Switzerland: Effector molecules of pathogens prevent disease resistance in plants

A conserved RxLR effector interacts with host RABA-type GTPases to inhibit vesicle-mediated secretion of antimicrobial proteins

Iga Tomczynska, Michael Stumpe and Felix Mauch | Department of Biology, University of Fribourg, chemin du musee 10, 1700, Fribourg, Switzerland | 2018 | The Plant Journal; vol. 95, pp. 187-203

Plants immune systems contain plasma membrane localized pattern recognition receptors (PRRs) that monitor for molecules of pathogen origin and provide disease resistance to plants. Pathogens have evolved to counteract the negative effects of PRR immunity by delivering effector molecules that interfere with the plants defense responses. The largest group of effector proteins found in Phytophthora pathogen is defined by a conserved Arg-any amino acid-Leu-Arg (RxLR) sequence motif. In this study expression levels of RxLR were analyzed, where RxLR24 was found to be expressed early in the interaction between the pathogen and the plant. Co-immunoprecipitation, followed by mass spectrometry experiments identified that RxLR24 physically interact with various RABA GTPases to inhibit host vesicular trafficking and interfere with the secretion of antimicrobial compounds in the plant.