Using electrophoresis, CRISPR and a variety of breeding techniques, both traditional and engineered, Sachin Rustgi and his team are trying to develop less allergenic varieties of wheat and peanuts. These two food groups are especially critical as they make up 2/8 of “The Big 8,” eight common foods in the U.S. that account for 90 percent of food allergies. (Milk, eggs, tree nuts, fish, crustacean shellfish and soy being the other six).
In addition to being a difficult task, simply avoiding wheat and peanuts due to an allergy can have nutritional side effects. Wheat is a great source of energy, fiber and vitamins, while peanuts provide proteins, good fats, vitamins and minerals. Additionally, severe allergies to these foods can cause hospitalizations or even prove fatal.
“For some, avoiding wheat and peanuts is not easy due to geographical, cultural or economic reasons,” adds Rustgi, who is a professor of molecular breeding at Clemson University.
But Rustgi’s research goals are not new. Researchers have been trying to breed varieties of wheat with lower gluten content for years. It’s easier said than done though, since gluten isn’t a single protein—it’s a group of many different proteins. Peanuts are the same—they contain 16 different proteins recognized as allergens.
Since the instructions cells need to make individual proteins are contained within different genes, disrupting that cellular signal means interfering with many different portions of wheat and peanut DNA.
“When we started this research, a major question was whether it would even be possible to work on a characteristic controlled by so many genes,” says Rustgi.
In previous research, Rustgi proved successful in creating a new wheat variety safe for those with celiac disease. The new wheat contains two enzymes: one from barley that attacks gluten and another from the bacterium Flavobacterium meningosepticum.
Now, Rustgi and his team are testing many varieties of wheat and peanuts to find ones that are naturally less allergenic than others. These low-allergenic varieties can then be bred with crop varieties that have desirable traits, such as high yields or pest resistance.
Another approach for the team relies on using genetic engineering to reduce allergenic proteins in wheat and peanuts. Recent improvements in the gene-editing technology CRISPR allow researchers to target many genes at once.
“Disrupting the gluten genes in wheat could yield wheat with significantly lower levels of gluten. A similar approach would work in peanuts,” says Rustgi.
A third approach includes understanding how gluten production is regulated in wheat cells. As it turns out, one protein serves as a “master regulator” for many gluten genes. Disrupting the master regulator could lead to reduced amounts of gluten in wheat in a simplified workflow—after all, targeting a single gene is much easier than trying to disrupt several gluten genes at once.
Rustgi uses laboratories provided by Clemson’s Advanced Plant Technology Program (APT) to conduct his research. The program is a key part of an overall effort at Clemson to optimize plants for production in South Carolina and the Southeast for all agricultural stakeholders—from large-scale producers to small-scale landowners who work with heirloom varieties for restaurants, brewers and more.
Photo: Clemson researchers are using state-of-the-art facilities at the Pee Dee Research and Education Center to develop a wheat variety people with celiac disease can eat. Credit: Clemson University