AIT1 by SOS2-mediated phosphorylation in Arabidopsis

作者：Xiaoxiao Liu, Lei Zhang, Zeqi Zhao, Yue Zheng, Yue Ren, Xiaomin Zhao, Shizhong Zhang, Guodong Yang, Jinguang Huang, Kang Yan, Chunlong Li, Chengchao Zheng, Changai Wu · 发表于：Cell Reports · 年份：2025 · DOI：10.1016/j.celrep.2025.115729 · 被引用次数：11 · 研究领域：Plant nutrient uptake and metabolism、Plant Stress Responses and Tolerance、Aluminum toxicity and tolerance in plants and animals

Although preventing sodium ion import is crucial for salt tolerance, the mechanisms and the Na + importers involved remain unclear. We identified NRT1.2/NPF4.6/AIT1 as a non-selective Na + importer. NRT1.2 overexpression in Arabidopsis increased salt sensitivity due to Na + accumulation, while nrt1.2 mutants exhibited opposite results. Non-invasive micro-test technology indicated Na + uptake capability of NRT1.2 in Arabidopsis roots. When expressed in Xenopus laevis oocytes, NRT1.2 displayed low-pH-dependent and NO 3 − -promoted Na + , K + , and Li + importer capacity, conferring higher potassium and lithium tolerance in NRT1.2 overexpression plants. Mechanically, salt overly sensitive 2 (SOS2) phosphorylated NRT1.2 at Thr248, reducing its Na + import and preventing excessive Na + accumulation. Prolonged salt stress also downregulated NRT1.2 transcripts. In summary, our findings unveil a role of NRT1.2 in Na + transport and a regulatory pathway via SOS2-mediated phosphorylation of NRT1.2 at Thr248, crucial for plant salt-stress adaptation.