刘坤祥等《Science》2022年

论文题目：NIN-like protein 7 transcription factor is a plant nitrate sensor

论文作者：Kun-Hsiang Liu（刘坤祥）, Menghong Liu（刘孟红）, Ziwei Lin（林子炜）, Zi-Fu Wang, Binqing Chen（陈斌卿）, Cong Liu（刘聪）,Aping Guo（郭阿萍）, Mineko Konishi, Shuichi Yanagisawa, Gerhard Wagner, Jen Sheen

论文摘要：Nitrate is an essential nutrient and signaling molecule for plant growth. Plants sense intracellular nitrate to adjust their metabolic and growth responses. Here we identify the primary nitrate sensor in plants. We found that mutation of all seven Arabidopsis NIN-like protein (NLP) transcription factors abolished plants’ primary nitrate responses and developmental programs. Analyses of NIN-NLP7 chimeras and nitrate binding revealed that NLP7 is derepressed upon nitrate perception via its amino terminus. A genetically encoded fluorescent split biosensor, mCitrine-NLP7, enabled visualization of single-cell nitrate dynamics in planta. The nitrate sensor domain of NLP7 resembles the bacterial nitrate sensor NreA. Substitutions of conserved residues in the ligand-binding pocket impaired the ability of nitrate-triggered NLP7 to control transcription, transport, metabolism, development, and biomass. We propose that NLP7 represents a nitrate sensor in land plants.

硝酸盐是植物生长的必需营养素和信号分子。 植物感知细胞内硝酸盐以调整其代谢和生长反应。在这里，我们鉴定到了植物中的主要硝酸盐传感器。 我们发现拟南芥 NIN 样蛋白 (NLP) 转录因子家族的七成员突变破坏了植物的初级硝酸盐反应和发育进程。豆科植物NIN和拟南芥NLP7 蛋白之间做的不同嵌合体和硝酸盐结合的分析表明，NLP7蛋白活性有自抑制效应，而NLP7氨基端通过与硝酸盐的结合而解除NLP7蛋白的自抑制。一种遗传改造的荧光硝酸盐生物传感器mCitrine-NLP7可以实现植物中单细胞硝酸盐动力学的可视化。 NLP7的硝酸盐传感器域类似于细菌硝酸盐传感器 NreA。 配体结合口袋中保守残基的替换削弱了硝酸盐触发的NLP7的活性，进而影响了它控制转录、转运、代谢、发育和生物量的能力。本研究认为NLP7代表了陆地植物中的一种硝酸盐传感器。

文章链接：https://www.science.org/doi/10.1126/science.add1104