title: Cloning and characterization of the 1-deoxy-D-xylulose 5-phosphate reductoisomerase gene for diterpenoid tanshinone biosynthesis in Salvia miltiorrhiza (Chinese sage) hairy roots.
abstract: Salvia miltiorrhiza Bunge (Chinese sage; Lamiaceae) is a valuable Chinese herbal plant, and its rhizome, known as Danshen in Chinese because of its characteristic red pigment, is the part of the plant used in herbal medicine. The red pigment in S. miltiorrhiza roots is mainly composed of numerous diterpenoid tanshinones, as the major bioactive ingredients of the herb. In plants, diterpenes are synthesized through the MEP (2-C-methyl-D-erythritol 4-phosphate) pathway in the plastids, and DXR [DXP (1-deoxy-D-xylulose 5-phosphate) reductoisomerase] is an enzyme catalysing the first step of the MEP pathway. In the present study, a full-length cDNA encoding DXR (GenBank Nucleotide Sequence Database accession no. DQ991431) was cloned from the hairy roots of S. miltiorrhiza in culture. The enzyme activity of DXR protein was verified by complementation of an Escherichia coli mutant deficient in dxr. The transcription level of the dxr gene in the hairy roots was up-regulated after exposure to hyperosmotic stress and a yeast elicitor in parallel with increased tanshinone accumulation in the hairy roots. This is the first report, to our knowledge, of elicitor-induced dxr transcription and its correlation with the accumulation of diterpenoid tanshinones in S. miltiorrhiza roots.
authors.affiliation: Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong Special Administrative Region, People's Republic of China.
authors.forename: Shu Jing
authors.initials: SJ
authors.lastname: Wu
authors.forename: Ming
authors.initials: M
authors.lastname: Shi
authors.forename: Jian Yong
authors.initials: JY
authors.lastname: Wu
mesh_terms: D045784:Abietanes; D019747:Aldose-Ketose Isomerases / Q000235:genetics* / Q000502:physiology; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004224:Diterpenes / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D053858:Metabolic Networks and Pathways / Q000235:genetics; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics* / Q000502:physiology; D010088:Oxidoreductases / Q000235:genetics* / Q000502:physiology; D010616:Phenanthrenes / Q000378:metabolism*; D010802:Phylogeny; D018517:Plant Roots / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D027561:Salvia miltiorrhiza / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013312:Stress, Physiological / Q000502:physiology; D015854:Up-Regulation / Q000502:physiology
chemical_list: D045784:Abietanes; D004224:Diterpenes; D009097:Multienzyme Complexes; D010616:Phenanthrenes; C021751:tanshinone; D010088:Oxidoreductases; C114231:1-deoxy-D-xylulose 5-phosphate reductoisomerase; D019747:Aldose-Ketose Isomerases