Genetically edited tomatoes may provide a new source of vitamin D

Gene-edited tomato plants that produce precursors of vitamin D may one day provide an animal-free source of important nutrients.

An estimated 1 billion people do not have enough vitamin D. This is a condition that can cause a variety of health problems, including immune and neuropathy. Plants are generally poor in nutrients, and most people get vitamin D from animal foods such as eggs, meat, and dairy products.

For genetically edited tomatoes Natural plants May 23¹Is exposed to UV light in the laboratory and some of the precursors called provitamin D3 are converted to vitamin D3. However, the plant has not yet been developed for commercial use and it is unclear how it will be transported when grown outdoors.

However, this is a promising and rare example of using genetic editing to increase the nutritional value of crops, says Jonathan Napier, a plant biologist at Rosamsted Research in Harpenden, England. I needed a deep knowledge of tomato biochemistry. “You can only edit what you understand,” he says. “And we can do that kind of intervention because we understand biochemistry.”

Target changes

Gene editing is a technique that allows researchers to make targeted changes to the genome of an organism and is welcomed as a potential way to develop better crops.Genetically modified crops made by inserting genes into the plant genome often have to undergo extensive review by government regulators, but in many countries Made that process easier For crops with an edited genome — relatively easy to edit and create mutations that may occur naturally.

However, Napier says there are relatively few ways to use that kind of genetic editing to increase the nutrient content of a crop. Gene editing can be used to turn off genes in a way that is beneficial to consumers (for example, by removing plant compounds that can cause allergies), but mutations in the gene lead to the production of the gene. Finding the situation is much more difficult. New nutrients. “For actual fortification, we need to go back a bit and think about how useful this tool can be,” says Napier.

Some plants naturally produce the form of vitamin D, which is often later converted to chemicals that regulate plant growth. Blocking the conversion pathway can cause the accumulation of vitamin D precursors, but it also leads to plant dysgenesis. “If you want to produce high-yielding plants, this is a very important consideration,” says Kathy Martin, a plant biologist at the John Innes Institute in Norwich, England.

However, lonely plants also have parallel biochemical pathways that convert provitamin D3 into protective compounds. Martin and her colleagues used it to design plants that produce provitamin D3. It was found that blocking that pathway leads to the accumulation of vitamin D precursors without impeding plant growth in the laboratory.

Dominique VanDer Straeten, a plant biologist at Ghent University in Belgium, said researchers whether blocking the production of protective compounds affects the ability of tomatoes grown outside the laboratory to handle environmental stress. You need to judge.

Depends on the weather

Martin and her colleagues plan to study this, Grow genetically edited tomatoes in the field.. The team also wants to measure the effect of outdoor UV exposure on the conversion of provitamin D.₃ To vitamin D₃ For leaves and fruits of plants. “In Britain, we are destined to fail,” Martin jokes, referring to the country’s infamous rainy weather. When she asked an Italian collaborator if she could run the experiment under more sunny conditions, she said she replied that it would take about two years to get regulatory approval. increase.

If tomatoes work well in field research, they may eventually join the limited list of fortified crops available to consumers. However, Napier warns that the road to the market is long and complicated with intellectual property, regulatory requirements, and logistical challenges. Golden rice, an artificial version of a crop that produces a precursor to vitamin A, took decades to move from the bench to the farm and was approved for commercial cultivation only in the Philippines last year.

Van Der Straeten’s lab creates genetically modified plants that increase levels of multiple nutrients such as folic acid, provitamin A, and B vitamins.₂.. But she quickly points out that such fortified crops will only take a tiny path to deal with malnutrition. “It’s just one of the approaches we can help people with,” she says. “Obviously, it will take a combination of measures.”