Gene technology a 'game changer' in fight against wheat disease

The fungal disease known as rust has always posed a risk to wheat crops. That risk increased about 20 years ago when a much more virulent strain of the disease began spreading across Africa.

University of Minnesota researchers, in collaboration with scientists from Australia, the U.K. and Denmark, have now successfully inserted multiple resistance genes into a wheat variety.

"This is really a new game-changing technique to breed crops for more durable resistance,” said U of M plant pathologist Brian Steffenson. “And it could cut off anywhere from 10 to 15 years from the normal process of developing a resistant wheat variety."

Plant breeders typically use traditional cross breeding methods that take more than a decade to add a single new gene to a wheat variety. This technology can insert what’s called a cassette of up to seven genes into a plant in a process that takes about a year.

“We're also hoping that not only will it be fast and efficient to produce these resistant wheats, but that they remain durably resistant for a long time,” Steffenson said.

Three years of field testing in Minnesota show the genetically modified wheat has what Steffenson called “exceptional resistance” to common rust varieties.

U of M researchers also tested the wheat plants in a bio-secure greenhouse against a powerful variety of rust, Ug99, which has been spreading across Africa for more than 20 years.

"And this particular strain of the stem rust pathogen can destroy 80 percent of the world's wheat so it has the ability to attack that great a percentage of the world's wheat,” said Steffenson.

The new variety showed strong resistance to the African rust strain in the greenhouse, but the next step will be to test it in field trials in Africa.

Minnesota farmers grow about 1.5 million acres of wheat a year, ranking eighth among states in wheat production. North Dakota is the second largest wheat-producing state.

Steffenson said farmers now use fungicides sprayed on the crop to help control rust, and this gene technology could reduce or eliminate the need for those chemical applications.

Farmers may not have access to the technology for many years.

“We have to do a lot more testing to make sure that there aren't other places in the genome or other traits that are altered by incorporating this five gene resistance cassette,” said Steffenson.

For example, researchers will need to prove that modifying the wheat plant won’t change the wheat in a way that might cause an allergic reaction in people who eat it.

Meanwhile, researchers are already looking at other crop diseases where this gene technology could give farmers an edge.

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