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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Emerging Pests and Pathogens Research » Research » Publications at this Location » Publication #419725
Research Project: Management and Biology of Arthropod Pests and Arthropod-borne Plant Pathogens

Location: Emerging Pests and Pathogens Research

Title: Fungal parasites of nematode eggs for integrated pest management of soybean cyst nematode

Author
item Green, Emily
item KIM, DONG-GYU - Washington University
item HAARITH, DEEPAK - University Of Wisconsin
item KNIGHT, NIN - Cornell University
item CHEN, SENYU - University Of Minnesota
item Bushley, Kathryn

Submitted to: Society for Invertebrate Pathology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2024
Publication Date: 7/25/2024
Citation: Green, E.A., Kim, D., Haarith, D., Knight, N., Chen, S., Bushley, K.E. 2024. Fungal parasites of nematode eggs for integrated pest management of soybean cyst nematode. Society for Invertebrate Pathology Annual Meeting. 56th Annuanl Society of Invertebrate Pathology Meeting, July 28 - August 1, 2024.

Interpretive Summary:

Technical Abstract: Fungal parasites of nematodes occupy unique niches in the environment and have evolved sophisticating mechanisms for sensing and parasitizing their prey. Nematode trapping fungi are best known because of their charismatic constricting rings that actively capture nematodes in soil, but two other ecological guilds of fungal nematode parasites, including those attacking nematode eggs (egg parasites) and those that parasitize the juvenile worms in soil (endoparasites), also have potential for biocontrol of nematode pests. Our work investigated fungal egg-parasites of the soybean cyst nematode (Heterodera glycines; SCN), a major pathogen of soybean in the Midwest of the U.S. and globally. Using culturing, metabarcode sequencing (16S V3V4 and ITS1 regions), and shotgun metagenomics of SCN cysts, soil, and soybean roots from a long-term agricultural field, we identified microbial pathogens enriched in soils suppressive to the soybean cyst nematode, including several early diverging lineages of fungi that have not previously been identified as nematode parasites. In-vitro bioassay testing identified fungi antagonistic to SCN, distinguishing those that are parasites directly infecting and killing live nematode eggs from those that may secrete bioactive secondary metabolites or enzymes toxic towards nematodes. Using genomic and transcriptomic approaches, we evaluate possible mechanisms of nematode antagonism among egg-parasites versus toxin producers. As many of these egg-parasitic fungi also colonize plant roots as endophytes and showed efficacy in preliminary greenhouse trials, they show promise either as seed or root bio- inoculants for integrated pest management of plant pathogenic nematodes in agriculture.