Iron deficiency is also the leading nutritional disorder in people worldwide. Most of the world's humans get their daily iron supply in the form of plant foods. Though iron deficiency is a global nutrition problem, iron overload is lethal to people with an inherited disorder called hemochromatosis, which causes their bodies to store excess iron. Iron has also been implicated as a risk factor in heart disease. This protein converts an unusable form of iron in soil into a form that can be taken up by cells.
Yeast use a similar mechanism to obtain iron.
Both mechanisms are known to have a genetic basis. To find the new gene, the researchers inserted pieces of DNA from the weed, which has the Latin name Arabidopsis, into mutant yeast cells known to lack the ability to survive in low-iron conditions. The transformed yeast cells were then grown in an iron-restricted medium, where most died. The yeast cells that thrived were assumed to have received the piece of Arabidopsis DNA that confers the ability to take up iron under iron-limited conditions. The gene identified by the team encodes a protein that loops in and out of a cell's membrane, forming a portal through which iron may enter the cell.