Researchers at MIT recently unveiled a project where they inserted the enzyme that makes fireflies glow into a watercress plant. The result is a plant whose leaves glow for about four hours. At present, the glow produced is quite dim, but the engineers hope that via this technique they can convert the watercress into a functional reading lamp. Indeed, they imagine using nanoengineered plants as a way to illuminate entire interiors.
And why not?
“The light is ultimately powered by the energy metabolism of the plant itself,” says Michael Strano, one of the leaders of the project. “Plants can self-repair, they have their own energy, and they are already adapted to the outdoor environment.”
Because they produce their own energy, plants-as-lights would presumably be more energy efficient than even LED lights. The plants would serve a variety of functions: in addition to proving energy-efficient illumination, they would improve the aesthetics and air quality of an interior.
The engineers hope to develop techniques that would allow one to spray the enzymes directly onto the plants. If they can increase the luminosity and duration of the light, the goal then would be to use this method on outdoor plants, even trees. A tree-lined street could be converted into a row of light-emitting structures that would replace street lamps. Think of how an urban streetscape such as the Short North would be aesthetically altered were electric streetlights replaced by glowing trees.
The group at MIT have named their work “plant nanobionics.” Their goals are to change the properties of plants in order to make them useful for humans, and they are especially keen to replace electrical devices with living plants.
Other experiments include engineering plants in order to detect explosives. Combining spinach plants with carbon nanotubes, the researchers have created a living device that communicates information about the presence of explosives wirelessly to a smartphone. The engineered spinach plants sniff out nitroaromatics, which are found in explosives like land mines. If one of these nitroaromatics seeps into groundwater, the carbon nanotubes in the plant give off a light that can be picked up by an infrared camera like one on a smartphone.
“Plants are very good analytical chemists,” says Strano. “They have an extensive root network in the soil, are constantly sampling groundwater, and have a way to self-power the transport of that water up into the leaves.”
The MIT researchers have also developed a sensor on plants that would give early-indications if it were under water stress. Small openings in plants called stomata open and close in response to, among other things, lack of water. By using carbon nanotubes again, the engineers have created an electric circuit. When the stomata open, they break the circuit and thereby alert the farmer of a water problem. The vision here would be to give farmers a way to detect whether crops were in distress.
About 20 years ago, the physicist Freeman Dyson imagined a future where trees would be re-engineered to serve as energy producers. As we sequence the genomes of trees, we will eventually be able to, in his words, “breed trees that will turn sunlight into fuel and still preserve the diversity that makes natural forests beautiful.”
Designing trees in this fashion would use the plant’s natural processes and functions to serve human ends, all the while maintaining the natural environment. There would no longer be an economic logic that says we need to cut down trees in order to have economic growth: indeed, the new economic logic would be that we need to plant more trees in order to produce more energy which might fuel economic growth.
Dyson did not mean simply engineering plants to become living solar panels. These altered plants would produce liquid fuel.
“An energy crop,” as he termed them, “could be a permanent forest of trees that convert sunlight to liquid fuel and deliver the fuel directly through their roots to a network of underground pipelines…[in effect], we would have a supply of solar energy that was cheap, abundant, and environmentally benign.”
And, it would have the potential to spearhead the repopulation of rural areas, or at least make rural areas as important as urban. “Economic forces will then move industries from cities to the country,” predicted Dyson. As rural and small town America searches for ways regain economic vitality, these areas might start to look to plant nanobionics as an economic driver.
But, at the same time, cities might be incentivized to plant more energy-producing trees. “Urban forests” might become a regular feature of large cities. Columbus’ Metro Parks might serve not only as natural settings for recreation but as liquid solar energy refineries.
The idea of redesigning and engineering plants might strike us as distasteful and unnatural. But, in reality, humans have been re-engineering plants in order to make them “useful” since the dawn of civilization. Indeed, re-engineering plants might be the very definition of civilization.
Take the teosinte plant for example. Teosinte is a wild grass found in central Mexico. Thousands of years ago, humans began the slow, laborious process of redesigning the plant, which produces a tiny “ear.” Controlling the number of stalks on the teosinte plant over time yielded fewer ears, with each ear growing larger with each successive generation. Eventually, teosinte was so re-engineered to produce one stalk with a few — but considerably larger — ears such that the modern maize plant — corn — was the result. The teosinte plant was, slowly, refashioned into a plant that humans used for food.
All such domesticated plants — wheat, barley, rice, millet — were bred by humans to geminate at specific times and to increase in yield to provide food. That is, we designed these wild plants to be useful for human needs. A more stable, predictable and plentiful food supply meant that humans no longer had to forage for plants, could remain sedentary, and thereby could gather in larger numbers in the first cities. Re-engineering plants was a necessary part of the civilization process.
Plant nanobionics is but the latest step in this long history of making plants useful for human needs, although it uses techniques that rapidly speed up the process. How else might we redesign plants to serve other such non-obvious functions?
David Staley is interim director of the Humanities Institute and a professor at The Ohio State University. He is president of Columbus Futurists and host of CreativeMornings Columbus.
The next CreativeMornings Columbus will be Friday, April 20 at 8:30 a.m. at Shadowbox Live. Blake Compton will speak on the theme “Game.”
The next Columbus Futurists monthly forum will be Thursday, April 26 at 6:30 p.m. at the Panera Bread community room (875 Bethel Rd.) The topic for the evening will be “The Future of Humanity.”