Scientists search for drought-resistant wheat, the “Holy Grail” of agriculture


It is a staple food for 35% of the world's population, but requires more water than other crops.

Plant biologist Marcus Samuel has been working for more than a decade to improve the climate resilience of crops.

In his research greenhouse at the University of Calgary, he uses cutting-edge genome editing techniques to create more resilient plant varieties that can withstand temperature fluctuations, flooding and frost.

But although he has worked on canola, peas and other crops, the search for drought-resistant wheat is perhaps the most difficult and exciting part of his job.

“It's definitely the Holy Grail. I think it was one of the hardest things to crack,” Samuel said.

Samuel is just one of many scientists in Canada and around the world working to develop a drought-resistant wheat variety.

If this were to succeed, it would be one of the greatest successes in agricultural research.

Wheat is the most widely grown cereal grain, occupying 17 percent of the world's total cultivated land, according to the International Development Research Centre, a U.S. government-owned enterprise. Wheat is a staple food for 35 percent of the world's population and provides more calories and protein to the world's diet than any other crop.

However, wheat is a “thirstier” crop than other staple crops such as corn, rice and soy, and is therefore more vulnerable to water shortages. The Washington, DC-based World Resources Institute estimates that by 2040, nearly three-quarters of global wheat production will be threatened due to drought and water shortages caused by climate change.

Santosh Kumar, a wheat breeder who works on drought resistance for Agriculture and Agri-Food Canada in Brandon, Manitoba, said he sometimes feels like he is in a race against time.

“If our world population is expected to double by 2050, we need to feed people,” Kumar said.

“If we don’t grow enough wheat, there will be food shortages.”

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Although wheat cannot survive at all in water-free conditions, scientists have found that wheat plants with certain characteristics – such as longer, deeper roots – have a better chance of surviving in low-water conditions.

Using traditional plant breeding methods, it is possible to isolate plants with these desirable traits and cross them with other selected plants to create new, more drought-resistant varieties.

Progress has been made—the wheat Canadian farmers grow today is tougher and more resilient than the wheat of 100 years ago. But the process is still laborious and requires years of field testing.

And truly drought-resistant wheat remains hard to find, despite its increasing need due to climate change. In Canada, for example, total wheat production fell by nearly 40 percent in 2021 compared to the previous year due to extreme heat and drought in the Prairies.

Drought hit Canadian wheat production hard again last year. According to Statistics Canada, farmers saw yields decline 12 percent compared to 2022 levels.

One reason science has not yet solved the problem is the enormous complexity of the wheat plant itself. The wheat genome is huge, containing five times more DNA than the human genome. Finding better wheat traits is infinitely more difficult than working with a plant that has a simpler genetic profile.

“It’s like a puzzle with 50 pieces compared to 10,000 pieces,” Kumar said.

In 2018, international scientists finally succeeded in completely sequencing the wheat genome. This breakthrough led to recent advances in genetic research, the most spectacular of which was the 2020 announcement that Argentine scientists had developed the first genetically modified wheat containing a drought-resistant gene from the sunflower.

Argentine wheat is not allowed to be grown or consumed in Canada, and many markets around the world remain hostile to genetically modified crops. But genome editing is less controversial than wholesale genetic modification, and it is an area in which Canadian scientists – like Samuel at the University of California – are making progress.

Unlike wholesale genetic modification, genome editing does not involve combining genetic material from different species. Instead, it is a precision technique that allows scientists to make small, targeted changes to DNA sequences.

In 2021, the Canadian government relaxed its regulations on genetically modified crops, arguing that seeds produced using this technology were safe and did not require special assessment by Health Canada and the Canadian Food Inspection Agency.

Ellen Sparry, president of industry group Seeds Canada, said the decision was a milestone that should accelerate the search for drought-resistant wheat.

However, she said a promising variety discovered in a research lab tomorrow would still require several years of testing and regulatory work before it could reach farmers' hands.

For this reason, it is crucial that scientists receive the public and private funding they need to do their work as quickly as possible so that the Holy Grail of agriculture can be discovered before the climate crisis has an even greater impact.

“The question is not, 'Can we do it?' The question is how quickly can we do it to meet the challenges we face,” Sparry said.

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Amanda Stephenson, The Canadian Press