The gene that keeps plants off Geritol.

When plants in poor soil get low on iron, a protein in the roots of many species helps them take in oxidized iron compounds that are normally unusable. David Eide of the University of Minnesota School of Medicine in Duluth and his colleagues report that they have now found the gene that encodes this iron-transporting protein.

They hope to use the gene, iron-regulated transporter 1 (IRT1), to create plants that take up lots of iron and thus serve as a source of iron-rich food. IRT1 may also promote the uptake of cadmium. If so, researchers could engineer plants that help remove this pollutant from contaminated soil. Eide and his colleagues inserted DNA fragments from Arabidopsis thaliana, a weed that manages well in poor soil, into yeast cells, they report in the May 28 Proceedings of the National Academy of Sciences. Each fragment contained a single gene. They then grew the yeast in an iron-poor medium, where it would normally die. However, some yeast survived-those that absorbed iron more efficiently because they had received an IRT1 gene, the team concludes. IRT1 resembles genes involved in zinc transport in other types of yeast. Nematodes, rice, and people have similar-looking genes of unknown function. Eide suspects that IRT1 may be part of a new family of genes that encode metal-transporting proteins.