PlantSeeFe · Plants seeking iron: unraveling the molecular mechanisms involved in iron-mobilizing coumarins distribution and trafficking

Iron (Fe) is an essential micronutrient for the productivity of crops and the quality of their derived products. Fe deficiency-induced anemia affects billions of people worldwide. This could be mitigated by improving the capacity of plants to absorb and store Fe, which will help to provide adequate dietary Fe to the growing global population. Decrypting the molecular mechanisms plants have evolved to acquire Fe from the soil is essential for reaching this objective. Recently, the secretion in the soil of root-borne coumarins has emerged as a key factor affecting Fe uptake in non-grass species. However, the mechanisms that modulate coumarin storage and trafficking within plant roots are not well understood. The candidate has coupled microarray data mining with in vivo coumarin transport assays and identified four novel Arabidopsis coumarin transporters, namely NPF7.2, NPF2.3, NPF2.4 and NPF2.5. The objective of this project is to determine the precise function of each of these four transporters in coumarin trafficking and plant Fe nutrition. In work package 1 (WP1), the coumarin transport activities of NPF candidates will be examined in detail using yeast cells and Xenopus oocytes. Moreover, we will generate single (insertion/transposon lines) and multiple (CRISPR/Cas9) mutants in order to precisely define the role of each NPF in plant roots. Next, in vivo imaging of coumarin and NFP candidate protein localization will be conducted to ascertain the role of each candidate in the spatiotemporal distribution of coumarins within the roots (WP2). Finally, the posttranslational regulation of the NPF candidates will be investigated using proteomic approaches (WP3). The proposed project is both feasible and appropriate for a Marie Skłodowska-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.