Navigation Links
Evidence of 600-million-year old fungi-algae symbiosis discovered in marine fossils

Researchers from China and the United States have found evidence of lichen-like symbiosis in 600-million-year-old fossils from South China. The previous earliest evidence of lichen was 400 million years old, discovered in Scotland. The discovery also adds to the scarce fossil record of fungi and raises new questions about lichen evolution.

Xunlai Yuan, a paleontologist with the Nanjing Institute of Geology and Palaeontology; Shuhai Xiao, assistant professor of geosciences at Virginia Tech; and Thomas N. Taylor, professor of ecology and evolutionary biology at the University of Kansas, report their finding in the May 13 issue of Science ("Lichen-Like Symbiosis 600 Million Years Ago").

Yuan, Xiao, and their collaborators have been exploring the Doushantuo Formation in South China for a decade and have co-authored numerous reports of fossil discoveries, including algae and animal embryos. Taylor, a member of the National Academy of Sciences, is a paleobotanist who has reported on fossil lichens in Scotland.

Lichen is a consortium of two organisms that collaborate to survive in a harsh environment, such as exposed rock. One partner, a cyanobacterium or a photosynthetic alga, or both, are able to form food from carbon dioxide, while the other partner, a fungus, provides moisture, nutrients, and protection for the consortium.

"When and where did they first learn the tricks to form this collaboration?" Xiao asked. "The earliest lichen fossils described by Professor Taylor were from non-marine deposits about 400 million years old, when plants began to massively colonize the land. But did cyanobacteria or other algae form similar relationships with fungi in the marine environment, perhaps long before the evolution of land plants?"

Present-day examples of such relationships in the sea are abundant. Now, there is an example from ancient ocean life.

At a site where abundant algae lived in a shallow sub-tidal environment about 600 m illion years ago, Yuan and Xiao found three specimens that have evidence of two partners in a familiar relationship. "Enlargements of thin-section photomicrographs of the tiny specimens -- each of which was less than a millimeter in size -- show fossils of coccoidal or spherical cells surrounded by a net of fine filaments," Yuan said, describing the new fossils.

The scientists interpret the coccoidal cells as being sheathed cyanobacteria or possibly green algae. "The filaments have reproductive characteristics that make us think they are fungi," Xiao said.

Taylor said, "Clearly, there are two kinds of organisms living together and, we believe, interacting in more than a chance association."

In modern lichens and in the 400-million-year-old Scotland fossils, the coccoidal cells provide the nutrients and the fungal filaments provide protection against dehydration. But in the marine environment, dehydration is not an issue and the 600-million-year-old rocks also contain many fossils of coccoidal cells that are not surrounded by filaments. "So it is a loose lichen-like association," said Xiao. "The organisms are not obliged to live together."

Now there is a new question. "We know that this symbiotic relationship was forged 600 million years ago or earlier. But, was it carried over to land, or did each organism invade land and forge a new relationship independent of the marine relationship? If the latter, then the 600-million-year-old relationship may not be the direct ancestor of the 400-million-year-old relationship," Xiao said.

Fungi and algae in modern lichens can easily marry and divorce, he said. "Given the ease with which the symbiotic relationship is formed, I wouldn't be surprised if the land-based relationships formed independently of the older marine relationships."

"In fact, studies of modern lichens demonstrate that the lichen symbiosis evolved many times," Taylor said.

"The ability to form a symbiotic relationship between fungi and algae may have evolved long before the colonization of land by land-based lichens and green plants, which also form symbiotic relationships with various fungi," Xiao said.

"The Doushantuo Formation opens a window into ancient marine life. There is a lot more remains to be learned from these rocks," Yuan added.


'"/>

Source:Virginia Tech


Related biology news :

1. Evidence for omega 3 fats less conclusive than we thought, say experts
2. Surprising symbiosis: Glassy-winged sharpshooter eats with friends
3. Newly-discovered class of genes determines ?and restricts ?stem cell fate
4. Newly discovered virus linked to childhood lung disorders and Kawasaki disease
5. New protein discovered by Hebrew University researchers
6. New RNA polymerase discovered in plants
7. Newly discovered pathway might help in design of cancer drugs
8. New tumor-suppressor gene discovered
9. Newly discovered protein an important tool for sleeping sickness research
10. Function of new cancer genes discovered
11. Natural tumor suppressor in body discovered by UCSD medical researchers
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/2/2016)... -- The Department of Transport Management (DOTM) of ... US Dollar project, for the , Supply and ... and IT Infrastructure , to Decatur ... of Identity Management Solutions. Numerous renowned international vendors participated in ... was selected for the most compliant and innovative solution. ...
(Date:5/20/2016)... , May 20, 2016  VoiceIt is ... partnership with VoicePass. By working together, ... experience.  Because VoiceIt and VoicePass take slightly different ... engines increases both security and usability. ... excitement about this new partnership. "This ...
(Date:4/28/2016)... India , April 28, 2016 ... Infosys (NYSE: INFY ), and Samsung SDS, a ... that will provide end customers with a more secure, ... services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ) , ... services, but it also plays a fundamental part in enabling ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... June 27, 2016 , ... Newly created 4Sight Medical ... to the healthcare market. The company's primary focus is on new product introductions, ... strategies that are necessary to help companies efficiently bring their products to market. ...
(Date:6/27/2016)... , June 27, 2016   Ginkgo Bioworks , ... industrial engineering, was today awarded as one of ... of the world,s most innovative companies. Ginkgo Bioworks ... for the real world in the nutrition, health ... work directly with customers including Fortune 500 companies ...
(Date:6/24/2016)... ... June 24, 2016 , ... While the majority of commercial spectrophotometers and fluorometers ... the 6000i models are higher end machines that use the more unconventional z-dimension of ... beam from the bottom of the cuvette holder. , FireflySci has developed several ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... is pleased to announce the launch of their brand, UP4™ Probiotics, into Target ... over 35 years, is proud to add Target to its list of well-respected ...
Breaking Biology Technology: