Featured Research

from universities, journals, and other organizations

Hidden soil fungus, now revealed, is in a class all its own

Date:
August 11, 2011
Source:
University of Michigan
Summary:
A type of fungus that's been lurking underground for millions of years, previously known to science only through its DNA, has been cultured, photographed, named and assigned a place on the tree of life.

SEM (scanning electron microscopy) image of fixed culture. A swelling has cracked and looks like a face. Scale: 300 nm
Credit: Anna Rosling & Karelyn Cruz Martinez

A type of fungus that's been lurking underground for millions of years, previously known to science only through its DNA, has been cultured, photographed, named and assigned a place on the tree of life.

Researchers say it represents an entirely new class of fungi: the Archaeorhizomycetes. Like the discovery of a weird type of aquatic fungus that made headlines a few months ago, this finding offers a glimpse at the rich diversity of microorganisms that share our world but remain hidden from view.

The fungal phenomenon, brought to light by researchers at the University of Michigan, the Swedish University of Agricultural Sciences, the Imperial College London and Royal Botanic Gardens and the University of Aberdeen, is described in the Aug. 12 issue of the journal Science.

Although unseen until recently, the fungus was known to be extremely common in soil. Its presence was detected in studies of environmental DNA -- genetic material from a living organism that is detected in bulk environmental samples, such as samples of the soil or water in which the organism lives.

"You couldn't really sample the soil without finding evidence of it," said Timothy James, a U-M assistant professor of ecology and evolutionary biology and an assistant curator at the university's herbarium. "So people really wanted to know what it looks like."

That became possible thanks to the work of the Swedish researchers, led by mycologist Anna Rosling. The researchers were studying mycorrhizae -- fungi that colonize plant roots -- when they discovered that some root tips harbored not only the mycorrhizae they were interested in, but also an unfamiliar fungus.

"When culturing mycorrhizal fungi from coniferous roots we were exited to find that one of the cultures represented this unfamiliar fungus," said Anna Rosling.

Later the culture was identified as a member of Soil Clone Group 1 (SCG1), a ubiquitous but enigmatic lineage known only from environmental DNA. It's not especially impressive to look at, James concedes: "It doesn't make some crazy structure that nobody's ever seen." But simply seeing and photographing a form of life that's been invisible until now is cause for excitement.

Having in hand a member of the elusive fungal group, the Swedish scientists and their collaborators have been able to study the group in more detail than ever before possible, using electron microscopy, DNA sequencing and in vitro growth studies to characterize it. The fungus they cultured is a slow-growing form that produces none of the typical aerial or aquatically dispersed spores most fungi typically reproduce with, suggesting it seldom if ever sees the light of day.

"By finding that it is slow growing and only produces spores in the soil, we can provide an explanation for why it has taken so long to be cultured," James said. The researchers also performed experiments aimed at understanding how the fungus, dubbed Archaeorhizomyces finlayi, interacts with the environment and with other organisms.

"We don't have any evidence that it's pathogenic; we don't have any evidence that it's mutualistic and doing anything beneficial for the plant," James said. "It's a little bit of a boring fungus." It may, however, help break down and recycle dead plants, a common -- and extremely important -- job for fungi. Hints of this role come from the observation that A. finlayi grows in the lab if provided with food in the form of glucose or cellulose (the main structural component of plant cell walls).

"Because it is so common in the soil, it must be very successful at what it does, and that role must be ecologically relevant," Rosling said.

Now that the researchers have ruled out some typical fungal roles -- such as pathogen, benign endophyte, and member of a mycorrhizal association -- they hope to find out through additional experiments exactly what role the fungus does play in nature and how it interacts with plants and other fungi.

"At this point we're still in the early stages of understanding what it's doing out there," James said.

Whether A. finlayi turns out to be beneficial or detrimental to the plants or microbes it interacts with, it's sure to contribute to understanding the diverse array of fungi in the world.

Though environmental DNA of SCG1 had been collected and reported in more than 50 previous studies, the type of DNA collected in the past didn't lend itself to analyses that would definitively pinpoint the group's position on the tree of life.

"Now that we have the culture, we can sequence almost any gene we want, so that's what we've done," James said.

The resulting information, combined with DNA data from the previous studies, revealed that A. finlayi belongs in an eclectic subphylum known as Taphrinomycotina, other members of which include the yeast Schizosaccharomyces, often used in studies of cell biology and evolution, and Pneumocystis, which can cause pneumonia in people with weakened immune systems, such as those who have cancer or HIV/AIDS or are undergoing treatment with immune-suppressing drugs.

In addition to James and Rosling, who is currently a visiting research associate at Indiana University, the paper's authors include Filipa Cox of the Imperial College London and Royal Botanic Gardens; Karelyn Cruz-Martinez, Katarina Ihrmark, Bjφrn Lindahl and Audrius Menkis of the Swedish University of Agricultural Sciences; and Gwen-Aλlle Grelet of the University of Aberdeen.

The research was funded by the Carl Trygger Foundation, The Swedish Research Council Formas and the National Environment Research Council (UK).


Story Source:

The above story is based on materials provided by University of Michigan. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. Rosling, F. Cox, K. Cruz-Martinez, K. Ihrmark, G.-A. Grelet, B. D. Lindahl, A. Menkis, T. Y. James. Archaeorhizomycetes: Unearthing an Ancient Class of Ubiquitous Soil Fungi. Science, 2011; 333 (6044): 876 DOI: 10.1126/science.1206958

Cite This Page:

University of Michigan. "Hidden soil fungus, now revealed, is in a class all its own." ScienceDaily. ScienceDaily, 11 August 2011. <www.sciencedaily.com/releases/2011/08/110811142819.htm>.
University of Michigan. (2011, August 11). Hidden soil fungus, now revealed, is in a class all its own. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2011/08/110811142819.htm
University of Michigan. "Hidden soil fungus, now revealed, is in a class all its own." ScienceDaily. www.sciencedaily.com/releases/2011/08/110811142819.htm (accessed October 22, 2014).

Share This



More Plants & Animals News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Cadaver Dogs Aid Search for More Victims of Suspected Indiana Serial Killer

Reuters - US Online Video (Oct. 21, 2014) — Police in Gary, Indiana are using cadaver dogs to search for more victims after a suspected serial killer confessed to killing at least seven women. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
White Lion Cubs Unveiled to the Public

White Lion Cubs Unveiled to the Public

Reuters - Light News Video Online (Oct. 21, 2014) — Visitors to Belgrade zoo meet a pair of three-week-old lion cubs for the first time. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
'Cadaver Dog' Sniffs out Human Remains

'Cadaver Dog' Sniffs out Human Remains

AP (Oct. 21, 2014) — Where's a body buried? Buster's nose can often tell you. He's a cadaver dog, specially trained to find human remains and increasingly being used by law enforcement and accepted in courts. These dogs are helping solve even decades-old mysteries. (Oct. 21) Video provided by AP
Powered by NewsLook.com
White Lion Cubs Born in Belgrade Zoo

White Lion Cubs Born in Belgrade Zoo

AFP (Oct. 20, 2014) — Two white lion cubs, an extremely rare subspecies of the African lion, were recently born at Belgrade Zoo. They are being bottle fed by zoo keepers after they were rejected by their mother after birth. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

More Coverage


New Fungi Class Formally Identified

Aug. 11, 2011 — Scientists have cultured, characterized and formally named a new class of fungi that previously had only been identified through DNA sequencing from environmental ... read more

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins