Einfluss der Wandtemperatur auf die Stoß-Grenzschicht-Wechselwirkung an einer Rampe im Hyperschall

The C4-metabolism in Maize (Zea mays) serves to efficiently concentrate CO2 near the enzyme RuBisCo. Therefore the photorespiration, as we can find in C3-plants, is suppressed. Although numerous investigations deal with the regulation of the C4-photosynthesis, a lot of factors which take part in it are unknown. To make a contribution to the identification of necessary elements of the C4-photosynthesis in maize plants with defects in the C4-cycle should be identified by analysis of mutated maize populations. Based on the mechanism of the CO2-fixation and their enzymatic equipment during the CO2- absorption C3-plants discriminate far stronger against the heavy carbon isotope 13C than C4-plants do. By screening a mutated maize population regarding the 13C-content, mutants with clear differences in the anatomy, the metabolism and the transcription status in comparison to a wildtype were identified. The mutants show a reduction in the number of chloroplasts and changes in the morphology of bundle sheet- and mesophyllchloroplasts. The plants photosynthesis rate is reduced and the apparent compensation point approaches that of C3-plants. Furthermore the abundance of C4-specific transcripts and metabolites has changed. Physiological and genetic reasons for the phenotype are comparatively assessed in the discussion. In another population of mutated maize plants a line with transposon integration in the putative promoter of the Dof1 gene was identified by PCR-screening. DOF1 is described to play a central role in the regulation of the C4-specific gene expression. The insertion of the transposon leads to an inactivation of the Dof1 promoter and to a restricted transcription of Dof1 in the mutants. The analysis of the mutants shows, that in contrast to published data, DOF1 is not necessary for the induction of the transcription of Pepc, the key enzyme of the C4-photosynthesis. For Dof1 a light induced expression with an exceptional fast reaction to the light stimulus was observed. The parameters of the nitrogen and carbon metabolism are unchanged in comparison to wildtype plants.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2005

Author dc:creator

• Bleilebens, Martin

Contributors dc:contributor

• Olivier, Herbert

• info:eu-repo/classification/ddc/620
• Stoßwellenrohr
• Hyperschallströmung
• Stoß-Grenzschicht-Wechselwirkung
• Grenzschichtablösung
• Oberflächentemperatur
• Temperaturverteilung
• Ingenieurwissenschaften
• Stoß
• Grenzschicht
• Wechselwirkung
• Rampe
• Hyperschall
• Machzahl
• Wandtemperatur

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-121704%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:59968