Cloning an iron‐regulated metal transporter from rice

Rice cDNA and genomic libraries were screened in order to clone an Fe(ll) transporter gene. A cDNA clone highly homologous to the Arabidopsis Fe(ll) transporter gene IRT1 was isolated from Fe-deficient rice roots. The cDNA clone was named OslRTI. A genomic clone corresponding to the cDNA was also obtained, sequenced and analysed. When expressed in yeast cells, OslRTI cDNA reversed the growth defects of the yeast iron-uptake mutant. Northern blot analysis revealed that OslRTI mRNA was pre dominantly expressed in roots and was Induced by Fe- and Cu-deficiency. This suggests that OslRTI is a functional metal transporter for iron, and is actively engaged in Fe uptake from soils, especially under limiting conditions.