Artemisinin, a sesquiterpenoid endoperoxide, isolated from the plant L., is widely used in the treatment of malaria. Another sesquiterpenoid, β-caryophyllene having antibiotic, antioxidant, anticarcinogenic and local anesthetic activities, is also presented in . The role played by sesquiterpene transporters in trichomes and accumulation of these metabolites is poorly understood in and in trichomes of other plant species. We identified , encoding a pleiotropic drug resistance (PDR) transporter located to the plasma membrane from . Expression of is tissue-specifically and developmentally regulated in . GUS activity is primarily restricted to T-shaped trichomes of old leaves and roots of transgenic plants expressing : . The level of β-caryophyllene was decreased in transgenic plants expressing -RNAi while transgenic plants expressing increased levels of accumulated higher levels of β-caryophyllene. When AaPDR3 was expressed in transformed yeast, yeasts expressing accumulated more β-caryophyllene, rather than germacrene D and β-farnesene, compared to the non-expressing control.