AUTHOR=Fu Xueqing , Shi Pu , He Qian , Shen Qian , Tang Yueli , Pan Qifang , Ma Yanan , Yan Tingxiang , Chen Minghui , Hao Xiaolong , Liu Pin , Li Ling , Wang Yuliang , Sun Xiaofen , Tang Kexuan 

TITLE=AaPDR3, a PDR Transporter 3, Is Involved in Sesquiterpene β-Caryophyllene Transport in Artemisia annua

JOURNAL=Frontiers in Plant Science

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2017.00723

DOI=10.3389/fpls.2017.00723

ISSN=1664-462X

ABSTRACT=<p>Artemisinin, a sesquiterpenoid endoperoxide, isolated from the plant <italic>Artemisia annua</italic> 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 <italic>A. annua</italic>. The role played by sesquiterpene transporters in trichomes and accumulation of these metabolites is poorly understood in <italic>A. annua</italic> and in trichomes of other plant species. We identified <italic>AaPDR3</italic>, encoding a pleiotropic drug resistance (PDR) transporter located to the plasma membrane from <italic>A. annua</italic>. Expression of <italic>AaPDR3</italic> is tissue-specifically and developmentally regulated in <italic>A. annua</italic>. GUS activity is primarily restricted to T-shaped trichomes of old leaves and roots of transgenic <italic>A. annua</italic> plants expressing <italic>proAaPDR3</italic>: <italic>GUS</italic>. The level of β-caryophyllene was decreased in transgenic <italic>A. annua</italic> plants expressing <italic>AaPDR3</italic>-RNAi while transgenic <italic>A. annua</italic> plants expressing increased levels of <italic>AaPDR3</italic> accumulated higher levels of β-caryophyllene. When AaPDR3 was expressed in transformed yeast, yeasts expressing <italic>AaPDR3</italic> accumulated more β-caryophyllene, rather than germacrene D and β-farnesene, compared to the non-expressing control.</p>