AUTHOR=Fu Xueqing , Liu Hang , Hassani Danial , Peng Bowen , Yan Xin , Wang Yuting , Wang Chen , Li Ling , Liu Pin , Pan Qifang , Zhao Jingya , Qian Hongmei , Sun Xiaofen , Tang Kexuan 

TITLE=AaABCG40 Enhances Artemisinin Content and Modulates Drought Tolerance in Artemisia annua

JOURNAL=Frontiers in Plant Science

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2020.00950

DOI=10.3389/fpls.2020.00950

ISSN=1664-462X

ABSTRACT=<p>The phytohormone Abscisic acid (ABA) regulates plant growth, development, and responses to abiotic stresses, including senescence, seed germination, cold stress and drought. Several kinds of researches indicate that exogenous ABA can enhance artemisinin content in <italic>A. annua</italic>. Some transcription factors related to ABA signaling are identified to increase artemisinin accumulation through activating the artemisinin synthase genes. However, no prior study on ABA transporter has been performed in <italic>A. annua</italic>. Here, we identified a pleiotropic drug resistance (PDR) transporter gene <italic>AaPDR4/AaABCG40</italic> from <italic>A. annua</italic>. <italic>AaABCG40</italic> was expressed mainly in roots, leaves, buds, and trichomes. GUS activity is primarily observed in roots and the vascular tissues of young leaves in <italic>proAaABCG40</italic>: <italic>GUS</italic> transgenic <italic>A. annua</italic> plants. When <italic>AaABCG40</italic> was transferred into yeast AD12345678, yeasts expressing <italic>AaABCG40</italic> accumulated more ABA than the control. The <italic>AaABCG40</italic> overexpressing plants showed higher artemisinin content and stronger drought tolerance. Besides, the expression of <italic>CYP71AV1</italic> in OE-<italic>AaABCG40</italic> plants showed more sensitivity to exogenous ABA than that in both wild-type and i<italic>AaABCG40</italic> plants. According to these results, they strongly suggest that AaABCG40 is involved in ABA transport in <italic>A. annua</italic>.</p>