A NIGT1-centred transcriptional cascade regulates nitrate signalling and incorporates phosphorus starvation signals in Arabidopsis

• Published in: Nature communications Vol. 9; no. 1; pp. 1376 - 14
• Main Authors: Maeda, Yoshie, Konishi, Mineko, Kiba, Takatoshi, Sakuraba, Yasuhito, Sawaki, Naoya, Kurai, Tomohiro, Ueda, Yoshiaki, Sakakibara, Hitoshi, Yanagisawa, Shuichi
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10-04-2018; Nature Publishing Group; Nature Portfolio
• Subjects: 38/109; 38/15; 38/5; 38/61; 38/77; 38/88; 38/90; 631/449/2675; Anion Transport Proteins - genetics; Anion Transport Proteins - metabolism; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Biological Transport; Biosynthesis; Cascades; Complexity; Gene expression; Gene Expression Regulation, Developmental; Gene Expression Regulation, Plant; Gene regulation; Gene silencing; Genes; Genes, Reporter; Genomes; Humanities and Social Sciences; Luciferases - genetics; Luciferases - metabolism; multidisciplinary; Nitrates; Nitrates - metabolism; Nutrients; Nutrition; Oryza - genetics; Oryza - growth & development; Oryza - metabolism; Phosphate starvation response; Phosphorus; Phosphorus - deficiency; Plants, Genetically Modified; Repressors; Science; Science (multidisciplinary); Seeds - genetics; Seeds - growth & development; Seeds - metabolism; Signal Transduction; Signaling; Transcription factors; Transcription Factors - genetics; Transcription Factors - metabolism; Transcription, Genetic
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-03832-6

Nitrate is a nutrient signal that triggers complex regulation of transcriptional networks to modulate nutrient-dependent growth and development in plants. This includes time- and nitrate concentration-dependent regulation of nitrate-related gene expression. However, the underlying mechanisms remain poorly understood. Here we identify NIGT1 transcriptional repressors as negative regulators of the
Arabidopsis
NRT2
.
1
nitrate transporter gene, and show antagonistic regulation by NLP primary transcription factors for nitrate signalling and the NLP-NIGT1 transcriptional cascade-mediated repression. This antagonistic regulation provides a resolution to the complexity of nitrate-induced transcriptional regulations. Genome-wide analysis reveals that this mechanism is applicable to
NRT2
.
1
and other genes involved in nitrate assimilation, hormone biosynthesis and transcription. Furthermore, the PHR1 master regulator of the phosphorus-starvation response also directly promotes expression of NIGT1 family genes, leading to reductions in nitrate uptake. NIGT1 repressors thus act in two transcriptional cascades, forming a direct link between phosphorus and nitrogen nutritional regulation.
Plants respond to nutrients by modulating gene expression. Here, the authors show that nitrate suppresses
NRT2.1
nitrate transporter expression via NIGT1 transcriptional repressors and that phosphate starvation enhances this pathway via PHR1, thus linking phosphorus and nitrogen signalling.