Abstract
In mammals, the molecular mechanisms that regulate iron homeostasis that is coordinating both responses to deficiency and excess iron are well described. Conversely, any major integrator of these responses has not been described to date in plants. By studying the expression of AtFER1 (the main marker of plant response to iron excess), we have identified a bHLH transcription factor (IRI1: Iron Response Integrator 1) that integrates the response to the iron deficiency and excess. From these findings, it emerges that IRI1 is the master regulator of iron homeostasis in plants. The identification of this transcription factor is therefore a major advance in our understanding of the molecular mechanisms that control the mineral nutrition of plants, and thus their growth and development, opening new avenues for the development of new strategies aiming at improving crop production and bio-fortification. This PhD project aims at further characterizing the molecular mechanisms that control iron homeostasis in plants, focusing on Arabidopsis thaliana as a model. Two main axes will be developed based on the accumulated knowledge that has been gathered by the host laboratory. First, the study of the transcriptional control of AtFER1 expression will be pursued. Second, IRI1 function in controlling iron homeostasis will be further characterize (i.e. target genes, protein partners, etc.).