Nitrate-Inducible NIGT1 Proteins Modulate Phosphate Uptake and Starvation Signaling via Transcriptional Regulation of SPX Genes

The study demonstrated that NIGT1 proteins in Arabidopsis were crucial for modulating phosphate uptake and starvation signaling by repressing SPX genes, particularly SPX1, with regulation influenced by nitrate levels. Overexpression of NIGT1.1 enhanced phosphate uptake and related signaling, while the nigtQ mutation impaired these processes. NIGT1 proteins modulated the expression of phosphate transporters and affected root hair development and anthocyanin accumulation. The NIGT1-SPX-PHR regulatory pathway was identified as essential for balancing nitrogen and phosphorus acquisition, allowing plants to adapt to varying nutrient conditions. The study highlighted the complex interplay between nitrogen and phosphate signaling pathways in plants.