Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: November 5, 2008
Publication Date: July 1, 2009
Citation: Grunwald, N.J., Goss, E.M. 2009. Evolution and genetics of the invasive sudden oak death pathogen Phytophthora ramorum. In: Lamour, K. and Kamoun, S. editors. Oomycete Genetics and Genomics: Diversity, Interactions, and Research Tools. Hoboken, NJ. John Wiley and Sons Inc. p.179-196. Technical Abstract: Phytophthora ramorum is an emerging pathogen of oaks and tanoak, among other trees, as well as an increasing number of woody and herbaceous perennials. It causes rapid mortality in tanoak and coast live oak and has been responsible for the precipitous decline of forest populations of these species in coastal California. Its infection of common nursery crops has served as a means of dispersal across the United States. Phytophthora ramorum has an extraordinarily wide host range, which currently includes over 109 plant species and continues to expand. This book chapter reviews the genetics and evolution of this pathogen. New insights have been gained from the availability of the whole genome sequence. The P. ramorum genome size is 65 Mb, smaller than P. sojae (95 Mb) and P. infestans (240 Mb), but approximately the same size as P. capsici. Comparison of the P. ramorum and P. sojae genomes showed secreted proteins to be evolving faster than the rest of the proteome as well as family-specific expansion of pathogenicity-related genes.