Phylogenetic tree analysis of strictosidine synthases (STR) and the expression profile detection of CaG10H, CaSCS , and CaSTR. (A) Protein sequences for 22 STRs were aligned using the ClustalW module and phylogenetic tree was constructed using MEGA 4.0. (B) Relative expression of three genes after induction by MeJA. Expression levels in young leaves without treatment served as controls (M0). M1, M3, M6, M12 and M24 indicate that the treatment times of 1 h, 3 h, 6 h, 12 h and 24 h, respectively. (C) The quantification of three genes involved in CPT biosynthesis in different tissues. Expression levels in young leaves served as controls. Y: young leaves; O: old leaves; P: petioles; S: stems; H: root bark; R: root.