2003 Annual Report

1. What major problem or issue is being resolved and how are you resolving it?
Microscopic soil worms called plant-parasitic nematodes are some of the most serious crop pathogens affecting U.S. agriculture. There exists an urgent need to develop environmentally safe, cost-effective means to control these serious pests. The research program identifies natural products that regulate critical physiological processes involved in nematode reproduction, as well as genes that control metabolism, development and the nematode's response to stress.

2. How serious is the problem? Why does it matter?
Plant-parasitic nematodes attack all plants and cause nearly 10 billion dollars in crop losses annually in the United States. Nematode control has relied upon the use of highly toxic and expensive chemical pesticides, one of which (methyl bromide) is being banned in the United States because of environmental concerns. The development of new nematode control strategies is important to growers of agricultural crops.

3. How does it relate to the National Program(s) and National Program Component(s) to which it has been assigned?
The project has been completely assigned to National Program 303, Plant Diseases. The overall goal of this program is "to develop and improve ways to reduce crop losses caused by plant diseases." The research impacts the component "Pathogen Biology, Genetics, Population Dynamics, Spread, and Relationship with Hosts".

4. What were the most significant accomplishments this past year?
A. Single Most Significant Accomplishment during FY 2003. One way of reducing crop losses caused by nematodes is to interfere with the nematode's ability to respond to chemical and environmental stresses. Therefore, scientists at the Nematology Laboratory in Beltsville examined the effects of a naturally-occurring, bacteria-produced compound that is known to affect a protein that controls responses to stress in nematodes. The compound inhibited both egg hatch and parasitic nematode movement, thereby extending prior studies that revealed effects on muscle and reproductive development. The potential impact is the production of highly specific molecular agents that will prevent the growth and development of plant-parasitic nematodes and thereby reduce crop losses.

B. Other Significant Accomplishment(s), if any:

None.

C. Significant Accomplishments/Activities that Support Special Targeted Populations: None

D. Progress Report

A logical approach for designing target-specific, environmentally friendly methods for controlling plant-parasitic nematodes is to discover specific ways of inhibiting their natural developmental processes. Scientists at the Nematology Laboratory in Beltsville discovered and fully characterized genes in the soybean cyst nematode responsible for the production of several enzymes that are essential for nematode survival. The enzymes included a few involved in known vital processes, such as energy metabolism. The potential impact is that scientists now have additional specific targets to exploit in nematodes for the design of highly specific molecular control agents.

5. Describe the major accomplishments over the life of the project, including their predicted or actual impact.
This CRIS continues the work performed in CRIS 1275-22000-187-00D, in which innovative strategies based upon the developmental biology of nematodes were pursued at Beltsville to develop tools for managing plant-parasitic nematode damage. Major accomplishments in the previous project include the discovery that plant-parasitic and nonparasitic nematodes contain vastly different tiny proteins called neuropeptides, as well as the discovery of a gene and enzymes that control neuropeptide production and degradation. Methods were developed to examine the interactions of proteins involved in nematode stress responses. This research has led to the design of future potential control strategies and to the creation of formal joint research projects with the private sector, academia, and international research organizations. Moreover, some of the novel methods are being utilized by other scientists performing collaborative research on the identification of developmentally important compounds within nematodes.

6. What do you expect to accomplish, year by year, over the next 3 years?
In FY 2004, we will develop methods for disrupting genes involved in stress responses and hatching, and characterize the biochemical interaction between the stress protein and molecular inhibitors or other proteins needed for development. We will determine the effect of physiological stress on the activity of metabolic enzymes in cyst nematodes and the roles of these enzymes in nematode starvation. We will examine the effects of known inhibitors of steroid metabolism on nematode sterol metabolism and gene expression. In FY 2005, we will use nematode bioassays to determine which biochemical steps involved in hatching and movement are affected by the stress protein inhibitor and to identify additional biological processes that are affected. We will characterize additional genes, including those for selected neuropeptides, involved with metabolism and cellular function. We will examine the effects of lipid biosynthesis inhibitors on nematode life processes. In FY 2006, we will examine microbes or their secretions that include the stress protein inhibitor for effects on nematode development and reproduction, we will disrupt the expression of stress genes and characterize the expression of peptide and enzyme genes in soybean cyst nematodes, and we will examine the effects of lipid biosynthesis inhibitors on nematode lipid metabolism pathways.

7. What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Five complete SCN gene sequences were placed in an Internet-accessible public database. A material transfer agreement was initiated with a major non-profit research center to examine the effect of disrupting stress protein gene expression within plants on the ability of soybean cyst nematode to infect its host. Collaborative research projects on nematode control, sanctioned by federally supported initiatives, were continued with scientists in Russia and Kazakhstan, and procedures for a new project with Kazakhstan were initiated. No constraints on the adoption of this technology are obvious.

8. List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: This does not replace your peer-reviewed publications listed below).
"Effects of the Hsp90 inhibitor geldanamycin on hatching and juvenile motility in Caenorhabditis elegans and Heterodera glycines," presented at BARC Poster Day 2003.

Review Publications
Chitwood, D.J. Research on plant-parasitic nematode biology conducted by the United States Department of Agriculture-Agricultural Research Service. Pest Management Science. 2003. v. 59. p. 748-753.

Project Team

Masler, Edward - Pete Chitwood, David Skantar, Andrea

Project Annual Reports

FY 2003

Related National Programs

Plant Diseases (303)

Related Projects

APPLICATION OF BIOTECHNOLOGY TO CONTROL THE SOYBEAN CYST NEMATODE