IRT1, an Arabidopsis Transporter Essential for Iron Uptake from the Soil and for Plant Growth

Plants are the principal source of iron in most diets, yet iron availability often limits plant growth. In response to iron deficiency, Arabidopsis roots induce the expression of the divalent cation transporter IRT1. Here, we present genetic evidence that IRT1 is essential for the uptake of iron from the soil. An Arabidopsis knockout mutant in IRT1 is chlorotic and has a severe growth defect in soil, leading to death. This defect is rescued by the exogenous application of iron. The mutant plants do not take up iron and fail to accumulate other divalent cations in low-iron conditions. IRT1-green fluorescent protein fusion, transiently expressed in culture cells, localized to the plasma membrane. We also show,…