Figure 5.

Terpenoid metabolism in engineered tobacco trichomes for triterpene production in plastids. The gray pathway represents the normal biosynthetic route for triterpenes and sterols. The enzymes are targeted to directly produce the triterpenes in the plastids. Overexpressed enzymes are denoted in dark blue. New products deriving from the engineering metabolism are denoted in light blue. The sinking plastidial isoprenoid pool might provoke undesirable consequences. Potentially affected metabolites are denoted in orange. ABA, Abscisic acid; CYP450, cytochrome P450; FDS, farnesyl diphosphate synthase; FPP, farnesyl diphosphate; GGPP, geranylgeranyl diphosphate; GPP, geranyl diphosphate; OSC, 2,3-oxidosqualene cyclase; SQE, squalene epoxidase; SQS, squalene synthase.