Most common fruit and vegetables are not exactly natural in the truest sense of the word. Centuries of selective breeding led farmers to develop produce that is efficient to grow, containing the desirable traits we tend to prefer. Along the way many crops fell by the wayside, unsuitable for large-scale agriculture either due to undesirable fruit characteristics or difficulties in producing big yields. These plant species are often referred to as orphan crops, occasionally found in local native regions but rarely hitting big supermarkets.
A team of researchers has been investigating ways to speed up this often long-winded domestication process using the latest CRISPR gene-editing technology. A new study recently published has outlined how an orphan crop, known as a groundcherry – or Physalis pruinosa – could be effectively modified to be better suited to large-scale farming.
"I firmly believe that with the right approach, the groundcherry could become a major berry crop," explains Zachary Lippman, one of the scientists working on the project.
Groundcherries are indigenous to Central and South America, and part of the same family as tomatoes. The research is specifically focusing on Physalis pruinosa, occasionally referred to as a strawberry groundcherry due to its small fruit tasting like a sweet berry but with a shape and texture closer to that of a cherry tomato.
Three major productivity traits were targeted by the CRISPR research: plant architecture, flower production and fruit size. Due to the genetic relationship between the groundcherry and the tomato the researchers could leverage what we already know about the tomato genome to see if similar traits and characteristics could be targeted. The work enabled the researchers to modify the plant to help create more clustered flowering, increasing fruit yields, and larger fruit size.
"It's exciting that we can take what we have learned in tomato and apply it to distantly related species," says Joyce Van Eck, another researcher working on the project.
One particular challenge in modifying the groundcherry for more efficient production was dealing with the plant's tendency to drop its fruit before fully ripening. This not only lowers the ultimate yield of the crop, but also increases the difficulty of the harvesting process. The trick to managing this was found in a joint mutation seen in tomatoes that has been found to alter its branch architecture.
"Physalis is the perfect candidate for looking at getting the fruit to not drop," said Van Eck. "Gene editing might be the only way to fix this in the groundcherry."
Looking forward the team suggests characteristics such as fruit color and flavor can also be manipulated to create an optimal fruit for mass production, but much of the work at this stage does feel like a proof-of-concept. Lippman does indeed point out: "This is about demonstrating what's now possible."
Realistically the hurdles to getting this kind of product onto supermarket shelves are significant. Debate is currently raging over what kind of regulation CRISPR gene-edited plants should be subjected to. While the USDA confirmed it will not, at this stage, treat gene-edited plants with the same regulation as GMOs, an EU court recently came to the exact opposite conclusion, leaving biotech companies around the world in a state of confusion.
Another complicated barrier to commercializing CRISPR gene-edited plants is dealing with the intellectual property rights of the technology itself. Since the CRISPR process has now been effectively patented, any company using the technology to create a commercial outcome will now have to pay for the privilege. It's unclear what dollar amount would be put on gaining the right to produce a CRISPR product, but in an interview with Inverse Van Eck did admit when she saw the number it, "just about knocked me off my chair."
The new research was published in the journal Nature Plants.
Source: Boyce Thompson Institute / Howard Hughes Medical Institute
