Identification and molecular characterization of novel MAMP activities from the gram-negative bacteria Ralstonia solanacearum and Escherichia coli perceived by RLP32 in Arabidopsis thaliana
E. MELZER (1), L. Fan (1), K. Fröhlich (1), T. Nürnberger (1) (1) Uni Tuebingen, Germany

Plant innate immunity is activated either upon perception of microbe-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs) or upon resistance (R) protein-mediated recognition of pathogen race-specific effector molecules. MAMP-triggered immunity (MTI) constitutes the primary plant immune response that has evolved to recognize invariant structures of microbial surfaces. Although several cell surface components of bacteria, fungi or oomycetes have been shown to act as MAMPs that trigger immune responses in various plant species, the enormous non-self recognition capacities of plants are not at all explored. To find new proteinaceous MAMPs we used protein preparations of the phytopathogenic gram-negative bacterium Ralstonia solanacearum. We found a proteinase-sensitive and heat stable MAMP activity, named Ralstonia solanacearum elicitor (RsE), which triggers immune responses in the model plant Arabidopsis thaliana. We further identified the receptor-like protein RLP32 as the corresponding receptor for RsE in A. thaliana. Additionally we could show that the RLP32 dependent MAMP activity is present in E. coli as well, confirming the concept of MAMPs as general elicitors of plant innate immunity.In further approaches we will now aim at isolating the protein as well as enlighten its interaction with RLP32.

Abstract Number: P17-572
Session Type: Poster