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Prabodh Kumar Trivedi - One of the best experts on this subject based on the ideXlab platform.

  • comparative transcriptome analysis of different chemotypes elucidates withanolide biosynthesis pathway from medicinal plant Withania somnifera
    Scientific Reports, 2015
    Co-Authors: Parul Gupta, Neelam S Sangwan, Ridhi Goel, Aditya Vikram Agarwal, Mehar Hasan Asif, Rajender S Sangwan, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera is one of the most valuable medicinal plants synthesizing secondary metabolites known as withanolides. Despite pharmaceutical importance, limited information is available about the biosynthesis of withanolides. Chemo-profiling of leaf and root tissues of Withania suggest differences in the content and/or nature of withanolides in different chemotypes. To identify genes involved in chemotype and/or tissue-specific withanolide biosynthesis, we established transcriptomes of leaf and root tissues of distinct chemotypes. Genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis with their alternatively spliced forms and paralogous have been identified. Analysis suggests differential expression of large number genes among leaf and root tissues of different chemotypes. Study also identified differentially expressing transcripts encoding cytochrome P450s, glycosyltransferases, methyltransferases and transcription factors which might be involved in chemodiversity in Withania. Virus induced gene silencing of the sterol ∆7-reductase (WsDWF5) involved in the synthesis of 24-methylene cholesterol, withanolide backbone, suggests role of this enzyme in biosynthesis of withanolides. Information generated, in this study, provides a rich resource for functional analysis of withanolide-specific genes to elucidate chemotype- as well as tissue-specific withanolide biosynthesis. This genomic resource will also help in development of new tools for functional genomics and breeding in Withania.

  • de novo assembly functional annotation and comparative analysis of Withania somnifera leaf and root transcriptomes to identify putative genes involved in the withanolides biosynthesis
    PLOS ONE, 2013
    Co-Authors: Parul Gupta, Ridhi Goel, Mehar Hasan Asif, Rajender S Sangwan, Sumya Pathak, Apeksha Srivastava, Surya Pratap Singh, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicine systems due to bioactive molecules known as withanolides. As genomic information regarding this plant is very limited, little information is available about biosynthesis of withanolides. To facilitate the basic understanding about the withanolide biosynthesis pathways, we performed transcriptome sequencing for Withania leaf (101L) and root (101R) which specifically synthesize withaferin A and withanolide A, respectively. Pyrosequencing yielded 8,34,068 and 7,21,755 reads which got assembled into 89,548 and 1,14,814 unique sequences from 101L and 101R, respectively. A total of 47,885 (101L) and 54,123 (101R) could be annotated using TAIR10, NR, tomato and potato databases. Gene Ontology and KEGG analyses provided a detailed view of all the enzymes involved in withanolide backbone synthesis. Our analysis identified members of cytochrome P450, glycosyltransferase and methyltransferase gene families with unique presence or differential expression in leaf and root and might be involved in synthesis of tissue-specific withanolides. We also detected simple sequence repeats (SSRs) in transcriptome data for use in future genetic studies. Comprehensive sequence resource developed for Withania, in this study, will help to elucidate biosynthetic pathway for tissue-specific synthesis of secondary plant products in non-model plant organisms as well as will be helpful in developing strategies for enhanced biosynthesis of withanolides through biotechnological approaches.

  • cloning and functional characterization of 3 hydroxy 3 methylglutaryl coenzyme a reductase gene from Withania somnifera an important medicinal plant
    Protoplasma, 2013
    Co-Authors: Nehal Akhtar, Neelam S Sangwan, Parul Gupta, Rajender S Sangwan, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera (L.) Dunal is one of the most valuable medicinal plants synthesizing a large number of pharmacologically active secondary metabolites known as withanolides, the C28-steroidal lactones derived from triterpenoids. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the biosynthetic pathway and genes responsible for biosynthesis of these compounds. In this study, we have characterized the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR; EC 1.1.1.34) catalyzing the key regulatory step of the isoprenoid biosynthesis. The 1,728-bp full-length cDNA of Withania HMGR (WsHMGR) encodes a polypeptide of 575 amino acids. The amino acid sequence homology and phylogenetic analysis suggest that WsHMGR has typical structural features of other known plant HMGRs. The relative expression analysis suggests that WsHMGR expression varies in different tissues as well as chemotypes and is significantly elevated in response to exposure to salicylic acid, methyl jasmonate, and mechanical injury. The functional color assay in Escherichia coli showed that WsHMGR could accelerate the biosynthesis of carotenoids, establishing that WsHMGR encoded a functional protein and may play a catalytic role by its positive influence in isoprenoid biosynthesis.

  • cloning and characterization of 2 c methyl d erythritol 4 phosphate pathway genes for isoprenoid biosynthesis from indian ginseng Withania somnifera
    Protoplasma, 2013
    Co-Authors: Parul Gupta, Aditya Vikram Agarwal, Rajender S Sangwan, Surya Pratap Singh, Nehal Akhtar, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera (L.) is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicines. Pharmaceutical activities of this herb are associated with presence of secondary metabolites known as withanolides, a class of phytosteroids synthesized via mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate pathways. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the genes responsible for biosynthesis of these compounds. In this study, we have characterized two genes encoding 1-deoxy-d-xylulose-5-phosphate synthase (DXS; EC 2.2.1.7) and 1-deoxy-d-xylulose-5-phosphate reductase (DXR; EC 1.1.1.267) enzymes involved in the biosynthesis of isoprenoids. The full-length cDNAs of W. somnifera DXS (WsDXS) and DXR (WsDXR) of 2,154 and 1,428 bps encode polypeptides of 717 and 475 amino acids residues, respectively. The expression analysis suggests that WsDXS and WsDXR are differentially expressed in different tissues (with maximal expression in flower and young leaf), chemotypes of Withania, and in response to salicylic acid, methyl jasmonate, as well as in mechanical injury. Analysis of genomic organization of WsDXS shows close similarity with tomato DXS in terms of exon–intron arrangements. This is the first report on characterization of isoprenoid biosynthesis pathway genes from Withania.

  • differential expression of farnesyl diphosphate synthase gene from Withania somnifera in different chemotypes and in response to elicitors
    Plant Growth Regulation, 2011
    Co-Authors: Parul Gupta, Rajender S Sangwan, Nehal Akhtar, S K Tewari, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera (L.) Dunal (Family, Solanaceae), commonly known as Ashwagandha is one of the most valuable medicinal plants synthesizing large number of pharmacologically active secondary metabolites known as withanolides. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the genes responsible for biosynthesis of these compounds. In this study, we have characterized a gene encoding farnesyl diphosphate synthase (FPPS; EC 2.5.1.10), a key enzyme in the pathway of biosynthesis of isoprenoids, from W. somnifera. The full-length cDNA of Withania somnifera FPPS (WsFPPS) of 1,253 bps encodes a polypeptide of 343 amino acids. The amino acid sequence homology and phylogenetic analysis suggest that WsFPPS has close similarity to its counterparts from tomato (SlFPPS) and capsicum (CaaFPPS). Using semi quantitative RT–PCR, the expression pattern of the WsFPPS gene was analyzed in different tissues of Withania chemotypes (NMITLI-101, NMITLI-108, NMITLI-118 and NMITLI-135) as well as in response to elicitors (salicylic acid and methyl jasmonate) and mechanical wounding. The expression analysis suggests that WsFPPS expression varies in different tissues (with maximal expression in flower and young leaf) and chemotypes (with highest level in NMITLI-101) and was significantly elevated in response to salicylic acid, methyl jasmonate and mechanical injury. This is the first report on characterization of an isoprenoid pathway gene involved in withanolide biosynthesis.

Parul Gupta - One of the best experts on this subject based on the ideXlab platform.

  • virus induced silencing of key genes leads to differential impact on withanolide biosynthesis in the medicinal plant Withania somnifera
    Plant and Cell Physiology, 2018
    Co-Authors: Parul Gupta, Aditya Vikram Agarwal, Deeksha Singh, Yogeshwar Vikram Dhar, Rahul Michael, Deepak Chandra
    Abstract:

    Withanolides are a collection of naturally occurring, pharmacologically active, secondary metabolites synthesized in the medicinally important plant, Withania somnifera. These bioactive molecules are C28-steroidal lactone triterpenoids and their synthesis is proposed to take place via the mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways through the sterol pathway using 24-methylene cholesterol as substrate flux. Although the phytochemical profiles as well as pharmaceutical activities of Withania extracts have been well studied, limited genomic information and difficult genetic transformation have been a major bottleneck towards understanding the participation of specific genes in withanolide biosynthesis. In this study, we used the Tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS) approach to study the participation of key genes from MVA, MEP and triterpenoid biosynthesis for their involvement in withanolide biosynthesis. TRV-infected W. somnifera plants displayed unique phenotypic characteristics and differential accumulation of total Chl as well as carotenoid content for each silenced gene suggesting a reduction in overall isoprenoid synthesis. Comprehensive expression analysis of putative genes of withanolide biosynthesis revealed transcriptional modulations conferring the presence of complex regulatory mechanisms leading to withanolide biosynthesis. In addition, silencing of genes exhibited modulated total and specific withanolide accumulation at different levels as compared with control plants. Comparative analysis also suggests a major role for the MVA pathway as compared with the MEP pathway in providing substrate flux for withanolide biosynthesis. These results demonstrate that transcriptional regulation of selected Withania genes of the triterpenoid biosynthetic pathway critically affects withanolide biosynthesis, providing new horizons to explore this process further, in planta.

  • comparative transcriptome analysis of different chemotypes elucidates withanolide biosynthesis pathway from medicinal plant Withania somnifera
    Scientific Reports, 2015
    Co-Authors: Parul Gupta, Neelam S Sangwan, Ridhi Goel, Aditya Vikram Agarwal, Mehar Hasan Asif, Rajender S Sangwan, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera is one of the most valuable medicinal plants synthesizing secondary metabolites known as withanolides. Despite pharmaceutical importance, limited information is available about the biosynthesis of withanolides. Chemo-profiling of leaf and root tissues of Withania suggest differences in the content and/or nature of withanolides in different chemotypes. To identify genes involved in chemotype and/or tissue-specific withanolide biosynthesis, we established transcriptomes of leaf and root tissues of distinct chemotypes. Genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis with their alternatively spliced forms and paralogous have been identified. Analysis suggests differential expression of large number genes among leaf and root tissues of different chemotypes. Study also identified differentially expressing transcripts encoding cytochrome P450s, glycosyltransferases, methyltransferases and transcription factors which might be involved in chemodiversity in Withania. Virus induced gene silencing of the sterol ∆7-reductase (WsDWF5) involved in the synthesis of 24-methylene cholesterol, withanolide backbone, suggests role of this enzyme in biosynthesis of withanolides. Information generated, in this study, provides a rich resource for functional analysis of withanolide-specific genes to elucidate chemotype- as well as tissue-specific withanolide biosynthesis. This genomic resource will also help in development of new tools for functional genomics and breeding in Withania.

  • de novo assembly functional annotation and comparative analysis of Withania somnifera leaf and root transcriptomes to identify putative genes involved in the withanolides biosynthesis
    PLOS ONE, 2013
    Co-Authors: Parul Gupta, Ridhi Goel, Mehar Hasan Asif, Rajender S Sangwan, Sumya Pathak, Apeksha Srivastava, Surya Pratap Singh, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicine systems due to bioactive molecules known as withanolides. As genomic information regarding this plant is very limited, little information is available about biosynthesis of withanolides. To facilitate the basic understanding about the withanolide biosynthesis pathways, we performed transcriptome sequencing for Withania leaf (101L) and root (101R) which specifically synthesize withaferin A and withanolide A, respectively. Pyrosequencing yielded 8,34,068 and 7,21,755 reads which got assembled into 89,548 and 1,14,814 unique sequences from 101L and 101R, respectively. A total of 47,885 (101L) and 54,123 (101R) could be annotated using TAIR10, NR, tomato and potato databases. Gene Ontology and KEGG analyses provided a detailed view of all the enzymes involved in withanolide backbone synthesis. Our analysis identified members of cytochrome P450, glycosyltransferase and methyltransferase gene families with unique presence or differential expression in leaf and root and might be involved in synthesis of tissue-specific withanolides. We also detected simple sequence repeats (SSRs) in transcriptome data for use in future genetic studies. Comprehensive sequence resource developed for Withania, in this study, will help to elucidate biosynthetic pathway for tissue-specific synthesis of secondary plant products in non-model plant organisms as well as will be helpful in developing strategies for enhanced biosynthesis of withanolides through biotechnological approaches.

  • cloning and functional characterization of 3 hydroxy 3 methylglutaryl coenzyme a reductase gene from Withania somnifera an important medicinal plant
    Protoplasma, 2013
    Co-Authors: Nehal Akhtar, Neelam S Sangwan, Parul Gupta, Rajender S Sangwan, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera (L.) Dunal is one of the most valuable medicinal plants synthesizing a large number of pharmacologically active secondary metabolites known as withanolides, the C28-steroidal lactones derived from triterpenoids. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the biosynthetic pathway and genes responsible for biosynthesis of these compounds. In this study, we have characterized the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR; EC 1.1.1.34) catalyzing the key regulatory step of the isoprenoid biosynthesis. The 1,728-bp full-length cDNA of Withania HMGR (WsHMGR) encodes a polypeptide of 575 amino acids. The amino acid sequence homology and phylogenetic analysis suggest that WsHMGR has typical structural features of other known plant HMGRs. The relative expression analysis suggests that WsHMGR expression varies in different tissues as well as chemotypes and is significantly elevated in response to exposure to salicylic acid, methyl jasmonate, and mechanical injury. The functional color assay in Escherichia coli showed that WsHMGR could accelerate the biosynthesis of carotenoids, establishing that WsHMGR encoded a functional protein and may play a catalytic role by its positive influence in isoprenoid biosynthesis.

  • cloning and characterization of 2 c methyl d erythritol 4 phosphate pathway genes for isoprenoid biosynthesis from indian ginseng Withania somnifera
    Protoplasma, 2013
    Co-Authors: Parul Gupta, Aditya Vikram Agarwal, Rajender S Sangwan, Surya Pratap Singh, Nehal Akhtar, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera (L.) is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicines. Pharmaceutical activities of this herb are associated with presence of secondary metabolites known as withanolides, a class of phytosteroids synthesized via mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate pathways. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the genes responsible for biosynthesis of these compounds. In this study, we have characterized two genes encoding 1-deoxy-d-xylulose-5-phosphate synthase (DXS; EC 2.2.1.7) and 1-deoxy-d-xylulose-5-phosphate reductase (DXR; EC 1.1.1.267) enzymes involved in the biosynthesis of isoprenoids. The full-length cDNAs of W. somnifera DXS (WsDXS) and DXR (WsDXR) of 2,154 and 1,428 bps encode polypeptides of 717 and 475 amino acids residues, respectively. The expression analysis suggests that WsDXS and WsDXR are differentially expressed in different tissues (with maximal expression in flower and young leaf), chemotypes of Withania, and in response to salicylic acid, methyl jasmonate, as well as in mechanical injury. Analysis of genomic organization of WsDXS shows close similarity with tomato DXS in terms of exon–intron arrangements. This is the first report on characterization of isoprenoid biosynthesis pathway genes from Withania.

K K Anand - One of the best experts on this subject based on the ideXlab platform.

  • adaptogenic activity of a novel withanolide free aqueous fraction from the roots of Withania somnifera dun part ii
    Phytotherapy Research, 2001
    Co-Authors: B Singh, B K Chandan, Kamlesh Kumar Bhutani, A. K. Saxena, D. K. Gupta, K K Anand
    Abstract:

    The practitioners of the traditional Indian system of medicine regard Withania somnifera Dun. as the ‘Indian ginseng’. A new withanolide-free aqueous fraction was isolated from the roots of this plant and was evaluated for putative antistress activity against a battery of tests such as hypoxia time, antifatigue effect, swimming performance time, swimming induced gastric ulceration and hypothermia, immobilization induced gastric ulceration, autoanalgesia and biochemical changes in the adrenal glands. This bioactive fraction exhibited significant antistress activity in a dose-related manner in all the parameters studied. The extract of Withania somnifera root (a commercial preparation available locally) was used to compare the results. A preliminary acute toxicity study in mice showed a good margin of safety. Copyright � 2001 John Wiley & Sons, Ltd.

  • adaptogenic activity of a novel withanolide free aqueous fraction from the roots of Withania somnifera dun
    Phytotherapy Research, 2001
    Co-Authors: B Singh, B K Chandan, Kamlesh Kumar Bhutani, A. K. Saxena, D. K. Gupta, K K Anand
    Abstract:

    The practitioners of the traditional Indian system of medicine regard Withania somnifera Dun. as the 'Indian ginseng'. A new withanolide-free aqueous fraction was isolated from the roots of this plant and was evaluated for putative antistress activity against a battery of tests such as hypoxia time, antifatigue effect, swimming performance time, swimming induced gastric ulceration and hypothermia, immobilization induced gastric ulceration, autoanalgesia and biochemical changes in the adrenal glands. This bioactive fraction exhibited significant antistress activity in a dose-related manner in all the parameters studied. The extract of Withania somnifera root (a commercial preparation available locally) was used to compare the results. A preliminary acute toxicity study in mice showed a good margin of safety.

Rajender S Sangwan - One of the best experts on this subject based on the ideXlab platform.

  • comparative transcriptome analysis of different chemotypes elucidates withanolide biosynthesis pathway from medicinal plant Withania somnifera
    Scientific Reports, 2015
    Co-Authors: Parul Gupta, Neelam S Sangwan, Ridhi Goel, Aditya Vikram Agarwal, Mehar Hasan Asif, Rajender S Sangwan, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera is one of the most valuable medicinal plants synthesizing secondary metabolites known as withanolides. Despite pharmaceutical importance, limited information is available about the biosynthesis of withanolides. Chemo-profiling of leaf and root tissues of Withania suggest differences in the content and/or nature of withanolides in different chemotypes. To identify genes involved in chemotype and/or tissue-specific withanolide biosynthesis, we established transcriptomes of leaf and root tissues of distinct chemotypes. Genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis with their alternatively spliced forms and paralogous have been identified. Analysis suggests differential expression of large number genes among leaf and root tissues of different chemotypes. Study also identified differentially expressing transcripts encoding cytochrome P450s, glycosyltransferases, methyltransferases and transcription factors which might be involved in chemodiversity in Withania. Virus induced gene silencing of the sterol ∆7-reductase (WsDWF5) involved in the synthesis of 24-methylene cholesterol, withanolide backbone, suggests role of this enzyme in biosynthesis of withanolides. Information generated, in this study, provides a rich resource for functional analysis of withanolide-specific genes to elucidate chemotype- as well as tissue-specific withanolide biosynthesis. This genomic resource will also help in development of new tools for functional genomics and breeding in Withania.

  • de novo assembly functional annotation and comparative analysis of Withania somnifera leaf and root transcriptomes to identify putative genes involved in the withanolides biosynthesis
    PLOS ONE, 2013
    Co-Authors: Parul Gupta, Ridhi Goel, Mehar Hasan Asif, Rajender S Sangwan, Sumya Pathak, Apeksha Srivastava, Surya Pratap Singh, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicine systems due to bioactive molecules known as withanolides. As genomic information regarding this plant is very limited, little information is available about biosynthesis of withanolides. To facilitate the basic understanding about the withanolide biosynthesis pathways, we performed transcriptome sequencing for Withania leaf (101L) and root (101R) which specifically synthesize withaferin A and withanolide A, respectively. Pyrosequencing yielded 8,34,068 and 7,21,755 reads which got assembled into 89,548 and 1,14,814 unique sequences from 101L and 101R, respectively. A total of 47,885 (101L) and 54,123 (101R) could be annotated using TAIR10, NR, tomato and potato databases. Gene Ontology and KEGG analyses provided a detailed view of all the enzymes involved in withanolide backbone synthesis. Our analysis identified members of cytochrome P450, glycosyltransferase and methyltransferase gene families with unique presence or differential expression in leaf and root and might be involved in synthesis of tissue-specific withanolides. We also detected simple sequence repeats (SSRs) in transcriptome data for use in future genetic studies. Comprehensive sequence resource developed for Withania, in this study, will help to elucidate biosynthetic pathway for tissue-specific synthesis of secondary plant products in non-model plant organisms as well as will be helpful in developing strategies for enhanced biosynthesis of withanolides through biotechnological approaches.

  • cloning and functional characterization of 3 hydroxy 3 methylglutaryl coenzyme a reductase gene from Withania somnifera an important medicinal plant
    Protoplasma, 2013
    Co-Authors: Nehal Akhtar, Neelam S Sangwan, Parul Gupta, Rajender S Sangwan, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera (L.) Dunal is one of the most valuable medicinal plants synthesizing a large number of pharmacologically active secondary metabolites known as withanolides, the C28-steroidal lactones derived from triterpenoids. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the biosynthetic pathway and genes responsible for biosynthesis of these compounds. In this study, we have characterized the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR; EC 1.1.1.34) catalyzing the key regulatory step of the isoprenoid biosynthesis. The 1,728-bp full-length cDNA of Withania HMGR (WsHMGR) encodes a polypeptide of 575 amino acids. The amino acid sequence homology and phylogenetic analysis suggest that WsHMGR has typical structural features of other known plant HMGRs. The relative expression analysis suggests that WsHMGR expression varies in different tissues as well as chemotypes and is significantly elevated in response to exposure to salicylic acid, methyl jasmonate, and mechanical injury. The functional color assay in Escherichia coli showed that WsHMGR could accelerate the biosynthesis of carotenoids, establishing that WsHMGR encoded a functional protein and may play a catalytic role by its positive influence in isoprenoid biosynthesis.

  • cloning and characterization of 2 c methyl d erythritol 4 phosphate pathway genes for isoprenoid biosynthesis from indian ginseng Withania somnifera
    Protoplasma, 2013
    Co-Authors: Parul Gupta, Aditya Vikram Agarwal, Rajender S Sangwan, Surya Pratap Singh, Nehal Akhtar, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera (L.) is one of the most valuable medicinal plants used in Ayurvedic and other indigenous medicines. Pharmaceutical activities of this herb are associated with presence of secondary metabolites known as withanolides, a class of phytosteroids synthesized via mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate pathways. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the genes responsible for biosynthesis of these compounds. In this study, we have characterized two genes encoding 1-deoxy-d-xylulose-5-phosphate synthase (DXS; EC 2.2.1.7) and 1-deoxy-d-xylulose-5-phosphate reductase (DXR; EC 1.1.1.267) enzymes involved in the biosynthesis of isoprenoids. The full-length cDNAs of W. somnifera DXS (WsDXS) and DXR (WsDXR) of 2,154 and 1,428 bps encode polypeptides of 717 and 475 amino acids residues, respectively. The expression analysis suggests that WsDXS and WsDXR are differentially expressed in different tissues (with maximal expression in flower and young leaf), chemotypes of Withania, and in response to salicylic acid, methyl jasmonate, as well as in mechanical injury. Analysis of genomic organization of WsDXS shows close similarity with tomato DXS in terms of exon–intron arrangements. This is the first report on characterization of isoprenoid biosynthesis pathway genes from Withania.

  • differential expression of farnesyl diphosphate synthase gene from Withania somnifera in different chemotypes and in response to elicitors
    Plant Growth Regulation, 2011
    Co-Authors: Parul Gupta, Rajender S Sangwan, Nehal Akhtar, S K Tewari, Prabodh Kumar Trivedi
    Abstract:

    Withania somnifera (L.) Dunal (Family, Solanaceae), commonly known as Ashwagandha is one of the most valuable medicinal plants synthesizing large number of pharmacologically active secondary metabolites known as withanolides. Though the plant has been well characterized in terms of phytochemical profiles as well as pharmaceutical activities, not much is known about the genes responsible for biosynthesis of these compounds. In this study, we have characterized a gene encoding farnesyl diphosphate synthase (FPPS; EC 2.5.1.10), a key enzyme in the pathway of biosynthesis of isoprenoids, from W. somnifera. The full-length cDNA of Withania somnifera FPPS (WsFPPS) of 1,253 bps encodes a polypeptide of 343 amino acids. The amino acid sequence homology and phylogenetic analysis suggest that WsFPPS has close similarity to its counterparts from tomato (SlFPPS) and capsicum (CaaFPPS). Using semi quantitative RT–PCR, the expression pattern of the WsFPPS gene was analyzed in different tissues of Withania chemotypes (NMITLI-101, NMITLI-108, NMITLI-118 and NMITLI-135) as well as in response to elicitors (salicylic acid and methyl jasmonate) and mechanical wounding. The expression analysis suggests that WsFPPS expression varies in different tissues (with maximal expression in flower and young leaf) and chemotypes (with highest level in NMITLI-101) and was significantly elevated in response to salicylic acid, methyl jasmonate and mechanical injury. This is the first report on characterization of an isoprenoid pathway gene involved in withanolide biosynthesis.

Kamarul Imran Musa - One of the best experts on this subject based on the ideXlab platform.