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dc.contributor.advisorVisser, B
dc.contributor.advisorViljoen, C. D.
dc.contributor.authorAppelgryn, Johanness Jacobus
dc.date.accessioned2017-10-24T06:12:26Z
dc.date.available2017-10-24T06:12:26Z
dc.date.issued2003
dc.identifier.urihttp://hdl.handle.net/11660/7337
dc.description.abstractEnglish: The aim of this study was to isolate a gene encoding a protein kinase that is involved in the specific recognition of the leaf rust fungus by wheat. It was determined that the susceptible Thatcher and resistant Thatcher/Lr34 plants reacted within 12 h.p.i to the presence of the leaf rust by activating the P-1,3- glucanase enzyme. A second increase in β-1,3-glucanase activity was found 24 h.p.i in the resistant plants and 54 h.p.i in the susceptible plants. The second increase occurred after an increase in β-1,3-glucanase protein levels, which occurred at 18 h.p.i in the resistant plants and 24 h.p.i in the susceptible plants. The initial activation could have been the result of the activation of already existing pl, 3-glucanase proteins within the cell, while the second was due to elevated protein levels. Thetime study was refined by concentrating on the very early events after infection. β-l,3-Glucanase activity increased within 12 hours in the resistant and at 15 h.p.i in the susceptible plants. The latter also showed an increase at 6 h.p.i. Thiscorrelated with increased β-1,3-glucanase polypeptide levels. In both the resistant and susceptible infected plants there was an increase in H202 levels within 6 hours that was accompanied by a simultaneous increase in peroxidase activity. possible communication event between infected and uninfected resistant Thatcher/Lr34 plants was investigated since the biochemical results suggested the occurrence of such an event. At this stage no concrete evidence supporting possible interplant communication could however be presented. DDRT-peRwas used to isolate potential differentially expressed protein kinase genes from the resistant plants during the first 18 h after infection. Nine cDNA sequences were cloned. The first five encoded a putative glutamine-dependent asparaginyl synthetase normally involved in nitrogen metabolism, an asparagine endopeptidase/legumain-like protease normally involved in the degradation of storage peptides, a mitochondrial 18S rDNA subunit, a high-molecular-weight glutenin subunit normally involved in storage of reserve metabolites, while the last clone did not show any similarity with any known gene, The DO RT-peR was repeated at more stringent conditions and another 30 putative protein kinase genes that were differentially expressed, were isolated, These cDNAs are currently being characterized.en_ZA
dc.description.abstractAfrikaans: Die doel van hierdie studie was om 'n geen wat kodeer vir 'n proteïen kinase betrokke by die herkenning van blaarroes deur koring, te isoleer, Verhoogde β-1,3- glukanase-aktiwiteit is binne 12 uur na infeksie in beide vatbare Thatcher en weerstandbiedende Thatcher/Lr34 lyne gevind, 'n Tweede toename in β-1,3- glukanase aktiwiteit was 24 uur na infeksie in die weerstandbiedende en 54 uur na infeksie in die vatbare plante, waargeneem, Die latere toename was die gevolg van verhoogde β-l,3-glukanaseproteïenvlakke, Die vroeë toename in aktiwiteit kan waarskynlik toegeskryf word aan die aktivering van reeds bestaande β-1,3- glukanaseproteïene in die sel, terwyl die tweede die gevolg van verhoogde transkripsie was. Die tydstudie was verder verfyn deur die eerste 15 uur van besmetting te bestudeer, β-l,3-Glukanase aktiwiteit het binne 12 uur in die weerstandbiedende plante toegeneem, terwyl die vatbare plante 'n toename eers na 15 uur getoon het, Laasgenoemde plante het egter 'n tweede verhoging in β-l,3-glukanase aktiwiteit na 6 uur getoon, Hierdie toenames was weereens die gevolg van verhoogde β- l,3-glukanasevlakke, In beide die weerstandbiedende en vatbare plante was daar 'n toename in H202-vlakke binne 6 ure na besmetting, 'n Gelyktydige toename in peroksidase-aktiwiteit was ook gevind, Die moontlike kommunikasie tussen geïnfekteerde en ongeïnfekteerde weerstandbiedende Thatcher/L34 plante was ondersoek na aanleiding van die biochemiese resultate wat op so 'n moontlikheid gedui het, Daar is egter geen konkrete resultate verkrywat dit kon bevestig nie, DD RT-peRwas gebruik om differensieël uitgedrukte proteïenkinase-gene te kloneer. Nege cDNA volgordes wat binne die eerste 15 uur na infektering differensiële uiting getoon het, was geïsoleer, Die eerste vyf het onderskeidelik kodeer vir 'n glutamienafhanklike asparaginielsintetase wat normaalweg by stikstof metabolisme betrokke is, 'n asparagienendopeptidase/protease wat normaalweg by die afbraak van bergingsproteïene betrokke is, 'n mitochondriale 18S rONA subeenheid, 'n hoë molekulêre-massa gluteniensubeenheid wat 'n bergingproteïen is, terwyl die laaste een geen homologie met enige bekende geen gehad het nie. Die DO RT-peR was toe teen 'n hoër strengheid herhaal en 'n verdere 30 cDNA fragmente wat moontlik vir proteïnkinases kodeer, was gevind. Hierdie fragmente word tans gekarakteriseer.af
dc.description.sponsorshipNational Research Funding (NRF)en_ZA
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectPuccinio triticinoen_ZA
dc.subjectPlant defenceen_ZA
dc.subjectSignal transductionen_ZA
dc.subjectProtein kinaseen_ZA
dc.subjectWheat -- Disease and pest resistance -- Genetic aspectsen_ZA
dc.subjectWheat rustsen_ZA
dc.subjectLeaf rust of wheaten_ZA
dc.subjectTriticum aestivumen_ZA
dc.subjectDissertation (M.Sc. (Plant Sciences))--University of the Free State, 2003en_ZA
dc.titleThe identification of genes involved in the interaction between Triticum aestivum and Puccinia triticinaen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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