Functional analysis of evolutionary conserved Phytophthora RxLR24 effector
I. TOMCZYNSKA (1), M. Stumpe (1), F. Mauch (1) (1) Department of Plant Biology, University of Fribourg, Chemin du Musee 10, CH-1700 Fribourg, Switzerland

The Oomycete Phytophthora infestans infects plants from Solanaceae family and is considered as one of the most destructive pathogens worldwide. In order to successfully infect and colonize the host plant, Phytophthora secrets virulence factors, called effectors. They interact with plant proteins (targets) to inhibit the immune response of the host plant and to modulate host metabolism in favor of pathogen growth. One class of such effectors contains a conserved RxLR amino acid motif that mediates the translocation into host cells. The precise function of many of effectors is not well known. Our research aims to better understand the mode of action of conserved RxLR effectors. It is hypothesized that despite diverse host plants, homologous effectors will interfere with the same conserved process of plant immunity and target the same type of host protein. Our strategy is based on using the model pathosystem Arabidopsis- Phytophthora brassicae to analyze a group of RxLR effectors, which share extended sequence homology between P. infestans and P. brassicae. One such example is the effector RxLR24. Co-Immunoprecipitation experiment demonstrated that the effector Pi_RxLR24 and Pb_RxLR24 target the same type of host protein in potato and Arabidopsis, respectively. The target protein is mechanistically involved in vesicle dependent secretion processes. Arabidopsis plants directly expressing RxLR24 show compromised secretion and are more susceptible to P. brassicae.

Abstract Number: P9-314
Session Type: Poster