St. Paul fights wheat disease

Few can claim that their work affects millions of lives. For researchers at the Cereal Disease Laboratory, that figure might be an underestimate.

CDL Director Martin Carson and his colleagues are the foremost experts in the world on a wheat-killing disease that is threatening to take out a significant portion of the world’s wheat crop.

The culprit is Ug99, a strain of fungus called stem rust. It severely damages and often kills the entire plant.

CDL is located on the University of Minnesota’s St. Paul campus, but the CDL is actually a part of the United States Department of Agriculture, not the University.

Ug99 is an airborne disease, which gives it the potential to spread quickly. Within 10 days of landing on the plant, a pod erupts on the surface of the stem and releases “literally thousands of spores” into the air, Carson said.

Once it attaches itself to the stem, Ug99 burrows inside of it.

“What happens is that [the disease] sends in parts of the fungus into the plant’s stem, and so nutrients being transported through the stem — like water or sugar — get used up by the fungus instead of the plant,” said Matt Rouse, a University master’s student working on the problem at the CDL.

CDL is working on the solution: a more resistant strain of wheat that will be able to resist Ug99 in the future.

“We try to stay ahead of the fungus, that’s what we’ve been successful at,” Carson said. “Our strategy is to try and get more than one effective gene into these new wheats.”

Another major episode of stem rust in the United States occurred in the 1950s.

“We know from experience from the ’50s epidemic that it has the potential to be devastating. Like 40 percent of the wheat crop in North Dakota was lost,” Carson said. The disease has mutated at least twice since then.

Ug99 was first discovered in Uganda in 1998, but it’s moving, Ronnie Coffman, vice chairman of the Borlaug Global Rust Initiative, said.

“It’s as far north as Iran and as far south as South Africa and it will keep moving,” Coffman said. “If conditions are right it will grow into an epidemic and become an unpredictable disaster.”

Melissa Kessler, spokeswoman for the National Association of Wheat Growers, said Uganda has seen the greatest impact by Ug99. Other countries in the Middle East have been affected as well.

Researchers at the CDL said Ug99 is a problem in Africa, Asia and the Middle East at the moment, where wheat growers are a year or two behind combating stem-rust diseases.

Experts agreed it is highly unlikely that a resistant strain will not be introduced, and the wheat crop lost, because if researchers fail, the result could be catastrophic.

“It could be devastating,” Carson said, “In many countries [wheat] represents most of the caloric intake.”

If nothing else, the persistence of Ug99 would cause a very sharp spike in food prices, which could be devastating in countries with unstable governments, Carson said, adding that if a resistant strain isn’t introduced, there could be food riots like those that seized several countries in 2008.

Experts at the NWGA agreed.

“The potential damage is incalculable,” Jane DeMarchi, director of government affairs for research and technology with the NWGA, said.

Coffman is sure a solution is in the near future.

“There is no chance that a resistance will not be found,” Coffman said. “We hope we now have the technology to develop durable resistances.”

Carson and Rouse said they both feel a major responsibility to tackle the problem.

“We are the epicenter of research in the United States,” Carson said. “We have more people working on cereal rust diseases than anywhere else in the world. Some of the most ground-breaking work on stem rust has been done here.”

“The big question now is, ‘Can we get resistant varieties in Pakistan in order to prevent an epidemic?’” Carson said.

Experts across the nation agreed.

“It is important to emphasize how important the University’s activities are for the whole world,” DeMarchi said. “The whole world is very reliant right now on the CDL.”