
Peptide Discovery in Soybean
Pest Could Lead to ControlsBy Hank Becker March 9, 2000Compounds called peptides that may
regulate insect feeding and movement have now been discovered in extracts of
soybean cyst nematodes. The discovery, a scientific first, opens a new path for
investigating nature-based controls for these microscopic wormlike pests. Agricultural Research Service scientists reported the discovery in Volume
897 of Annals, published by the New York
Academy of Sciences. They hope further studies will provide clues on how to
turn the peptides against the pest, perhaps by disrupting its reproduction. Soybean growers now ineffectively battle the soybean cyst nematode, their
greatest foe, with resistant varieties and crop rotation. However, resistant
varieties are not effective against all of the races of the nematode and
usually do not yield as well as susceptible varieties when nematodes are
absent. Soybean cyst nematodes are the most destructive pests of U.S. soybeans,
annually costing growers $1.5 billion. The peptides discovered by the ARSscientists may have essential roles in controlling feeding and movement by
regulating nervous transmission and muscle activity. The peptides in the
soybean cyst nematode differ from those in non-parasitic species of nematodes,
according to Edward P. Masler at the ARS
Nematology
Laboratory in Beltsville, Md. Masler and colleagues detected at least three different peptides in extracts
from the nematodes grown on soybean plants, by using a modified version of a
standard test called an ELISA (enzyme-linked immunosorbent assay). The peptide levels vary during the worms' development, but the researchers
are focusing on those most active in female nematodes. The females lay the eggs
that will yield new generations of hungry, root-eating offspring. ARS is the chief scientific agency of the U.S. Department of Agriculture. Scientific contact: Edward P. Masler, ARS Nematology Laboratory,
Beltsville, Md., (301) 504-8732, fax (301) 504-5589,
[email protected]. U.S. Department of Agriculture |