Creating a New Kind of Night Light: Glow-in-the-Dark Trees
A group in California is starting to engineer plants that could one day replace streetlights
San Francisco-based entrepreneur Antony Evans has come up with a radical idea for curbing power usage: “What if we use trees to light our streets instead of electric street lamps?”
Evans and his colleagues, biologists Omri Amirav-Drory and Kyle Taylor, want to create plants that literally glow. Evans was inspired by transgenic organisms, plants or animals with genes of other species in their own DNA, which have been used to fill many human needs. A gene from the bacteria Bacillus thuringiensis is routinely introduced to corn and cotton, for instance, to make the crops insect-resistant. In one method called “pharming,” scientists have inserted human genes into plants and animals so that these hosts can produce proteins for pharmaceuticals. Others have added a gene from the crystal jelly responsible for creating green fluorescent protein to animals such as cats and pigs; this way, they can determine if a disease has been transmitted from one generation to another, just by seeing if the offspring glows in the dark.
This spring, Evans’ team posted a video to Kickstarter, explaining how they plan to insert genes from bioluminescent bacteria into a species of flora as a first step to creating glowing trees. To feed viewers’ imaginations, the video included an image of Pandora, the luminous, mid-22nd century setting from the movie Avatar. In a raucously successful 46-day campaign the group raised nearly $500,000 to fund the effort. I spoke with Evans about his project.
Scientists genetically engineered the very first glow-in-the-dark plant in the 1980s, a tobacco plant with a firefly gene inserted into it. Historically, what has been the purpose of doing this?
The first time, I think, was just a demonstration project. But scientists have used it since to study things like root growth. They really use it for basic research purposes.
Traditionally, what they’ve done is insert the gene for luciferase [an enzyme from a luminescent organism] along with a promoter [a region at the beginning of a gene that tells a cell to start transcription, the first step to producing a protein] and then add the luciferin [a chemical that produces light when oxidized] manually. They have even had these glowing plants up on the International Space Station, so it is a pretty well established technique.
For your glowing plant project, you have chosen to use a flowering species called Arabidopsis thaliana. Why this plant?
We chose this plant because it has been extremely well studied by the academic community. It is the fruit fly of plant biology. The reason it has been studied so much is because it has the shortest genome of any [flowering] plant.
What gene are you adding to create the glow?
We are using genes from Vibrio fischeri. It is marine bacteria.
How is this done? Can you take me through the process of creating a glowing plant?
We start with software called Genome Compiler. Genome Compiler allows us to search for gene sequences and then modify those gene sequences in a nice graphical user interface. We use that software to look up the Vibrio fischeri genes, and then we do something called code and optimization, which basically adjusts the sequences so that they [work] in plants instead of in bacteria. We then synthesize the DNA. There is a “print” button, and we “print” that DNA. That emails the file to a company, who makes the DNA for us. They FedEx that back to us, and then we do two things.
First, we insert the DNA into some bacteria called agrobacterium. That bacterium is very clever, it has figured out how to do genetic engineering on its own. [The bacterium] inserts the DNA into the female gametes of the plant. We can grow the seeds that come from those flowers, and we’ll have the DNA that we designed on the computer in the plant. The second thing we are doing is using a gene gun, which is a piece of equipment that fires the DNA at high velocity into the cells of the plant. Some of those cells will absorb the DNA and start to express it.
You are doing your end of the work at BioCurious, a community bio lab in Sunnyville, California, in Silicon Valley. But how DIY is this? Is this something that a garage tinkerer can manage?
As part of the Kickstarter campaign, we have a kit, which you can use to make one of these plants. The tough part is designing the sequences, but once someone has figured them out, you can follow the recipe.
All told, you had 8,433 Kickstarter backers pledge $484,013. Did this reaction surprise you?
We were targeting $65,000, so it is great that we got so much. With Kickstarter, you never know. We knew we had something interesting, because everyone wanted to talk about it. But, we didn’t know it would get this big.
How realistic is it to think that one day we could have glow-in-the-dark trees lining streets instead of streetlights?
We do think it should be viable, but it is definitely a long-term goal. The big challenge with the trees is that trees take a long time to grow. Doing experiments on trees and testing different promoters will take a long time. We really need one of a few different technologies to come out. One would be a better simulation technology, so that we could simulate the gene sequences on a computer. Two would be a bio printer or something similar, so that we could print a leaf and test realistically the sequences on the leaf [instead of having to wait for a whole tree to grow]. Or, third would be some way of doing gene therapy on trees and adjusting them in situ and using that to change their DNA. We do need some developments in one of those before we will be able to really take on big trees.
In preliminary calculations, you figure that a glowing tree that covers about 1,000 square feet would cast as much light as a streetlight.
It will be a very different type of lighting effect. If you think about the way that the day is lit, the light comes from the whole sky; it doesn’t just come from a point, whereas light bulbs come from a point. Our lighting will be much more diffused and we think much more beautiful.
What are your sights set on now?
We are focused on executing on the things that we promised our Kickstarter backers. So, we are doing the work, getting the lab set up, ordering the DNA and starting to transform the [Arabidopsis] plants.
You and your colleagues promised to send each supporter, of a certain donation level, a glowing plant. What can people expect? How strong will the light be and how long lasting?
The light will be on at night as long as the plant is alive, but it won’t be super bright. We are aiming for something like glow-in-the-dark paint. You need to be in a dark room, and then you can see it dimly glowing. From there, we will work on optimizing and boosting the light output.
In the campaign video, you say, “the glowing plant is a symbol of the future.” What does this future look like to you?
The future we are referring to there is a synthetic biology future. We think that this kind of technology is going to become democratized; it will be accessible to many people. I’d like to see a future where teenagers and amateurs are genetically engineering things at home or in DIY bio labs. We want to represent that future, to tell people that it’s coming and to start a discussion around this technology—what it means and what it means for us.
This technology is rapidly being adopted. It is going to be very transformational, and I think that it’s time that people sort of became aware of it and the potential of it, to take an interest in it. There are going to be some fantastic opportunities in it, so if people look at the project and think “I’d like to do that,” I think the answer is “You can.” Just go to your local DIY bio lab and start playing around, start learning.
Are there other transgenic organisms being created that you find promising?
There are tons of people working on stuff, tons and tons and tons. If you look at the iGEM [International Genetically Engineered Machine] Foundation projects, you can see some of the breadth and variety of things that are being done. The spider silk is cool. I think the guys working on new versions of meat are cool. There is some interesting stuff happening with algae in the bio lab down in South Bay [San Francisco], BioCurious. Engineering algae so that we can use it for energy production—I think there is a lot of work to be done on that, but it’s very promising.
Are there any projects that worry you?
Not for now. But, I think some scary stuff will happen eventually.
Some people have expressed concern with you distributing glowing plants and releasing synthetic plants into the wild. What do you have to say to those who fear this?
People have been genetically engineering plants for many decades now. We are just following in the footsteps of all of the other plants that have already been released in the last 20 years. We don’t think we are doing anything radically different. What is different about this project is how it’s been funded and that the work is taking place in a DIY bio lab rather than in a professional research institution.