Publications by authors named "Ulrike Pfeifer"

A containment experiment was carried out in order to evaluate possible shifts in eubacterial and Pseudomonas rhizosphere community structures due to the release of genetically modified Basta-tolerant oilseed rape and the associated herbicide application. Treatments included cultivation of the transgenic plant as well as of the wild-type cultivar in combination with mechanical removal of weeds and the application of the herbicides Basta (active ingredient: glufosinate) and Butisan S (active ingredient: metazachlor). Rhizosphere soil was sampled from early and late flowering plants as well as from senescent plants.

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The impact of three different RNA isolation methods on the community analysis of metabolically active bacteria was determined by reverse transcription (RT) and PCR amplification of 16S rRNA genes and subsequent terminal restriction fragment length polymorphism (T-RFLP) analysis. Furthermore, soil samples were stored at different conditions in order to evaluate the effect of soil conservation methods on the outcome of the population analysis. The quality of mRNA was assessed by reverse transcription and PCR amplification of eubacterial glutamine synthetase genes.

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The term endophyte refers to interior colonization of plants by microorganisms that do not have pathogenic effects on their hosts, and various endophytes have been found to play important roles in plant vitality. In this study, cultivation-independent terminal restriction fragment length polymorphism analysis of 16S ribosomal DNA directly amplified from plant tissue DNA was used in combination with molecular characterization of isolates to examine the influence of plant stress, achieved by infection with the blackleg pathogen Erwinia carotovora subsp. atroseptica, on the endophytic population in two different potato varieties.

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Abstract Endophytic bacteria are ubiquitous in most plants and colonise plants without exhibiting pathogenicity. Studies on the diversity of bacterial endophytes have been mainly approached by characterisation of isolates obtained from internal tissues. Despite the broad application of culture-independent techniques for the analysis of microbial communities in a wide range of natural habitats, little information is available on the species diversity of endophytes.

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