The groundcherry (Physalis pruinosa), also called ‘husk cherry’ and ‘strawberry tomato,’ is native to Central and South America. This tropical-tasting fruit is approximately the same size as a cherry tomato, but with a much sweeter flavor. It contains vitamins B and C, beta-carotene, phytosterols and antioxidants, and has anti-inflammatory and medicinal properties. To prepare the fruit for mainstream farming, a team of researchers led by the Howard Hughes Medical Institute and the Boyce Thompson Institute combined genomics and gene editing to rapidly improve traits such as fruit size, plant shape, and flower production. Their work appears in the journal Nature Plants.
The groundcherry (Physalis pruinosa). Image credit: Steve Buissinne.
Groundcherries belong to a group of plants known as orphan crops. They’re grown as small-scale crops, regionally, or for subsistence.
Orphan crops rarely make it into mainstream agriculture because of limitations such as poor shelf life or low productivity.
Improving these plants for large-scale production through breeding is a huge investment of time and money. It can take anywhere from a decade to thousands of years to domesticate a crop from the wild.
“I firmly believe that with the right approach, the groundcherry could become a major berry crop. Some scientists might consider the idea a reach. But I think we’re now at a place where the technology allows us to reach,” said Howard Hughes Medical Institute researcher Dr. Zach Lippman, co-lead author of the study.
“We feel there is potential for these to become a specialty fruit crop and to be grown on a larger scale in the United States,” added Boyce Thompson Institute’s Dr. Joyce Van Eck, co-lead author of the study.
With the help of CRISPR genome editing, Lemmon et al have found a way to take the groundcherry (Physalis pruinosa) from almost wild to almost domesticated in a matter of years. Image credit: Howard Hughes Medical Institute.
The team’s work lays out how genome editing can give orphan crops like the groundcherry an agricultural advantage.
Scientists currently use genome editing to engineer desirable traits in mainstream crops like corn, soybeans, and many others. But until now, no one had used the technique to bolster desirable traits in orphan crops.
To ready the groundcherry for store shelves, the study authors needed to address some of the plant’s shortcomings. They wanted to make its weedy shape more compact, its fruits larger, and its flowers more prolific.
They used a three-pronged approach to tackle the problem: they sequenced a sampling of the groundcherry’s genome, figured out how to use the genome editing tool CRISPR in the plant, and identified the genes underlying the groundcherry’s undesirable traits.
“Physalis is the perfect candidate for looking at getting the fruit to not drop. Gene editing might be the only way to fix this in the groundcherry,” Dr. Van Eck said.
Next, the researchers want to fine-tune the groundcherry traits they have begun to improve and manipulate additional characteristics like fruit color and flavor.
“Some traditional plant breeding will still be necessary to perfect the groundcherry as a mainstream crop,” Dr. Lippman said.
“We can’t say exactly when the fruit might make it to market. Releasing a new variety will first require navigating CRISPR intellectual property rights.”
“This work will inspire researchers to examine other orphan crops with well-studied relatives and consider how those crops, too, have potential for rapid domestication. This is about demonstrating what’s now possible.”
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Zachary H. Lemmon et al. 2018. Rapid improvement of domestication traits in an orphan crop by genome editing. Nature Plants 4: 766-770; doi: 10.1038/s41477-018-0259-x
