OsNLP4-OsD3 module integrates nitrogen-iron nutrient signals to promote rice tillering by repressing strigolactone signaling

Abstract

Rice tillers are a major yield component regulated by phytohormones and nutrients. How nutrients interact with phytohormones to control tillering remains largely elusive. Here, we report a novel mechanism by which the transcription factor NIN-like protein 4 (OsNLP4) integrates nitrogen (N)-iron (Fe) nutrient signals to promote tillering by repressing OsD3 in strigolactone (SL) signaling. We show that the N-Fe balance modulates OsNLP4 nuclear accumulation, which is increased by Fe through H2O2 reduction. Furthermore, OsNLP4 upregulates multiple H2O2 scavenging genes, providing a positive regulatory loop for OsNLP4 nuclear accumulation. Our findings uncover a fundamental mechanism by which the OsNLP4-OsD3 module integrates N-Fe nutrient signals to downregulate SL signaling and thereby promote rice tillering and yield, thus facilitating sustainable agriculture worldwide.