The Arabidopsis NLP7-HB52/54-VAR2 pathway modulates energy utilization in diverse light and nitrogen conditions
The Arabidopsis NLP7-HB52/54-VAR2 pathway modulates energy utilization in diverse light and nitrogen conditions
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DOI：
10.1016/j.cub.2022.10.024
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发表时间：
2022-12-19
期刊：
影响因子：
9.2
通讯作者：
Yanagisawa, Shuichi
中科院分区：
文献类型：
--
作者：
Ariga, Takuto;Sakuraba, Yasuhito;Yanagisawa, Shuichi
在植物中，硝酸盐是主要的氮（N）源，并且是调节各种生理和发育过程的关键营养信号。1 -4硝酸盐响应基因调控网络被广泛认为除了控制N的获取和利用之外还控制生长、发育和生命周期，1-4和NIN样蛋白（NLP）转录激活因子已被鉴定为控制网络的主要调节因子。5-7然而，硝酸盐信号传导如何调节各自的生理和发育过程仍有待阐明。在这里，我们已经确定了一个新的硝酸盐激活的转录级联参与叶绿体发育和叶绿体功能的维持在拟南芥。该级联由NLP 7和两个同源域亮氨酸拉链（HD-Zip）I类转录因子HOMEOBOX PROTEIN 52（HB 52）和HB 54组成，8，9负责编码叶绿体FtsH蛋白酶的FtsH 2亚基的VAR 2的硝酸盐依赖性和光依赖性表达，所述叶绿体FtsH蛋白酶参与光损伤类囊体膜蛋白的质量控制。硝酸盐激活的NLP 7-HB 52/54-VAR 2途径支持光合作用光能利用，尤其是在高光环境中。此外，通过遗传增强NLP 7-HB 52/54-VAR 2途径，可以提高高光低氮条件下的光能利用率，这是一个上级农艺性状。这些发现揭示了硝酸盐信号转导的新作用和整合氮营养和光环境信息的新机制，为提高低氮环境下植物的光能利用率提供了线索。
In plants, nitrate is the dominant nitrogen (N) source and a critical nutrient signal regulating various phy-siological and developmental processes.1-4 Nitrate-responsive gene regulatory networks are widely believed to control growth, development, and life cycle in addition to N acquisition and utilization,1-4 and NIN-LIKE PROTEIN (NLP) transcriptional activators have been identified as the master regulators governing the net-works.5-7 However, it remains to be elucidated how nitrate signaling regulates respective physiological and developmental processes. Here, we have identified a new nitrate-activated transcriptional cascade involved in chloroplast development and the maintenance of chloroplast function in Arabidopsis. This cascade consisting of NLP7 and two homeodomain-leucine zipper (HD-Zip) class I transcription factors, HOMEOBOX PROTEIN52 (HB52) and HB54,8,9 was responsible for nitrate-and light-dependent expression of VAR2 encoding the FtsH2 subunit of the chloroplast FtsH protease involved in the quality control of photo -damaged thylakoid membrane proteins.10,11 Consistently, the nitrate-activated NLP7-HB52/54-VAR2 pathway underpinned photosynthetic light energy utilization, especially in high light environments. Further-more, genetically enhancing the NLP7-HB52/54-VAR2 pathway resulted in improved light energy utilization under high light and low N conditions, a superior agronomic trait. These findings shed light on a new role of nitrate signaling and a novel mechanism for integrating information on N nutrient and light environments, providing a hint for enhancing the light energy utilization of plants in low N environments.