Li Minglong, You Hongguang, Jiang Wenya, Lu Shixi, Hou Yuechuan, Xiao Jialei, Zeng Weizhong, Xu Pengfei, Ding Xiaodong, Wu Xiuju, Zhang Shuzhen, Li Qiang
Key Laboratory of Agricultural Biological Functional Genes, College of Life Science, Northeast Agricultural University, Harbin, China.
Key Laboratory of Soybean Biology of Chinese Education Ministry, Northeast Agricultural University, Harbin, China.
Plant Cell Environ. 2025 Sep 1. doi: 10.1111/pce.70152.
Wild soybean (Glycine soja) is a leguminous species known for its ability to thrive in challenging and barren environments. It has been reported that the nitrate transporters (NRTs) play critical roles for plants to survive in the nutrient-poor soils. However, the molecular mechanisms of GsNRTs in governing nitrogen (N) uptake remain largely elusive. In the present study, we identified a NRT2.4-like protein (GsNRT2.4a) as an interactor of GsSnRK1.1 kinase. Our biophysical and physiological analyses indicate that GsNRT2.4a functions as an active NRT, and GsSnRK1.1 kinase phosphorylates the Ser518 residue at the carboxyl region of GsNRT2.4a. Under N starvation conditions, the double mutant nrt2.1/nrt2.2 (2nrtm) and the quadruple mutant nrt2.1/nrt2.2/kin10/kin11 (2kinm/2nrtm) exhibited compromised growth of Arabidopsis. However, introduction of GsNRT2.4a or GsSnRK1.1/GsNRT2.4a genes into the mutants rescued their defective growth to different extent. Furthermore, we determined that GsSnRK1.1 plays a pivotal role in modulating GsNRT2.4a activity in planta by phosphorylating GsNRT2.4a at the Ser518 site, thereby collaboratively modulating plant growth under N starvation. Our findings suggest that GsNRT2.4a is essential for optimising nitrate uptake in plants, and it also elucidates a novel regulatory mechanism of GsSnRK1.1-GsNRT2.4a module for potential enhancement of nitrogen use efficiency (NUE) in plants.
野生大豆(Glycine soja)是一种豆科植物,以其在具有挑战性的贫瘠环境中茁壮成长的能力而闻名。据报道,硝酸盐转运蛋白(NRTs)对植物在营养贫瘠土壤中生存起着关键作用。然而,GsNRTs调控氮(N)吸收的分子机制在很大程度上仍不清楚。在本研究中,我们鉴定出一种NRT2.4样蛋白(GsNRT2.4a)作为GsSnRK1.1激酶的相互作用蛋白。我们的生物物理和生理学分析表明,GsNRT2.4a作为一种活性NRT发挥作用,并且GsSnRK1.1激酶使GsNRT2.4a羧基区域的Ser518残基磷酸化。在氮饥饿条件下,双突变体nrt2.1/nrt2.2(2nrtm)和四突变体nrt2.1/nrt2.2/kin10/kin11(2kinm/2nrtm)表现出拟南芥生长受损。然而,将GsNRT2.4a或GsSnRK1.1/GsNRT2.4a基因导入突变体中在不同程度上挽救了它们的生长缺陷。此外,我们确定GsSnRK1.1通过在Ser518位点磷酸化GsNRT2.4a在植物中调节GsNRT2.4a活性方面起关键作用,从而在氮饥饿条件下协同调节植物生长。我们的研究结果表明,GsNRT2.4a对于优化植物硝酸盐吸收至关重要,并且它还阐明了GsSnRK1.1-GsNRT2.4a模块在潜在提高植物氮利用效率(NUE)方面的一种新的调控机制。