Mizzou uncovers breakthrough clue to help soybeans fight a billion-dollar pest

By Brian Consiglio

July 1, 2026
Contact: Brian Consiglio, [email protected]
Photo by Mizzou Visual Productions

Beneath the surface of soybean fields, an invisible threat is costing farmers billions. Now, researchers at the University of Missouri are uncovering how nature itself may hold the key to fighting back.

The soybean cyst nematode - a microscopic worm that attacks plant roots and siphons off nutrients - devastates soybean yield worldwide, leaving crops stunted, weakened and prematurely yellow.

A new study led by Mizzou researchers reveals how a naturally occurring mutation impacts a soybean plant's ability to fend off the nematode, offering a potential target for developing more pest-resistant soybeans.

Scientists first identified the mutation - located in a soybean enzyme called SHMT8 - more than a decade ago. The Mizzou team has been able to visualize the makeup of the enzyme at an unprecedented level of detail thanks to the university's high-powered electron microscopes.

In the recent study, Lesa Beamer, a professor of biochemistry in the School of Medicine and College of Agriculture, Food and Natural Resources, and Vindya Samarakoon, a doctoral student in the College of Arts and Science, discovered that the mutated version of this enzyme has a structure made up of just two protein pieces rather than its typical four-piece structure.

That change alters the functions of the enzyme, which plays a role in the folate metabolism that plant cells need to grow. Researchers have a theory about why the SHMT8 mutation actually helps the plant by making it more resistant to the nematode.

"Perhaps if the plant is only producing less folate in the roots due to this mutation, the nematode can't get enough nutrients to grow and reproduce," Beamer said.

While there are many versions of the SHMT enzyme throughout soybean plants, scientists only looked at ones specifically located in the roots where the nematodes feed.

As long as the other versions of the SHMT enzyme are operating normally, the plant likely still produces enough folate to remain healthy.

"Since plants need folate to grow, our challenge is to perhaps figure out a way to reduce folate metabolism enough to hurt the nematode but not so much that the soybean itself suffers or decreases in yield," Beamer said. "While the research in its early stages, if our efforts were to one day lead to breeding new mutant plants that ultimately help soybean farmers out in the field, that would be a dream come true."

"Oligomeric defects in soybean serine hydroxymethyltransferase 8: tetramer destabilization by A149T and other variants associated with soybean cyst nematode resistance" was published in The Federation of European Biochemical Societies Journal.