Engineers Create Plants That Glow
Illumination from nanobionic plants might one day replace some electrical lighting.
Written by Anne Trafton
MIT News
Imagine that instead of switching on a lamp when it gets dark, you could read by the light of a glowing plant on your desk.
MIT engineers have taken a critical first step toward making that vision a reality. By embedding specialized nanoparticles into the leaves of a watercress plant, they induced the plants to give off a dim light for nearly four hours. They believe that, with further optimization, such plants will one day be bright enough to illuminate a workspace.
“The vision is to make a plant that will function as a desk lamp — a lamp that you don’t have to plug in. The light is ultimately powered by the energy metabolism of the plant itself,” says MIT professor and senior author of the study Michael Strano.
This technology could also be used to provide low-intensity indoor lighting, or to transform trees into self-powered streetlights, the researchers say.
RELATED: Ex-NASA Engineer to Plant One Billion Trees a Year Using Drones
Plant nanobionics, a new research area pioneered by Strano’s lab, aims to give plants novel features by embedding them with different types of nanoparticles. The group’s goal is to engineer plants to take over many of the functions now performed by electrical devices. The researchers have previously designed plants that can detect explosives and communicate the information to a smartphone, as well as plants that can monitor drought conditions.
Lighting, which accounts for about 20% of worldwide energy consumption, seemed like a logical next target. “Plants can self-repair, they have their own energy, and they are already adapted to the outdoor environment,” Strano says. “We think this is an idea whose time has come. It’s a perfect problem for plant nanobionics.”
LOOK: Trees Growing Out of Buildings Could Help Heal China’s Air Pollution Problem
The MIT team packaged each of these three components into a different type of nanoparticle carrier. The nanoparticles, which are all made of materials that the U.S. Food and Drug Administration classifies as “generally regarded as safe,” help each component get to the right part of the plant. They also prevent the components from reaching concentrations that could be toxic to the plants.
The researchers used silica nanoparticles about 10 nanometers in diameter to carry luciferase, and they used slightly larger particles of the polymers PLGA and chitosan to carry luciferin and coenzyme A, respectively. To get the particles into plant leaves, the researchers first suspended the particles in a solution. Plants were immersed in the solution and then exposed to high pressure, allowing the particles to enter the leaves through tiny pores called stomata.
Particles releasing luciferin and coenzyme A were designed to accumulate in the extracellular space of the mesophyll, an inner layer of the leaf, while the smaller particles carrying luciferase enter the cells that make up the mesophyll. The PLGA particles gradually release luciferin, which then enters the plant cells, where luciferase performs the chemical reaction that makes luciferin glow.
CHECK OUT: Man Creates Gardens For Unwanted Bees, Grows Free Food in 30 Abandoned Lots
The researchers’ early efforts at the start of the project yielded plants that could glow for about 45 minutes, which they have since improved to 3.5 hours. The light generated by one 10-centimeter watercress seedling is currently about one-thousandth of the amount needed to read by, but the researchers believe they can boost the light emitted, as well as the duration of light, by further optimizing the concentration and release rates of the components.
Previous efforts to create light-emitting plants have relied on genetically engineering plants to express the gene for luciferase, but this is a laborious process that yields extremely dim light. Those studies were performed on tobacco plants and Arabidopsis thaliana, which are commonly used for plant genetic studies. However, the method developed by Strano’s lab could be used on any type of plant. So far, they have demonstrated it with arugula, kale, and spinach, in addition to watercress.
For future versions of this technology, the researchers hope to develop a way to paint or spray the nanoparticles onto plant leaves, which could make it possible to transform trees and other large plants into light sources.
MORE: IKEA Releases Free Design For Garden Sphere That Feeds a Neighborhood
“Our target is to perform one treatment when the plant is a seedling or a mature plant, and have it last for the lifetime of the plant,” Strano says. “Our work very seriously opens up the doorway to streetlamps that are nothing but treated trees, and to indirect lighting around homes.”
The researchers have also demonstrated that they can turn the light off by adding nanoparticles carrying a luciferase inhibitor. This could enable them to eventually create plants that shut off their light emission in response to environmental conditions such as sunlight, the researchers say.
The research, which was conducted by lead author and MIT postdoc Seon-Yeong Kwak was funded by the U.S. Department of Energy and published in the journal Nano Letters.
Reprinted with permission from MIT News
(WATCH the mesmerizing video below)
Illuminate Your Friends: Click To Share The Cool News – Photo by Seon-Yeong Kwak