Imagine stepping into your garden in the morning and seeing vibrant red flowers swaying in the breeze.
By midday, they’ve turned a soft lavender, and by evening, they’ve shifted to a deep, mesmerizing blue.
No, this isn’t a trick of the light or some exotic plant you’ve never heard of before—it’s the future of gardening, and it’s being developed in a lab right now.
Scientists in the U.S. are engineering a new variety of petunia that naturally changes color throughout the day, reflecting the rhythm of the sun.
Dubbed the ‘Petunia Circadia,’ this remarkable plant harnesses its own circadian rhythm to adjust the expression of its pigment molecules, called anthocyanins, over a 12-hour period.
Unlike traditional flowers that maintain a single color throughout their bloom cycle, this petunia shifts hues seamlessly, requiring no chemicals, no special care—just sunlight and water.
“Plants have circadian rhythms just like we do,” explains Nikolai Braun, co-founder and chief scientific officer of Revolution Bioengineering, the biotech company behind this innovation.
“These rhythms allow them to start photosynthesis when the sun comes up, release fragrance in the evening when their pollinators are active, and now, with a little help from genetic engineering, change colors throughout the day.”
The Science Behind the Magic
Braun and his research partner, Keira Havens, have made significant strides in developing this technology.
Although the full red-to-blue color transition isn’t perfected yet, they have already engineered petunias that change from white to pink over a 24-hour period when exposed to an ethanol solution.
Here’s how it works: When a petunia bud is about to bloom, it lacks the pigment-containing anthocyanins necessary for color, causing the flower to appear white.
However, introducing ethanol repairs a broken enzymatic pathway within the plant, triggering pigment production and allowing the petals to shift to a rich pink or purplish-red hue.
Remarkably, washing the plant with fresh water resets it, restoring the original color.
“The petunia typically produces white blooms,” Braun explained in an interview with Smithsonian Magazine. “But if you water it with the ethanol solution, the flowers will turn red, and new blooms will emerge in a purplish shade.”
A Shift in How We See Genetic Engineering
For many people, the term “genetically modified organism” (GMO) carries a stigma. Whether due to concerns about food safety, environmental impact, or corporate control over agriculture, GMO technology has been widely debated.
However, Braun and Havens hope that their color-changing petunia will change public perception by demonstrating the beauty and harmlessness of genetic modification in a way that’s both interactive and fun.
“For most people outside the farming world, this will be their first experience with a genetically modified organism,” Braun told Smithsonian Magazine.
“By engineering plants with traits that consumers find exciting—like changing colors, new flower shapes, and unique fragrances—we hope to normalize the technology and help people appreciate the potential of plant biotech.”
This shift in perception could have far-reaching implications beyond just ornamental flowers.
Genetic modification is already playing a crucial role in global food security.
For instance, Pam Ronald, a plant geneticist at the University of California, Davis, has developed genetically engineered bananas resistant to Xanthomonas wilt disease, a devastating condition that has already destroyed millions of acres of banana crops in East Africa.
“It can be hard for people to connect with the reality of farmers struggling to feed their families thousands of miles away,” Ronald noted.
“But when you tell them that genetic engineering can fight hunger by reducing crop loss and increasing vitamin content, it starts to click. Seeing this technology in their own backyard—on a flower they can touch and admire—makes the science more accessible.”
The Future of Petunia Circadia and Beyond
Braun and Havens are already looking ahead.
Their ultimate goal is to create petunias that don’t require ethanol treatments to change color, but instead shift naturally throughout the day based on their internal genetic clock.
They’re also exploring the possibility of single plants that bloom in multiple colors simultaneously and petunias with entirely new fragrance profiles.
While these advances are still in development, they represent just the tip of the iceberg in consumer-friendly biotech innovations.
The same genetic tools that allow a petunia to change color could one day be used to grow houseplants that signal when they need water, crops that self-regulate their vitamin content, or even flowers that emit natural mosquito repellents.
For now, however, the Petunia Circadia remains a stunning proof-of-concept—a plant that not only delights gardeners but also challenges everything we thought we knew about what’s possible in nature.
And who knows?
The next time you step outside, you might just find your garden looking a little more magical than you remembered.
Sources: Smithsonian Magazine, UC Davis
