Unraveling the molecular mechanisms involved in the regulation of iron-mobilizing coumarins biosynthesis, trafficking and secretion

Iron (Fe) is an essential micronutrient for the productivity of crops and the quality of their derived products. Fe is also the most deficient mineral nutrient in human diet. Decrypting the molecular mechanisms plants have evolved to acquire Fe from the soil is essential for improving their capacity to absorb and store Fe, which will help to provide adequate dietary Fe to the growing global population. The secretion in the soil of root-borne coumarins has emerged as a key factor affecting Fe uptake in non-grass species. The mechanisms by which Fe mobilizing coumarins biosynthesis, trafficking and secretion is regulated is still not well understood. Using an original bioinformatic pipeline, the candidate has identified conserved DNA-signatures in the promoter of key genes involved in this process in different plants species, including crops. The objective of this project is to identify and characterized in Arabidopsis the regulatory proteins associated with these DNA-signatures and determine their role in plant Fe nutrition. In work package 1 (WP1), the developed bioinformatic pipeline will be further used to enhance the detection accuracy of conserved potential regulatory DNA motifs present in the promoter of Fe-mobilizing coumarin genes. Candidate proteins interacting with the selected potential DNA motifs will be identified using in silico and in vivo approaches (WP2). Last, we will generate mutants in order to precisely define the role of each candidate identified. In vivo imaging of coumarin and candidate protein localization will be conducted to ascertain the role of each candidate in the spatiotemporal distribution of coumarins within the roots (WP3). The proposed project is both feasible and appropriate for a Marie Skodowska-Curie Individual Fellowship, since the expected outcomes are innovative and will generate knowledge for both fundamental and industrial research, while the candidate will improve his skills and knowledge in a specialized research area.