Iron-Fortification Of Rice Seeds By Expressing Ferritin Genes Along With Enhancing Iron Absorption And Translocation - Second Report

Abstract

Iron-fortified rice will contribute to ameliorate the iron deficiency anemia which is a serious problem of insufficient nourishment in Asia. We have already expressed ferritin gene in rice seeds using an endosperm-specific promoter and obtained transgenic rice seeds whose iron concentrations were increased. However, higher levels of ferritin expression in rice seeds hardly increased iron concentration. In this report, we aimed to further increase iron concentration in rice seeds by enhancing iron absorption and transport ability by introducing the barley HvNAS1, HvNAAT-A,-B and IDS3 genes encoding biosynthetic genes of mugineic acid family phytosiderophores. First, we investigated iron concentrations of transgenic rice seeds with introduced HvNAS1alone, HvNAS1 and HvNAAT-A,-B, or IDS3 gene alone. Second, we introduced soybean ferritin gene, SoyferH2 connected to two endosperm-specific promoters, along with HvNAS1, HvNAAT-A,-B and IDS3 genes, using a marker-free vector. We will report ferritin expression and iron concentrations of T₂ seeds.