Researchers attempt to turn weed into a crop

Early adopters might want to take a little time to explain to the neighbours why their entire field is covered by what looks like, and from a genetic standpoint, is mostly stinkweed.

What may resemble the worst weed infestation ever may be just a new cover crop and oilseed called domestic pennycress, or formally, Thlaspi arvense.

John Sedbrook is a professor of genetics at Illinois State University and one of the researchers working to turn this weed into a crop. In some ways it echoes the development of its plant relative, canola.

Sedbrook and his colleagues have been using plant-breeding tools such as CRISPR gene editing to modify pennycress.

“We’ve gotten to the point where this crop can be economical,” he said.

Like canola’s rapeseed ancestors, pennycress suffers from two problems: high levels of antinutritional erucic acid in the oil and high levels of glucosinalates, particularly one called sinigrin, in the meal. If you’ve experienced the sinus-clearing effects of a good horseradish sauce, you are familiar with sinigrin.

This limits pennycress’s value as animal feed. Raw glucosinalate-containing plants contain enzymes that break them down into toxic products in the body. While heating deactivates this enzyme, the glucosinalates can add an off taste to products such as milk, for example, if dairy cattle are fed rapeseed meal.