A CU-discovered protein wins presidential 'green' chemistry award

By Blaine P. Friedlander Jr.

Harpin, a Cornell-discovered protein that induces a plant to mobilize its own defenses against pathogens and insects, has won the Presidential Green Chemistry Challenge Award for its developer, EDEN Bioscience Corp., Bothell, Wash. The protein also enhances plant growth.

The award was presented June 25 at the National Academy of Sciences in Washington, D. C., by Stephen L. Johnson, the Environmental Protection Agency's (EPA) assistant administrator for prevention, pesticides and toxic substances. The award, established in 1995, was judged by a panel of the American Chemical Society.

The award is given annually through the EPA Office of Pollution Prevention and Toxics to recognize organizations and individuals that are successfully researching, developing and implementing outstanding green chemical technologies.

"The harpin protein signals the plant to turn on its natural defense systems," said Steven V. Beer, Cornell professor of plant pathology and one of the protein's discoverers in 1991. "The plant must be treated before the pathogen attacks, and it takes several days for the plant's system to mobilize its own defenses."

The protein is derived from a plant pathogen, Erwinia amylovora, the bacterium responsible for fire blight, a scourge in Northeast fruit orchards since the 18th century. The bacterium attacks apple and pear trees and many ornamentals in the rose family, leaving dead and blackened branches, trunks, leaves, flowers and fruit.

While the bacterial blight is ruinous for plants, its protein derivative is quite the opposite. "In fact, the range of its beneficial effects is rather surprising," said Alan Collmer, Cornell professor of plant pathology and a co-discoverer of the protein.

The discovery of harpin was spearheaded by Zhongmin Wei, then a Cornell postdoctoral fellow and research associate in Beer's lab and now EDEN's vice president for research. Former Cornell researchers Ron Laby and Cathy Zumoff participated in identifying the harpin protein, together with David Bauer and Sheng Yang He, then researchers in Collmer's lab. Their findings were reported in a cover story in the journal Science (1992, Vol. 257, pp 85-88) titled "Harpin elicitor of the hypersensitive response produced by plant pathogen Erwinia amylovora."

EDEN's brand of harpin, called Messenger, was approved by the EPA in April 2000 as a biochemical pesticide for disease management and yield enhancement in more than 40 crop groupings plus turf and ornamentals. Messenger is approved for use in 49 states, including New York, where it is recommended for use on apple trees to manage fire blight, and in California for use on strawberries for disease management.