Poster: Plant Pathogen/Symbiont Interactions

Abs # 743: Insights into flagellin signaling and its role in general resistance

Presenter:	Robatzek, Silke , robatzek@fmi.ch
Authors	Robatzek, Silke  (A)   Zipfel, Cyril B (A)   Boller, Thomas  (A)
Affiliations:	(A): Friedrich Miescher Institute for Biomedical Research

Similar to the innate immune system in animals, plants possess highly specific and sensitive perception systems for characteristic „non-self“ molecules, which enables them to sense microbes and initiate defense programs. In Arabidopsis, the elicitor peptide flg22, corresponding to the most conserved domain of bacterial flagellin, is recognized and percieved by the receptor kinase FLS2. Its signal is further transmitted by a MAP kinase cascade, and leads to typical defense responses such as ethylene production, oxydative burst, and callose deposition. To date, unlike in animals, many elements of flg22 signaling in plants, and also its portion towards general resistance are still unknown. Since genes displaying early transcriptional changes are likely to encode regulatory elements and/or targets of flg22 signaling themselves, we applied a large scale genomic approach. Using the whole genome gene chip we identified about 1000 early flg22-regulated genes. Interestingly, many genes code for resistance proteins and receptor-like kinases. Thus, we assess the contribution of flg22 during different plant-pathogen interactions. Furthermore, to identify new mutants potentially impaired in their flg22 response, T-DNA insertion lines of selected flg22-regulated genes are characterized. Addressing the missing link between flg22 signaling and flg22-regulated gene expression, we are using a proteomic approach. Nuclear extracts of control and elicited cell culture exhibit few, but clear changes upon flg22 treatment.