Cloning method can make wheat fungus-resistant, UMN study finds

The identified genes can make wheat resistant to stem rust disease, a fungus that threatens to destroy crops.

Illustrated by Morgan La Casse

Morgan La Casse

Illustrated by Morgan La Casse

Kait Ecker

Researchers from the University of Minnesota published a study earlier this month exploring a new gene cloning method that would make wheat resistant to a fungus that costs the agriculture industry more than a billion dollars of wheat annually.

In the study, University plant pathologist Brian Steffenson used a new cloning method to isolate four genes in wheat that would strongly resist stem rust pathogens. Now that these genes are identified, there is potential to either breed or genetically modify the disease-resistant genes from the wild wheat species into the domesticated species. Farmers plant disease-resistant wheat because it protects against pathogens that threaten to destroy their crops, something that has widespread economic impact.

“Our goal was to try to identify and clone as many genes as we could from this wild species,”  Steffenson said. 

Scientists have been developing disease-resistant forms of wheat to minimize crop losses for centuries. However, pathogens typically overcome the disease-resistant genes. The four genes identified by Steffenson and his team would provide stronger resistance to these pathogens. He said there is an extremely small chance the pathogen would overpower the genes. 

Richard Magnusson, a farmer from Roseau, Minnesota, said a fungus destroyed his entire wheat crop in 1993.

“We ended up burning our whole crop,” Magnusson said. “That’s how bad disease can get, so obviously it’s a concern.”

The fastest, easiest way for this wheat to become available to the public would be through genetic modification, which takes the resistant genes from the wild wheat species and directly inserts them into the domesticated wheat species, Steffenson said. While the disease-resistant wheat could be developed by conventional breeding methods, this typically takes several years while the genetic modification process can be done in about half a year.

“I think that it’s a safe and effective strategy because these genes are already found in wheat,” Steffenson said. “This is a very sound and also safe method of disease control.”

James Anderson, a professor of wheat breeding at the University, agrees the genetic modification process of creating new varieties of wheat is ideal, but said there is not enough public acceptance of genetically modified wheat. 

“Right now, there are no GMO wheats marketed anywhere in the world,” Anderson said.

As a wheat grower, Magnusson sees wheat falling behind with the advancements corn and soybeans are making with genetic modification. 

“I think the challenge is getting the public to accept genetically modified wheat,” Magnusson said. “If the public doesn’t accept it, it’s not worth having.”

According to United States Department of Agriculture regulations, certified organic growers and handlers are prohibited from using GMOs because it is not something that would be “possible under natural conditions or processes,” according to the policy. If the gene resistance was bred into the wheat through the traditional methods, organic growers would be able to use it.

Besides planting varieties bred for disease resistance, many farmers use fungicides to protect their crops. Many fungicides, insecticides and herbicides are prohibited in organic farming.

If the genetically modified disease-resistant wheat ever made it to market, David Torgerson, executive director of the Minnesota Wheat Council, said it would benefit farmers and the public.

“If our wheat productivity was increased, it would help farmers and our whole economy in Minnesota,” Torgerson said. 

Steffenson and his team will continue their research in other cereal crops like barley and oats.

“This technique can be applied to many different crops and many different plant species,” he said. “The same technology could be used to clone out or isolate resistance genes, from not just wheat, not just wheat relatives, but many different cereal species and perhaps even a wider range of plants.”

Correction: A previous version of this article misstated cloning method. The cloning method used in the study can make wheat resistant to the stem rust pathogens.