RCD1 nuclear shuttling releases WRKY47 to trigger bHLH105 / bHLH115 ‐dependent iron acquisition

Iron (Fe) deficiency limits plant growth, yet its upstream regulatory mechanisms remain unclear. Here, we identify WRKY47 as a positive regulator of Fe-deficiency responses in Arabidopsis. WRKY47 directly binds and activates bHLH105 and bHLH115, key IVc bHLH factors that trigger the Fe uptake cascade. We further show that RCD1 interacts with WRKY47 and suppresses its DNA-binding and transcriptional activity. Fe deficiency also promotes the redistribution of RCD1 from the nucleus to the cytoplasm, suggesting a potential mechanism for modulating WRKY47 activity during the response. Our findings uncover a previously uncharacterized regulatory mechanism linking WRKY transcription factors and the bHLH cascade through RCD1-mediated modulation, providing a conceptual framework for engineering crops with enhanced Fe acquisition and stress resilience.