Résumé
Iron is one of the most important micronutrient for plant growth and development. It functions as the enzyme cofactor or component of electron transport chains in various vital metabolic processes, including photosynthesis, respiration and amino acid biosynthesis. For maintaining iron homeostasis, and therefore preventing any deficiency or excess that could be detrimental, plants have evolved complex transcriptional regulatory networks to tightly control iron uptake, translocation, assimilation and storage. Such regulatory networks are composed of various transcription factors among them members from the basic helix-loop-helix (bHLH) family play an essential role. Here, we first review recent advances in understanding the roles of bHLH transcription factors involved in the regulatory cascade controlling iron homeostasis in the model plant Arabidopsis, extending it to rice and other plant species. The importance of other classes of transcription factors will also be discussed. Secondly, we elaborate on the posttranslational mechanisms involved in the regulation of these regulatory networks. Finally, we give some perspectives on future research that should be conducted in order to precisely depict how plants control the homeostasis of this micronutrient.