Scientists have long been puzzled as to why some mushrooms are bioluminescent, and new research may have come across an explanation. The researchers studied a mushroom which grows among decaying leaves underneath young palm trees in Brazil, known as “flor de coco,” writes Will Dunham for Reuters.
Bioluminescence attracts insects, disperses spores
The team carried out experiments which proved that the big, yellow mushroom attracts insects and other creatures using its bioluminescence, which then spread its spores to different areas of the forest. Biochemist Cassius Stevani of Brazil’s Instituto de Química-Universidade de São Paulo said that the team’s research provides an answer to the question of why fungi make light, first asked by Aristotle over 2,000 years ago.
“The answer appears to be that fungi make light so they are noticed by insects who can help the fungus colonize new habitats,” he said.
According to Jay Dunlap, a geneticist and molecular biologist at Dartmouth College’s Geisel School of Medicine, bioluminescence has independently evolved in many different life forms, including fungi, insects and fish. “Most of these make light in their own way, that is, with biochemistry that is unique to each organism,” Dunlap said.
Which insects are attracted to bioluminescent mushrooms?
Of a total of 100,000 known species of fungus, 71 are bioluminescent. The “flor de coco” is one of the biggest and brightest of them. Its bioluminescence depends on a circadian clock, which means that it only glows at nighttime.
The scientists created two sets of replica mushrooms made out of plastic, one with LED lights replicating bioluminescence, and another set with no light. Given that the team already suspected that the glow might help to attract insects, they applied glue to both sets of fake mushrooms in order to monitor which insects became stuck.
The glowing phony mushrooms attracted ants, cockroaches, flies, beetles, spiders, harvestmen, slugs, snails and centipedes, all of which disperse fungal spores around the forest after coming into contact with a real bioluminescent mushroom.
Dunlap hypothesized that the need to disperse spores was likely the reason behind the bioluminescence of many mushrooms. “Because it has evolved so many times in so many different organisms, each with their own biology, studying bioluminescence gives one a window on living things in all their wonderful diversity, and it sends you off to questions that you did not know existed,” he said.