The Key Laboratory of Plant Development and Environmental Adaptation Biology, Ministry of Education, School of Life Sciences, Shandong University, Qingdao, China.
Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Agriculture, Shanxi Agricultural University, Taigu, China.
Nat Plants. 2022 Sep;8(9):1094-1107. doi: 10.1038/s41477-022-01236-5. Epub 2022 Sep 1.
The coordinated metabolism of carbon and nitrogen is essential for optimal plant growth and development. Nitrate is an important molecular signal for plant adaptation to a changing environment, but how nitrate regulates plant growth under carbon deficiency conditions remains unclear. Here we show that the evolutionarily conserved energy sensor SnRK1 negatively regulates the nitrate signalling pathway. Nitrate promoted plant growth and downstream gene expression, but such effects were repressed when plants were grown under carbon deficiency conditions. Mutation of KIN10, the α-catalytic subunit of SnRK1, partially suppressed the inhibitory effects of carbon deficiency on nitrate-mediated plant growth. KIN10 phosphorylated NLP7, the master regulator of the nitrate signalling pathway, to promote its cytoplasmic localization and degradation. Furthermore, nitrate depletion induced KIN10 accumulation, whereas nitrate treatment promoted KIN10 degradation. Such KIN10-mediated NLP7 regulation allows carbon and nitrate availability to control optimal nitrate signalling and ensures the coordination of carbon and nitrogen metabolism in plants.
碳氮代谢的协调对于植物的最佳生长和发育至关重要。硝酸盐是植物适应不断变化的环境的重要分子信号，但硝酸盐如何在碳匮乏条件下调节植物的生长仍不清楚。在这里，我们表明进化保守的能量传感器 SnRK1 负调控硝酸盐信号通路。硝酸盐促进植物生长和下游基因表达，但当植物在碳匮乏条件下生长时，这些效应受到抑制。SnRK1 的 α-催化亚基 KIN10 的突变部分抑制了碳匮乏对硝酸盐介导的植物生长的抑制作用。KIN10 磷酸化 NLP7，即硝酸盐信号通路的主调控因子，促进其细胞质定位和降解。此外，硝酸盐耗尽诱导 KIN10 积累，而硝酸盐处理促进 KIN10 降解。这种由 KIN10 介导的 NLP7 调节允许碳和硝酸盐的可用性来控制最佳的硝酸盐信号，并确保植物中碳和氮代谢的协调。
