Source: AGRICULTURAL RESEARCH SERVICE submitted to
CONTROL OF PLANT-PARASITIC NEMATODES BY INTERFERENCE WITH INTERNAL TARGETS
Sponsoring Institution
Agricultural Research Service/USDA
Project Status
TERMINATED
Funding Source
USDA INHOUSE
Reporting Frequency
Annual
Accession No.
0411697
Grant No.
(N/A)
Project No.
1275-22000-247-00D
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Feb 27, 2007
Project End Date
Feb 26, 2012
Grant Year
(N/A)
Project Director
MASLER E P
Recipient Organization
AGRICULTURAL RESEARCH SERVICE
RM 331, BLDG 003, BARC-W
BELTSVILLE,MD 20705-2351
Performing Department
(N/A)
Non Technical Summary
(N/A)
Animal Health Component
(N/A)
Research Effort Categories
Basic
80%
Applied
20%
Developmental
0%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2121310100010%
2121499104010%
2121820105030%
2123130112050%
Knowledge Area
212 - Pathogens and Nematodes Affecting Plants;

Subject Of Investigation
3130 - Nematodes; 1310 - Potato; 1499 - Vegetables, general/other; 1820 - Soybean;

Field Of Science
1120 - Nematology; 1050 - Developmental biology; 1000 - Biochemistry and biophysics; 1040 - Molecular biology;
Goals / Objectives
1) Discover nematode proteins and peptides that regulate development, growth and survival, and that provide new targets for controlling nematodes; and 2) Disrupt the function of steroid- or lipid-based regulatory systems unique to plant-parasitic nematodes and critical for their life processes.
Project Methods
1) Identify proteases and peptides that control hatching or molting in soybean cyst nematode and root-knot nematode and evaluate specific molecular inhibitors; and identify regulatory proteins, including membrane receptors, involved in the nematode response to its environment and plant host; and 2) Isolate and identify lipids and steroids with likely regulatory roles in plant-parasitic nematodes, and elucidate the biochemical pathways involved in the biosynthesis and metabolism of these compounds; and develop rational strategies for nematode management based upon the utilization of knowledge about the endogenous bioregulatory lipids or steroids in phytoparasitic nematodes.

Progress 02/27/07 to 02/26/12

Outputs
Progress Report Objectives (from AD-416): 1) Discover nematode proteins and peptides that regulate development, growth and survival, and that provide new targets for controlling nematodes; and 2) Disrupt the function of steroid- or lipid-based regulatory systems unique to plant-parasitic nematodes and critical for their life processes. Approach (from AD-416): 1) Identify proteases and peptides that control hatching or molting in soybean cyst nematode and root-knot nematode and evaluate specific molecular inhibitors; and identify regulatory proteins, including membrane receptors, involved in the nematode response to its environment and plant host; and 2) Isolate and identify lipids and steroids with likely regulatory roles in plant-parasitic nematodes, and elucidate the biochemical pathways involved in the biosynthesis and metabolism of these compounds; and develop rational strategies for nematode management based upon the utilization of knowledge about the endogenous bioregulatory lipids or steroids in phytoparasitic nematodes. This is the final report for project 1255-22000-247-00D, which terminated in February, 2012. A major problem with developing new methods for controlling plant-parasitic nematodes and the crop losses they cause comes from a poor understanding of which nematode developmental stages and molecular targets are the most vulnerable to new methods of control. This lack of knowledge is particularly deficient with respect to information about the internal nematode molecules that respond to the environment and are necessary for survival. We discovered that juvenile stages of plant-parasitic nematodes respond to very low levels of small peptide molecules that change behaviors required for both hatching and infecting host plants. In fact, we found that two of the most serious plant-parasitic nematode crop pests, the soybean cyst nematode and the root-knot nematodes, respond differently to these small peptides, and that the nematodes cannot properly metabolize modified forms of these peptides. This information is critical for designing control strategies based upon natural molecules that exploit nematode vulnerabilities and minimize effects on non-target organisms. We discovered that temperature stress affected embryo development and prevented the formation of the nematode life stage that infects plants. A number of nematode proteins were discovered to respond to stress, some increasing in amount while others decrease, thereby providing significant new guidance in targeting internal nematode molecules for plant protection. We also discovered that natural plant chemicals (isothiocyanates, catechins) affect nematode behavior and development potently and specifically, and that these effects result in a strong suppression of plant-parasitic nematode infectivity and reproduction on host plants. Suppression is accomplished at extremely low doses, making these plant chemicals highly specific against nematodes and environmentally benign. This discovery is being utilized by researchers developing safe and effective means for reducing nematode-induced crop losses. Accomplishments 01 Natural plant molecules disrupt nematode development. Safe strategies fo managing plant-parasitic nematodes should be potent and efficient in controlling these target pests, while having minimal impact upon the environment and non-target species. Plant metabolites used as nematode control agents are typically applied at substantial levels and their mod of action in nematodes are unknown. Working with root-knot nematodes, th most economically important nematode crop pest worldwide, we demonstrate that a specific plant chemical, a type of catechin, rapidly and severely disrupts the nematode life stage that infects plants at very low concentrations, may inhibit a specific enzyme, and greatly decreases hatching, and reduces infectivity by at least 50 percent. Further, we found that reduced hatch is due to entrapment of infective juveniles within the egg. This discovery is important because it is the first to demonstrate how this category of plant chemical suppresses plant-parasit nematode development and reproduction at low doses. This information is great value to scientists developing precision treatment strategies for controlling plant-parasitic nematodes and to growers seeking to decrease chemical use in crop protection.

Impacts
(N/A)

Publications

  • Masler, E.P. 2012. In vitro proteolysis of nematode FLPs by preparations from the free-living nematode Panagrellus redivivus and two plant- parasitic nematodes (Heterodera glycines and Meloidogyne incognita). Journal of Helminthology. 86(1):77-84.
  • Gibson, T., Farrugia, D., Barrett, J., Chitwood, D.J., Rowe, J., Subbotin, S.A., Dowton, M. 2011. The mitochondrial genome of the soybean cyst nematode, Heterodera glycines. Genome. 54(7):565-574.


Progress 10/01/10 to 09/30/11

Outputs
Progress Report Objectives (from AD-416) 1) Discover nematode proteins and peptides that regulate development, growth and survival, and that provide new targets for controlling nematodes; and 2) Disrupt the function of steroid- or lipid-based regulatory systems unique to plant-parasitic nematodes and critical for their life processes. Approach (from AD-416) 1) Identify proteases and peptides that control hatching or molting in soybean cyst nematode and root-knot nematode and evaluate specific molecular inhibitors; and identify regulatory proteins, including membrane receptors, involved in the nematode response to its environment and plant host; and 2) Isolate and identify lipids and steroids with likely regulatory roles in plant-parasitic nematodes, and elucidate the biochemical pathways involved in the biosynthesis and metabolism of these compounds; and develop rational strategies for nematode management based upon the utilization of knowledge about the endogenous bioregulatory lipids or steroids in phytoparasitic nematodes. A major problem with developing new methods of controlling plant- parasitic nematodes is that scientists do not know many unique aspects of nematode biology that would make these pests vulnerable to a new control method. We have discovered two vulnerabilities. First, we found that the juvenile stages of plant-parasitic nematodes respond to small natural molecules that change behaviors required for both hatching and infecting host plants. Two of the most serious plant-parasitic nematode crop pests, the soybean cyst nematode and the root-knot nematodes, responded differently to the small molecule treatments. Second, we discovered a number of nematode proteins that respond to nutritional and temperature stress; some of these proteins increase in amount while others decrease, thereby providing significant new guidance in targeting internal stress proteins for nematode control. Accomplishments 01 Natural plant molecules reduce nematode reproduction. Safe strategies fo managing plant-parasitic nematodes should be potent and efficient in controlling the target pest, while having minimal impact upon the environment and non-target species. Plant metabolites used as nematode control agents are typically applied at substantial levels. Working with root-knot nematodes, the most economically important nematode crop pest worldwide, we demonstrated that a specific plant defensive metabolite, BITC, rapidly and severely disrupts the infective nematode life stage at very low concentrations, and this disruption results in greatly decrease infectivity. Root-knot nematode reproduction on pepper was reduced 70 percent and reproduction on soybean was nearly eliminated when infective nematodes were exposed to BITC for as little as two hours. This discover is important because it is the first to suppress plant-parasitic nematod reproduction using greatly reduced levels of a plant chemical. This information is expected to be of great value to scientists developing precision treatment strategies for controlling plant-parasitic nematodes and to growers seeking to decrease chemical use in crop protection.

Impacts
(N/A)

Publications

  • Masler, E.P. 2010. In vitro comparison of protease activities in preparations from free-living (Panagrellus redivivus) and plant-parasitic (Meloidogyne incognita) nematodes using FMRFa and FMRFa-like peptides as substrates. Journal of Helminthology. 84(4):425-433.
  • Cheong, M.C., Na, K., Kim, H., Chitwood, D.J., Paik, Y.K. 2011. A potential biochemical mechanism underlying the influence of sterol deprivation stress on Caenorhabditis elegans longevity. Journal of Biological Chemistry. 286(9):7248-7256.
  • Riepsamen, A.H., Gibson, T., Rowe, J., Chitwood, D.J., Subbotin, S.A., Dowton, M. 2011. Poly(T) variation in heteroderid nematode mitochondrial genomes is predominantly an artifact of amplification. Journal of Molecular Evolution. 72(2):182-192.


Progress 10/01/09 to 09/30/10

Outputs
Progress Report Objectives (from AD-416) 1) Discover nematode proteins and peptides that regulate development, growth and survival, and that provide new targets for controlling nematodes; and 2) Disrupt the function of steroid- or lipid-based regulatory systems unique to plant-parasitic nematodes and critical for their life processes. Approach (from AD-416) 1) Identify proteases and peptides that control hatching or molting in soybean cyst nematode and root-knot nematode and evaluate specific molecular inhibitors; and identify regulatory proteins, including membrane receptors, involved in the nematode response to its environment and plant host; and 2) Isolate and identify lipids and steroids with likely regulatory roles in plant-parasitic nematodes, and elucidate the biochemical pathways involved in the biosynthesis and metabolism of these compounds; and develop rational strategies for nematode management based upon the utilization of knowledge about the endogenous bioregulatory lipids or steroids in phytoparasitic nematodes. A major problem with controlling plant-parasitic nematodes comes from a poor understanding of the vulnerable stages of the nematode life cycle. These provide the most important targets for designing new methods of nematode control, are in contact with the host plant, and are dependent upon specific behaviors for infection. We discovered that small, natural plant molecules that affect nematode behavior potently and specifically strongly suppress plant-parasitic nematode infectivity and reproduction on host plants. We also found that plant-parasitic nematodes cannot properly metabolize peptide mimics of natural nematode control peptides. Because these peptides are needed for normal nematode infectivity behavior, this discovery provides an additional option for designing control strategies that exploit nematode vulnerabilities in combination with potent and specific natural molecules. Accomplishments 01 Natural plant and nematode molecules control plant-parasitic nematode behavior at very low levels. Ideally, safe strategies for managing nematodes must be potent and efficient in controlling the target pest, b have minimal impact upon the environment and non-target species. ARS scientists at Beltsville, Maryland and Corvallis, Oregon demonstrated th infectivity of root-knot nematodes, the most economically important nematode crop pest worldwide, was reduced nearly 20-fold on pepper and nearly 100 percent on soybean by using very low levels of a specific pla metabolite to disrupt the infective nematode life stage. These ARS scientists also demonstrated that mimics of nematode regulatory peptides are abnormally metabolized in root-knot nematodes, and cannot function properly. These discoveries are important because they are the first tha quantify high impact suppression of plant-parasitic nematode reproductio by low levels of a plant chemical, and the first that demonstrate the disruption of plant-parasitic nematode metabolism by a modified nematode peptide. Therefore, this information is expected to be of great value to scientists who are developing precision treatment strategies for controlling plant-parasitic nematodes for the benefit of growers.

Impacts
(N/A)

Publications

  • Joo, H.J., Wim, Y.H., Jeong, P.Y., Jin, Y.X., Lee, J.E., Kim, H., Jeong, S. K., Chitwood, D.J., Paik, Y.K. 2009. Caenorhabditis elegans utilizes dauer pheromone biosynthesis to dispose of toxic peroxisomal fatty acids for cellular homoeostasis. Biochemical Journal. 422(1):61-71.
  • Chitwood, D.J., Perry, R.N. 2009. Reproduction, physiology and biochemistry. In: Perry, R.N., Moens, M., Starr, J.L., editors. Root- Knot Nematodes. Wallingford, UK: CAB International. p. 182-200.
  • Masler, E.P., Zasada, I.A., Sardanelli, S., Rogers, S.T., Halbrendt, J.M. 2010. Effects of Benzyl Isothiocyanate on the Reproduction of Meloidogyne incognita on Glycine max and Capsicum annuum. Nematology. 12(5):693-699.


Progress 10/01/08 to 09/30/09

Outputs
Progress Report Objectives (from AD-416) 1) Discover nematode proteins and peptides that regulate development, growth and survival, and that provide new targets for controlling nematodes; and 2) Disrupt the function of steroid- or lipid-based regulatory systems unique to plant-parasitic nematodes and critical for their life processes. Approach (from AD-416) 1) Identify proteases and peptides that control hatching or molting in soybean cyst nematode and root-knot nematode and evaluate specific molecular inhibitors; and identify regulatory proteins, including membrane receptors, involved in the nematode response to its environment and plant host; and 2) Isolate and identify lipids and steroids with likely regulatory roles in plant-parasitic nematodes, and elucidate the biochemical pathways involved in the biosynthesis and metabolism of these compounds; and develop rational strategies for nematode management based upon the utilization of knowledge about the endogenous bioregulatory lipids or steroids in phytoparasitic nematodes. Significant Activities that Support Special Target Populations A major problem with controlling plant-parasitic nematodes comes from a poor understanding of the vulnerable life cycle stages that provide the most important control targets. We discovered that the juvenile stages of plant-parasitic nematodes respond to small molecules that change behaviors required for both hatching and infecting host plants. We demonstrated that these molecules are effective at very low levels, which is important to minimize effects on non-target organisms. In fact, we found that two of the most serious plant-parasitic nematode crop pests, the soybean cyst nematode and the root-knot nematodes, respond differently to the small molecule treatments, which is important in designing control strategies to exploit nematode vulnerabilities. Another important problem involves the lack of information on internal nematode molecules that respond to the environment and are necessary for survival. We discovered a number of nematode proteins that respond to nutritional and temperature stress, with some proteins increasing in amount while others decrease, thereby providing significant new guidance in targeting internal stress proteins for nematode control. Technology Transfer Number of Other Technology Transfer: 2

Impacts
(N/A)

Publications

  • Masler, E.P. 2008. Digestion of invertebrate neuropeptides by preparations from the free-living nematode Panagrellus redivivus. Journal of Helminthology. 82:279-285.
  • Masler, E.P. 2008. Responses of Heterodera glycines and Meloidogyne incognita to exogenously applied biogenic amines. Nematology. 10:911-917.
  • Zasada, I.A., Masler, E.P., Rogers, S.T., Halbrendt, J.M. 2009. Behavioral response of Meloidogyne incognita to benzyl isothiocyanate. Nematology. 11:603-610.
  • Jeong, P.Y., Na, K., Jeong, M.J., Chitwood, D.J., Shim, Y.H., Paik, Y.K. 2009. Proteomic analysis of Caenorhabditis elegans. In: Sheehan, D., Tyther, R., editors. Two-Dimensional Electrophoresis Protocols. New York, NY:Humana Press. p. 145-169.
  • Lee, E.Y., Jeong, P.Y., Kim, S.Y., Shim, Y.H., Chitwood, D.J., Paik, Y.K. 2009. Effects of sterols on the development and aging of Caenorhabditis elegans. In: Larijani, B., Woscholski, R., Rosser, C.A., editors. Lipid Signaling Protocols. New York, NY: Humana Press. p. 167-179.


Progress 10/01/07 to 09/30/08

Outputs
Progress Report Objectives (from AD-416) 1) Discover nematode proteins and peptides that regulate development, growth and survival, and that provide new targets for controlling nematodes; and 2) Disrupt the function of steroid- or lipid-based regulatory systems unique to plant-parasitic nematodes and critical for their life processes. Approach (from AD-416) 1) Identify proteases and peptides that control hatching or molting in soybean cyst nematode and root-knot nematode and evaluate specific molecular inhibitors; and identify regulatory proteins, including membrane receptors, involved in the nematode response to its environment and plant host; and 2) Isolate and identify lipids and steroids with likely regulatory roles in plant-parasitic nematodes, and elucidate the biochemical pathways involved in the biosynthesis and metabolism of these compounds; and develop rational strategies for nematode management based upon the utilization of knowledge about the endogenous bioregulatory lipids or steroids in phytoparasitic nematodes. Significant Activities that Support Special Target Populations One problem with controlling soybean cyst nematodes is that many nematode eggs remain dormant in the field. We have found that egg populations consist of at least three distinct classes: those from which infective juveniles hatch immediately, hatch gradually over time, or do not hatch even after extended periods. Furthermore, we have developed experimental treatments to change the level of eggs in each class. In addition, we have developed methods to explore these three egg classes for proteins important for the regulation of hatching and thereby providing important targets for control strategies. This research directly addresses Component 2 (Biology, Ecology, Epidemiology, and Spread of Plant Pathogens and Their Relationships with Hosts and Vectors) of National Program 303 (Plant Diseases); specifically, Problem Statement 2A (Pathogen Biology, Virulence Determinants, and Genetics of the Pathogen.) Technology Transfer Number of Other Technology Transfer: 2

Impacts
(N/A)

Publications

  • Masler, E.P. 2008. Invertebrate Neuropeptides. In: Meyers, R.A., editor. Neurobiology. From Molecular Basis to Disease. Vol. 1. Weinheim: Wiley-VCH Verlag. p. 257-271.
  • Masler, E.P. 2007. Responses of Heterodera glycines and Meloidogyne incognita to exogenously applied neuromodulators. Journal of Helminthology. 81:421-427.
  • Masler, E.P. 2007. Characterization of aminopeptidase in the free-living nematode Panagrellus redivivus: subcellular distribution and possible role in neuropeptide metabolism. Journal of Nematology. 39(2):153-160.
  • Pridannikov, M.V., Petelina, G.G., Palchuk, M.V., Masler, E.P., Dzhavakhiya, V.G. 2007. Influence of components of Globodera rostochiensis cysts on the in vitro hatch of second-stage juveniles. Nematology. 9(6) :837-844.
  • Masler, E.P., Donald, P.A., Sardanelli, S.S. 2008. Stability of Heterodera glycines (Tylenchida: Heteroderidae) juvenile hatching from eggs obtained from different sources of soybean, Glycine max. Nematology. 10(2):271-278.
  • Masler, E.P., Zasada, I.A., Sardanelli, S. 2008. Hatching behavior in Heterodera glycines in response to low temperature. Comparative Parasitology. 75(1):76-81.


Progress 10/01/06 to 09/30/07

Outputs
Progress Report Objectives (from AD-416) 1) Discover nematode proteins and peptides that regulate development, growth and survival, and that provide new targets for controlling nematodes; and 2) Disrupt the function of steroid- or lipid-based regulatory systems unique to plant-parasitic nematodes and critical for their life processes. Approach (from AD-416) 1) Identify proteases and peptides that control hatching or molting in soybean cyst nematode and root-knot nematode and evaluate specific molecular inhibitors; and identify regulatory proteins, including membrane receptors, involved in the nematode response to its environment and plant host; and 2) Isolate and identify lipids and steroids with likely regulatory roles in plant-parasitic nematodes, and elucidate the biochemical pathways involved in the biosynthesis and metabolism of these compounds; and develop rational strategies for nematode management based upon the utilization of knowledge about the endogenous bioregulatory lipids or steroids in phytoparasitic nematodes. Significant Activities that Support Special Target Populations This project began on February 12, 2007; it progressed from project 1275- 22000-196-00D. Accomplishments A requirement for the development of new nematode controls is the discovery of internal nematode molecules that can be exploited in designing novel, safe nematode control agents. To accelerate this discovery, ARS scientists at Beltsville, Maryland have developed a bioassay system for efficiently screening potentially bioactive molecules on infective nematode juveniles and eggs. The assay is non-destructive, requires small amounts of test material, small numbers of nematodes, is rapid, and can be used to test molecule interactions as well as screening. Information can be generated quickly, and will allow discovery of bioactive molecules and their effects on nematode behavior and development, leading to new strategies for controlling plant-parasitic nematodes. (National Program 303 Component 2: Biology, Ecology, Epidemiology, and Spread of Plant Pathogens and Their Relationships with Hosts and Vectors. Problem Statement 2A: Pathogen Biology, Virulence Determinants, and Genetics of the Pathogen.) Technology Transfer Number of Active CRADAS and MTAS: 2 Number of Web Sites managed: 1 Number of Newspaper Articles,Presentations for NonScience Audiences: 2

Impacts
(N/A)

Publications