Luminous plants or animals are not new but MIT engineers have used technology to open up commercial possibilities for bioengineered plants. Barely two months ago, the scientific world was all agog about the possibility of luminous trees eventually lighting up sidewalks because of its impact on power costs.
The Strano Research Group’s research on plant nanobionics was funded by the U.S. Department of Energy for a good reason. They have the enviable track record of designing plants that could detect explosives and transmit this information to smartphones. Imagine these plants decorating airports, buildings, malls, schools and other areas prone to terrorist attacks – on alert 24/7, pretty, and even purifies the air! These researchers have also engineered plants that could monitor drought conditions and this third project aims to produce plants that can eventually replace some household electrical devices.
Nanobionics is an emerging field where plants (or living things) are embedded with different types of nanoparticles. Nanoparticles are extremely small particles (<100 nanometres) that can give a living thing new properties or capabilities. In a sense, it makes them “bionic”. The group focused on solving the lighting problem because it accounts for 1/5th of global energy consumption. Furthermore, Strano considers plants as the ultimate in sustainable energy: self-repairing, self-fueling, and adapted to the environment. The genes are not altered so there is no GMO involved. The nanoparticles used have been declared generally safe by the U.S. Food and Drug Administration and used in quantities that are not toxic to the plant itself.
In this research, plants that don’t usually give off fluorescence such as watercress, are embedded with luciferase, an enzyme that acts on luciferin, a protein so that it could emit a soft glow. Co-enzyme A is also needed to remove reaction substances that block or inhibit luciferase activity. Luciferase is the enzyme that gives fireflies and other fluorescent marine life and plankton their glow. Luciferase, luciferin, and co-enzyme A reacting together produce light that is considered dim when compared to a traditional bulb, but bright enough to read a book by. And this is just for starters.
Each of the important components had their specific nanoparticles carrier that enables them to reach the targeted part of the plant. Silica nanoparticles carried luciferase, PLGA a biodegradable polymer (Poly Lactic-co-Glycolic Acid) carried luciferin, and coenzyme A was carried by chitosan, a soluble polysaccharide derived from the shells of shrimps and crustaceans. To get these 3 critical substances into the plants, the plants were first immersed in a suspension containing the three and then subjected to high pressure so that they can enter the plant through the pores in its leaves called the stomata. When the particles release the active substances within the plant’s mesophyll, the reaction occurs and light is emitted. The experiments on leafy greens like kale, arugula, spinach, and watercress were all successful but not yet commercially marketable.
It might be some time before we can say, “Turn on the plant” but the research team continues to work on boosting the illumination and the duration of light. Strano’s group aims to eventually treat a plant so that light is emitted for the duration of its lifetime. Perfect for tree-lined avenues and indirect lighting. But how do you turn it off? They have also researched the release of luciferase inhibitors that turn off the plant’s light-emitting capacity by reacting to sunlight.
In a perfect world, we could just say, “let there be light” and not pay for it.
Want to understand how biofluorescence/bioluminescence works? Watch the animated explanation here: http://biolum.eemb.ucsb.edu/chem/