Research
Research in the department is focused on the characterization of molecular mechanisms underlying the interactions between Gram-negative plant-pathogenic bacteria and their host plants.
The plant-pathogenic bacteria we study enter plants via natural opernings in the plant surface and multiply in the apoplast. The plant innate immune system, however, can detect microbial invaders. Successful pathogens, therefore, must be able to suppress plant defense responses. Suppression of plant immunity depends on the presence of a type III secretion system in the bacterial pathogen, which transports effector proteins into plant cells. Type III effectors interfere with various cellular processes of the plant such as signaling pathways, proteasome-dependent protein degradation, gene expression or protein phopshorylation. Despite their virulence function, however, some effectors can be recognized in plants that carry a cognate resistance gene. The direct or indirect recognition of individual effectors in corresponding resistant plants leads to the initiation of defense reactions, termed effector-triggered immunity (ETI). The interaction of plant-pathogenic bacteria with their host plants has been compared to an evolutionary arms race in which the development of plant resistance mechanisms is constantly counteracted by the evolution of bacterial effectors that act as ETI suppressors and vice versa.