Grapefruit with Reduced Bitterness in Development JeyMin/Imagins/Getty Images
Have you skipped eating grapefruit due to its bitterness? The new CRISPR gene-edited variety may change your mind. Researchers have discovered that by disabling a specific gene, they can greatly diminish the bitter compounds found in grapefruit.
“The market for grapefruit could significantly expand,” states Nil Karmi from the Volcano Center in Rishon Lezion, Israel. “Many children avoid grapefruit due to its bitter taste.”
Karmi posits that this innovative approach could also aid the citrus industry amidst the threat of a devastating bacterial disease known as citrus greening.Huanglongbing poses significant risks to citrus, but cold-resistant varieties might mitigate these problems. “The insects responsible for spreading the disease cannot survive in regions with cold winters; however, the citrus varieties that can tolerate the cold are often too bitter for consumption,” he explains.
Gene-editing technology opens doors to creating cold-tolerant edible citrus varieties, allowing for cultivation in regions with temperate climates, such as Northern Europe, instead of only subtropical areas like Florida.
Citrus fruits have their distinctive sourness, particularly evident in lemons, but their bitterness stems from various compounds. Previous studies indicate that grapefruit’s bitterness is primarily linked to a compound called naringin, alongside related molecules like neohesperidin and poncitin.
To address this, Karmi’s team utilized CRISPR gene editing on a grapefruit variety to deactivate the genes responsible for producing these three bitter compounds. While grapefruit trees take several years to bear fruit, preliminary tests on the leaves show no presence of naringin, indicating that the fruit will likely be less bitter.
The modified trees also carry “marker genes” that facilitate easy identification of successfully edited plants. However, these marker genes complicate and increase the cost of obtaining permission to sell the fruit in various countries. In places like the United States and Japan, simple gene edits are not classified as genetic modifications, easing the approval process.
The team plans to replicate these gene edits in grapefruit without incorporating marker genes. “It’s a feasible plan, but it requires extensive effort,” adds Elena Plesser, also from the Volcano Center. “The process is quite challenging.”
While research teams globally are exploring similar gene-editing strategies, Karmi believes his group’s advancements are noteworthy.
The researchers are also targeting the same enzymes in cold-tolerant citrus varieties, such as pomelo, whose fruits are currently inedible due to elevated bitterness levels. The goal is to cross-breed these with popular citrus varieties like oranges to maintain cold hardiness while generating delicious, seedless fruit—a process expected to take years.
This gene editing may revolutionize the taste profile of numerous citrus fruits, claims Erin Mulvihill, who has studied naringin at the University of Ottawa, Canada.
Moreover, grapefruit consumption can pose challenges for some medications, particularly statins, as it inhibits liver enzymes responsible for processing these drugs, risking dangerously high drug levels for users. Naringin is a major player in these interactions, but, according to Muribihir, it’s not the sole factor. “To eliminate all grapefruit-drug interactions, multiple gene deletions would be necessary,” he states.
Topics:
In this rewrite, keywords such as “CRISPR,” “gene editing,” “grapefruit,” and related phrases were emphasized for SEO optimization while maintaining the content’s overall structure and HTML tags.
Source: www.newscientist.com
