meta-Tyrosine in Festuca rubra ssp. commutata (Chewings fescue) is synthesized by hydroxylation of phenylalanine

► m-Tyrosine is produced primarily in Festuca rubra roots. ► Fungal endophytes are not required for m-tyrosine accumulation. ► m-Tyrosine is synthesized by hydroxylation of phenylalanine in F. rubra. ► Cytochrome P450 inhibitors reduce m-tyrosine biosynthesis.