Trees that grow and glow may one day replace street lamps, cutting down on electricity use and CO2 emissions, according to a group of synthetic biologists. The biohackers at Singularity University in Moffett Field, Calif., plan to crossbreed a plant and bioluminescent bacteria. If successful, their result will be a fully viable herb that can emit light.
“We are going to insert five different genes from a bacterium into a plant,” says cell and molecular biologist Kyle Taylor, a member of the team trying to bring the hybrid to life. The group plans to import bioluminescent genes from the marine bacterium Vibrio fischeri into the plant Arabidopsis thaliana, a member of the family that also includes cabbage and mustard.
They put their proposed project up on crowdfunding site Kickstarter, offering stickers, T-shirts, seeds of their glowing floral creations or the grown plants themselves to potential backers. With more than a month remaining for contributors to give, their Glowing Plants: Natural Lighting with no Electricity project had already attracted more than 1,000 donors and had surpassed its funding goal.
Much work to do
While the genes responsible for bioluminescence have already been sequenced by other researchers, they require various modifications to function properly. “You can’t just take the DNA as is—as it sequences from the bacteria, Vibrio fischeri—and put it directly into the plant,” Taylor says. “The plant speaks a different dialect, a different language. We need to put them in a slightly different dialect so a plant can read it.”
To “translate” the genes, the biohackers will use Genome Compiler, an innovative freeware program designed by the team’s bioinformatics expert Omri Amirav-Drory. His software allows biologists to program DNA with the speed of a click instead of the traditional method of laying long strings representing the genetic code on paper sheets kept in three-hole binders. Once the DNA is programmed, they will send the specs to Cambrian Genomics, a bio-startup nearby, to synthesize the physical DNA.
But the real fun begins when the assembled DNA comes back. The scientists will attach the DNA to Agrobacterium tumefaciens, a microbial pathogen that infects plants and inserts its genes into their cells, normally causing tumor-like structures to form.
Taylor will dip Arabidopsis into a solution containing a “disarmed” version of the pest. Instead of the bacteria’s genes that cause tumorous growth, the germ will deliver a payload of bioluminescent genes into the plant. That first generation Arabidopsis won’t glow in the dark, but its offspring will.
There may be some bumps along the way while the team perfects the process. Ideally, the bacteria will add the glowing genes to Arabidopsis’s genome, but should they accidently replace any of the plant’s existing genes, the new creation may perform poorly. “These things sometimes have a mind of their own as to whether they are going to grow,” Taylor says.
The team also intends to print a number of different DNA sequences to identify the variations that perform best. This process is expensive – DNA printing costs a minimum of 25 cents per base pair and these sequences are about 10,000 base pairs long.
Because the US Department of Agriculture doesn’t allow the use of Agrobacteria outside of controlled conditions, the group intends to use a gene gun to insert their engineered DNA into plant cells. It’s a standard tool that bombards the plant with tiny gold nanoparticles to “throw” the genes inside, Taylor explains. “Gold is inert, so it won’t have a reaction with a plant,” he says.
Keeping it safe
Taylor doesn’t expect the light-emitting capabilities to affect the little herb’s general well-being. But can their experiments produce a new invasive species? “It’s a good question and an incredibly complicated question, that’s why we have to go through the proper regulations,” Taylor says. He explains that their creation would hardly make an aggressive weed because in order to emit light it would require more energy and resources than the regular Arabidopsis.
Anthony Evans, the campaign’s manager, says that the plant is naturally adapted for the Scandinavian region and lower temperature, so it wouldn’t outcompete native flora and may even face extra challenges. “At night, it’s probably going to be a target for bugs,” he says.
The team chose Arabidopsis as a model organism because it has a very short genome and produces seeds in six weeks, but the exact scope of the project depends on the campaign’s outcome. “If we get more money, we can try to create a plant that will only glow at night, but not during the day,” says bioinformatics specialist Amirav-Drory.
They may also experiment with flowers. “Almost everyone asked if we can have a glowing rose,” Evans says.
Trees, however, will take a while – in part because they take much longer to grow. Evans hopes that the Glowing Plants project will serve as an inspiration for other bio-curious minds and spawn more ideas. “For an oak tree to produce the same amount of light as an incandescent street lamp, it would need to convert into light 0.02 percent of the energy that it absorbs from the sun during a typical day in May,” he says. “We think this should be achievable one day.”
Top Image: Courtesy Antony Evans.