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Expression behaviour of primary carbon metabolism genes during sugarcane culm development

dc.contributor.advisorWatt, D.
dc.contributor.advisorHuckett, B. I.
dc.contributor.advisorBotha, F.
dc.contributor.authorMcCormick, Alistair James
dc.contributor.otherUniversity of Stellenbosch. Faculty of Agrisciences. Dept. of Genetics. Institute for Plant Biotechnology.
dc.date.accessioned2011-09-14T07:15:32Z
dc.date.available2011-09-14T07:15:32Z
dc.date.issued2004-04
dc.identifier.urihttp://hdl.handle.net/10019.1/16387
dc.descriptionThesis (MSc)--University of Stellenbosch, 2004.en_ZA
dc.description.abstractENGLISH ABSTRACT: Despite numerous attempts involving a variety of target genes, the successful transgenic manipulation of sucrose accumulation in sugarcane remains elusive. It is becoming increasingly apparent that enhancing sucrose storage in the culm by molecular means may depend on the modification of the activity of a novel gene target. One possible approach to identify target genes playing crucial coarse regulatory roles in sucrose accumulation is to assess gene expression during the developmental transition of the culm from active growth to maturation. This study has resulted in the successful optimisation of a mRNA hybridisation technique to characterise the expression of 90 carbohydrate metabolism-related genes in three developmentally distinct regions of sugarcane culm. A further goal of this work was to extend the limited knowledge of the regulation of sucrose metabolism in sugarcane, as well as to complement existing data from physiological and biochemical studies. Three mRNA populations derived from the different culm regions were assayed and their hybridisation intensities to the immobilised gene sequences statistically evaluated. The relative mRNA transcript abundance of 74 genes from three differing regions of culm maturity was documented. Genes exhibiting high relative expression in the culm included aldolase, hexokinase, cellulase, alcohol dehydrogenase and soluble acid invertase. Several genes (15) were demonstrated to have significantly different expression levels in the culm regions assessed. These included UDP-glucose pyrophosphorylase and UDP-glucose dehydrogenase, which were down-regulated between immature and mature internodes. Conversely, sucrose phosphate synthase, sucrose synthase and neutral invertase exhibited up-regulation in maturing internodal tissue. A variety of sugar transporters were also found to be up-regulated in mature culm, indicating a possible control point of flux into mature stem sink tissues. Combined with knowledge of the levels of key metabolites and metabolic intermediates this gene expression data will contribute to identifying key control points of sucrose accumulation in sugarcane and assist in the identification of gene targets for future manipulation by transgenic approaches.en_ZA
dc.description.abstractAFRIKAANSE OPSOMMING: Ondanks verskeie pogings, waartydens verskeie gene geteiken is, is daar nog weinig sukses behaal om sukrose-akkumulering te verhoog. Toenemend wil dit voorkom asof suksesvolle genetiese manipulering van sukroseberging in die stingel van die verandering van ‘n nuwe geen afhanklik sal wees. Een van die moontlike benaderings wat gevolg kan word om potensiële teiken gene wat ‘n belangrike rol in die beheer van sukrose-opberging speel te identifiseer, is om geen uitdrukkingspatrone in die stingel tydens die omskakeling van aktiewe groei tot volwassenheid te karakteriseer. In hierdie studie is ‘n metode gebaseer op die hibridisering van mRNA geoptimiseer en suksesvol aangewend om die uitdrukkingspatrone van 90 verskillende geselekteerde gene, wat vir sleutelensieme in die beheer van koolhidraatmetabolisme kodeer, te bestudeer. Die doel met die ondersoek was om die beperkte kennis oor die regulering van koolhidraatmetabolisme uit te brei en om die bestaande inligting afgelei van fisiologiese en biochemiese-studies aan te vul. Drie verskillende mRNApopulasies, verkry uit verskillende dele van die stingel, is ontleed deur verskillende peilers te gebruik. Die gegewens is statisties ontleed en dit het afleidings oor die verandering in uitdrukking van hierdie gene moontlik gemaak. Die relatiewe konsentrasies van 74 verskillende gene is gedokumenteer. Gene wat sterk uitgedruk word het aldolase, heksokinase, sellulase, alkoholdehidrogenase en ongebonde suurinvertase ingesluit. Die uitdrukkingspatrone van 15 gene het tussen die verkillende weefsels gevarieer. Gene waarvan die uitdrukking tydens die oorgang na volwassenheid verlaag sluit in UDP-glukose pirofosforilase en UDP-glukose dehidrogenase en waarvan die uitdrukking verhoog sukrosefosfaatsintase, sukrosesintase en neutrale invertase in. Die uitdrukking van verskeie suikertransporter gene verhoog tydens volwassewording. Hierdie inligting te same met die huidige kennis oor heersende metabolietvlakke sal bydrae tot die identifisering van geenteikens vir toekomstige genetiese manupulering.af
dc.format.extentxvi, 121 leaves : ill.
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : University of Stellenbosch
dc.subjectSugarcane -- Developmenten_ZA
dc.subjectPlant gene expressionen_ZA
dc.subjectTransgenic plantsen_ZA
dc.subjectCarbohydrates -- Metabolismen_ZA
dc.subjectTheses -- Plant biotechnologyen_ZA
dc.subjectDissertations -- Plant biotechnologyen_ZA
dc.subjectTheses -- Genetics
dc.subjectDissertations -- Genetics
dc.subjectTheses -- Agriculture
dc.subjectDissertations -- Agriculture
dc.titleExpression behaviour of primary carbon metabolism genes during sugarcane culm developmenten_ZA
dc.typeThesisen_ZA
dc.rights.holderUniversity of Stellenbosch


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