Scheme of the flavonoid biosynthetic pathway in plants.

<p>Genes encoding enzymes for each step are indicated as follows: <i>PAL, phenylalanine ammonia-lyase; C4H, cinnamate 4-hydroxylase; 4CL, 4-coumarate-CoA ligase; CHS, chalcone synthase; CHI, chalcone isomerase; F3H, flavanone 3-hydroxylase; F3′H, flavonoid 3′-hydroxylase; DFR, dihydro-flavonol 4-reductase; FNS, flavonol synthase; FLS, flavonol synthase; LAR, leucoanthocyanidin reductase; ANS, anthocyanidin synthase; UFGT, UDP-glucose: flavonoid-3-O-glycosyltransferase.</i>