Identification of class 2 1-deoxy-D-xylulose 5-phosphate synthase and 1-deoxy-D-xylulose 5-phosphate reductoisomerase genes from Ginkgo biloba and their transcription in embryo culture with respect to ginkgolide biosynthesis.
Diterpenoid ginkgolides having potent platelet-activating factor antagonist activity are major active ingredients of ginkgo extract. Class 2-type 1-deoxy-D-xylulose 5-phosphate synthase (GbDXS2) and 1-deoxy-D-xylulose 5-phosphate reductoisomerase (GbDXR), the first two enzymes in 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, operating in the earlier step of ginkgolide biosynthesis, were cloned from embryonic roots of Ginkgo biloba through a homology-based polymerase chain reaction for role assessment of the enzymes. Plasmids harboring each gene rescued the respective knockout E. coli mutants. The levopimaradiene synthase gene (LPS), responsible for the first committed step in ginkgolide biosynthesis, and GbDXS2 were transcribed exclusively in embryonic root, suggesting a specific role of GbDXS2 in ginkgolide biosynthesis. GbDXR retained a higher transcription level in roots than in leaves, whereas class 1 DXS (GbDXS1) showed 30 to 50 % higher level in leaves. Ginkgolides and bilobalide were found both in leaves and roots from an earlier stage of the embryo culture. Exclusive transcription of ginkgolide biosynthesis-specific LPS and GbDXS2 in roots and the appearance of ginkgolides in leaves was consistent with translocation of the compounds from roots to leaves.
Kim
Sang-Min
SM
School of Agricultural Biotechnology, Seoul National University, Korea.
Kuzuyama
Tomohisa
T
Chang
Yung-Jin
YJ
Song
Kwang-Seop
KS
Kim
Soo-Un
SU
D019747:Aldose-Ketose Isomerases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D017931:DNA Primers; D018744:DNA, Plant / Q000737:chemistry; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D020441:Ginkgo biloba / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D046934:Ginkgolides / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010088:Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D008517:Phytotherapy; D018515:Plant Leaves; D018517:Plant Roots; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D046509:Tissue Culture Techniques; D014166:Transferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
D017931:DNA Primers; D018744:DNA, Plant; D046934:Ginkgolides; D009097:Multienzyme Complexes; D010088:Oxidoreductases; C114231:1-deoxy-D-xylulose 5-phosphate reductoisomerase; D014166:Transferases; C109461:deoxyxylulose-5-phosphate synthase; D019747:Aldose-Ketose Isomerases