A unique Fd/FNR pair occurs in monoterpene-accumulating GTs. A, Maximum likelihood tree of FNR isoforms. B, Maximum likelihood tree of Fd isoforms. Comparisons employ nucleotide sequences corresponding to the mature proteins (excluding plastidial targeting sequences). Scale bars represent the number of substitutions per site. Species abbreviations are as follows: Aann (Artemisia annua), Athal (Arabidopsis thaliana), Csat (Cannabis sativa), Hlup (Humulus lupulus), Maqu (Mentha acquatica), Marv (Mentha arvensis), Mlon (Mentha longifolia), Mpip (Mentha × piperita), Mspi (Mentha × spicata), Obas (Ocimum basilicum), Pfru (Perilla frutescens), Slyc (Solanum lycopersicum). Other abbreviations are as follows: L, leaf isoform; maj, major GT isoform; min, minor GT isoform; R, root isoform. Colors indicate isoforms present in leaves (green), roots (gray), GTs (yellow), and both roots and GTs (yellow/gray).