Featured Research

from universities, journals, and other organizations

As mushrooms evolve to live with trees, they give up DNA associated with decomposing cellulose

Date:
July 18, 2012
Source:
Harvard University
Summary:
New research finds that Amanita mushrooms' evolution has largely been away from species that help decompose organic material and toward those that live symbiotically on trees and their roots. More interestingly, scientists found that the transition came at a steep price -- the loss of the genes associated with breaking down cellulose.

A sampling of the diversity of color and form within the genus Amanita.
Credit: From: Wolfe BE, Tulloss RE, Pringle A. The Irreversible Loss of a Decomposition Pathway Marks the Single Origin of an Ectomycorrhizal Symbiosis. PLoS ONE, 2012; 7 (7): e39597 DOI: 10.1371/journal.pone.0039597

Harvard researchers are unlocking the evolutionary secrets of one of the world's most recognizable groups of mushrooms, and to do it, they're using one of the most comprehensive fungal "family trees" ever created.

As reported in paper published July 18 in PLoS ONE, Associate Professor of Organismic and Evolutionary Biology Anne Pringle and Ben Wolfe, a Post-Doctoral Fellow in FAS Center for Systems Biology, studied the genetics of more 100 species of Amanita mushrooms -- about one-sixth of the genus' total diversity -- to create an elaborate phylogeny showing how each species is related to one another.

Arguably the most widely-recognized group of mushrooms in the world, Amanita mushrooms have appeared in popular culture ranging from Fantasia to the Super Mario Brothers video games. Though it includes a number of edible species, such as the Amanita caesarea, the group is probably best known for its many toxic species, including the death-cap mushroom.

Armed with their family tree, Pringle and Wolfe were able to determine that Amanita evolution has largely been away from species that help decompose organic material and toward those that live symbiotically on trees and their roots. More interestingly, they found that the transition came at a steep price -- the loss of the genes associated with breaking down cellulose.

"There had been earlier suggestions that this type of gene loss might be taking place, but our study is the first precise test of that hypothesis," Pringle said. "The idea makes sense -- if you're going to actively form a cooperative relationship with a tree, you probably shouldn't simultaneously be trying to break it apart and eat it. But it's a very tricky dance to form these kinds of tight, cooperative interactions, and I think this work shows there is a cost associated with that. You have to change, you have to commit, and it can become a sort of gilded cage -- these mushrooms are very successful, but they're stuck where they are."

In addition to many species which are housed in the Farlow Herbarium, located at the Harvard University Herbaria, Wolfe spent months tracking rare species in far-flung locations like London and Hawaii.

After extracting DNA from the samples, Wolfe used the genetic codes of four different genes to determine how the various species are related to one another. He then used a process called ancestral state reconstruction to show that the mushrooms have switched from being decomposers to being symbiotic with trees only once in their evolutionary history. Once the mushrooms switched to this new symbiotic lifestyle, they didn't go back to their free-living past.

Ultimately, Pringle said, the paper highlights one reason she finds such symbiotic partnerships "intrinsically interesting" -- for all their apparent benefits, the cost can be high.

"I think the really interesting thing is this idea that once you become symbiotic, some of your machinery is lost," she said. "It seems like a dead end in some ways -- you have to make this change to enter this niche, but once you're there, you can't go back -- you've lost the capacity to be free-living."


Story Source:

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


Journal Reference:

  1. Wolfe BE, Tulloss RE, Pringle A. The Irreversible Loss of a Decomposition Pathway Marks the Single Origin of an Ectomycorrhizal Symbiosis. PLoS ONE, 2012; 7 (7): e39597 DOI: 10.1371/journal.pone.0039597

Cite This Page:

Harvard University. "As mushrooms evolve to live with trees, they give up DNA associated with decomposing cellulose." ScienceDaily. ScienceDaily, 18 July 2012. <www.sciencedaily.com/releases/2012/07/120718192047.htm>.
Harvard University. (2012, July 18). As mushrooms evolve to live with trees, they give up DNA associated with decomposing cellulose. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2012/07/120718192047.htm
Harvard University. "As mushrooms evolve to live with trees, they give up DNA associated with decomposing cellulose." ScienceDaily. www.sciencedaily.com/releases/2012/07/120718192047.htm (accessed September 18, 2014).

Share This



More Plants & Animals News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Chimp Violence Study Renews Debate On Why They Kill

Chimp Violence Study Renews Debate On Why They Kill

Newsy (Sep. 17, 2014) The study weighs in on a debate over whether chimps are naturally violent or become that way due to human interference in the environment. Video provided by Newsy
Powered by NewsLook.com
Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
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:
from the past week

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