Gene-edited lettuce: Scientists unlock CRISPR techniques to enhance nutrition and tackle deficiencies

Scientists in Israel are addressing “hidden hunger” or micronutrient deficiency concerns by tapping CRISPR gene-editing techniques to enhance the nutritional value of lettuce. They have boosted β-carotene (provitamin A) and ascorbic acid (vitamin C) content in the crop by 2.7 times and 6.9 times, respectively, besides raising zeaxanthin to “levels not typically found in lettuce.”

The Hebrew University of Jerusalem team modified key genes that regulate vitamin and antioxidant production to make lettuce a more nutrient-rich food option.

“Lettuce is a widely consumed vegetable but not very nutritious. This made it an ideal candidate for improvement,” author Alexander Vainstein, professor Robert H. Smith Faculty of Agriculture, Food, and Environment at The Hebrew University of Jerusalem, tells Food Ingredients First.

Gene editing gives researchers an “unprecedented ability to improve the nutritional quality of crops without altering their growth or yield,” he adds. The lettuce also retained its normal appearance despite undergoing genetic modifications.

“This study is an important step toward developing healthier food options that can help address widespread nutrient deficiencies in modern diets.”

The findings are published in Plant Biotechnology Journal.

Modifying DNA for crop benefits

According to the researchers, CRISPR, or Clustered Regularly Interspaced Short Palindromic Repeats, is a “powerful and precise” tool for editing DNA. 

The technique is different from traditional genetic modification (GMO) methods. It does not introduce foreign DNA, allowing scientists to make targeted changes within a plant’s genetic code. 

CRISPR can modify or deactivate genes without introducing foreign DNA, says Prof. Vainstein (Image credit: Greg Solomon).“CRISPR involves modifying or deactivating genes without introducing foreign DNA, making the process more precise and subject to simpler regulatory approval compared to traditional GMOs,’ explains Prof. Vainstein.

“The genes targeted in this study using CRISPR included LCY, GGP1, GGP2, and others.”

During the study, the team faced challenges involving the development of new procedures, identifying the right target genes, and designing an approach that “integrates multiple biochemical pathways to enhance several traits simultaneously,” he tells us.

Gene editing also allows researchers to enhance crop traits such as nutritional content, disease resistance, and environmental adaptability more efficiently than ever before, note the scientists.

Addressing micronutrient deficiencies

According to experts, hidden hunger impacts nearly one to two billion people through deficiencies of essential nutrients such as vitamin A, iron, and zinc. This affects the immune system and restricts growth and cognitive development.

The increased β-carotene levels in the lettuce achieved during the study improve its role as a precursor to vitamin A, which is essential for vision, immune function, and skin health, notes the study.

Higher levels of antioxidant zeaxanthin help protect the eyes from blue light damage and age-related macular degeneration. Additionally, increased Vitamin C levels help strengthen the immune system and enhance iron absorption.

The team used CRISPR/Cas9 to enhance carotenoid and vitamin C production in ‘Noga’ lettuce (Image credit: Yarin Livneh).However, Prof. Vainstein says these levels are not a direct comparison with other naturally nutrient-rich vegetables since “each fruit and vegetable has its own unique nutritional profile.” 

“The best comparison is with other varieties of lettuce.”

Commercializing gene-edited foods

While regulations vary by country, each presenting its own challenges, several gene-edited products have already started entering the market,” Prof. Vainstein notes.

For instance, US-based Pairwise introduced its CRISPR-altered mixed leafy greens in the US in 2023. They claim the product to have double the nutritional value of traditional romaine lettuce. The firm also collaborated with Bayer to develop gene-edited short-stature corn to increase wind resistance and reduce crop losses.

For now, the scientists’ focus remains on improving lettuce’s nutritional value, shares Prof. Vainstein.

“Just a few days ago, one of our papers was accepted, demonstrating the enhancement of inulin fiber in lettuce. Our goal is to integrate this trait into the same improved lettuce variety,” he concludes.