Résumé
Rising atmospheric CO 2 negatively affects plant iron (Fe) content, yet the underlying mechanisms remain poorly understood. Here, we identified More Iron under elevated CO 2 (MIC) as a new player involved in Fe homeostasis under elevated CO 2 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 CO 2 , effectively mitigating the Fe decline observed in plants. MIC protein abundance is reduced in roots under elevated CO 2 , suggesting post‐transcriptional regulation of protein stability. This work identifies MIC as a novel component in the plant response to elevated CO 2 , with potential implications for improving the nutritional quality of crops under climate change.