Fig. 1
From: Divergent camptothecin biosynthetic pathway in Ophiorrhiza pumila
Distribution of CPT in the plant kingdom and possible biosynthesis of alkaloids through strictosidine or strictosidinic acid. a Phylogenetic tree of the major lineages of land plants summarizing the known taxonomic distribution of CPT-producing species. Orders that contain at least one CPT-producing species are indicated with red diamonds. The three CPT-producing plants used in this study are shown on the right and belong to the Cornales (C. acuminata), Icacinales (N. nimmoniana), and Gentianales (O. pumila) orders. b The biosynthesis of monoterpene indole alkaloids (MIAs) through strictosidine or strictosidinic acid derived from tryptamine and secoiridoids. STR, strictosidine synthase; STRAS, strictosidinic acid synthase