Molecular cloning and functional characterization of the flavonoid 3′-hydroxylase gene from Rubus coreanus Miquel

Rubus coreanus Miquel is a Korean black raspberry used in folk medicine and functional foods. To investigate the biosynthesis pathway of anthocyanin in R. coreanus Miquel, the complete coding sequence of flavonoid 3'-hydroxylase (F3'H), designated as RcMF3'H1, was cloned for the first time using the Korean black raspberry transcriptome library. The deduced amino acid sequence of RcMF3'H1 contained the proline-rich "hinge" region, P450 consensus hemebinding domain, and F3'H-specific motifs. Phylogenetic analysis revealed that RcMF3'H1 was clustered into the same subgroup as other plant F3'Hs. In addition, expression analysis by quantitative real-time PCR revealed the involvement of RcMF3'H1 in methyl jasmonate-mediated anthocyanin biosynthesis. Furthermore, the ability of the RcMF3'H1 gene to complement the Arabidopsis transparent testa 7-1 mutant suggested that RcMF3'H1 encodes the functional F3'H enzyme involved in anthocyanin biosynthesis. Taken together, the cloning and molecular characterization of RcMF3'H1 will facilitate a better insight into the anthocyanin biosynthesis pathway in R. coreanus Miquel.