Using genetics to reduce food waste
University of California - Riverside
Scientists have discovered a way to remove toxic compounds from potatoes, making them safer to eat and easier to store. The breakthrough could cut food waste and enhance crop farming in space and other extreme environments.
Potato plants naturally produce chemicals that protect them
from insects. The chemicals, called steroidal glycoalkaloids, or SGAs, are
found in high quantities in the green parts of potato peels, and in the
sprouting areas. They render the potatoes unsafe for insects as well as humans.
"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 reduce potatoes' toxicity while preserving
the plants' natural defenses. Taking SGA out of potatoes will also make them
easier to store and transport in open air.
The research, published in Science, focuses on a protein dubbed "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 produce SGAs while preventing toxic compounds from leaking into other parts of plant cells, where they would wreak havoc.
Tomatoes also produce SGAs, primarily in the green, unripe
fruit, as well as in the leaves, stems, and roots of the plants. When the
researchers silenced the GAME15 gene in tomatoes, they eliminated SGA
production but also made the plants highly susceptible to pests.
By engineering plants to control when and where SGAs are
produced, for example, in the leaves but not 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 sun, which makes them produce more SGAs. And 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 said.
The team achieved these insights by initially recreating the
SGA production process in tobacco plants. Surprisingly, they found that during
evolution the process redirected protein from the plasma membrane or Golgi
apparatus, where it is responsible for the production of cell wall components
crucial for cell growth, to the endoplasmic reticulum, a part of the cell where
toxin production begins.
"Essentially, the plant borrows from itself to create
GAME15," Jozwiak said. "We did not expect to find the plant hijacking
protein it needs for the production of cell walls."
Green, unripe fruit may be toxic, but during ripening these
molecules convert to something edible. By limiting SGAs to non-edible parts of
plants, farmers and consumers alike could benefit from safer, more versatile
crops.
"Our work demonstrates that plants have evolved
ingenious ways to balance growth, reproduction, and defense," Jozwiak
said. "Understanding these systems allows us to redesign crops to meet
modern needs without compromising their ability to thrive."
This research was a highly collaborative effort involving
researchers 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. The group's findings not only hold the promise of
healthier food but also represent a leap forward in sustainable agriculture and
space exploration.
"We're thrilled about the potential of this discovery," Jozwiak said. " It's exciting to think about how we can now significantly extend the shelf life of crops like potatoes and reduce food waste on Earth and beyond."
