Abstract
We have identified that the feruloyl-CoA ortho-(6'-) hydroxylase of Arabidopsis thaliana (AtF6'H1) catalyzes the key step of scopoletin biosynthesis. AtF6'H1 exhibits the high substrate specificity for feruloyl-CoA. A. thaliana mainly accumulates scopoletin (7-hydroxy-6-methoxycoumarin).
AtF6'H1 homologs are found in the EST database of the plants. Sweet potato (Ipomoea batatas) accumulates both scopoletin and umbelliferone (7-hydroxycoumarin). It is assumed that EST homologs of sweet potato exhibit the different substrate specificity from that of AtF6'H1 and that are involved in biosynthesis of scopoletin and umbelliferone. In order to investigate the substrate specificity of these homologs, we performed cloning and functional analysis of the homologs of sweet potato. The total sequences of the homologs were obtained by RT-PCR, 3'- and 5'-RACE methods. Expression pattern of the homologs were analyzed by RT-PCR.
