Nov. 28 (UPI) -- Scientists have for the first time isolated the biochemical pathway that allows fungi to glow-in-the-dark.
The ability to light up at night is called bioluminescence. Until now, scientists weren't exactly sure how organisms generate luminescence, but a rather ordinary brown fungus species, Neonothopanus nambi, one of 100 bioluminescent mushrooms, helped researchers solve the mystery.
The breakthrough, detailed this week in the journal PNAS, has allowed scientists to make other organisms glow-in-the-dark.
Bioluminescence is powered by luciferin, which is oxidized by the enzyme luciferase and converted into light. Until now, scientists were unable to identify the genes that code for the production of luciferin.
However, analysis of the eukaryote Neonothopanus nambi revealed the genes responsible for the enzymes that synthesize luciferin inside the fungus. The study also showed luciferin is very similar to caffeic acid, a common metabolite found in fungi.
The comparison of genes related to luciferin and caffeic acid suggested bioluminescence evolved in mushrooms more than 100 million years ago.
As to why mushrooms first developed bioluminescence, scientists aren't sure.
"Is bioluminescence beneficial or just a side product? We don't know yet," Fyodor Kondrashov, researcher at the Institute of Science and Technology Austria, said in a news release. "There are evidences that the glow attracts insects which distribute the spores. But I don't think that's convincing."
Currently, scientists make tissues, cells or other organisms glow in the dark by injecting them with bioluminescence protein. But using the new research, scientists can now manipulate an organism's genes to unlock their inherent bioluminescence capabilities.
In the lab, scientists used their newly discovered genetic codes to program non-bioluminescent eukaryotes to glow in the dark. In tests, the new coding caused yeast to turn metabolite caffeic acid into luciferin.
"We don't supply a chemical that makes the yeast glow," said Kondrashov. "Instead, we supply the enzymes it needs to convert a metabolic product that is already present in the yeast into light."
Researchers hope to use their findings to eventually make plants and animals light up the night.
"If we think of sci-fi scenarios in which glowing plants replace street lights -- this is it. This is the breakthrough that can lead to this," Kondrashov said. "However, it may take several years until such a plant street light is engineered."