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Gewählte Master / Diploma Thesis:

Eva Marianne Köhler (2017): Endophytic colonization of Setaria spp..
Master / Diploma Thesis - Institut für Bodenforschung (IBF), BOKU-Universität für Bodenkultur, pp 137. UB BOKU obvsg FullText

Abstract:

Endophytes are microorganisms which for all or part of their lifetime colonize internal plant tissues. The following study investigates the colonization of Setaria spp. by bacterial endophytes. Of special interest was the competitive behavior of closely related bacterial strains isolated from Setaria spp. grain and non – grain – tissue. It was tried to visualize five Pantoea spp. strains with phylogenetic markers (gusA, gfp) and three Microbacterium spp. strains with DOPE - FISH. In the scope of a germination experiment the effect of grain - associated vs. non – grain – associated Microbacterium spp. on S. viridis was tested. Sequences from the gyrB region of endophytes associated with Setaria spp. roots and panicles were analyzed and qualitatively compared with findings from previous studies. Electroporation of the five Pantoea spp. strains with the plasmid pUTgfp2x (gfp) did not result in fluorescent transformants. Furthermore, a natural GUS – activity and low sensitivity to kanamycin and ampicillin within all five Pantoea spp. isolates was observed. gusA and the plasmid pUTgfp2X were therefore not suitable as phylogenetic markers. In case of DOPE – FISH four probes were developed and evaluated in silico. In a pure culture test, a probe specific to one Microbacterium spp. strain resulted in a detectable signal by using the method of Hybridization in Eppendorf tubes. This results need further support by a repetition with control probes. Regarding seedling performance, the high standard deviation did not allow clear assumptions about the effect of the grain – associated strain vs. non grain – associated strains. The gyrB gene proved as valuable alternative molecular marker. The analysis of the gyrB sequences supported many findings that have been observed in previous studies. Summarized, the results provide further knowledge for an understanding of Setaria spp. as highly complex holobiont with promising possibilities for future agricultural applications.

Beurteilende(r):

1.Mitwirkender: Puschenreiter Markus