Although iron is an abundant element in most soils, its availability for plants can be limiting, especially in soils with a basic pH. From an agricultural point of view, iron deficiency is responsible for severe losses owing to chlorosis, decreasing the yield and nutritional value of the crops. Plants have evolved two main strategies to cope with low iron availability. The first one, used by most plants, but not by grasses, relies on the reduction of soluble iron(III) chelates and subsequent uptake of iron(II) by root transporters. By contrast, grasses have evolved a mechanism based on the release of small molecules into the rhizosphere that efficiently chelates iron(III), the phytosiderophores and subsequent iron import by uptake of the iron(III)-phytosiderophore complexes into root cells.If we want to understand and improve iron nutrition in major grass crops, such as rice, sorghum, wheat and corn, it is crucial to identify the components involved in iron uptake mechanisms at the molecular level.In the past few years, the genes encoding the key enzymes involved in phytosiderophore biosynthesis have been characterized. Catherine Curie and colleagues1xMaize yellow stripe 1 encodes a protein directly involved in Fe(III) uptake. Curie, C et al. Nature. 2001; 409: 346–349Crossref | PubMed | Scopus (441)See all References1 report the identification of a new gene family encoding the transporters responsible for the uptake of iron siderophore complexes from the rhizosphere to the root cells. Earlier physiological studies have shown that iron-siderophore complex uptake of the iron-deficient maize mutant, yellow stripe 1 (ys1), is impaired. The authors have taken advantage of transposon-tagged alleles of ys1 to identify the disrupted gene. They found that YS1 encodes a protein with 12 transmembrane domains. Furthermore, expression of this protein in a yeast mutant defective for iron transport, restores growth of this yeast strain on medium with low levels of iron, but only in the presence of phytosiderophores. Thus, YS1 encodes a maize iron-siderophore complex uptake transporter. The discovery of this gene family should help the selection or engineering of iron-efficient crop species. Interestingly, the occurrence of YS1-like genes in non-grass species suggests that this type of transporter could play a more general role in iron homeostasis in plants.