title: Identification and Functional Characterization of Sesquiterpene Synthases from Xanthium strumarium.
abstract: Xanthium strumarium synthesizes various pharmacologically active sesquiterpenes. The molecular characterization of sesquiterpene biosynthesis in X. strumarium has not been reported so far. In this study, the cDNAs coding for three sesquiterpene synthases (designated as XsTPS1, XsTPS2 and XsTPS3) were isolated using the X. strumarium transcriptome that we recently constructed. XsTPS1, XsTPS2 and XsTPS3 were revealed to have primary activities forming germacrene D, guaia-4,6-diene and germacrene A, respectively, by either ectopic expression in yeast cells or purified recombinant protein-based in vitro assays. Quantitative real-time PCRs and metabolite analysis for the different plant parts showed that the transcript abundance of XsTPS1-XsTPS3 is consistent with the accumulation pattern of their enzymatic products, supporting their biochemical functions in vivo. In particular, we discovered that none of the XsTPS2 product, guaia-4,6-diene, can be detected in one of the X. strumarium cultivars used in this study (it was named the Hubei-cultivar), in which a natural deletion of two A bases in the XsTPS2 cDNA disrupts its activity, which further confirmed the proposed biochemical role of XsTPS2 in X. strumarium in vivo.
authors: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan 430074, China University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Yuanjun
authors: Y
authors: Li
authors: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan 430074, China.
authors: Fangfang
authors: F
authors: Chen
authors: College of Life Sciences, Hebei University, Baoding 071002, China.
authors: Zhenqiu
authors: Z
authors: Li
authors: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan 430074, China.
authors: Changfu
authors: C
authors: Li
authors: CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden, The Chinese Academy of Science, Wuhan 430074, China zhangys@wbgcas.cn.
authors: Yansheng
authors: Y
authors: Zhang
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000378:metabolism*; D053898:Biosynthetic Pathways; D008401:Gas Chromatography-Mass Spectrometry; D018506:Gene Expression Regulation, Plant; D007783:Lactones / Q000737:chemistry / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D010938:Plant Oils / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D020539:Sequence Analysis, Protein; D012717:Sesquiterpenes / Q000737:chemistry / Q000378:metabolism*; D031210:Xanthium / Q000201:enzymology* / Q000235:genetics
chemical_list: D007783:Lactones; D010938:Plant Oils; D010940:Plant Proteins; D012333:RNA, Messenger; D012717:Sesquiterpenes; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase
keywords: Sesquiterpene lactone; Sesquiterpene synthase; Xanthium strumarium