Figure 1: Flavonoid biosynthetic pathway. The F3H gene is indicated in bold letters. ANS, FS, and FLS, which belong to 2OG-Fe(II) oxygenase superfamily, are shown in italic. Enzyme names are abbreviated as follows: ANS: anthocyanidin synthase, CHI: chalcone isomerase, CHS: chalcone synthase, DFR: dihydroflavonol 4-reductase, F3H: flavanone 3-hydroxylase, FS: and flavone synthase.