TS is a member of the terpene cyclase group of enzymes. It catalyzes the isomerization and cyclization of farnesyl pyro-phosphate to form trichodiene, the first cyclic intermediate in the biosynthetic pathway for trichothecenes. It serves to branch trichothecene biosynthesis from the isoprenoid pathway. (2E,6E)-farnesyl diphosphate = diphosphate + trichodiene Sesquiterpene biosynthesis; trichothecene biosynthesis. Trichothecenes are sesquiterpenoid toxins that act by inhibiting protein biosynthesis. Belongs to the trichodiene synthase family.