Isolation and molecular characterization of a subgroup 7 transcription factor gene.

We isolated an ortholog () of the Arabidopsis R2R3-MYB transcription factor (TF) gene from to investigate the regulation of flavonoid biosynthesis, which is driven by many paralogous genes in . We characterized the spatial and temporal expression of in leaves, stems, roots, flowers, immature seeds, seedling leaves, and seedling roots. Expression was much higher in flowers than in other tissues. To verify the relationship between the expression of and that of flavonoid biosynthesis genes, we generated transgenic plants overexpressing . Overexpression of resulted in the upregulation of genes for a chalcone synthase paralog (), flavanone 3-hydroxylase, and flavonol synthase. Interestingly, LjMYB12 strongly activated but did not activate other paralogs. This result suggests differences in the spatial or temporal activation of paralogs by R2R3-MYB TFs. Molecular characterization of R2R3-MYB TFs in will reveal the effects of gene duplication on the regulation of diverse flavonoid biosynthesis.