Metals, such as manganese or zinc, are vital elements for plant growth and development. They are involved in many biological processes and one third of characterized enzymes are metalloproteins. Because metal excess or metal deprivation is deleterious for cells, plants have developed mechanisms to regulate the uptake, the transport and the storage of metals. Dr Thomine’s group, in Gif-sur-Yvette (France), has obtained evidence that metal compartmentalization is essential for metal homeostasis. However, no tools are currently available to monitor the dynamics of metal concentrations in living plants. Prof Frommer’s group, in Stanford (USA), pioneered the design of genetically encodable FRET nanosensors for living cells. The project will aim at developing a set of metal nanosensors to image in vivo the dynamics of manganese and zinc localization and their regulation in Arabidopsis thaliana. An integrated approach in plants, combining the use of mutants impaired in metal transport and metal imaging, will enable us to further understand biological processes underlying the control of metal homeostasis in plants. This project will enable the researcher to acquire new expertise in the design of nanosensors for living cells.