Presence/absence, differential expression and sequence polymorphisms between PiAVR2 and PiAVR2-like in Phytophthora infestans determine virulence on R2 plants

• Published in: The New phytologist Vol. 191; no. 3; pp. 763 - 776
• Main Authors: Gilroy, Eleanor M., Breen, Susan, Whisson, Stephen C., Squires, Julie, Hein, Ingo, Kaczmarek, Maciej, Turnbull, Dionne, Boevink, Petra C., Lokossou, Anoma, Cano, Liliana M., Morales, Juan, Avrova, Anna O., Pritchard, Leighton, Randall, Eva, Lees, Alison, Govers, Francine, van West, Pieter, Kamoun, Sophien, Vleeshouwers, Vivianne G. A. A., Cooke, David E. L., Birch, Paul R. J.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-08-2011; John Wiley & Sons; Wiley Subscription Services, Inc
• Subjects: Amino Acid Sequence; Amino acids; avirulence genes; avr3a; Chromosome Mapping; Cloning; Cloning, Molecular; Deoxyribonucleic acid; Deployment; Disease resistance; DNA; dominant genes; downy mildew; durable disease resistance; effector‐triggered immunity; Gene expression; Gene Expression Regulation; Genes; Genes, Dominant - genetics; Genes, Plant - genetics; Genetic transformation; gene‐for‐gene; Genomes; Haustoria; hypersensitive response; Infections; Late blight; locus; molecular cloning; Molecular Sequence Data; Nucleotide sequence; nucleotide sequences; oomycete effectors; Oomycetes; pathogen phytophthora; Pathogens; Phenotypes; Phytophthora infestans; Phytophthora infestans - genetics; Phytophthora infestans - immunology; Phytophthora infestans - pathogenicity; Plant diseases; Plant Diseases - immunology; Plant Diseases - microbiology; Plant Immunity - genetics; Plant Leaves - genetics; Plant Leaves - immunology; Plant Leaves - microbiology; Plant Leaves - physiology; plant pathogens; Polymerase chain reaction; Polymorphism, Genetic - genetics; potato; potato blight; potato protein; Potatoes; protein; Protein Structure, Tertiary; Proteins; Proteins - genetics; Proteins - metabolism; Recognition; rxlr effectors; Sequencing; Solanum - genetics; Solanum tuberosum - genetics; Solanum tuberosum - immunology; Solanum tuberosum - microbiology; Solanum tuberosum - physiology; Transcription; Virulence; Virulence - genetics; Virulence Factors - genetics; Virulence Factors - metabolism
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/j.1469-8137.2011.03736.x

• 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.