Research Unit Keel
Bacteria belonging to the genus Pseudomonas have the astonishing ability to adapt to different environments and to interact with different host organisms. We would like to learn more about the ways by which these bacteria communicate with each other and with their hosts, and to find out about some fundamental regulatory mechanisms that govern this adaptability.
Certain root-associated bacteria can suppress crop diseases caused by fungal pathogens. We use Pseudomonas fluorescens CHA0 as a model biocontrol agent to investigate the molecular mechanisms involved in disease control. Strain CHA0 produces a series of antifungal compounds (diacetylphloroglucinol, pyoluteorin, pyrrolnitrin, cyanide) that make major contributions to pathogen suppression. We are particularly interested in biotic/abiotic signals and pathway-specific and global regulatory elements that govern the production of these compounds in the rhizosphere of the plant host. This approach is closely related to our search for traits and mechanisms that determine the capacity of P. fluorescens to effectively colonize roots and to withstand environmental stress, i.e. further basic requirements for biocontrol efficacy.