Résumé
Some metals such as iron (Fe) are essential to plants whilst others such as cadmium (Cd) are toxic even at low concentration. The identification of the chemical forms of these metals (speciation) and their localization at the tissue and cell level are crucial to understand theirtrafficking and storage and finally the ability for the plant to cope with their potential toxicity or requirement. LUCIA beamline offers the possibility to access the metal distribution thanks to micro X-ray fluorescence with a micrometer sized lateral resolution and to investigate the metal speciation using micro X-ray Absorption Near Edge Structure. Importantly, the beamline is designed for measurements in cryogenic conditions, which is necessary to limit metal redistribution and speciation change in biologic samples. Here, we present twoexamples of our work performed on Lucia during the last years. The first one deals with Fe homeostasis and the discovery of an important pool of iron in plant cell nucleus (1) as well as the Fe species in plant embryos (2). The second example is dedicated to the study of Cd sequestration in Anthyllis vulneraria used as a pioneer plant in the phytostabilization of mining sites (3).REFERENCES1. H. Roschzttardtz, L. Grillet, M.P. Isaure, G. Conejero, R. Ortega, C. Curie, and S. Mari, J. Biol. Chem. 286, 27863-27866 (2011).2. L. Grillet, L. Ouerdane, P. Flis, M. Thi Thanh Hoang, M. P. Isaure, R. Lobinski, C. Curie, and S. Mari, J. Biol. Chem. 289, 2515-2525(2014).3. S. Huguet, S. Soussou, J. C. Cleyet-Marel, N. Trcera, M. P. Isaure, ‘Rhizostabilization of a mine tailing highly contaminated:preliminary study of Cd localization and speciation in Anthyllis vulneraria in ‘Proceedings of the 16th International Conference onHeavy Metals in the Environment’, edited by N. Pirrone, Roma, Italy, 2013, n°19008.