Abstract
Graminacious plants secrete mugineic acid family phytosiderophores (MAs) from their roots to solubilize and absorb the external insoluble iron. The secretion of MAs increases under Fe-deficiency and follow the circadian rhythm. The particular vesicles derived from rER were observed to accumulate near the cell membrane in Fe-deficient barley roots, before sunrise. Many genes involved in the MAs biosynthesis and iron acquisition have been isolated and characterized. On the other hand, any gene involved in MAs secretion have not been isolated yet. To isolate these genes, we carried out the microarray analysis to examine gene expression in barley roots in response to Fe-deficiency. Many genes related to Fe acquisition mechanisms were recognized as Fe-deficiency inducible genes, suggesting that the microarray analysis was reliable. In addition to these genes, we could identify many Fe-deficiency inducible genes. The genes related to the MAs secretion.would be involved in these genes.
