Scientists examine wheat genes to boost the crop's disease resistance

New research that could increase the natural resistance of wheat to a devastating fungal disease has begun at Heriot-Watt University in Edinburgh.

Wheat is the world's second biggest grain crop by volume—with around 800 million metric tons produced last year—and is used in bread and many other food products, as well as animal feed and the distilling industry.

As the world's population rises from 8 billion to a projected 10 billion people by 2050, increasing the size of wheat crops and reducing the plant's vulnerability to disease is increasingly urgent, the scientists say.

But wheat faces a growing threat from a common fungal disease called septoria tritici blotch, which attacks and kills wheat plants. In the UK, the disease destroys up to 20% of wheat crops a year.

"Countries in Northern Europe are vulnerable to septoria because of the weather," explained Dr. Angela Feechan, a plant pathologist—an expert in plant diseases—at Heriot-Watt's Institute for Life and Earth Sciences. "We have more rain—and the fungus is a big fan of rainy, humid conditions."

The disease, which is also known as septoria leaf blotch, septoria or the acronym STB, is very difficult to control.

"We can't completely control it with fungicides—chemicals used to control fungal crop diseases," Dr. Feechan said. "So we need to think of different ways to try and control it. And one of the ways you can do that is through genetics."

The research will examine why some wheat varieties are more resistant than others to this disease.

Dr. Feechan and her team will examine specific genes in different wheat varieties, and how the products of these interact with the fungus that causes septoria. This fungus is called Zymoseptoria tritici (Z. tritici) and attacks the wheat plant through spores. These destroy the plant's ability to absorb sunlight through photosynthesis—turning the leaves of the wheat plant yellow and speckled, killing areas of the leaf.

"We think there are very small differences in the genes of different wheat varieties that determine whether or not they are resistant to this disease," Dr. Feechan said. "If we can find the difference in these genes that give us resistance, they could be used to breed resistant wheat varieties in the field."

The UK produced 14 million tonnes of wheat in 2023. Wheat accounts for about a third of total cereal production in Scotland, which produced more than 980 thousand tonnes of wheat in 2023.

The Heriot-Watt researchers will be working with a collection of 300 wheat varieties at INRAE, France's National Research Institute for Agriculture, Food and Environment, as part of a collaboration.

The research is funded through a postdoctoral fellowship from UK Research and Innovation—the UK's national funding agency for investing in science and research. Researcher Dr. Debabrata Dutta, a plant biology specialist, is joining Heriot-Watt University to work on the research.

Developing the natural resistance of wheat through the plant's existing genetic diversity is distinct from genetic modification, which involves altering a plant's genetic makeup, Dr. Feechan added.

Boosting crop yields—the volume of crops produced—is a core focus of global efforts to tackle food insecurity—not having access to enough affordable, nutritious food.

More than 300 million people in 71 countries are facing hunger this year because of food insecurity, according to the United Nation's World Food Program.

The Institute for Life and Earth Sciences specializes in researching the environment, health and food science and is part of Heriot-Watt's School of Energy, Geoscience, Infrastructure and Society.

Provided by Heriot-Watt University