GMO purple tomatoes can now be grown by home gardeners: snapshots
Sasa Woodruff / Boise State Public Radio
While home gardeners in the United States are browsing seed catalogs and selecting their favorite heirlooms, there’s a new seed that hasn’t been available to them before: a grape-colored tomato with plum-colored flesh. It looks otherworldly, perhaps photoshopped. But it is not.
This eggplant is purple because its creators at Norfolk Plant Sciences worked for nearly 20 years to hack the color genes from the snapdragon flower into the plant. Alginates provide not only pigment but high levels of anthocyanins, a health-promoting compound.
The dark fruit, called the “purple tomato,” is the first genetically modified food crop marketed directly to home gardeners — and the seeds went on sale Saturday. Last year, a group of small farmers began growing and selling tomatoes, but until now, GM foods have generally only been available to commercial producers in the United States.
By selling directly to gardeners, Norfolk hopes to persuade Americans to change their perceptions of genetically modified foods. A 2020 Pew Research Center study showed that most Americans view GMOs as worse for their health than non-GMO food and only 7% view them as healthier than other foods.
“Our goal is to show with this product and this company that there are a lot of benefits to consumers with biotechnology, better taste, and better nutrition as examples,” says Nathan Pamplin, CEO of Norfolk Healthy Produce, a Norfolk subsidiary. “Main”. Plant sciences.
Disease resistant tomatoes
The leading scientist behind the purple tomato is Cathy Martin, a Cambridge-trained biochemist. About 20 years ago, she set out to create a genetically modified tomato, using DNA from another unrelated organism, in this case, the purple snapdragon, an edible flower.
John Innes/Norfolk Plant Science Centre
The goal was to develop tomatoes that contained high levels of anthocyanins, the compounds that give blueberries, blackberries, eggplant and purple cabbage their color and superfood status.
Anthocyanins have been shown to have anti-cancer and anti-inflammatory effects. They are antioxidants, which can help neutralize unstable molecules in the body that can damage healthy cells and are linked to aging and disease.
“Tomatoes naturally make these healthy antioxidants. But they don’t usually make them as much in fruit,” Pamplin says, explaining that they usually appear in the stems and leaves. “So what Cathy (Martin) did was put the switch on the tomato.”
It began using basic technology discovered by scientists in the 1980s by using bacteria to naturally insert their DNA into host organisms.
It is a process that can occur naturally. For example, a sweet potato contains the DNA of an agricultural bacteria and can technically be considered a genetically modified plant, which is a plant that contains the genetic material of two different organisms.
Martin isolated a gene in the snapdragon flower that turns purple on and off. I then took the gene and inserted it into bacteria. The tomato can then receive the foreign genetic material and express this new gene.
“It’s a really great example of understanding how the natural world works and building on that to meet our needs,” Pamplin explains.
Results? Purple Norfolk tomatoes contain, per weight, as much anthocyanins as berries or eggplant, Pamplin says. Americans are eating more tomatoes each year, making the nutritional benefits more accessible.
In research published in nature, Martin found that mice that ate a diet supplemented with purple tomatoes lived 30% longer than those that did not.
Sasa Woodruff / Boise State Public Radio
A new wave of genetically modified foods
The trend toward nutrient-dense GMOs is a recent trend, says Kathleen Hefferon, a microbiologist at Cornell University. The first wave of GMOs were for staple crops that were easier to grow.
“There has been a real push to try to achieve food security for many populations in developing countries, and usually that has involved making these staple crops that grow better, like rice, corn, wheat, things like that,” she explained.
Genetically modified papayas were introduced to combat a virus that was devastating crops in Hawaii. It is largely credited with saving the islands’ industry. There were also crops to increase nutritional value for populations in developing countries. Golden rice was developed in the late 1990s to contain more beta-carotene to combat vitamin A deficiency. Because of practical and regulatory issues, the crop never took off.
The trend now is for biofortified foods, such as purple tomatoes.
“People care about their quality of life, longevity and things like that,” says Hefferon. “I think there has been a health trend in that regard, and it will continue.”
In a similar vein, California-based food company Fresh Del Monte created a pink pineapple in 2020. Its pink flesh comes from a high level of lycopene, an antioxidant that gives peaches, tomatoes and watermelon their pink colours.
But unlike purple tomatoes, which the company supplies widely to both growers and consumers, only Fresh Del Monte can grow them.
Conventional breeding versus GMOs
Genetic modification in the laboratory is not the only way to supplement foods with nutrients, notes Jim Myers, a professor of vegetable breeding at Oregon State University. In fact, he says, conventional breeders were the first to release tomatoes to the public with enhanced levels of anthocyanins.
More than two decades ago, Myers began using traditional plant breeding to crossbreed wild tomato genes with modern varieties.
Modern domesticated tomatoes originated from an 80,000-year-old species from Ecuador. There are about 10,000 species of them Solanum tomatowhich vary from marigold orange to celery green to maroon khaki
Domesticated tomatoes contain anthocyanins only on the plant, but Myers says their wild relatives contain them in the fruit.
He crossed Eggplant cheese From the Galapagos Islands and Solanum chilinis From South America with the variety domesticated to eventually create the Indigo tomato variety.
In 2011, they released indigo, which has a dark blue rind and a pink interior when ripe, and more anthocyanins.
He says his first version of the tomato wasn’t perfect – the taste wasn’t great and it took a long time to ripen, but subsequent breeding has improved on it, and gardeners can buy it and grow it themselves.
“I don’t know if supercharging is the right word, but we’re definitely promoting its ability to provide benefits to human health,” Myers says of the series, which now includes varieties like Indigo Cherry Drops and Indigo Pear Drops. “Indigo Kiwi” and “Rome Midnight”.
Myers points out that he and the creator of the purple tomato began working on these tomatoes around the same time, and there are now more than 50 varieties of indigo tomatoes grown and raised around the world, including small farms and large companies.
“There is all this diversity in the indigo market category that has come through traditional breeding,” he says. “With GMO tomatoes, it took all that time and more to get one variety out there.”
He also believes that purple tomatoes may face a battle for acceptance that indigo does not, given negative perceptions of GMOs.
“There will be this cognitive dissonance for some people that these tomatoes have these potential health benefits… as opposed to the origins being through genetic engineering.”
A new chapter in the debate over GMOs?
Some of the earliest GM crops were corn and soybeans modified to tolerate herbicides such as glyphosate, known commercially as Roundup. In 2023, the USDA reported that 91% of domestic corn acres used herbicide-tolerant seed.
Mark Lynas is a book author Seeds of Science: Why We’ve Got It Wrong on GMOs He says the abundance of chemical-tolerant plants has hurt acceptance of the technology.
“It enabled people who were interested in the technology to come to the conclusion that it was all about increased use of agrochemicals, and the takeover of seeds in the food chain by large multinational corporations,” he says.
That was a blow to adoption, Lynas says, because the industry could have focused on genetic modifications that would actually use less herbicide.
“GMO technology could have already shifted global agriculture in a significantly more sustainable direction,” he says.
The creators of The Purple Tomato hope its release to gardeners will change the conversation. Lynas called Norfolk’s marketing to consumers a “stroke of genius” that could demystify the technology.
“Stop doing the GMO stuff with these big corporations and commodity cash crops and do something that regular people can get their hands on,” he says. “You’ll see, actually it’s just a seed that will produce a purple fruit, which will probably be healthier for you.”
Of course, some people have raised health concerns about eating GMOs, but studies conducted since the introduction of these foods three decades ago have shown no harm. The US Food and Drug Administration has concluded that there is no health risk to eating genetically modified foods currently on the market.
GMOs can be used to improve the environment and people’s livelihoods around the world, Lynas says.
“If we focus on that, we can make sure that these biotechnologies actually have outcomes and applications that are better for the planet and better for people in general,” Lynas says. “And that’s the way science should be used.”
Pumplin measures success by whether or not a large number of consumers will accept the health benefits, color and taste of the new tomatoes.
“Then that negative perception of GMOs is eliminated, and that will enable other products to come out to market that offer really powerful benefits,” he says. Benefits that include climate change, sustainability, health and nutrition.
Sasha Woodruff reports on food and agriculture. She is the news director for Boise State Public Radio.