Abstract
Graminaceous plants solubilize Fe(III) by secreting phytosiderophores, which are chelators for Fe(III) and take up Fe(III)-phytosiderophores by roots via YS1 transporters. By studying the mutant of Zea maize the Fe(III)-phytosiderophore transporter, ZmYS1, was isolated. To understand the mechanism of Fe(III)-phytosiderophore transport we searched for YS1-like genes in the rice genome and identified 18 putative OsYSLs(OsYSL1-18). Northern blot analysis and quantitative real time PCR revealed that the expression of OsYSL18 was regulated by iron. OsYSL18:green fluorescent protein (GFP) was localized in the plasma membrane of onion epidermal cells. Yeast complementation assay and Xenopus oocytes uptake assay revealed that OsYSL18 transport Fe(III)-deoxymugineic acid. Now we are producing transgenic rice plants that express GUS genes under the control of OsYSL18 promoter.
