title: Over-expression of DXS gene enhances terpenoidal secondary metabolite accumulation in rose-scented geranium and Withania somnifera: active involvement of plastid isoprenogenic pathway in their biosynthesis.
abstract: Rose-scented geranium (Pelargonium spp.) is one of the most important aromatic plants and is well known for its diverse perfumery uses. Its economic importance is due to presence of fragrance rich essential oil in its foliage. The essential oil is a mixture of various volatile phytochemicals which are mainly terpenes (isoprenoids) in nature. In this study, on the geranium foliage genes related to isoprenoid biosynthesis (DXS, DXR and HMGR) were isolated, cloned and confirmed by sequencing. Further, the first gene of 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway, 1-deoxy-d-xylulose-5-phosphate synthase (GrDXS), was made full length by using rapid amplification of cDNA ends strategy. GrDXS contained a 2157 bp open reading frame that encoded a polypeptide of 792 amino acids having calculated molecular weight 77.5 kDa. This study is first report on heterologous expression and kinetic characterization of any gene from this economically important plant. Expression analysis of these genes was performed in different tissues as well as at different developmental stages of leaves. In response to external elicitors, such as methyl jasmonate, salicylic acid, light and wounding, all the three genes showed differential expression profiles. Further GrDXS was over expressed in the homologous (rose-scented geranium) as well as in heterologous (Withania somnifera) plant systems through genetic transformation approach. The over-expression of GrDXS led to enhanced secondary metabolites production (i.e. essential oil in rose-scented geranium and withanolides in W. somnifera). To the best of our knowledge, this is the first report showing the expression profile of the three genes related to isoprenoid biosynthesis pathways operated in rose-scented geranium as well as functional characterization study of any gene from rose-scented geranium through a genetic transformation system.
authors: Department of Metabolic and Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow 226015, India.
authors: Jyoti Singh
authors: JS
authors: Jadaun
authors: Department of Metabolic and Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow 226015, India.
authors: Neelam S
authors: NS
authors: Sangwan
authors: Department of Metabolic and Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow 226015, India.
authors: Lokesh K
authors: LK
authors: Narnoliya
authors: Department of Metabolic and Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow 226015, India.
authors: Neha
authors: N
authors: Singh
authors: Department of Metabolic and Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow 226015, India.
authors: Shilpi
authors: S
authors: Bansal
authors: Department of Metabolic and Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow 226015, India.
authors: Bhawana
authors: B
authors: Mishra
authors: Department of Metabolic and Structural Biology, CSIR-Central Institute of Medicinal and Aromatic Plants (CSIR-CIMAP), Lucknow 226015, India.|Center of Innovative and Applied Bioprocessing (A National Institute under Department of Biotechnology, Govt. of India), C-127, Phase-8, Industrial Area, S.A.S. Nagar, Mohali - 160071, Punjab, India.
authors: Rajender Singh
authors: RS
authors: Sangwan
mesh_terms: D000085:Acetates / Q000494:pharmacology; D001483:Base Sequence; D055162:Biocatalysis / Q000187:drug effects; D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D002070:Butadienes / Q000378:metabolism*; D003001:Cloning, Molecular; D019295:Computational Biology; D003517:Cyclopentanes / Q000494:pharmacology; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D017343:Genes, Plant; D031315:Geranium / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D045782:Hemiterpenes / Q000378:metabolism*; D008027:Light; D054883:Oxylipins / Q000494:pharmacology; D010420:Pentanes / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018087:Plastids / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D011994:Recombinant Proteins / Q000378:metabolism; D064210:Secondary Metabolism / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D040681:Structural Homology, Protein; D013729:Terpenes / Q000378:metabolism*; D032341:Withania / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects
chemical_list: D000085:Acetates; D002070:Butadienes; D003517:Cyclopentanes; D045782:Hemiterpenes; D054883:Oxylipins; D010420:Pentanes; D010940:Plant Proteins; D011994:Recombinant Proteins; D013729:Terpenes; C005059:isoprene; C072239:methyl jasmonate