PROTEIN HELPS PLANTS FIGHT DISEASE
ITHACA, New York, May 2, 2000 (ENS) - A protein
that induces a plant to mobilize its own defenses against
pathogens and insects has been given conditional
registration for commercial agricultural use by the U.S.
Environmental Protection Agency (EPA). Harpin, a
Cornell University discovered protein, also enhances
plant growth. "Treating plants with the harpin protein
signals the plant to turn on its natural defense systems,"
says Steven 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."
After being subjected to a pathogen, the tomato plant on the left wilts and dies,
while the harpin treated one remains robust (Photo by Kent Loeffler, courtesy Cornell
University)
The protein combined with other ingredients will be sold under the name Messenger(tm) by
Eden Bioscience Corp., under license from the Cornell Research Foundation, which aids in the
development of Cornell discovered technology. Since entering into a licensing agreement in
1995, Eden has conducted over 500 field trials of the product on about 45 crops in four
countries. 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. While the
bacterial blight is ruinous for plants, its protein derivative is quite the opposite. "It's a really
peculiar protein," Beer says. "When the isolated protein from the bacteria is applied to many
sorts of plants, pathogen resistance develops and other beneficial effects occur too."