Two Iowa State researchers are taking a cue from nature in trying to stop a harmful and yield-affecting soybean pest.

George Kraus, professor of chemistry, and Greg Tylka, associate professor of plant pathology, are developing a synthetic form of a naturally occurring chemical compound known as Glycinoeclepin A, the compound that inhibits the hatching of soybean cyst nematodes. The compounds, if developed, could be used to increase the yields of soybean crops.

“The compounds that we have produced are quite encouraging because not only did they affect the nematode, they affected by very little quantities of the compound,” Kraus said.

A soybean cyst nematode lies dormant until a natural-hatching stimulus produced by the nearby roots of a soybean plant causes it to bloom.

Then the worm-like pest hatches and begins to attach itself to the roots of a soybean plant and inhibit its growth.

The nematode is a very durable pest, as its eggs can lie dormant for as many as 10 to 12 years inside of a husk before hatching.

Once hatched, the nematode worm must attach itself to the root within about two weeks or it will starve and die, Tylka said.

“Our strategy was to trick the nematode into hatching in a year when soybeans aren’t being grown to induce a ‘suicidal hatch,'” he said.

Tylka said a nematode can only travel an inch or so on its own during its entire lifetime.

A group of scientists from Japan published a report of their research in the journal “Nature” that described a complex compound extracted from kidney bean roots, also affected by soybean cyst nematodes.

The compound, Glycinoeclepin A, was found to be an effective natural hatching stimulus.

Only a small, very concentrated quantity of the compound was able to be extracted from about one ton of roots during that research.

About a drop was all they got — not enough of the natural compound to be effective, Tylka said.

In 1990, Kraus joined with Tylka to begin research in an attempt to replicate the structure of the elusive compound synthetically.

The partnership consisted of Kraus developing the various compounds in the chemistry lab and Tylka testing them in a plant pathology lab.

“Part of the research rationale is to the develop an inexpensive and easy method to make this compound,” Kraus said. “And it is a very complex compound.”

For example, the simple chemical compound of water is one oxygen and two hydrogen atoms.

Glycinoeclepin A has 24 carbon, 32 hydrogen and seven oxygen atoms with hundreds of thousands of possible combinations, Kraus said.

Kraus and Tylka were surprised at test results after various attempts to synthesize Glycinoeclepin A. Results from lab tests showed some parts of the compound inhibited hatching of the nematode.

The development of compounds that inhibit nematode hatching opened up other avenues of the research that seemed necessary to explore, Kraus said.

Besides being cost effective, the natural model that is forming the base of the research assures the compounds will be biodegradable, offering an environmentally friendly method of controlling the pest.

But soybean experts were quick to point out these compounds still won’t solve the soybean nematode problem.

“Soybean cyst nematodes are the No. 1 pest problem in soybean production,” said Kevin Smith, a research consultant for the Iowa Soybean Producers Association, which has helped fund Kraus and Tylka’s research for almost six years. “We’re not going to get rid of them.”