title: Overexpression of artemisinic aldehyde Δ11 (13) reductase gene-enhanced artemisinin and its relative metabolite biosynthesis in transgenic Artemisia annua L.
abstract: Artemisinic aldehyde Δ11 (13) reductase (DBR2) is the checkpoint enzyme catalyzing artemisinic aldehyde to form dihydroartemisinic aldehyde directly involved in artemisinin biosynthetic pathway. In the present study, DBR2 was employed to engineer the biosynthetic pathway of artemisinin in transgenic plants of Artemisia annua L. Seven independent transgenic plants of A. annua with DBR2 overexpression driven by the cauliflower mosaic virus 35S promoter were obtained by Agrobacterium-mediated genetic transformation and confirmed by genomic PCR. The results of real-time qPCR analysis showed that the expression levels of DBR2 gene in all the seven transgenic lines were significantly higher than in nontransgenic control. The high-performance liquid chromatography analysis of artemisinin and its relative metabolites demonstrated that the contents of artemisinin and its direct precursor dihydroartemisinic acid were remarkably increased in the transgenic plants of A. annua with DBR2 overexpression. Interestingly, it was also found that the contents of arteannuin B and its direct precursor artemisinic acid in the branch pathway competing against artemisinin biosynthesis were also improved in DBR2-overexpressed A. annua plants. The transgenic results in the present study indicated that DBR2 is a useful structural gene in engineering the artemisinin biosynthetic pathway to develop genetically modified A. annua with the higher yield of artemisinin.
authors.affiliation: Key Laboratory of Eco-Environments in Three Gorges Reservoir Region (Ministry of Education), Chongqing Engineering and Technology Research Center for Sweetpotato, School of Life Sciences, Southwest University, Chongqing 400715, People's Republic of China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
authors.forename: Wanhong
authors.initials: W
authors.lastname: Liu
authors.forename: Qiaozhuo
authors.initials: Q
authors.lastname: Zhang
authors.forename: Lien
authors.initials: L
authors.lastname: Xiang
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Zhi
authors.initials: Z
authors.lastname: Lin
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Liao
mesh_terms: D031172:Artemisia annua / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D037621:Artemisinins / Q000378:metabolism*; D015870:Gene Expression; D007783:Lactones / Q000378:metabolism*; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism*; D030821:Plants, Genetically Modified
chemical_list: D037621:Artemisinins; D007783:Lactones; D010940:Plant Proteins; D010088:Oxidoreductases; C531287:artemisinic aldehyde delta11(13) reductase, Artemisia annua; C075875:artemisin
keywords: Artemisia annua L; DBR2; artemisinin biosynthesis; overexpression