Grantee Research Project Results
Final Report: Development of Methods for Control of Parasitic Nematodes
EPA Grant Number: X832282Center: Donald Danforth Plant Science Center
Center Director: Beachy, Roger N.
Title: Development of Methods for Control of Parasitic Nematodes
Investigators: Taylor, Christopher G. , Jez, Joseph M. , Schubert, Karel , McCarter, James P. , Williams, Deryck J. , Shortt, Barry J. , Hresko, Michelle C.
Institution: Donald Danforth Plant Science Center
EPA Project Officer: Aja, Hayley
Project Period: April 1, 2005 through December 31, 2008
Project Amount: $969,000
RFA: Targeted Research Center (2004) Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research
Objective:
The development of new methods of nematode control requires a better understanding of the parasite and the parasitism process. To this end, scientists at Divergence and the Donald Danforth Plant Science Center are elucidating the basic biology of nematode parasitism and using that information to produce novel methods of nematode control. In our proposal, we outlined methods and strategies to reach the following objectives:
- Development and characterization of new nematicidal molecules based upon identified nematode-specific methyl transferase targets.
- Development and characterization of new nematicidal molecules based upon identified nematode-specific amino acid metabolism targets.
- Identification and characterization of feeding site genes using laser-capture microdissection.
- Identification and characterization of new nematode target genes using laser-capture microdissection.
In addition to research, these grant also funded a small seminar series bringing in noted speakers in the nematode and soil biology fields.
Summary/Accomplishments (Outputs/Outcomes):
To achieve our goal of elucidating the basic biology of nematode parasitism to produce methods of nematode control, we proposed to identify inhibitors for nematode-specific genes and identify genes within the host that are important in the parasitism response. Those genes essential to nematode-biology or the parasitic process make potent new targets for disruption leading to new methods of nematode control. During the first year of the program Divergence successfully identified inhibitors for two essential methyltransferases found only in nematodes. During the second year, the mechanism of inhibition was determined and new inhibitors developed using the initial inhibitors as a scaffold. In the third year field trials were conducted to determine efficacy for several of the inhibitors. In these trials, a significant reduction in galling and a significant increase in yield (up to 136%) was seen with DC5823 at rates as low as 2 kg/hectare. Initial toxicity studies indicated that the lead compounds are significantly safer for acute exposure than current nematicidal alternatives, likely by a factor of 50-1,000 in mammals and at least 50-fold in birds. Divergence has developed a plan for submitting a nematicide for regulatory review in approximately 2012. A second key enzyme (DIV4792) involved in amino acid metabolism that is absent from vertebrate genomes as well as most eukaryotes was found in selected plant-parasitic nematodes. Based on the structure of the enzyme’s substrate, potential inhibitors were identified and one was found to have nematicidal properties against root-knot nematodes. A positive correlation between nematode control and reduction in root weight was observed with this and related compounds. Further tests showed that this compound reduced galling indirectly through a plant-based mechanism of action. In addition to identifying these inhibitors, the laser-capture microdissection (LCM) system at the Donald Danforth Plant Science Center has been worked out to identify potential new gene targets in nematode-feeding sites. The conditions for LCM on Arabidopsis and maize tissue were optimized and used to capture RNA from nematode-feeding sites. Microarray analysis of nematode feeding site-specific RNAs identified over 2000 up-regulated genes. Many of these genes appear to be expressed in tissues that act as strong sinks including anthers, stigmas, and siliques. Analysis of knockouts for many of the up-regulated genes showed reduced nematode loads. The LCM was also used to capture RNA from the digestive system of adult root-knot nematodes. Analysis of these RNAs is ongoing since the development of microarrays specific for root-knot nematodes have yet to be developed.
Journal Articles: 4 Displayed | Download in RIS Format
Other center views: | All 14 publications | 6 publications in selected types | All 4 journal articles |
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Brendza KM, Haakenson W, Cahoon RE, Hicks LM, Palavalli LH, Chiapelli BJ, McLaird M, McCarter JP, Williams DJ, Hresko MC, Jez JM. Phosphoethanolamine N-methyltransferase (PMT-1) catalyses the first reaction of a new pathway for phosphocholine biosynthesis in Caenorhabditis elegans. The Biochemical Journal 2007;404(3):439-448. |
X832282 (2006) |
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Fester T, Berg RH, Taylor CG. An easy method using glutaraldehyde‐introduced fluorescence for the microscopic analysis of plant biotrophic interactions. Journal of microscopy 2008;231(2):342-8. |
X832282 (Final) |
Exit |
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Jez JM. Phosphatidylcholine biosynthesis as a potential target for inhibition of metabolism in parasitic nematodes. Current Enzyme Inhibition. 2007;3(2):133-42. |
X832282 (2006) X832282 (Final) |
Exit |
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Palavalli LH, Brendza KM, Haakenson W, Cahoon RE, McLaird M, Hicks LM, McCarter JP, Williams DJ, Hresko MC, Jez JM. Defining the role of phosphomethylethanolamine N-methyltransferase from Caenorhabditis elegans in phosphocholine biosynthesis by biochemical and kinetic analysis. Biochemistry 2006;45(19):6056-6065. |
X832282 (2005) X832282 (2006) X832282 (Final) |
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Supplemental Keywords:
nematode, root-knot nematode (Meloidogyne incognita), methyl transferase, phosphoethanolamine N-methyltransferases, sinefungin, S-adenosyl homocysteine, laser-capture microdissectionProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.