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dc.contributor.authorRaymond, Michelle Jeanen_US
dc.date.accessioned2014-03-14T20:44:34Z
dc.date.available2014-03-14T20:44:34Z
dc.date.issued2004-08-17en_US
dc.identifier.otheretd-08312004-174505en_US
dc.identifier.urihttp://hdl.handle.net/10919/34869
dc.description.abstractThe pharmacologically important alkaloids morphine and codeine are found in latex of opium poppy (Papaver somniferum). Latex is harbored in laticifers, a specialized vascular cell-type. Isolation and characterization of latex-specific genes may provide a useful tool to metabolically engineer increased alkaloid production. Previous research in the Nessler laboratory identified genes that exhibit latex-specific gene expression. Latex-specific genes were an 2-oxoglutarate-dioxygense (DIOX), involved in hydroxylation, desaturation and epoxidation reactions, and two of the major latex proteins, MLP146 and MLP149. MLP-like proteins function in fruit ripening in various species that do not have the laticifer cell type. The latex-specific promoters (LSPs) for the three genes were sequenced. The 2.5 kb DIOX promoter was fused to the reporter gene Β-glucuronidase (GUS) to characterize its expression pattern. To assess the functional sites within the DIOX promoter, deletions were made 1.5 kb and 0.14 kb upstream of the ATG start codon, fused to GUS, and transformed into opium poppy, Arabidopsis thaliana, and tobacco (Nicotiana tabacum). The 2.5 kb DIOX:GUS and 1.5 kb EcoRIDIOX:GUS reporter gene constructs showed vascular specific expression in opium poppy, Arabidopsis, and tobacco. The 0.14 kb SpeIDIOX promoter deletion construct showed no activity in opium poppy, and limited expression in the shoot apical meristem and root hypocotyl axis in Arabidopsis. These results indicate that the minimum active DIOX promoter is greater than 0.14 kb. Over 1 kb of the LSPs were sequenced and analyzed for regulatory elements using the Plant cis-acting regulatory DNA elements database, PLACE (http://www.dna.affrc.go.jp/PLACE). Knowledge of the cis-elements and regulatory regions of LSPs would serve as a tool for metabolic engineering of poppy alkaloids. Sixty-five elements were conserved among 2 of the 3 LSPs. Among the cis-elements identified, some are associated with basic functions such as: light regulation, carbon metabolism and plant defense. Other elements include: WRKY elements that are binding sites of transcription factors known for signaling plant defense genes, a vascular cis-element, and a fruit specific element. The presence of plant defense and vascular cis-elements in the LSPs, correlate with the concept that latex is a protective defense mechanism found in the vascular system. The latex-specific promoters isolated and cis-elements identified in this research are potential tools for driving increased alkaloid production in opium poppy.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartMRFrontMatter.pdfen_US
dc.relation.haspartMRthesis2004.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectpromoter analysisen_US
dc.subjectsecondary metabolitesen_US
dc.subject2-oxoglutarate dioxygenaseen_US
dc.subjectmajor latex proteinen_US
dc.subjectlaticiferen_US
dc.titleIsolation and characterization of latex-specific promoters from Papaver somniferum L.en_US
dc.typeThesisen_US
dc.contributor.departmentPlant Pathology, Physiology, and Weed Scienceen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplinePlant Pathology, Physiology, and Weed Scienceen_US
dc.contributor.committeechairNessler, Craig L.en_US
dc.contributor.committeememberWestwood, James H.en_US
dc.contributor.committeememberBeers, Eric P.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08312004-174505/en_US
dc.date.sdate2004-08-31en_US
dc.date.rdate2009-04-30
dc.date.adate2004-09-03en_US


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