Lack of glyphosate resistance gene transfer from Roundup Ready soybean to Bradyrhizobium japonicum under field and laboratory conditions.

A field study was conducted at the Russell E. Larson Agricultural Research Center to determine the effect of transgenic glyphosate-resistant soybean in combination with herbicide (Roundup) application on its endosymbiont Bradyrhizobium japonicum. DNA of bacteroids from isolated nodules was analysed for the presence of the transgenic 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSPS) DNA sequence using polymerase chain reaction (PCR).

High specificity but contrasting biodiversity of Sphagnum-associated bacterial and plant communities in bog ecosystems independent of the geographical region.

Mosses represent ecological niches that harbor a hitherto largely uncharacterized microbial diversity. To investigate which factors affect the biodiversity of bryophyte-associated bacteria, we analyzed the bacterial communities associated with two moss species, which exhibit different ecological behaviors and importance in bog ecosystems, Sphagnum magellanicum and Sphagnum fallax, from six temperate and boreal bogs in Germany and Norway. Furthermore, their surrounding plant communities were studied.

Investigations of the structure and function of bacterial communities associated with Sphagnum mosses.

High acidity, low temperature and extremely low concentration of nutrients form Sphagnum bogs into extreme habitats for organisms. Little is known about the bacteria associated with living Sphagnum plantlets, especially about their function for the host. Therefore, we analysed the endo- and ectophytic bacterial populations associated with two widely distributed Sphagnum species, Sphagnum magellanicum and Sphagnum fallax, by a multiphasic approach.

Burkholderia bryophila sp. nov. and Burkholderia megapolitana sp. nov., moss-associated species with antifungal and plant-growth-promoting properties.

A polyphasic taxonomic study including DNA-DNA reassociation experiments and an extensive biochemical characterization was performed on 14 Burkholderia isolates from moss gametophytes of nutrient-poor plant communities on the southern Baltic Sea coast in northern Germany. The strains were classified within two novel species, for which the names Burkholderia bryophila sp. nov.

Pseudomonas community structure and antagonistic potential in the rhizosphere: insights gained by combining phylogenetic and functional gene-based analyses.

The Pseudomonas community structure and antagonistic potential in the rhizospheres of strawberry and oilseed rape (host plants of the fungal phytopathogen Verticillium dahliae) were assessed. The use of a new PCR-DGGE system, designed to target Pseudomonas-specific gacA gene fragments in environmental DNA, circumvented common biases of 16S rRNA gene-based DGGE analyses and proved to be a reliable tool to unravel the diversity of uncultured Pseudomonas in bulk and rhizosphere soils. Pseudomonas-specific gacA fingerprints of total-community (TC) rhizosphere DNA were surprisingly diverse, plant-specific and differed markedly from those of the corresponding bulk soils.

The bryophyte genus Sphagnum is a reservoir for powerful and extraordinary antagonists and potentially facultative human pathogens.

Sphagnum plants grow in natural, species-poor carpets at low pH but without any known substantial fungal disease. To investigate this phenomenon, we analysed bacterial populations associated with two Sphagnum species with different ecological behaviour, namely S. magellanicum and S.

The rhizosphere effect on bacteria antagonistic towards the pathogenic fungus Verticillium differs depending on plant species and site.

Rhizobacteria with antagonistic activity towards plant pathogens play an essential role in root growth and plant health and are influenced by plant species in their abundance and composition. To determine the extent of the effect of the plant species and of the site on the abundance and composition of bacteria with antagonistic activity towards Verticillium dahliae, bacteria isolated from the rhizosphere of two Verticillium host plants, oilseed rape and strawberry, and from bulk soil were analysed at three different locations in Germany over two growing seasons. A total of 6732 bacterial isolates screened for in vitro antagonism towards Verticillium resulted in 560 active isolates, among which Pseudomonas (77%) and Serratia (6%) were the most dominant genera.

Diversity and antagonistic potential of bacteria associated with bryophytes from nutrient-poor habitats of the Baltic Sea Coast.

Very little is known about the interaction of bryophytes with bacteria. Therefore, we analyzed bacteria associated with three bryophyte species, Tortula ruralis, Aulacomnium palustre, and Sphagnum rubellum, which represent typical moss species of three nutrient-poor plant communities at the southern Baltic Sea coast in Germany. By use of two cultivation-independent techniques, denaturing gradient gel electrophoresis and single-strand conformation polymorphism analysis of the 16S ribosomal DNA, a high degree of moss specificity was found for associated bacterial communities.