The sci-fi dream that gardens and parks would one day glow like Pandora, the alien moon in Avatar, is decades old. Early attempts to splice genes into plants to make them glow date back to the 1980s, but experiments emitted little light and required special food.
Then in 2020, scientists made a breakthrough. Adding genes from luminous mushrooms yielded brightly glowing specimens that needed no special care. The team has refined the approach—writing last month they’ve increased their plants’ luminescence as much as 100-fold—and spun out a startup called Light Bio to sell them.
Light Bio received USDA approval in September and this month announced the first continuously glowing plant, named the firefly petunia, is officially available for purchase in the US. The petunias look and grow like their ordinary cousins—green leaves, white flowers—but after sunset, they glow a gentle green. The company is selling the plants for $29 on its website and says a crop of 50,000 will ship in April.
“This is an incredible achievement for synthetic biology. Light Bio is bringing us leaps and bounds closer to our solarpunk dream of living in Avatar’s Pandora,” Jason Kelly, CEO and co-founder of Ginkgo Bioworks, a Light Bio partner, said in a statement.
Glow Up
In synthetic biology, glowing plants and animals have been a staple for years. Scientists will often insert a gene to make an organism glow as visual proof that some intended biological process has taken effect. Keith Wood, Light Bio cofounder and CEO, was a pioneer of the approach in plants. In 1986, he gave tobacco plants a firefly gene that produces luciferin, the molecule behind the bugs’ signature glow. Those plants glowed weakly, but needed special plant food to provide fuel for the chemical reaction. Later work tried genes from bioluminescent bacteria instead, but the plants were similarly dim.
Then in 2020, a team including Light Bio cofounders Karen Sarkisyan and Ilia Yampolsky turned to the luminous mushroom, Neonothopanus nambi. The mushroom runs a chemical reaction involving caffeic acid—a molecule also commonly found in plants—to produce luciferin and light. The scientists spliced the associated genes into tobacco plants and found the plants glowed too, no extra ingredients needed.
They later tried the genes in petunias, found the effect was even more pronounced, and began refining their work. In a paper published in Nature Methods in January, the team added genes from other mushrooms and employed directed evolution to further enhance the luminescence. After experimentation with a few collections of genes, they landed on a combination that worked in multiple species and significantly upped the brightness.
From here, they hope to further increase the luminescence by as much as 10-fold, add different colors to the lineup, and expand their work into different plant varieties.
Lab to Living Room
The plants are a scientific achievement, but the creation and approval of a commercial product is also noteworthy. Prior attempts to offer people glowing plants, including a popular 2013 Kickstarter, failed to materialize.
Last fall, the USDA gave Light Bio the go-ahead to sell their firefly petunias to the general public. The approval concluded the plants as described didn’t pose new risks to agriculture compared to naturally occurring petunias.
Jennifer Kuzma, codirector of the Genetic Engineering and Society Center at North Carolina State University, told Wired last year she would have liked the USDA to do a more thorough review. But scientists recently contacted by Nature did not voice major concerns. The plants are largely grown indoors or in gardens and aren’t considered invasive, lowering the risk the new genes would make their way into other species. Though, as Kuzma noted, that risk may depend on how many are grown and where they take root.
Beyond household appeal, the system at work here could also find its way into agricultural applications. Diego Orzáez, a plant biologist in Spain, is extending the luciferase system to other plants. He envisions such plants beginning to glow only when they’re in trouble, allowing farmers to take quick visual stock of crop health with drones or satellites.
Other new genetically modified plants are headed our way soon too. As of this month, gardeners can buy seeds for bioengineered purple tomatoes high in antioxidants. Another startup is developing a genetically engineered houseplant to filter harmful chemicals from the air. And Pairwise is using CRISPR to make softer kale, seedless berries, and pitless cherries.
“People’s reactions to genetically modified plants are complicated,” Steven Burgess, a plant biologist at the University of Illinois Urbana–Champaign, told Nature. That’s due, in part, to the association with controversial corporations and worry about what we put in our bodies. The new glow-in-the-dark petunias are neither the product of a big company—indeed, Sarkisyan said Light Bio doesn’t plan to be overly combative when it comes to people sharing plant cuttings—nor are they food. But they are compelling.
“They invite people to experience biotechnology from a position of wonder,” Drew Endy told Wired. Apart from conjuring popular sci-fi, perhaps such examples can introduce a wider audience to the possibilities and risks of synthetic biology, kickstart thoughtful conversations, and help people decide for themselves where to draw lines.
Image Credit: Light Bio
