Abstract
Iron is an essential nutrient for normal plant growth, and involved in many cellular activities. Graminaceous plants use the iron chelators known as mugineic acid family phytosiderophores (MAs) to acquire iron from the rhizosphere. The secreted MAs solubilize Fe(III) in the rhizosphere, and the resulting Fe(III)-MAs complexs are reabsorbed into the root cells. Nicotianamine (NA), an essential intermediate in the biosynthesis of MAs, was found in all plant, and chelates metal cations, including Fe(II) and Fe(III). Therefore, NA is thought to play a role in the internal transport of Fe and other metals. In this study, we examined the expression pattern of the genes encoding enzymes involved in the MAs biosynthesis and the iron transporters during seed germination by promoter-GUS analysis. All genes examined were expressed in germinating rice seeds prior to radicle protrusion. It was suggested that NA and DMA are produced and involved in iron transport during germination.
