A mushroom documentation project in the forests of Northeast India has revealed not only 600 varieties of fungi, but also led to a new discovery: a bioluminescent — or light emitting — variety of mushroom. The new species — named Roridomyces phyllostachydis — was first sighted on a wet August night near a stream in Meghalaya’s Mawlynnong in East Khasi Hills district and later at Krang Shuri in West Jaintia Hills district. It is now one among the 97 known species of bioluminescent fungi in the world.
How did the scientists chance upon the luminous mushrooms?
In August 2018, Assam-based conservation NGO Balipara Foundation collaborated with scientists from the Kunming Institute of Botany, Chinese Academy of Sciences on a project to assess the fungal biodiversity of four states in Northeast India: Meghalaya, Assam, Sikkim and Arunachal Pradesh. This particular mushroom was spotted on the Meghalaya leg of their expedition.
“Whenever we go mushroom documenting, we always ask locals if there are bioluminescent mushrooms around,” said team photographer Stephen Axford, who has documented fungi over the world for 15 years. “In Meghalaya, we did the same, and to our surprise, they said ‘Of course, we do’.”
The villagers then guided the team down a dark forest path, towards a stream. “We could see tiny pinpricks of light along the way,” said Axford, who set up a small outdoor studio to photograph the mushrooms in the dark, “They were striking.”
Later, on closer examination, and post sequencing the ITS gene of the mushroom, the researchers found that the mushroom belonged to the Roridomyces genus, and was altogether a new species, named after the host bamboo tree, Phyllostachys, from where it was first collected.
The research results were published in the botany journal Phytotaxa under the title “Roridomyces phyllostachydis (Agaricales, Mycenaceae), a new bioluminescent fungus from Northeast India”.
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What are bioluminescent fungi and why do they glow?
Bioluminescence is the property of a living organism to produce and emit light. “Animals, plants, fungi and bacteria show bioluminescence,” said Samantha Karunarathna, mycologist from the Kunming Institute of Botany, Chinese Academy of Sciences, who was part of the team that discovered the mushroom. “Bioluminescent organisms are usually found in the ocean environments, but they are also found on terrestrial environments. The colour of the light emitted by the organism depends on their chemical properties.”
In the case of fungi, the luminescence comes from the enzyme, luciferase. “The [green] light emits when luciferans is catalysed by the enzyme luciferase, in the presence of oxygen. During the chemical reaction, several unstable intermediate products are released as excess energy that makes them visible as light,” said Karunarathna, who is the lead author of the paper.
Rajesh Kumar, a scientist at the Rain Forest Research Institute in Jorhat, Assam said such mushrooms may glow for a number of reasons. “The simplest explanation could be that bioluminescence attracts insects, which helps in dispersing spores,” he said.
Karunarathna added that it may also be a mechanism for the organism to protect itself from frugivorous (or fruit-eating) animals.📣 Express Explained is now on Telegram
Is the Roridomyces phyllostachydis unique in any way?
The researchers said the new species was important because it was the first mushroom in the Roridomyces genus to be found in India. However, its uniqueness lay in the fact that it was the only member in its genus to have light emitting from its stipe or stalk. “The beige coloured pileus [cap-like part] is not bioluminescent” said Karunarathna. “Why only the stipe is bioluminescent in this mushroom is still a mystery.”
The paper described the stipe as “glutinous, slimy and moist”.
While locals in Meghalaya had refrained from consuming the mushroom as they did not know if it was edible, Karunarathna said they “used it as an alternative to torch light, by collecting bamboo clumps with lots of the fungi in it.”
Are there other bioluminescent mushrooms in India?
According to the paper, there are “scattered reports” on bioluminescent fungi from India from the Western Ghats, Eastern Ghats and Kerala. Kumar said there were many in Goa too, located about 50 km from Panjim.
“Some regional newspapers have written about bioluminescent fungi but they were not scientifically reported,” said Karunarathna, adding that the actual number of bioluminescent fungi in India could be higher.
Kumar agreed, adding that there was a need for more scientific documentation. “These can only be spotted at night but rarely do people look for mushrooms at night,” he said.
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