title: Molecular cloning and characterization of three cDNAs encoding 1-deoxy-d-xylulose-5-phosphate synthase in Aquilaria sinensis (Lour.) Gilg.
abstract: Agarwood is an expensive resinous heartwood derived from Aquilaria plants that is widely used in traditional medicines, incense and perfume. The major constituents of agarwood oils are sesquiterpenes, which are obtained from isopentenyl diphosphate and dimethylallyl diphosphate precursors through the plastidial methylerythritol phosphate (MEP) pathway and/or the cytosolic mevalonate pathway. 1-deoxy-d-xylulose-5-phosphate synthase (DXS) is the first rate-limiting enzyme for sesquiterpene synthesis in the MEP pathway. In this study, 3 cDNAs of DXS genes were cloned and characterized from the Aquilaria sinensis (Lour.) Gilg. These genes represent 3 phylogenetically distinct clades conserved among plants. Functional complementation in a DXS-deficient Escherichia coli strain EcAB4-2 demonstrated that they are active DXS, which rescued the E. coli mutant. Their expression profiles in different tissues and in response to different treatments were analyzed by real-time PCR. All 3 genes are highly expressed in stem, followed by leaf and root. AsDXS1 was significantly stimulated by mechanical, chemical, and H2O2 treatment, whereas AsDXS2 and AsDXS3 only responded to chemical treatment and mechanical treatment, respectively. All three genes were oscillation in respond to MJ treatment, with expression peaks occurring at different time points. Our results suggest the conservation of DXS in evolution and imply their distinct functions in primary and defensive sesquiterpene metabolism in A. sinensis.
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Liu
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Liang
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, China; Hainan Branch Institute of Medicinal Plant (Hainan Provincial Key Laboratory of Resources Conservation and Development of Southern Medicine), Chinese Academy of Medical Sciences & Peking Union Medical College, Wanning 571533, China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, China.
authors.forename: Zhihui
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Sui
authors.affiliation: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, Haidian District, Beijing 100193, China; Hainan Branch Institute of Medicinal Plant (Hainan Provincial Key Laboratory of Resources Conservation and Development of Southern Medicine), Chinese Academy of Medical Sciences & Peking Union Medical College, Wanning 571533, China. Electronic address: wjianh@263.net.
authors.forename: Jianhe
authors.initials: J
authors.lastname: Wei
mesh_terms: D018076:DNA, Complementary / Q000235:genetics*; D012717:Sesquiterpenes / Q000378:metabolism; D029645:Thymelaeaceae / Q000201:enzymology* / Q000235:genetics*; D014166:Transferases / Q000235:genetics*
chemical_list: D018076:DNA, Complementary; D012717:Sesquiterpenes; D014166:Transferases; C109461:deoxyxylulose-5-phosphate synthase
keywords: Agarwood; Aquilaria sinensis; Characterization; DXS; Expression; Sesquiterpene