Bioluminescence, or the ability for life to emit light, shows up in the transient flares of fireflies, the auroral glow of oceanic plankton, and the eerily bright lures of predatory animals. Plants, however, have never evolved bioluminescence in the wild, though scientists have tried to engineer them to shine for many decades.
Now, a team of researchers has reached a breakthrough on that front by creating “glowing plants that are at least an order of magnitude brighter than was previously achieved,” according to a study published on Monday in Nature Biotechnology.
Tobacco plants, injected with DNA from bioluminescent mushrooms, emitted more than a billion photons per minute, achieving a “self-sustained luminescence that is visible to the naked eye,” said the study’s authors.
The plants were developed by a team of scientists in collaboration with Planta LLC, a biotech startup based in Moscow, Russia, that seeks to commercialize glowing plants. While plants have been previously tweaked to emit light using bioluminescent bacteria, the new study unveils the brightest genetically engineered plants to date.
The tobacco plants were able to attain such high wattage (metaphorically speaking) thanks to caffeic acid, which was recently identified as a core molecular driver of light emission in the bioluminescent group of Neonothopanus fungus. Since caffeic acid is also present in all plants, the team decided to introduce this fungal DNA into the genomes of tobacco plants to see if its light-emitting pathways would be replicated in a botanical host.
The technique culminated in gleaming “autoluminescent” plants that are able to produce their own light at every stage of their life cycle. Not only did the fungal DNA cause the plants to outshine their precursors, it also shed literal light into the internal processes occuring inside these leafy species.
“As plants developed, luminescence increased at the transition zone between the root and the stem,” the researchers said in the study. “Young shoots were brightest at the terminal and axillary buds and at the upper part of the stem; older parts of the shoot dimmed as plants matured.”
Likewise, aging leaves dimmed due to reduced caffeic acid content, though “some leaves displayed waves of intense light emission during the final stages of senescence,” the team said.
The team used tobacco plants because they grow fast and are well-studied, but in principle, the same technique could illuminate popular household flowers such as periwinkle, petunia, and rose.
Stunning visions of bioluminescent plants have become popular in science fiction and fantasy, but it might not be too long before you can plant glowing greens in your own garden.