Molecular regulation of iron uptake in the dicot species Lycopersicon esculentum and Arabidopsis thaliana

Two important factors which regulate iron mobilisation and iron uptake mechanisms in the root have been identified in the past years from the tomato genome. The LeFER protein is a root-specific transcription factor central for positive regulation of iron mobilisation genes (activation). Nicotianamine synthase (NAS) produces the diffusible iron and metal chelator nicotianamine which serves transport of intracellular and intercellular iron to its final compartments. Nicotianamine influences iron mobilisation positive (activation) if iron is limiting, however negative (repression) if sufficient iron is taken up. Full genome sequence has allowed to identify the homologs of LeFER and LeNAS genes in Arabidopsis thatiana. Their analysis revealed conserved functions in iron mobilisation in the two dicot species.