"It's like radar detecting an incoming missile" says Gregory B. Martin, senior scientist at BTI and a Cornell plant pathologist. "Consider it trench warfare at the molecular level." While Cornell and BTI are both located in Ithaca, N.Y., Martin will present this information to a plenary session of the American Society of Plant Biologists on Tuesday, July 24, at 4 p.m. at the Rhode Island Convention Center in Providence. The session is titled "Signal transduction mechanisms in plant defense activation."
One combatant is Pseudomonas syringae , the bacterium responsible for causing bacterial speck disease. Martin and his colleagues have learned that P. syringae attacks healthy tomato plants by attaching itself to the plant cell, inserting a microscopic tube and sending a pathogenic protein -- like ammunition -- into the cell.
Despite the attack, the plant cell is prepared for the invading onslaught. Using a molecular surveillance system behind the cell wall, the plant cell detects alien proteins and mounts a defense.
Although bacterial speck disease has been known since the early 1930s, it did not result in serious losses until the winter tomato crop of 1977-78 in southern Florida. Cool, moist
environmental conditions contributed to the development of the disease, and it has now established itself as a major production problem, according to Thomas A. Zitter, Cornell professor of plant pathology.
The disease produces black lesions, often with a discrete yellow halo that can appear on the plant leaves and cause them to curl. Growers had been instructed
Contact: Blaine P. Friedlander, Jr.
Cornell University News Service