An intracellular transporter mitigates the CO2-induced decline in iron content in Arabidopsis shoots.

Rising atmospheric CO2 negatively affects plant iron (Fe) content, yet the underlying mechanisms remain poorly understood. Here, we identified More Iron under elevated CO2 (MIC) as a new player involved in Fe homeostasis under elevated CO2 in Arabidopsis thaliana. MIC is a previously uncharacterized transmembrane protein which we found predominantly localized to the Golgi apparatus. Loss of MIC function results in increased Fe content under elevated CO2, effectively mitigating the Fe decline observed in plants. MIC protein abundance is reduced in roots under elevated CO2, suggesting post-transcriptional regulation of protein stability. This work identifies MIC as a novel component in the plant response to elevated CO2, with potential implications for improving the nutritional quality of crops under climate change.