Authors as Published

Associate Professor John McDowell’s research group has been using Hyaloperonospora arabidopsidis (Hpa), a naturally occurring parasite of Arabidopsis thaliana, to study the molecular basis of plant diseases and immunity. John’s group, in collaboration with Brett Tyler, professor in PPWS and the Virginia Bioinformatics Institute, has been involved in a multinational collaboration to sequence the genome of Hpa. Analysis of the Hpa genome revealed adaptations that enable the pathogen to go into “stealth mode” inside the plant and avoid activating defense responses.

This work was published in the journal “Science.” The full article, “Signatures of adaptation to obligate biotrophy in the Hyaloperonospora arabidopsidis genome,” can be found at

The McDowell lab is following up on this research with additional molecular studies to better understand how oomycetes can cause disease. In addition, they are testing a new approach based on genome information to screen for new plant disease resistance genes that can be bred into crops.

Image Cover
Ph.D. candidate Ryan Anderson’s (McDowell lab) image of the downy mildew pathogen (Hpa) sporulating on an Arabidopsis seedling was featured on the cover of the December 2010 issue of “Science.�

Virginia Cooperative Extension materials are available for public use, reprint, or citation without further permission, provided the use includes credit to the author and to Virginia Cooperative Extension, Virginia Tech, and Virginia State University.

Issued in furtherance of Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Administrator, 1890 Extension Program, Virginia State University, Petersburg.

Publication Date

September 7, 2011