Abstract
Gene regulations under Fe-deficiency conditions are still not clear although iron-deficiency-responsible cis-elements were identified in barley. HvIRO1, encoding a putative basic leucine zipper protein (bZIP), was isolated from barley. The predicted protein of IRO1 belongs to a group of bZIP which would have a role in the vascular bundle development. We also isolated a homolog of this putative bZIP transcription factor from rice. The expression of IRO1 gene increased at the early stage of Fe-deficiency and soon after decreased to the control level in roots of barley and rice. Transgenic rice of dominant negative (DN) was made by overexpressing the bZIP domain of OsIRO1. The severe phenotype of DN rice was characterized by ‘dwarf’, ‘dried leaves’ and ‘sterile’. By rice oligo 22K microarray, we analyzed gene profiling of the moderate phenotype of DN rice to elucidate the OsIRO1 function under Fe-deficient conditions.
