Ferrous iron uptake via IRT1/ZIP evolved at least twice in green plants.

Iron (Fe) is essential for virtually all organisms, being irreplaceable because of its electrochemical properties that enable many biochemical processes, including photosynthesis. Besides its abundance, Fe is generally found in the poorly soluble form of ferric iron (Fe ), while most plants uptake the soluble form Fe . The model angiosperm Arabidopsis thaliana, for example, captures Fe through a mechanism that lowers rhizosphere pH through proton pumping that increases Fe solubility, which is then reduced by a membrane-bound reductase and transported into the cell by the zinc-regulated, iron-regulated transporter-like protein (ZIP) family protein AtIRT1.