Differential recognition of AVR2 variants of Phytophthora infestans by diverse R genes from wild Solanum species
C. AGUILERA GALVEZ (1), N. Champouret (1), E. Eggers (1), H. Rietman (1), R. Visser (2), V. Vleeshouwers (1) (1) Wageningen University, Netherlands; (2) Wageningen University, Netherlands

Late blight, caused by the oomycete Phytophthora infestans, remains the most devastating disease for potato. Therefore, late blight resistance is a priority in potato breeding. Unfortunately, single-dominant R genes have rapidly been overcome due by P. infestans. Modern management of late blight requires the use of multiple broad-spectrum R genes. For educated R gene deployment, molecular knowledge of the corresponding avirulence (Avr) gene is essential. Various P. infestans AVR proteins have been identified, e.g. AVR2 that is recognized by R2. AVR2 represents a highly diverse effector family that contains 14 sequence-divergent members with some level of similarity in the C-terminal effector domain. Phylogenetic clustering of the AVR2 family resulted in three classes. Some members of class I and II are recognized by R2 homologs that occur in Mexican Solanum species. Interestingly, differential patterns of recognition have been identified in South American Solanum species. Those plants do not carry R2. We identified an R gene from Solanum huancabambense that is involved in recognition of AVR2. Transient co-expression assays with members of the AVR2 family revealed recognition patterns that are different from R2-mediated responses. Our results also show that some AVR proteins can be recognized by more than one R protein. We aim to determine whether combining R gene families with diverse recognition spectra can enhance the level and spectrum of resistance to P. infestans isolates.

Abstract Number: P17-485
Session Type: Poster