image: Asia Kud, an assistant professor of nematology in the department of entomology and plant pathology for the Arkansas Agricultural Experiment Station, the research arm of the University of Arkansas Division of Agriculture, was awarded a $298,913 grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture to continue researching a strategy to stop these pest nematodes from feeding and reproducing.
Credit: UADA photo
By John Lovett
University of Arkansas Division of Agriculture
FAYETTEVILLE, Ark. — Agricultural scientists are rethinking their battle plans against plant parasites that cause billions of dollars in annual yield losses for American farmers.
Plant-parasitic nematodes cause an estimated $10 billion in crop losses each year in the United States alone and more than $100 billion globally. Among them is the soybean cyst nematode, responsible for more than $1 billion in annual yield losses in U.S. soybean fields, according to the Crop Protection Network.
Soybean cyst nematodes are microscopic roundworms that live in the soil and infect plant roots. Rather than chewing on roots like insect pests, the nematodes invade root tissue and reprogram a small number of plant cells to serve as feeding sites.
“This plant pest can be absolutely devastating for soybean production, particularly because growers can experience up to 30 percent yield loss without any visible symptoms above ground,” said Asia Kud, an assistant professor of nematology in the department of entomology and plant pathology for the Arkansas Agricultural Experiment Station, the research arm of the University of Arkansas Division of Agriculture.
Chemical nematicides, soil treatments and biological controls have had mixed success against the soybean cyst nematode, and many potential solutions carry environmental or economic limitations.
Host resistance — breeding soybean varieties that can withstand infection — has been the most effective and environmentally friendly management tool, but its usefulness is declining, Kud said.
“The same resistance mechanisms have been used over and over for years,” Kud said. “Over time, nematodes adapt. Something that worked a decade ago may no longer be effective today, so there’s a real need to develop new sources of resistance.”
Taking away the keys to the pantry
To help strengthen the nematode-fighting arsenal, Kud was awarded a $298,913 grant from the U.S. Department of Agriculture’s National Institute of Food and Agriculture to continue researching a strategy to stop these pest nematodes from feeding and reproducing. Essentially, she’s taking away their keys to the food pantry.
Soybean cyst nematodes inject proteins — known as effectors — directly into cells of the plant’s roots to enlarge them and transform them into feeding sites. Once established, the nematode remains attached to the root, feeding and reproducing over several weeks and producing the next generation that continues the cycle.
In Kud’s preliminary research with Shahid Siddique, an associate professor of entomology and nematology at the University of California, Davis, they identified two effectors of particular interest.
“Typically, these nematodes will have hundreds of effectors, and some of them are more important than others,” Kud said. “We have high confidence that these two effectors this project focuses on are very important because we actually looked at those feeding sites inside plant cells and found those proteins are very abundant.”
Breaking the nematode life cycle
Rather than targeting the nematode directly, the goal of the research is to identify weak points in the nematode’s life cycle by understanding how these effectors interact with soybean proteins.
The project will examine where these effector proteins function inside plant cells, determine how important they are to nematode infection and reproduction, and identify which soybean proteins they interact with during parasitism.
In the long term, this knowledge could guide the development of new soybean varieties using gene-editing or RNA-based technologies that prevent nematodes from exploiting the plant — without harming normal plant growth or function, Kud said. Gene-editing approaches can make precise changes without introducing foreign DNA, and some gene-edited plants may fall outside certain USDA biotechnology regulations.
The idea would be to maintain the normal function of the plant proteins but change them slightly so the nematode effector can no longer bind to or manipulate them, she added. There shouldn’t be any negative effects on plant health, yield or nitrogen fixation.
Preliminary data supporting the NIFA proposal were generated through a Research Incentive Grant from the University of Arkansas Division of Agriculture and built on collaborative work with Siddique, who contributed key data identifying nematode effectors inside plant cells.
This work is supported by the Pests and Beneficial Species in Agricultural Production Systems program within the Agriculture and Food Research Initiative under NIFA grant no. 2026-67039-45888, titled “Managing Nematodes by Targeting Plant Genes Essential for Successful Parasitism.” The grant is part of $9.2 million in NIFA funding for 18 projects.
To learn more about ag and food research in Arkansas, visit aaes.uada.edu. Follow the Arkansas Agricultural Experiment Station on LinkedIn and sign up for our monthly newsletter, the Arkansas Agricultural Research Report. To learn more about the Division of Agriculture, visit uada.edu. To learn about extension programs in Arkansas, contact your local Cooperative Extension Service agent or visit uaex.uada.edu.
About the Division of Agriculture
The University of Arkansas Division of Agriculture’s mission is to strengthen agriculture, communities, and families by connecting trusted research to the adoption of best practices. Through the Agricultural Experiment Station and the Cooperative Extension Service, the Division of Agriculture conducts research and extension work within the nation’s historic land grant education system.
The Division of Agriculture is one of 22 entities within the University of Arkansas System. It has offices in all 75 counties in Arkansas and faculty on three system campuses.
Pursuant to 7 CFR § 15.3, the University of Arkansas Division of Agriculture offers all its Extension and Research programs and services (including employment) without regard to race, color, sex, national origin, religion, age, disability, marital or veteran status, genetic information, sexual preference, pregnancy or any other legally protected status, and is an equal opportunity institution.
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Media Contact:
John Lovett
U of A Division of Agriculture
Arkansas Agricultural Experiment Station
(479) 763-5929
jlovett@uada.edu