We know how some insects, fungi, and sea creatures harness bioluminescence to glow in the dark. Pretty soon, we might see genetically-modified garden plants that also produce their own light. Scientists have experimented for years to introduce fluorescent proteins into plants, or to get plants to combine certain chemicals (luciferin in and luciferase, which sound downright diabolical) to produce light, with little luck. Now a new process uses a more natural pathway to trick plants into producing the necessary chemicals.
The new work relies on the discovery of a new pathway in fungi that feeds on rotting wood. As you might imagine, a fungus that feeds on wood has to have some metabolic pathways that overlap with those of the plants that provide its food source. In this case, the fungus produces its luciferin through a biochemical pathway called the caffeic acid cycle. Conveniently, caffeic acid is an intermediate on the pathway that plants use to make lignin, a key component of plant cell walls and a major contributor to the robustness of wood.
It turns out that only three enzymes were needed to convert caffeic acid to a luciferin. Add in the need for a luciferase to get the glow and the researchers were looking at a total of four genes. They engineered them into a single stretch of DNA and inserted that into the cells of a tobacco plant. While tobacco may seem like an odd choice, it has been intensively researched and is often used for experiments like this.
There are research applications for this work, but you know that someone will monetize this to make garden plants that glow in the dark, so you might be able to put off spending money on backyard illumination by electricity. Read about the research at Ars Technica.
(Image credit: Mitiouchkina et al)