De novo synthesis of plant sesquiterpenes in yeast. GC-MS analysis of metabolites from EPY300 yeast expressing sesquiterpene synthases. Peaks of sesquiterpene products are indicated with asterisks; the corresponding structures are depicted to the right. Negative control was EPY300 transformed with empty pESC-Leu-2d vector. GaCDS, cotton (Gossypium aboreum) δ-cadinene synthase; ScGDS, Canadian goldenrod (Solidago canadensis) germacrene D synthase; VoVDS, valerian (Valeriana officinalis) valerenadiene synthase; SynGUS, synthetic guaiene synthase; NtEAS, tobacco (Nicotiana tabacum) 5-epi-aristolochene synthase; SynVLS, synthetic valencene synthase.