U of S profs identify wild genes resisting disease

EAGLE STAFF

Researchers in Saskatoon looking for resistance to pathogens found “a unique pair of genes that work together to protect against disease.”

Valentyna Klymiuk and Curtis Pozniak, with the Crop Development Centre at the University of Saskatchewan, are among other researchers examining wild wheat varieties for traits they can use, indicated an article by Erin Matthews on the centre’s website.

Workers there have “been diving back into the gene pool of wheat and screening its wild relatives for useful traits that can be effectively deployed in new wheat cultivars,” Matthews wrote. “Wild wheat has not been domesticated, so it cannot be used directly in breeding, but it contains useful diversity to respond to environmental threats.”

“Part of our research is keeping one step ahead of pathogens by identifying new resistance genes which ideally could be stacked, like Lego blocks, so the pathogen can’t easily overcome the resistance,” Klymiuk said.

One wild strain “demonstrated significant resistance to stripe rust, a type of fungal infection that is one of the top five diseases of concern for producers,” the article said. They “soon realized that the resistance they identified in this wild strain was behaving differently than expected,” it said.

Their discovery was published in Nature Genetics, which covers “genetic and functional genomic studies on human and plant traits and on other model organisms,” its website says.

“We were quite intrigued about what was really going on,” said Pozniak who directs the centre.

Klymiuk, a research officer in Pozniak’s program, said that they determined that two genes working together as a pair were required for full resistance in this variety.

“One gene is responsible for sensing the invading pathogen while the other activates the immune response of the plant to stop the pathogen in its tracks,” the article said. They had to retest before “the results became clear,” Klymiuk said. They determined that the genes “interact at a protein level, physically coming together to initiate the resistance response,” the article said.

“A lot of the time when things don’t line up, the temptation is to move forward, but we really dug into the weeds to figure out what was going on and that’s when we realized that the genes were communicating and working together and that’s what’s really new,” Pozniak said. “If we had given up after the first set of experiments, we never would have concluded that two genes coming together was needed for resistance. It’s a great science story.”

Identifying complex gene interactions that offer greater resistance, like the ones published in this Because of the genes’ behaviour, Klymiuk developed a DNA test to ensure the pair of genes are present in new plants. With this DNA test, these genes can be used routinely in the breeding program.

“The interconnectivity of research and breeding lets us keep the eye on the prize and develop the most productive varieties for farmers,” Pozniak said. “This project also really helps us understand and appreciate the complexity of plant biology. Plants really need to adapt, and they do it in cool and interesting ways.”