Advances in Iron Retrograde Signaling Mechanisms and Uptake Regulation in Photosynthetic Organisms

Iron (Fe) is an essential metal for the growth and development of different organisms, including plants and algae. This metal participates in different biological processes, among which are cellular respiration and photosynthesis. Fe is found associated with heme groups and as part of inorganic Fe-S groups as cofactors of numerous cellular proteins. Although Fe is abundant in soils, it is often not bioavailable due to soil pH. For this reason, photosynthetic organisms have developed different strategies for the uptake, the sensing of Fe intracellular levels but also different mechanisms that maintain and regulate adequate concentrations of this metal in response to physiological needs. This work focuses on discussing recent advances in the characterization of the mechanisms of Fe homeostasis and Fe retrograde signaling in photosynthetic organisms.