Did you know that potato plants naturally produce chemicals called steroidal glycoalkaloids (SGAs), which are found in high quantities in the green parts of the potato peels and in the sprouting areas? While these compounds help the plants protect themselves from insects, these are harmful in case consumed by humans.
Now, scientists have discovered a way to remove these toxic compounds from potatoes, making them safer to eat and easier to store. This breakthrough could reduce food waste and enhance crop farming in space and other extreme environments.
"These compounds are critical for plants to ward off insects, but they make certain parts of these crops inedible," said Adam Jozwiak, a UCR molecular biochemist who led the study. "Now that we've uncovered the biosynthetic pathway, we can potentially create plants that produce these compounds only in the leaves while keeping the edible parts safe."
Sunlight can induce the production of SGAs in potato tubers—the part of the potato plant that is eaten—even after they've been harvested. By identifying a key genetic mechanism in SGA production, UC Riverside researchers may be able to reduce potatoes' toxicity while preserving the plants' natural defenses. Removing SGAs from potatoes will also make them easier to store and transport in open air.
The research, published in Science, focuses on a protein called "GAME15," which plays a key role in directing the plant's production of SGAs. This protein acts both as an enzyme and a scaffold, organizing other enzymes into a "conversion factory" that efficiently produces SGAs while preventing toxic compounds from leaking into other parts of plant cells, where they would cause damage.
By engineering plants to control when and where SGAs are produced—such as in the leaves but not in the potatoes themselves—the researchers envision crops that can be stored without the risk of toxicity from sunlight exposure.
"You could store the potatoes in your kitchen and not worry about exposure to the sun, which makes them produce more SGAs. Then, you could eat them whenever you want, reducing food waste," Jozwiak said.
Additionally, the findings could enable the use of other plant parts, such as leaves, for food in limited-space environments like space missions or vertical farming systems. "For space farming, where every part of a plant may need to be edible, these findings are especially promising," Jozwiak added.
"Our work demonstrates that plants have evolved ingenious ways to balance growth, reproduction, and defense," Jozwiak said. This research involved scientists from the Weizmann Institute of Science in Israel, as well as Kobe University, the RIKEN Center for Sustainable Resource Science, and Osaka University in Japan.
