Résumé
Our lab studies iron (Fe) and manganese (Mn) homeostasis in the model plant Arabidopsis thaliana.Both metals are well-known to be scarcely available in the vast majority of the soils of the planetand hence to limit plant growth. In the past, we have identified and characterized the function ofa number of transporters including IRT1 and NRAMP1 that carry out respectively, Fe and Mnhigh-affinity transport at the root surface and that are thus of paramount importance to cope withmetal deficiency. Recently, we have reported that NRAMP2 mediates efflux of Mn from the trans-Golgi Network into the cytosol and acts as a central hub to distribute Mn to the main cell organelles(Alejandro, 2017). We are now focusing on the role of NRAMP2 in the seed. We will presentunpublished data combining μXRF and laser ablation-ICP-MS (LaICP-MS) techniques applied onknock-out mutants of NRAMP2, that show the crucial role of NRAMP2 in partitioning Mnbetween seed coat and embryo.The presentation will also describe new tools that we recently implemented in the lab, including (i)single particle-ICP-MS (SP-ICP-MS) analysis of metal content in Arabidopsis single pollen grains(Jimenez-Lamana et al., 2023), and (ii) new redox Fe fluorescent sensors that allow to selectivelyimage either Fe 2+ or Fe 3+ species, separately or in combination, within living roots (Alcon et al.,2024). These redox Fe sensors helped reveal polar distribution of Fe 2+ in root epidermis.