2025-03-28 中国科学院(CAS)
<関連情報>
- https://english.cas.cn/newsroom/research_news/life/202503/t20250328_908904.shtml
- https://academic.oup.com/plcell/article-abstract/37/3/koaf046/8092165
シロイヌナズナ種子発芽における硝酸塩のNIN-LIKE PROTEIN8を介したアブシジン酸シグナル伝達を抑制する機構の解明 Nitrate attenuates abscisic acid signaling via NIN-LIKE PROTEIN8 in Arabidopsis seed germination
Zhichong Huang, Xiao Han, Kunrong He, Jingwen Ye, Chunlan Yu, Tingting Xu, Juping Zhang, Jiancan Du, Qiantang Fu, Yanru Hu
The Plant Cell Published:24 March 2025
DOI:https://doi.org/10.1093/plcell/koaf046
Abstract
Abscisic acid (ABA) suppresses Arabidopsis (Arabidopsis thaliana) seed germination and post-germinative growth. Nitrate stimulates seed germination, but whether it directly regulates ABA signaling and the associated underlying molecular mechanisms remain unknown. Here, we showed that nitrate alleviates the repressive effects of ABA on seed germination independently of the nitric oxide (NO) pathway. Moreover, nitrate attenuates ABA signaling activated by ABSCISIC ACID INSENSITIVE3 (ABI3) and ABI5, two critical transcriptional regulators of the ABA pathway. Mechanistic analyses demonstrated that ABI3 and ABI5 physically interact with the nitrate signaling-related core transcription factor NIN-LIKE PROTEIN 8 (NLP8). After ABA treatment, NLP8 suppresses ABA responses during seed germination without affecting ABA content. Notably, nitrate represses ABA signaling mainly through NLP8. Genetic analyses showed that NLP8 acts upstream of ABI3 and ABI5. Specifically, NLP8 inhibits the transcriptional functions of ABI3 and ABI5, as well as their ABA-induced accumulation. Additionally, NLP8 overexpression largely suppresses the ABA hypersensitivity of mutant plants exhibiting impaired NO biosynthesis or signaling. Collectively, our study reveals that nitrate counteracts the inhibitory effects of ABA signaling on seed germination and provides mechanistic insights into the NLP8–ABI3/ABI5 interactions and their antagonistic relationships in ABA signaling.
