Fig. 2. Schematic representation of dhurrin biosynthesis (left) derived from the aromatic amino acid tyrosine and phenylpropanoid biosynthesis derived from the aromatic amino acid phenylalanine. The core phenylpropanoid pathway branches out into a metabolic grid of downstream pathways leading to the production of e.g. flavonoids and stilbenes and monomeric units as building blocks for plant polymers. Selected phenylpropanoid branches discussed in the main text are presented. P450 enzymes are colored in orange and other enzymes are colored in green. Abbreviations: C3′H, p-coumaroylshikimate 3′-hydroxylase (CYP98A); C4H, cinnamate-4-hydroxylase (CYP73A); CHI, chalcone isomerase; CHR, chalcone reductase; CHS, chalcone synthase, 4CL, 4-coumaric acid CoA ligase; F3H, flavanone 3-hydroxylase; F3′H, flavonoid 3′ hydroxylase (CYP75B); FNSII, flavone synthase II (CYP93B); HCT, hydroxycinnamoyl transferase; IFS, isoflavone synthase; PAL, phenylalanine lyase; VAN, vanillin synthase. Broken arrows indicate multistep enzymatic reactions. Box around vanillin glucoside indicates compartmentalization.