研究人员确定了植物中主要的硝酸盐传感器。研究人员发现，全部七个拟南芥NIN样蛋白（NLP）转录因子的突变废除了植物的主要硝酸盐反应和发育程序。对NIN-NLP7嵌合体和硝酸盐结合的分析表明，NLP7在硝酸盐感知时通过其氨基末端被解压。一个遗传编码的荧光分割生物传感器（mCitrin-NLP7）使单细胞的硝酸盐动态在植物体中得到了可视化。NLP7的硝酸盐传感器结构域类似于细菌的硝酸盐传感器NreA。配体结合袋中保守残基的替换削弱了硝酸盐触发的NLP7控制转录、运输、代谢、发育和生物量的能力。研究人员认为NLP7代表了陆地植物中的一个硝酸盐传感器。
据介绍，硝酸盐是植物生长的重要营养物质和信号分子。植物感知细胞内的硝酸盐来调整其代谢和生长反应。
附：英文原文
Title: NIN-like protein 7 transcription factor is a plant nitrate sensor
Author: Kun-Hsiang Liu, Menghong Liu, Ziwei Lin, Zi-Fu Wang, Binqing Chen, Cong Liu, Aping Guo, Mineko Konishi, Shuichi Yanagisawa, Gerhard Wagner, Jen Sheen
Issue&Volume: 2022-09-23
Abstract: 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.
DOI: add1104
Source: https://www.science.org/doi/10.1126/science.add1104