Publikationsserver der RWTH Aachen University
Phosphoenolpyruvat-Carboxylasen in Solanum tuberosum : Charakterisierung und Expression
Abstract
dc:descriptionA model for the photorespiratory reduction in C3 plants has been developed at the department of Biology 1 (RWTH-Aachen) which proposes the development of a prefixing CO2 mechanism in the model plant Solanum tuberosum. A central role therein is the initial carboxylation reaction catalysed by the enzyme phosphoenolpyruvate-carboxylase (PEPC). This thesis presents research into increasing this enzyme’s activity in S.tuberosum. Two clones carrying the stppc1 or the stppc2 gene were isolated from a S.tuberosum genomic phage bank by plaque and Southern hybridisation. The inserts of the phage clones were subcloned and the complete genomic sequence of the stppc2 gene (8438 bp; EMBL Accession Number AJ011844) and the promoter sequence of the stppc1 gene (873 bp; EMBL Accession Number AJ278827) were determined. There are at least three copies of the ppc gene present in S.tuberosum as shown by Southern hybridisation. The stppc1 gene could be detected in all leaf cells using in situ-hybridisation of S.tuberosum leaf cross sections. Through crossing or self-fertilisation of transgenic lines containing the highly expressed phosphoenolpyruvate-carboxylase (PEPC)-gene from Corynebacterium glutamicum, plants were produced in which the PEPC activity was detected to be 6 times higher than in the parental plants. Similarly, F1-descendants were obtained in which the phosphoenolpyruvate synthase gene from E.coli, as well as the C. glutamicum-PEPC gene, was also expressed. The respective proteins were detected in the F1-descendants by western blots and enzyme assays. They were also analysed for their content of physiologically important metabolites to see if there was a correlation between the plant’s metabolite content and the PEPC activity or the total amount of PEPS in the plant. In plants with over-expressed PEPC activity, the amount of some metabolites rises with an increase in the enzyme’s activity. This is in contrast to the F1-plants expressing both foreign enzymes in which on the whole the amount of some metabolites decreased.
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2000
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Smets, Helga
- Contributors dc:contributor
-
- Kreuzaler, Fritz
Subjects
dc:subject × 6Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger