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Sun J, Manmathan H, Sun C, Peebles CAM. Examining the transcriptional response of overexpressing anthranilate synthase in the hairy roots of an important medicinal plant Catharanthus roseus by RNA-seq. BMC PLANT BIOLOGY 2016; 16:108. [PMID: 27154243 PMCID: PMC4859987 DOI: 10.1186/s12870-016-0794-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 04/29/2016] [Indexed: 05/04/2023]
Abstract
BACKGROUND Clinically important anti-cancer drugs vinblastine and vincristine are solely synthesized by the terpenoid indole alkaloid (TIA) pathway in Catharanthus roseus. Anthranilate synthase (AS) is a rate-limiting enzyme in the TIA pathway. The transgenic C. roseus hairy root line overexpressing a feedback insensitive ASα subunit under the control of an inducible promoter and the ASβ subunit constitutively was previously created for the overproduction of TIAs. However, both increases and decreases in TIAs were detected after overexpressing ASα. Although genetic modification is targeted to one gene in the TIA pathway, it could trigger global transcriptional changes that can directly or indirectly affect TIA biosynthesis. In this study, Illumina sequencing and RT-qPCR were used to detect the transcriptional responses to overexpressing AS, which can increase understanding of the complex regulation of the TIA pathway and further inspire rational metabolic engineering for enhanced TIA production in C. roseus hairy roots. RESULTS Overexpressing AS in C. roseus hairy roots altered the transcription of most known TIA pathway genes and regulators after 12, 24, and 48 h induction detected by RT-qPCR. Changes in the transcriptome of C. roseus hairy roots was further investigated 18 hours after ASα induction and compared to the control hairy roots using RNA-seq. A unigene set of 30,281 was obtained by de novo assembly of the sequencing reads. Comparison of the differentially expressed transcriptional profiles resulted in 2853 differentially expressed transcripts. Functional annotation of these transcripts revealed a complex and systematically transcriptome change in ASαβ hairy roots. Pathway analysis shows alterations in many pathways such as aromatic amino acid biosynthesis, jasmonic acid (JA) biosynthesis and other secondary metabolic pathways after perturbing AS. Moreover, many genes in overall stress response were differentially expressed after overexpressing ASα. CONCLUSION The transcriptomic analysis illustrates overexpressing AS stimulates the overall stress response and affects the metabolic networks in C. roseus hairy roots. The up-regulation of endogenous JA biosynthesis pathway indicates the involvement of JA signal transduction to regulate TIA biosynthesis in ASαβ engineered roots and explained why many of the transcripts for TIA genes and regulators are seen to increase with AS overexpression.
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Affiliation(s)
- Jiayi Sun
- Chemical and Biological Engineering Department, Colorado State University, Campus delivery 1370, Fort Collins, 80523, USA
| | - Harish Manmathan
- Soil and Crop Sciences Department, Colorado State University, Campus deliver 1170, Fort Collins, Colorado, 80523, USA
| | - Cheng Sun
- Department of biology, Colorado State University, 1878 Campus Delivery, Fort Collins, Colorado, 80521, USA
- Key Laboratory of Pollinating Insect Biology of the Ministry of Agriculture, Institute of Apicultural Research, Chinese Academy of Agriculture Science, Beijing, 10093, China
| | - Christie A M Peebles
- Chemical and Biological Engineering Department, Colorado State University, Campus delivery 1370, Fort Collins, 80523, USA.
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Dugé de Bernonville T, Clastre M, Besseau S, Oudin A, Burlat V, Glévarec G, Lanoue A, Papon N, Giglioli-Guivarc'h N, St-Pierre B, Courdavault V. Phytochemical genomics of the Madagascar periwinkle: Unravelling the last twists of the alkaloid engine. PHYTOCHEMISTRY 2015; 113:9-23. [PMID: 25146650 DOI: 10.1016/j.phytochem.2014.07.023] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 07/11/2014] [Accepted: 07/15/2014] [Indexed: 05/12/2023]
Abstract
The Madagascar periwinkle produces a large palette of Monoterpenoid Indole Alkaloids (MIAs), a class of complex alkaloids including some of the most valuable plant natural products with precious therapeutical values. Evolutionary pressure on one of the hotspots of biodiversity has obviously turned this endemic Malagasy plant into an innovative alkaloid engine. Catharanthus is a unique taxon producing vinblastine and vincristine, heterodimeric MIAs with complex stereochemistry, and also manufactures more than 100 different MIAs, some shared with the Apocynaceae, Loganiaceae and Rubiaceae members. For over 60 years, the quest for these powerful anticancer drugs has inspired biologists, chemists, and pharmacists to unravel the chemistry, biochemistry, therapeutic activity, cell and molecular biology of Catharanthus roseus. Recently, the "omics" technologies have fuelled rapid progress in deciphering the last secret of strictosidine biosynthesis, the central precursor opening biosynthetic routes to several thousand MIA compounds. Dedicated C. roseus transcriptome, proteome and metabolome databases, comprising organ-, tissue- and cell-specific libraries, and other phytogenomic resources, were developed for instance by PhytoMetaSyn, Medicinal Plant Genomic Resources and SmartCell consortium. Tissue specific library screening, orthology comparison in species with or without MIA-biochemical engines, clustering of gene expression profiles together with various functional validation strategies, largely contributed to enrich the toolbox for plant synthetic biology and metabolic engineering of MIA biosynthesis.
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Affiliation(s)
- Thomas Dugé de Bernonville
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France
| | - Marc Clastre
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France
| | - Sébastien Besseau
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France
| | - Audrey Oudin
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France
| | - Vincent Burlat
- Université de Toulouse, UPS, UMR 5546, Laboratoire de Recherche en Sciences Végétales, BP 42617 Auzeville, F-31326 Castanet-Tolosan, France; CNRS, UMR 5546, BP 42617 Auzeville, F-31326 Castanet-Tolosan, France
| | - Gaëlle Glévarec
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France
| | - Arnaud Lanoue
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France
| | - Nicolas Papon
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France
| | | | - Benoit St-Pierre
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France
| | - Vincent Courdavault
- Université François-Rabelais de Tours, EA2106 "Biomolécules et Biotechnologies Végétales", Tours, France.
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Weitemier K, Straub SCK, Cronn RC, Fishbein M, Schmickl R, McDonnell A, Liston A. Hyb-Seq: Combining target enrichment and genome skimming for plant phylogenomics. APPLICATIONS IN PLANT SCIENCES 2014; 2:apps1400042. [PMID: 25225629 PMCID: PMC4162667 DOI: 10.3732/apps.1400042] [Citation(s) in RCA: 242] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 06/25/2014] [Indexed: 05/18/2023]
Abstract
PREMISE OF THE STUDY Hyb-Seq, the combination of target enrichment and genome skimming, allows simultaneous data collection for low-copy nuclear genes and high-copy genomic targets for plant systematics and evolution studies. • METHODS AND RESULTS Genome and transcriptome assemblies for milkweed (Asclepias syriaca) were used to design enrichment probes for 3385 exons from 768 genes (>1.6 Mbp) followed by Illumina sequencing of enriched libraries. Hyb-Seq of 12 individuals (10 Asclepias species and two related genera) resulted in at least partial assembly of 92.6% of exons and 99.7% of genes and an average assembly length >2 Mbp. Importantly, complete plastomes and nuclear ribosomal DNA cistrons were assembled using off-target reads. Phylogenomic analyses demonstrated signal conflict between genomes. • CONCLUSIONS The Hyb-Seq approach enables targeted sequencing of thousands of low-copy nuclear exons and flanking regions, as well as genome skimming of high-copy repeats and organellar genomes, to efficiently produce genome-scale data sets for phylogenomics.
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Affiliation(s)
- Kevin Weitemier
- Department of Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, Oregon 97331 USA
| | - Shannon C. K. Straub
- Department of Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, Oregon 97331 USA
| | - Richard C. Cronn
- Pacific Northwest Research Station, USDA Forest Service, 3200 SW Jefferson Way, Corvallis, Oregon 97331 USA
| | - Mark Fishbein
- Department of Botany, Oklahoma State University, 301 Physical Sciences, Stillwater, Oklahoma 74078 USA
| | - Roswitha Schmickl
- Institute of Botany, Academy of Sciences of the Czech Republic, CZ-25243 Průhonice, Czech Republic
| | - Angela McDonnell
- Department of Botany, Oklahoma State University, 301 Physical Sciences, Stillwater, Oklahoma 74078 USA
| | - Aaron Liston
- Department of Botany and Plant Pathology, Oregon State University, 2082 Cordley Hall, Corvallis, Oregon 97331 USA
- Author for correspondence:
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Kumar S, Shah N, Garg V, Bhatia S. Large scale in-silico identification and characterization of simple sequence repeats (SSRs) from de novo assembled transcriptome of Catharanthus roseus (L.) G. Don. PLANT CELL REPORTS 2014; 33:905-918. [PMID: 24482265 DOI: 10.1007/s00299-014-1569-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 12/17/2013] [Accepted: 01/09/2014] [Indexed: 06/03/2023]
Abstract
Transcriptomic data of C. roseus offering ample sequence resources for providing better insights into gene diversity: large resource of genic SSR markers to accelerate genomic studies and breeding in Catharanthus . Next-generation sequencing is an efficient system for generating high-throughput complete transcripts/genes and developing molecular markers. We present here the transcriptome sequencing of a 26-day-old Catharanthus roseus seedling tissue using Illumina GAIIX platform that resulted in a total of 3.37 Gb of nucleotide sequence data comprising 29,964,104 reads which were de novo assembled into 26,581 unigenes. Based on similarity searches 58 % of the unigenes were annotated of which 13,580 unique transcripts were assigned 5016 gene ontology terms. Further, 7,687 of the unigenes were found to have Cluster of Orthologous Group classifications, and 4,006 were assigned to 289 Kyoto Encyclopedia of Genes and Genome pathways. Also, 5,221 (19.64 %) of transcripts were distributed to 81 known transcription factor (TF) families. In-silico analysis of the transcriptome resulted in identification of 11,004 SSRs in 26.62 % transcripts from which 2,520 SSR markers were designed which exhibited a non-random pattern of distribution. The most abundant was the trinucleotide repeats (AAG/CTT) followed by the dinucleotide repeats (AG/CT). Location specific analysis of SSRs revealed that SSRs were preferentially associated with the 5'-UTRs with a predicted role in regulation of gene expression. A PCR validation of a set of 48 primers revealed 97.9 % successful amplification, and 76.6 % of them showed polymorphism across different Catharanthus species as well as accessions of C. roseus. In summary, this study will provide an insight into understanding the seedling development and resources for novel gene discovery and SSR development for utilization in marker-assisted selective breeding in C. roseus.
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Affiliation(s)
- Santosh Kumar
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, PO Box 10531, New Delhi, 110067, India
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Yu F, Thamm AMK, Reed D, Villa-Ruano N, Quesada AL, Gloria EL, Covello P, De Luca V. Functional characterization of amyrin synthase involved in ursolic acid biosynthesis in Catharanthus roseus leaf epidermis. PHYTOCHEMISTRY 2013; 91:122-7. [PMID: 22652241 DOI: 10.1016/j.phytochem.2012.05.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 02/20/2012] [Accepted: 05/01/2012] [Indexed: 06/01/2023]
Abstract
Catharanthus roseus accumulates high levels of the pentacyclic triterpene, ursolic acid, as a component of its wax exudate on the leaf surface. Bioinformatic analyses of transcripts derived from the leaf epidermis provide evidence for the specialized role of this tissue in the biosynthesis of ursolic acid. Cloning and functional expression in yeast of a triterpene synthase derived from this tissue showed it to be predominantly an α-amyrin synthase (CrAS), since the α-amyrin to β-amyrin reaction products accumulated in a 5:1 ratio. Expression analysis of CrAS showed that triterpene biosynthesis occurs predominantly in the youngest leaf tissues and in the earliest stages of seedling development. Further studies using laser capture microdissection to harvest RNA from epidermis, mesophyll, idioblasts, laticifers and vasculature of leaves showed the leaf epidermis to be the preferred sites of CrAS expression and provide conclusive evidence for the involvement of this tissue in the biosynthesis of ursolic acid in C. roseus.
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Affiliation(s)
- Fang Yu
- Department of Biological Sciences, Brock University, St. Catharines, ON, Canada.
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Hairy root cultures: A suitable biological system for studying secondary metabolic pathways in plants. Eng Life Sci 2012. [DOI: 10.1002/elsc.201200030] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Albornos L, Martín I, Iglesias R, Jiménez T, Labrador E, Dopico B. ST proteins, a new family of plant tandem repeat proteins with a DUF2775 domain mainly found in Fabaceae and Asteraceae. BMC PLANT BIOLOGY 2012; 12:207. [PMID: 23134664 PMCID: PMC3499167 DOI: 10.1186/1471-2229-12-207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 10/12/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Many proteins with tandem repeats in their sequence have been described and classified according to the length of the repeats: I) Repeats of short oligopeptides (from 2 to 20 amino acids), including structural cell wall proteins and arabinogalactan proteins. II) Repeats that range in length from 20 to 40 residues, including proteins with a well-established three-dimensional structure often involved in mediating protein-protein interactions. (III) Longer repeats in the order of 100 amino acids that constitute structurally and functionally independent units. Here we analyse ShooT specific (ST) proteins, a family of proteins with tandem repeats of unknown function that were first found in Leguminosae, and their possible similarities to other proteins with tandem repeats. RESULTS ST protein sequences were only found in dicotyledonous plants, limited to several plant families, mainly the Fabaceae and the Asteraceae. ST mRNAs accumulate mainly in the roots and under biotic interactions. Most ST proteins have one or several Domain(s) of Unknown Function 2775 (DUF2775). All deduced ST proteins have a signal peptide, indicating that these proteins enter the secretory pathway, and the mature proteins have tandem repeat oligopeptides that share a hexapeptide (E/D)FEPRP followed by 4 partially conserved amino acids, which could determine a putative N-glycosylation signal, and a fully conserved tyrosine. In a phylogenetic tree, the sequences clade according to taxonomic group. A possible involvement in symbiosis and abiotic stress as well as in plant cell elongation is suggested, although different STs could play different roles in plant development. CONCLUSIONS We describe a new family of proteins called ST whose presence is limited to the plant kingdom, specifically to a few families of dicotyledonous plants. They present 20 to 40 amino acid tandem repeat sequences with different characteristics (signal peptide, DUF2775 domain, conservative repeat regions) from the described group of 20 to 40 amino acid tandem repeat proteins and also from known cell wall proteins with repeat sequences. Several putative roles in plant physiology can be inferred from the characteristics found.
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Affiliation(s)
- Lucía Albornos
- Dpto. de Fisiología Vegetal, Centro Hispano Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Plaza Doctores de la Reina s/n. Campus Miguel Unamuno, Salamanca, 37007, Spain
| | - Ignacio Martín
- Dpto. de Fisiología Vegetal, Centro Hispano Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Plaza Doctores de la Reina s/n. Campus Miguel Unamuno, Salamanca, 37007, Spain
| | - Rebeca Iglesias
- Dpto. de Fisiología Vegetal, Centro Hispano Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Plaza Doctores de la Reina s/n. Campus Miguel Unamuno, Salamanca, 37007, Spain
| | - Teresa Jiménez
- Dpto. de Fisiología Vegetal, Centro Hispano Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Plaza Doctores de la Reina s/n. Campus Miguel Unamuno, Salamanca, 37007, Spain
| | - Emilia Labrador
- Dpto. de Fisiología Vegetal, Centro Hispano Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Plaza Doctores de la Reina s/n. Campus Miguel Unamuno, Salamanca, 37007, Spain
| | - Berta Dopico
- Dpto. de Fisiología Vegetal, Centro Hispano Luso de Investigaciones Agrarias (CIALE), Universidad de Salamanca, Plaza Doctores de la Reina s/n. Campus Miguel Unamuno, Salamanca, 37007, Spain
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Verma P, Mathur AK, Srivastava A, Mathur A. Emerging trends in research on spatial and temporal organization of terpenoid indole alkaloid pathway in Catharanthus roseus: a literature update. PROTOPLASMA 2012; 249:255-68. [PMID: 0 DOI: 10.1007/s00709-011-0291-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 05/17/2011] [Indexed: 05/21/2023]
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De Luca V, Salim V, Levac D, Atsumi SM, Yu F. Discovery and functional analysis of monoterpenoid indole alkaloid pathways in plants. Methods Enzymol 2012; 515:207-29. [PMID: 22999176 DOI: 10.1016/b978-0-12-394290-6.00010-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Numerous difficulties have been associated with forward genetic approaches to identify, and functionally characterize genes involved in the biosynthesis, regulation, and transport of monoterpenoid indole alkaloids (MIAs). While the identification of certain classes of genes associated with MIA pathways has facilitated the use of homology-based approaches to clone other genes catalyzing similar reactions in other parts of the pathway, this has not greatly speeded up the pace of gene discovery for the diversity of reactions involved. Compounding this problem has been the lack of knowledge or even availability of certain MIA intermediates that would be required to establish a novel enzyme reaction to functionally identify a biosynthetic step or the candidate gene product involved. The advent of inexpensive sequencing technologies for transcriptome and genome sequencing, combined with proteomics and metabolomics, is now revolutionizing the pace of gene discovery associated with MIA pathways and their regulation. The discovery process uses large databases of genes, proteins, and metabolites from an ever-expanding list of nonmodel plant species competent to produce and accumulate MIAs. Comparative bioinformatics between species, together with gene expression analysis of particular tissue, cell, and developmental types, is helping to identify target genes that can then be investigated for their possible role in an MIA pathway by virus-induced gene silencing. Successful silencing not only confirms the involvement of the candidate gene but also allows identification of the pathway intermediate involved. In many circumstances, the pathway intermediate can be isolated for use as a substrate in order to confirm gene function in heterologous bacterial, yeast, or plant expression systems.
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Affiliation(s)
- Vincenzo De Luca
- Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada.
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Luo H, Sun C, Sun Y, Wu Q, Li Y, Song J, Niu Y, Cheng X, Xu H, Li C, Liu J, Steinmetz A, Chen S. Analysis of the transcriptome of Panax notoginseng root uncovers putative triterpene saponin-biosynthetic genes and genetic markers. BMC Genomics 2011; 12 Suppl 5:S5. [PMID: 22369100 PMCID: PMC3287501 DOI: 10.1186/1471-2164-12-s5-s5] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background Panax notoginseng (Burk) F.H. Chen is important medicinal plant of the Araliacease family. Triterpene saponins are the bioactive constituents in P. notoginseng. However, available genomic information regarding this plant is limited. Moreover, details of triterpene saponin biosynthesis in the Panax species are largely unknown. Results Using the 454 pyrosequencing technology, a one-quarter GS FLX titanium run resulted in 188,185 reads with an average length of 410 bases for P. notoginseng root. These reads were processed and assembled by 454 GS De Novo Assembler software into 30,852 unique sequences. A total of 70.2% of unique sequences were annotated by Basic Local Alignment Search Tool (BLAST) similarity searches against public sequence databases. The Kyoto Encyclopedia of Genes and Genomes (KEGG) assignment discovered 41 unique sequences representing 11 genes involved in triterpene saponin backbone biosynthesis in the 454-EST dataset. In particular, the transcript encoding dammarenediol synthase (DS), which is the first committed enzyme in the biosynthetic pathway of major triterpene saponins, is highly expressed in the root of four-year-old P. notoginseng. It is worth emphasizing that the candidate cytochrome P450 (Pn02132 and Pn00158) and UDP-glycosyltransferase (Pn00082) gene most likely to be involved in hydroxylation or glycosylation of aglycones for triterpene saponin biosynthesis were discovered from 174 cytochrome P450s and 242 glycosyltransferases by phylogenetic analysis, respectively. Putative transcription factors were detected in 906 unique sequences, including Myb, homeobox, WRKY, basic helix-loop-helix (bHLH), and other family proteins. Additionally, a total of 2,772 simple sequence repeat (SSR) were identified from 2,361 unique sequences, of which, di-nucleotide motifs were the most abundant motif. Conclusion This study is the first to present a large-scale EST dataset for P. notoginseng root acquired by next-generation sequencing (NGS) technology. The candidate genes involved in triterpene saponin biosynthesis, including the putative CYP450s and UGTs, were obtained in this study. Additionally, the identification of SSRs provided plenty of genetic makers for molecular breeding and genetics applications in this species. These data will provide information on gene discovery, transcriptional regulation and marker-assisted selection for P. notoginseng. The dataset establishes an important foundation for the study with the purpose of ensuring adequate drug resources for this species.
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Affiliation(s)
- Hongmei Luo
- The Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, PR China
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Suttipanta N, Pattanaik S, Kulshrestha M, Patra B, Singh SK, Yuan L. The transcription factor CrWRKY1 positively regulates the terpenoid indole alkaloid biosynthesis in Catharanthus roseus. PLANT PHYSIOLOGY 2011; 157:2081-93. [PMID: 21988879 PMCID: PMC3327198 DOI: 10.1104/pp.111.181834] [Citation(s) in RCA: 242] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Accepted: 10/06/2011] [Indexed: 05/18/2023]
Abstract
Catharanthus roseus produces a large array of terpenoid indole alkaloids (TIAs) that are an important source of natural or semisynthetic anticancer drugs. The biosynthesis of TIAs is tissue specific and induced by certain phytohormones and fungal elicitors, indicating the involvement of a complex transcriptional control network. However, the transcriptional regulation of the TIA pathway is poorly understood. Here, we describe a C. roseus WRKY transcription factor, CrWRKY1, that is preferentially expressed in roots and induced by the phytohormones jasmonate, gibberellic acid, and ethylene. The overexpression of CrWRKY1 in C. roseus hairy roots up-regulated several key TIA pathway genes, especially Tryptophan Decarboxylase (TDC), as well as the transcriptional repressors ZCT1 (for zinc-finger C. roseus transcription factor 1), ZCT2, and ZCT3. However, CrWRKY1 overexpression repressed the transcriptional activators ORCA2, ORCA3, and CrMYC2. Overexpression of a dominant-repressive form of CrWRKY1, created by fusing the SRDX repressor domain to CrWRKY1, resulted in the down-regulation of TDC and ZCTs but the up-regulation of ORCA3 and CrMYC2. CrWRKY1 bound to the W box elements of the TDC promoter in electrophoretic mobility shift, yeast one-hybrid, and C. roseus protoplast assays. Up-regulation of TDC increased TDC activity, tryptamine concentration, and resistance to 4-methyl tryptophan inhibition of CrWRKY1 hairy roots. Compared with control roots, CrWRKY1 hairy roots accumulated up to 3-fold higher levels of serpentine. The preferential expression of CrWRKY1 in roots and its interaction with transcription factors including ORCA3, CrMYC2, and ZCTs may play a key role in determining the root-specific accumulation of serpentine in C. roseus plants.
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Liscombe DK, O’Connor SE. A virus-induced gene silencing approach to understanding alkaloid metabolism in Catharanthus roseus. PHYTOCHEMISTRY 2011; 72:1969-77. [PMID: 21802100 PMCID: PMC3435519 DOI: 10.1016/j.phytochem.2011.07.001] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 06/13/2011] [Accepted: 07/05/2011] [Indexed: 05/02/2023]
Abstract
The anticancer agents vinblastine and vincristine are bisindole alkaloids derived from coupling vindoline and catharanthine, monoterpenoid indole alkaloids produced exclusively by the Madagascar periwinkle (Catharanthus roseus). Industrial production of vinblastine and vincristine currently relies on isolation from C. roseus leaves, a process that affords these compounds in 0.0003-0.01% yields. Metabolic engineering efforts to either improve alkaloid content or provide alternative sources of the bisindole alkaloids ultimately rely on the isolation and characterization of the genes involved. Several vindoline biosynthetic genes have been isolated, and the cellular and subcellular organization of the corresponding enzymes has been well studied. However, due to the leaf-specific localization of vindoline biosynthesis, and the lack of production of this precursor in cell suspension and hairy root cultures of C. roseus, further elucidation of this pathway demands the development of reverse genetics approaches to assay gene function in planta. The bipartite pTRV vector system is a Tobacco Rattle Virus-based virus-induced gene silencing (VIGS) platform that has provided efficient and effective means to assay gene function in diverse plant systems. A VIGS method was developed herein to investigate gene function in C. roseus plants using the pTRV vector system. The utility of this approach in understanding gene function in C. roseus leaves is demonstrated by silencing known vindoline biosynthetic genes previously characterized in vitro.
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Affiliation(s)
- David K. Liscombe
- Jack H. Skirball Center for Chemical Biology & Proteomics, The Salk Institute for Biological Studies, La Jolla, CA 92037, U.S.A
| | - Sarah E. O’Connor
- Department of Biological Chemistry, The John Innes Centre, Colney Lane, Norwich NR4 6PG, UK
- School of Chemistry, The University of East Anglia, Norwich NR4 7TJ, UK
- Corresponding author: Sarah E. O’Connor, Sarah.O’ , Department of Biological Chemistry, The John Innes Centre, Colney Lane, Norwich NR4 6PG, UK, phone: (+44) (0)1603 450 334
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Hagel JM, Krizevski R, Kilpatrick K, Sitrit Y, Marsolais F, Lewinsohn E, Facchini PJ. Expressed sequence tag analysis of khat (Catha edulis) provides a putative molecular biochemical basis for the biosynthesis of phenylpropylamino alkaloids. Genet Mol Biol 2011; 34:640-6. [PMID: 22215969 PMCID: PMC3229120 DOI: 10.1590/s1415-47572011000400017] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 08/17/2011] [Indexed: 11/21/2022] Open
Abstract
Khat (Catha edulis Forsk.) is a flowering perennial shrub cultivated for its neurostimulant properties resulting mainly from the occurrence of (S)-cathinone in young leaves. The biosynthesis of (S)-cathinone and the related phenylpropylamino alkaloids (1S,2S)-cathine and (1R,2S)-norephedrine is not well characterized in plants. We prepared a cDNA library from young khat leaves and sequenced 4,896 random clones, generating an expressed sequence tag (EST) library of 3,293 unigenes. Putative functions were assigned to > 98% of the ESTs, providing a key resource for gene discovery. Candidates potentially involved at various stages of phenylpropylamino alkaloid biosynthesis from L-phenylalanine to (1S,2S)-cathine were identified.
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Affiliation(s)
- Jillian M Hagel
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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Shokeen B, Choudhary S, Sethy NK, Bhatia S. Development of SSR and gene-targeted markers for construction of a framework linkage map of Catharanthus roseus. ANNALS OF BOTANY 2011; 108:321-336. [PMID: 21788377 PMCID: PMC3143056 DOI: 10.1093/aob/mcr162] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Accepted: 04/27/2011] [Indexed: 05/31/2023]
Abstract
BACKGROUND AND AIMS Catharanthus roseus is a plant of great medicinal importance, yet inadequate knowledge of its genome structure and the unavailability of genomic resources have been major impediments in the development of improved varieties. The aims of this study were to develop co-dominant sequence-tagged microsatellite sites (STMS) and gene-targeted markers (GTMs) and utilize them for the construction of a framework intraspecific linkage map of C. roseus. METHODS For simple sequence repeat (SSR) isolation, a genomic library enriched for (GA)(n) repeats was constructed from C. roseus 'Nirmal' (CrN1). In addition, GTMs were also designed from 12 genes of the TIA (terpenoid indole alkaloid) pathway - the medicinally most significant pathway in C. roseus. An F(2) mapping population was also generated by crossing two diverse accessions of C. roseus CrN1 (Nirmal)×CrN82 (Kew). KEY RESULTS A new set of 314 STMS markers and 64 GTMs were developed in this study. A segregating F(2) mapping population consisting of 111 F(2) individuals was generated. For generating the linkage map, a set of 423 co-dominant markers (378 newly developed and 45 published earlier) were screened for polymorphism between the parental genotypes, of which 134 were identified to be polymorphic. A total of 114 markers were mapped on eight linkage groups that spanned a 632·7 cM region of the genome with an average marker distance of 5·55 cM. Further, the mechanism of hypervariability at the gene-targeted loci was investigated at the sequence level. CONCLUSIONS For the first time, a large array of STMS markers and GTMs was generated in the model medicinal plant C. roseus. Moreover, the first microsatellite marker-based linkage map was described in this study. Together, these will serve as a foundation for future genomics studies related to quantitative trait loci analysis and molecular breeding in C. roseus.
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Affiliation(s)
- Bhumika Shokeen
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, Post Box No. 10531, New Delhi 110067, India
| | - Shalu Choudhary
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, Post Box No. 10531, New Delhi 110067, India
| | - Niroj Kumar Sethy
- Peptide and Proteomics Division, Defence Institute of Physiology and Allied Sciences, DRDO, Timarpur, Delhi-110054, India
| | - Sabhyata Bhatia
- National Institute of Plant Genome Research, Aruna Asaf Ali Marg, Post Box No. 10531, New Delhi 110067, India
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Weeks AM, Chang MCY. Constructing de novo biosynthetic pathways for chemical synthesis inside living cells. Biochemistry 2011; 50:5404-18. [PMID: 21591680 DOI: 10.1021/bi200416g] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Living organisms have evolved a vast array of catalytic functions that make them ideally suited for the production of medicinally and industrially relevant small-molecule targets. Indeed, native metabolic pathways in microbial hosts have long been exploited and optimized for the scalable production of both fine and commodity chemicals. Our increasing capacity for DNA sequencing and synthesis has revealed the molecular basis for the biosynthesis of a variety of complex and useful metabolites and allows the de novo construction of novel metabolic pathways for the production of new and exotic molecular targets in genetically tractable microbes. However, the development of commercially viable processes for these engineered pathways is currently limited by our ability to quickly identify or engineer enzymes with the correct reaction and substrate selectivity as well as the speed by which metabolic bottlenecks can be determined and corrected. Efforts to understand the relationship among sequence, structure, and function in the basic biochemical sciences can advance these goals for synthetic biology applications while also serving as an experimental platform for elucidating the in vivo specificity and function of enzymes and reconstituting complex biochemical traits for study in a living model organism. Furthermore, the continuing discovery of natural mechanisms for the regulation of metabolic pathways has revealed new principles for the design of high-flux pathways with minimized metabolic burden and has inspired the development of new tools and approaches to engineering synthetic pathways in microbial hosts for chemical production.
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Affiliation(s)
- Amy M Weeks
- Department of Chemistry, University of California, Berkeley, California 94720-1460, USA
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Straub SCK, Fishbein M, Livshultz T, Foster Z, Parks M, Weitemier K, Cronn RC, Liston A. Building a model: developing genomic resources for common milkweed (Asclepias syriaca) with low coverage genome sequencing. BMC Genomics 2011; 12:211. [PMID: 21542930 PMCID: PMC3116503 DOI: 10.1186/1471-2164-12-211] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2011] [Accepted: 05/04/2011] [Indexed: 01/05/2023] Open
Abstract
Background Milkweeds (Asclepias L.) have been extensively investigated in diverse areas of evolutionary biology and ecology; however, there are few genetic resources available to facilitate and compliment these studies. This study explored how low coverage genome sequencing of the common milkweed (Asclepias syriaca L.) could be useful in characterizing the genome of a plant without prior genomic information and for development of genomic resources as a step toward further developing A. syriaca as a model in ecology and evolution. Results A 0.5× genome of A. syriaca was produced using Illumina sequencing. A virtually complete chloroplast genome of 158,598 bp was assembled, revealing few repeats and loss of three genes: accD, clpP, and ycf1. A nearly complete rDNA cistron (18S-5.8S-26S; 7,541 bp) and 5S rDNA (120 bp) sequence were obtained. Assessment of polymorphism revealed that the rDNA cistron and 5S rDNA had 0.3% and 26.7% polymorphic sites, respectively. A partial mitochondrial genome sequence (130,764 bp), with identical gene content to tobacco, was also assembled. An initial characterization of repeat content indicated that Ty1/copia-like retroelements are the most common repeat type in the milkweed genome. At least one A. syriaca microread hit 88% of Catharanthus roseus (Apocynaceae) unigenes (median coverage of 0.29×) and 66% of single copy orthologs (COSII) in asterids (median coverage of 0.14×). From this partial characterization of the A. syriaca genome, markers for population genetics (microsatellites) and phylogenetics (low-copy nuclear genes) studies were developed. Conclusions The results highlight the promise of next generation sequencing for development of genomic resources for any organism. Low coverage genome sequencing allows characterization of the high copy fraction of the genome and exploration of the low copy fraction of the genome, which facilitate the development of molecular tools for further study of a target species and its relatives. This study represents a first step in the development of a community resource for further study of plant-insect co-evolution, anti-herbivore defense, floral developmental genetics, reproductive biology, chemical evolution, population genetics, and comparative genomics using milkweeds, and A. syriaca in particular, as ecological and evolutionary models.
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Affiliation(s)
- Shannon C K Straub
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon 97331, USA.
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He X, Blount JW, Ge S, Tang Y, Dixon RA. A genomic approach to isoflavone biosynthesis in kudzu (Pueraria lobata). PLANTA 2011; 233:843-55. [PMID: 21221632 DOI: 10.1007/s00425-010-1344-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Accepted: 12/22/2010] [Indexed: 05/18/2023]
Abstract
Roots of kudzu (Pueraria lobata) are a rich source of isoflavone O- and C-glycosides. Although O-glycosylation of (iso)flavonoids has been well characterized at the molecular level, no plant isoflavonoid C-glycosyltransferase genes have yet been isolated. To address the biosynthesis of kudzu isoflavonoids, we generated 6,365 high-quality expressed sequence tags (ESTs) from a subtraction cDNA library constructed using RNA from roots that differentially accumulate puerarin. The ESTs were clustered into 722 TCs and 3,913 singletons, from which 15 family I glycosyltransferases (UGTs) were identified. Hierarchical clustering analysis of the expression patterns of these UGTs with isoflavone synthase (IFS) in a range of tissues identified UGTs with potential functions in isoflavone glycosylation. The open reading frames of these UGTs were expressed in E. coli for functional analysis, and one was shown to preferentially glycosylate isoflavones at the 7-O-position. In addition, ESTs corresponding to chalcone synthase, chalcone reductase, chalcone isomerase (CHI) and 2-hydroxyisoflavanone dehydratase were identified. Recombinant CHI proteins had high activities with both 6'-deoxy- and 6'-hydroxy chalcones, typical of Type II CHIs. Establishment of this EST database and identification of genes associated with kudzu isoflavone biosynthesis and glycosylation provide a new resource for metabolic engineering of bioactive kudzu isoflavones.
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Affiliation(s)
- XianZhi He
- Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA
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Homolog of tocopherol C methyltransferases catalyzes N methylation in anticancer alkaloid biosynthesis. Proc Natl Acad Sci U S A 2010; 107:18793-8. [PMID: 20956330 DOI: 10.1073/pnas.1009003107] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Madagascar periwinkle (Catharanthus roseus) is the sole source of the anticancer drugs vinblastine and vincristine, bisindole alkaloids derived from the dimerization of the terpenoid indole alkaloids vindoline and catharanthine. Full elucidation of the biosynthetic pathways of these compounds is a prerequisite for metabolic engineering efforts that will improve production of these costly molecules. However, despite the medical and commercial importance of these natural products, the biosynthetic pathways remain poorly understood. Here we report the identification and characterization of a C. roseus cDNA encoding an S-adenosyl-L-methionine-dependent N methyltransferase that catalyzes a nitrogen methylation involved in vindoline biosynthesis. Recombinant enzyme produced in Escherichia coli is highly substrate specific, displaying a strict requirement for a 2,3-dihydro bond in the aspidosperma skeleton. The corresponding gene transcript is induced in methyl jasmonate-elicited seedlings, along with the other known vindoline biosynthetic transcripts. Intriguingly, this unique N methyltransferase is most similar at the amino acid level to the plastidic γ-tocopherol C methyltransferases of vitamin E biosynthesis, suggesting an evolutionary link between these two functionally disparate methyltransferases.
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cDNA-AFLP analysis on transcripts associated with hydroxysafflor yellow A(HSYA) biosynthetic pathway in Carthamus tinctorius. BIOCHEM SYST ECOL 2010. [DOI: 10.1016/j.bse.2010.09.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Luo H, Sun C, Li Y, Wu Q, Song J, Wang D, Jia X, Li R, Chen S. Analysis of expressed sequence tags from the Huperzia serrata leaf for gene discovery in the areas of secondary metabolite biosynthesis and development regulation. PHYSIOLOGIA PLANTARUM 2010; 139:1-12. [PMID: 20059733 DOI: 10.1111/j.1399-3054.2009.01339.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Huperzia serrata produces various types of lycopodium alkaloids, especially the huperzine A (HupA) that is a promising drug candidate for Alzheimer's disease. Despite the medicinal importance of H. serrata, little genomic or transcriptomic data are available from the public databases. A cDNA library was thus generated from RNA isolated from the leaves of H. serrata. A total of 4012 clones were randomly selected from the library, and 3451 high-quality expressed sequence tags (ESTs) were assembled to yield 1510 unique sequences with an average length of 712 bp. The majority (79.4%) of the unique sequences were assigned to the putative functions based on the BLAST searches against the public databases. The functions of these unique sequences covered a broad set of molecular functions, biological processes and biochemical pathways according to GO and KEGG assignments. The transcripts involved in the secondary metabolite biosynthesis of alkaloids, terpenoids and flavone/flavonoids, such as cytochrome P450, lysine decarboxylase (LDC), flavanone 3-hydroxylase, squalene synthetase and 2-oxoglutarate 3-dioxygenase, were well represented by 34 unique sequences in this EST dataset. The corresponding peptide sequence of the LDC contained the Pfam 03641 domain and was annotated as a putative LDC. The unique sequences encoding transcription factors, phytohormone biosynthetic enzymes and signaling components were also found in this EST collection. In addition, a total of 501 potential SSR-motif microsatellite loci were identified from the 393 H. serrata leaf unique sequences. This set of non-redundant ESTs and the molecular markers obtained in this study will establish valuable resources for a wide range of applications including gene discovery and identification, genetic mapping and analysis of genetic diversity, cultivar identification and marker-assisted selections in this important medicinal plant.
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Affiliation(s)
- Hongmei Luo
- Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences & Peking Union Medical College, No. 151, Malianwa North Road, HaiDian District, Beijing 100193, China
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Campos-Tamayo F, Hernández-Domínguez E, Vázquez-Flota F. Vindoline formation in shoot cultures of Catharanthus roseus is synchronously activated with morphogenesis through the last biosynthetic step. ANNALS OF BOTANY 2008; 102:409-415. [PMID: 18587132 PMCID: PMC2701790 DOI: 10.1093/aob/mcn108] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2008] [Revised: 05/08/2008] [Accepted: 06/04/2008] [Indexed: 05/26/2023]
Abstract
BACKGROUND AND AIMS The Madagascar periwinkle (Catharanthus roseus) produces the monoterpenoid alkaloid vindoline, which requires a specialized cell organization present only in the aerial tissues. Vindoline content can be affected by photoperiod and this effect seems to be associated with the morphogenetic capacity of branches; this association formed the basis of the study reported here. METHODS Vindoline-producing in vitro shoot cultures were exposed either to continuous light or a 16-h photoperiod regime. New plantlet formation and alkaloid biosynthesis were analysed throughout a culture cycle. KEY RESULTS In cultures under the photoperiod, the formation of new plantlets occurred in a more synchronized fashion as compared to those under continuous light. The accumulation of vindoline in cultures under the photoperiod occurred in co-ordination with plantlet formation, in contrast to cultures under continuous light, and coincided with a peak of activity of deacetylvindoline acetyl CoA acetyltransferase (DAT), the enzyme that catalyses the last step in vindoline biosynthesis. When new plantlet formation was blocked in cultures under the photoperiod by treatment with phytoregulators, vindoline synthesis was also reduced via an effect on DAT activity. No association between plantlet formation and other biosynthetic enzymes, such as tryptophan decarboxylase (TDC) and deacetoxyvindoline 4-hydroxylase (D4H), was found. Effects of light treatment on vindoline synthesis were not mediated by ORCA-3 proteins (which are involved in the induction of alkaloid synthesis in response to elicitation), suggesting that the presence of a different set of regulatory proteins. CONCLUSIONS The data suggest that vindoline biosynthesis is associated with morphogenesis in shoot cultures of C. roseus.
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Facchini PJ, De Luca V. Opium poppy and Madagascar periwinkle: model non-model systems to investigate alkaloid biosynthesis in plants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 54:763-84. [PMID: 18476877 DOI: 10.1111/j.1365-313x.2008.03438.x] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Alkaloids represent a large and diverse group of compounds that are related by the occurrence of a nitrogen atom within a heterocyclic backbone. Unlike other types of secondary metabolites, the various structural categories of alkaloids are unrelated in terms of biosynthesis and evolution. Although the biology of each group is unique, common patterns have become apparent. Opium poppy (Papaver somniferum), which produces several benzylisoquinoline alkaloids, and Madagascar periwinkle (Catharanthus roseus), which accumulates an array of monoterpenoid indole alkaloids, have emerged as the premier organisms used to study plant alkaloid metabolism. The status of these species as model systems results from decades of research on the chemistry, enzymology and molecular biology responsible for the biosynthesis of valuable pharmaceutical alkaloids. Opium poppy remains the only commercial source for morphine, codeine and semi-synthetic analgesics, such as oxycodone, derived from thebaine. Catharanthus roseus is the only source for the anti-cancer drugs vinblastine and vincristine. Impressive collections of cDNAs encoding biosynthetic enzymes and regulatory proteins involved in the formation of benzylisoquinoline and monoterpenoid indole alkaloids are now available, and the rate of gene discovery has accelerated with the application of genomics. Such tools have allowed the establishment of models that describe the complex cell biology of alkaloid metabolism in these important medicinal plants. A suite of biotechnological resources, including genetic transformation protocols, has allowed the application of metabolic engineering to modify the alkaloid content of these and related species. An overview of recent progress on benzylisoquinoline and monoterpenoid indole alkaloid biosynthesis in opium poppy and C. roseus is presented.
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Affiliation(s)
- Peter J Facchini
- Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
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Murata J, Roepke J, Gordon H, De Luca V. The leaf epidermome of Catharanthus roseus reveals its biochemical specialization. THE PLANT CELL 2008; 20:524-42. [PMID: 18326827 PMCID: PMC2329939 DOI: 10.1105/tpc.107.056630] [Citation(s) in RCA: 180] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2007] [Revised: 02/01/2008] [Accepted: 02/13/2008] [Indexed: 05/17/2023]
Abstract
Catharanthus roseus is the sole commercial source of the monoterpenoid indole alkaloids (MIAs), vindoline and catharanthine, components of the commercially important anticancer dimers, vinblastine and vincristine. Carborundum abrasion technique was used to extract leaf epidermis-enriched mRNA, thus sampling the epidermome, or complement, of proteins expressed in the leaf epidermis. Random sequencing of the derived cDNA library established 3655 unique ESTs, composed of 1142 clusters and 2513 singletons. Virtually all known MIA pathway genes were found in this remarkable set of ESTs, while only four known genes were found in the publicly available Catharanthus EST data set. Several novel MIA pathway candidate genes were identified, as demonstrated by the cloning and functional characterization of loganic acid O-methyltransferase involved in secologanin biosynthesis. The pathways for triterpene biosynthesis were also identified, and metabolite analysis showed that oleanane-type triterpenes were localized exclusively to the cuticular wax layer. The pathways for flavonoid and very-long-chain fatty acid biosynthesis were also located in this cell type. The results illuminate the biochemical specialization of Catharanthus leaf epidermis for the production of multiple classes of metabolites. The value and versatility of this EST data set for biochemical and biological analysis of leaf epidermal cells is also discussed.
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Affiliation(s)
- Jun Murata
- Department of Biological Sciences, Brock University, St. Catharines, Ontario L2S3A1 Canada
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Abstract
Alkaloids represent a highly diverse group of compounds that are related only by the occurrence of a nitrogen atom in a heterocyclic ring. Plants are estimated to produce approximately 12,000 different alkaloids, which can be organized into groups according to their carbon skeletal structures. Alkaloid biosynthesis in plants involves many catalytic steps, catalyzed by enzymes that belong to a wide range of protein families. The characterization of novel alkaloid biosynthetic enzymes in terms of structural biochemistry, molecular and cell biology, and biotechnological applications has been the focus of research over the past several years. The application of genomics to the alkaloid field has accelerated the discovery of cDNAs encoding previously elusive biosynthetic enzymes. Other technologies, such as large-scale gene expression analyses and metabolic engineering approaches with transgenic plants, have provided new insights into the regulatory architecture of alkaloid metabolism.
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Affiliation(s)
- Jörg Ziegler
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
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Levac D, Murata J, Kim WS, De Luca V. Application of carborundum abrasion for investigating the leaf epidermis: molecular cloning of Catharanthus roseus 16-hydroxytabersonine-16-O-methyltransferase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 53:225-36. [PMID: 18053006 DOI: 10.1111/j.1365-313x.2007.03337.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The Madagascar periwinkle (Catharanthus roseus) produces the well-known and remarkably complex anti-cancer dimeric alkaloids vinblastine and vincristine that are derived from the coupling of vindoline and catharanthine monomers. This study describes the novel application of a carborundum abrasion (CA) technique for large-scale isolation of leaf epidermis-enriched proteins in order to purify to apparent homogeneity 16-hydroxytabersonine-16-O-methyltransferase (16OMT), which catalyses the second of six steps in the conversion of tabersonine into vindoline, and to clone the gene. Functional expression and biochemical characterization of recombinant 16OMT demonstrated its very narrow substrate specificity and high affinity for 16-hydroxytabersonine. In addition to allowing the cloning of this gene, the CA technique clearly showed that 16OMT is predominantly expressed in Catharanthus leaf epidermis. The results provide compelling evidence that most of the pathway for vindoline biosynthesis, including the O-methylation of 16-hydroxytabersonine, occurs exclusively in the leaf epidermis, with subsequent steps occurring in other leaf cell types.
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Affiliation(s)
- Dylan Levac
- Department of Biological Sciences, Brock University, St Catharines, Ontario, L2S 3A1, Canada
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