Presence/absence, differential expression and sequence polymorphisms between PiAVR2 and PiAVR2-like in Phytophthora infestans determine virulence on R2 plants
Article first published online: 3 MAY 2011
© 2011 The Authors. New Phytologist © 2011 New Phytologist Trust
Volume 191, Issue 3, pages 763–776, August 2011
How to Cite
Gilroy, E. M., Breen, S., Whisson, S. C., Squires, J., Hein, I., Kaczmarek, M., Turnbull, D., Boevink, P. C., Lokossou, A., Cano, L. M., Morales, J., Avrova, A. O., Pritchard, L., Randall, E., Lees, A., Govers, F., van West, P., Kamoun, S., Vleeshouwers, V. G. A. A., Cooke, D. E. L. and Birch, P. R. J. (2011), Presence/absence, differential expression and sequence polymorphisms between PiAVR2 and PiAVR2-like in Phytophthora infestans determine virulence on R2 plants. New Phytologist, 191: 763–776. doi: 10.1111/j.1469-8137.2011.03736.x
- Issue published online: 20 JUL 2011
- Article first published online: 3 MAY 2011
- Received: 15 January 2011, Accepted: 9 March 2011
- durable disease resistance;
- effector-triggered immunity;
- hypersensitive response;
- potato blight
- •A detailed molecular understanding of how oomycete plant pathogens evade disease resistance is essential to inform the deployment of durable resistance (R) genes.
- •Map-based cloning, transient expression in planta, pathogen transformation and DNA sequence variation across diverse isolates were used to identify and characterize PiAVR2 from potato late blight pathogen Phytophthora infestans.
- •PiAVR2 is an RXLR-EER effector that is up-regulated during infection, accumulates at the site of haustoria formation, and is recognized inside host cells by potato protein R2. Expression of PiAVR2 in a virulent P. infestans isolate conveys a gain-of-avirulence phenotype, indicating that this is a dominant gene triggering R2-dependent disease resistance. PiAVR2 presence/absence polymorphisms and differential transcription explain virulence on R2 plants. Isolates infecting R2 plants express PiAVR2-like, which evades recognition by R2. PiAVR2 and PiAVR2-like differ in 13 amino acids, eight of which are in the C-terminal effector domain; one or more of these determines recognition by R2. Nevertheless, few polymorphisms were observed within each gene in pathogen isolates, suggesting limited selection pressure for change within PiAVR2 and PiAVR2-like.
- •Our results direct a search for R genes recognizing PiAVR2-like, which, deployed with R2, may exert strong selection pressure against the P. infestans population.