Study Finds Genes in Corn Important in Defense Response

Researchers at North Carolina State University have identified candidate genes and cellular processes believed to control hypersensitive defense response (HR) in corn. Hypersensitive defense is a response by corn plants when they are under pathogen attack, where they sometimes respond by killing their own cells near the site of the attack to thwart further damage from the attacker. This cell sacrifice can cause very small, often microscopic, spots or lesions on the plant.

The NC State researchers worked with their colleagues from Purdue University and examined more than 3,300 corn plants that had exaggerated HR because one particular resistance gene, Rp1-D21, won't turn off. They examined the entire corn gene blueprint to find the genes most closely associated with HR. They found 44 candidate genes that seem to be involved in defense response, programmed cell death, cell wall modification and a few other responses linked to resisting attack, says Dr. Peter Balint-Kurti, a U.S. Department of Agriculture (USDA) professor who works in NC State's plant pathology and crop science departments.

"It's similar to a human having an auto-immune response that never stops," Balint-Kurti says. "This mutation causes a corn plant to inappropriately trigger this hypersensitive defense response, causing spots on the corn plant as well as stunted growth."

The research findings are available as an open access paper in PLOS Genetics. For details, read the NC State news release at: http://news.ncsu.edu/2014/09/corn-spots-study-finds-important-genes-in-defense-response/.