Abstract
Graminaceous plants have developed a chelation strategy to efficiently acquire insoluble iron, which includes the synthesis and secretion of the iron-chelator phytosiderophore (PS) such as mugineic acids (MAs) and the transportation of Fe(III) complexed with PS. We have identified a specific Fe(III)-PS transporter HvYS1 in barley. In this reports, we have introduced the HvYS1 gene to petunia, which have reduction mechanism, but not chelation strategy to acquire iron upon iron deficiency. When these transgenic petunia were grown hydroponically in medium containing Fe(III)-2'-deoxymugineic acid (DMA) complex, the Fe-DMA complex were detected in the root by ESI-FT-ICRMS. Consequently, transgenic petunia exhibited an enhanced tolerance to low iron concentration in alkaline hydroponic culture in the presence of Fe(III)-DMA complex, which led to 2 times mass weight and 1.5 times iron concentration as compared with nontransformed plants. These results show that plants, which possess reduction mechanism for iron acquisition, confer resistance to Fe deficiency in alkaline condition by acquiring the chelation strategy.
