The seeds of truly green technologies are being planted now.
By Linda Rodriguez McRobbie – November 29, 2020
Karen Sarkisyan’s tobacco plants glow. Not quite enough to read by, and less than, say, a freshly cracked glow stick, but much more than your average tobacco plant glows, because your average tobacco plant doesn’t glow at all. In fact, although many species of marine creatures, insects, fungi, and bacteria naturally emit light, no plants do.
“I personally am amazed every time when I look at them in the dark room,” says Sarkisyan, a synthetic biologist at the London Institute of Medical Sciences at Imperial College London and the CEO of the biotech startup Planta, based in Russia, where Sarkisyan got his degree. A time-lapse video of the plants growing over several weeks shows their
glowing leaves and trumpet-shaped flowers, green as an alien invasion, flaring bright as they curl upwards. Sarkisyan acknowledges that the video makes the genetically modified plants look a bit brighter than they are to the naked eye, but in any case, the sight is captivating.
Sarkiysan’s company is one of a handful of research labs, startups, and design studios that are trying to augment what plants do. Over the past decade, radical botany and synthetic biology, propelled by leaps in genetic modification, nanotechnology, and bioelectrical engineering, have emerged as areas of research whose possibilities are limited only by imagination (and funds). Researchers have prototyped self-repairing walls built from climbing runner beans, houseplants that act as motion sensors, spinach plants that can sense the presence of explosives, and hybrid trees — made of natural and artificial leaves — that generate electricity. One startup even genetically engineered petunias that could change color when watered with diluted beer. Meanwhile, a fern named Pete at the London Zoo takes selfies on a camera powered by bacteria and Pete’s own biomatter.
It’s difficult to overstate the importance of plants in every aspect of life on our planet. Which means that tinkering with how they work could be vital for their and our survival.
Between climate change, pollution, and diminished biodiversity, humans have put extraordinary stress on natural and agricultural environments. But extraordinary science, tempered by caution, could get us out of trouble. It’s possible to help plants better withstand climate change. At a time when global food security is by no means assured, crops more resistant to blight and disease can balance sustainable agriculture with human need. Meanwhile, creatively harnessing plants for use in applications as wide-ranging as architecture and electronics can produce a far greener future, deepening humans’ appreciation of flora in the process. AsSarkisyan says, “There is an enormous potential in engineering plants for something useful and interesting.”
Some of the most compelling plant research involves learning from the ways plants adapt and solve complex problems using the simplest of tools — water, sunlight, and cellulose. “Speaking as an engineer, plants can do things that we still can’t,” says Heiko Hamann, robotics professor at the University of Lübeck and researcher with Flora Robotica, a project of the EU’s Future and Emerging Technologies program, which has demonstrated that it’s possible to construct strong, self-repairing, living architecture by combining robots and plants.
The project took its inspiration, Hamann says, from living root bridges, which people form by guiding the roots of a pliable tree across a stream or river. These are common in parts of India. “From an engineering point of view, it grows stronger over time, and it also self-repairs,” Hamann says. “Compare that to a steel suspension bridge that’s sitting there and degrading over time.”
The project, which concluded in 2019, used robotic assemblies, which the group called “artificial plants,” as a scaffold for real plants — in this experiment, fast-growing climbing runner beans — to cling to. The assembly also automatically controlled the plants’ exposure to water and light to exploit their natural growth tendencies. The project showed that the wall could repair itself when it was damaged and also that it didn’t grow indiscriminately. With the help of the robotic gardeners, the four-meter long wall could be “programmed” to have windows: spaces where the beans were discouraged from growing. The plants were so robust that Hamann’s students were able to harvest beans from the wall. By the end of the experiment, the plants were clinging to the pipes in the ceiling and had to be pried off. It’s a step toward incorporating plants into buildings not as mere ornaments but as sturdy and regenerating parts of the structures themselves.
Plants’ natural tendencies can be harnessed for myriad uses. Harpreet Sareen, who led a project called Cyborg Botany at the MIT Media Lab and is now an assistant professor of media design at Parsons School of Design, says that although their lack of perceptible motion tends to make us regard plants as static, they are constantly sensing and adapting to their environment. Reaching — very slowly — for water or sunlight, for example, is a simple behavior that plants regulate with internal electrochemical signaling. Cyborg Botany tapped that process, growing plants with conductive wires in their intercellular spaces. That allowed the plants to become inconspicuous motion sensors, sending a signal via microelectrodes to a laptop every time someone walked by. A video made for Cyborg Botany depicted another use case: A plant positioned by the door let a cat owner know that her pet had escaped.
Asked whether a motion-detecting plant is a little creepy, Sareen laughs, acknowledging that he wouldn’t want to create a situation “where we are scared of nature instead of loving it.” Figuring out how to safely and ethically develop the tech is part of the field’s future. He envisions a wide range of applications that need very small amounts of computational power and could be implemented with plants rather than conventional electronics, “so that our environment looks a little bit greener.” For example, cyborg plants could monitor and report on the quality of the water in their environments.
“Plants are self-powered, self-regenerating, self-fabricating organisms — plants are the best ‘electronics’ that we have,” says Sareen. “If nature already has those capabilities of sensing . . . why not tap into those capabilities?”
Radical botanical research is still emerging. It’s still limited in functionality and funding. And tinkering with how plants work can cause discomfort; the phrase “genetically modified organisms” raise a lot of hackles, especially as international regulations vary on how GMOs are defined. But many of the most consequential past changes to plants have come as a result of human intervention. We humans have been shaping the plants on this planet for our needs for millennia, primarily through selective breeding: Carrots weren’t originally orange, corn’s ancestor was tiny and tasted like raw potatoes, and watermelons had to be opened with a hammer and were horribly bitter. Our impulse to manipulate nature is deep-seated. It hasn’t always been positive, though, and historically it was pursued without regard to environmental impact. It is welcome, then, that the fundamental impulse behind much of this new research is to work with nature in the pursuit of sustainability — and changing our relationship with plants.
That theme runs through Sarkisyan’s glowing-plant research. His lab isn’t the first to make a plant glow, and his startup is not the first to promise glowing houseplants. But it’s the first that might actually succeed in producing a consumer product.
Fungi, bacteria, insects, and marine animals use upwards of 30 different systems of bioluminescence. Previous efforts to make plants glow relied on transplanting the genes of bacterial systems into multicelled organisms. These tended to produce chemical byproducts within the plant that were toxic to it, and its glow was weak and short-lived. The big breakthrough in Sarkisyan’s research — which was done in concert with an American company, Light Bio, and the Yampolsky lab at the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry in Russia, and was published in April in Nature Biotechnology — was to figure out how mechanisms of bioluminescence in some multicelled organisms could be transplanted into other ones in a lasting way. The scientists were able to insert genes from bioluminescent mushrooms into tobacco plants, with the only side effect being that the glowing plants grew a little taller.
The applications go beyond home decor. Because the parts of the plants that glow brightest are the ones where biochemical changes are taking place, researchers can more easily monitor the plants’ metabolic hot spots, which could lead to a better understanding of how plants grow. That knowledge could be useful for, say, making them hardier or less thirsty for water.
Right now, Planta and Light Bio are working on optimizing the system — trying to make the glow brighter, essentially — and are also trying to navigate inconsistent international regulations on genetically modified plants before bringing glowing plants to market. The lab’s next goal is to engineer plants that interact with humans — that, for example, glow when touched. A glowing, interactive plant isn’t going to replace a reading lamp, Sarkisyan said, but it is very cool. “My main motivation was . . . to make something that is beautiful, something that never existed on Earth, to make the plants be perceived as more alive than they would normally be perceived,” Sarkisyan says.
“In general,” says Sarkisyan, echoing the comments of every other person interviewed for this article, “people tend to ignore plants as something as complex and as alive as animals.”
The implications of this “plant blindness,” a phrase coined in 1999 by botanists Elisabeth Schussler and James Wandersee, are profound. In general, humans don’t investigate, save, or try to improve on what we’re not interested in. In recent years, although plants made up 57 percent of the species the US government recognized as endangered, less than 4 percent of the spending on threatened species went to protecting plants. Plant research doesn’t often win prizes, and grant-awarding institutions, researchers say, frequently pass on plant science. Even basic research is suffering: Between 1988 and 2015, the number of research universities offering degrees in botany and plant biology declined by half. In 2017, only 442 degrees in plant biology and botany were awarded in the United States. Even as universities continue to churn out PhDs in health and biomedical fields in ever-increasing numbers, the number of PhDs in agricultural fields has remained roughly the same, about 1,000 a year since 1982. Plant researchers warn that we are producing too few plant scientists to help solve the next generation of food crises, or to save the plants threatened by extinction — right now, an estimated 40 percent of all plants on the planet.
Cyborg shrubs and glowing plants won’t save the world themselves, but they do demonstrate that there’s a lot we can do to partner with plants to make life better.
Linda Rodriguez McRobbie is a freelance writer in London.