Brett Tyler, research professor at the Virginia Bioinformatics Institute (VBI) and Virginia Tech professor of plant pathology, physiology, and weed science, has been awarded a three-year, $980,000 grant from the U.S. Department of Agriculture (USDA) to identify the ways in which the plant pathogen Phytopthora sojae overcomes the defenses of its host soybean.

Phytophthora species and related pathogens cause tens of billions of dollars of damage every year to a wide range of both agriculturally and ornamentally important plants and also cause severe damage to forests and threaten entire natural ecosystems. More specifically, P. sojae causes serious damage to soybean crops and cost growers $1 billion worldwide in 2003. In order to develop improved methods for controlling Phytophthora infection, it is important to understand how these pathogens break down plants' defenses.

Many of the most important interactions between the pathogen and its host occur early in the infection process. Tyler and co-project director Kurt Lamour, assistant professor of entomology and plant pathology at the University of Tennessee, Knoxville, will focus on identifying and characterizing genes active at the earliest times during P. sojae infection, starting with spore germination and penetration of the host, and continuing through the first 16 hours of infection. This time period is the most crucial for a successful infection because this is when the pathogen seeks to establish itself within the host tissue. Collaborators Michael Scanlon at the University of Georgia, and Hayes McDonald at Oak Ridge National Laboratory also will assist in the study.

"A complex web of interactions between pathogen and plant genes occurs during the first hours of infection as the two organisms battle for supremacy," Tyler said. "By taking a whole genome approach that measures the activities of all the pathogen and plant genes simultaneously we can begin to tease apart this web."

Last year, Tyler and his colleagues successfully mapped the genomes of P. sojae and its sister pathogen, Phytophtora ramorum. P. ramorum, more commonly known as sudden oak death, is a serious fungus-like pathogen that has attacked and killed tens of thousands of oak trees in California and Oregon. These genome sequences are serving as important tools in combating these devastating diseases.

Virginia Bioinformatics Institute (VBI) at Virginia Tech has a research platform centered on understanding the "disease triangle" of host-pathogen-environment interactions. With almost $49 million in extramural research funding awarded to date, VBI researchers are working on many human, crop, and animal diseases.