Submitted to: Annals of the New York Academy of Sciences
Publication Type: Proceedings
Publication Acceptance Date: October 28, 1999
Publication Date: N/A
Interpretive Summary: Plant-parasitic nematodes attack all crops of agricultural importance, causing over $8 billion in losses annually to U. S. farmers. One problem facing growers is that environmental concerns will result in the elimination of some of the currently used chemical nematicides from the United States within the next two years. Consequently, the discovery of environmentally and economically sound replacement control agents is critical. In this paper, we report the discovery of naturally occurring chemicals within the soybean cyst nematode, a serious pest in the United States, which are associated with nematode movement and feeding. The chemicals are peptides, essential to growth and development of this pest, and appear to be different in the plant parasite than similar peptides in non-parasitic nematodes. This discovery is significant because it is the first report of such a biochemical difference between plant-parasitic and free-living nematodes, and provides an opportunity to study endogenous regulatory molecules for the development of novel approaches to pest control. This information will be used by researchers in the agrochemical and agricultural biotechnology industries who are developing safe, selective methods for nematode control.
The family of FMRFamide related peptides (FaRPs) is widely distributed among invertebrates, where the peptides serve as neuromodulators. Published reports indicate that numerous FaRP sequences exist in free- living and animal-parasitic nematodes. Using a FMRFamide ELISA, FaRP immunoreactivity was detected in extracts of the soybean cyst nematode, Heterodera glycines, in both sexes and at all developmental stages. HPLC- ELISA results revealed a number of immunoactive components in H. glycines preparations, and a comparison with extracts of the free-living nematodes Caenorhabditis elegans and Panagrellus redivivus showed significant qualitative differences in FaRP immunoreactivity between the plant parasite and the two free-living nematodes. Total and specific immunoactivities varied during H. glycines development, with the highest specific activity in juveniles and males, and the highest total activity in mature females. Total female immunoreactivity was located primarily within the mature eggs. A significant portion, however, was associated with the female body, perhaps with egg laying.