Navigation Links
'Extreme' genes shed light on origins of photosynthesis
Date:12/11/2009

While most school children understand that green plants photosynthesize, absorb carbon dioxide and produce oxygen, few people consider the profound global-scale effects that photosynthesis has had on Earth. One of those actively shedding light on the origins and evolution of photosynthesis is Jeffrey Touchman, assistant professor in Arizona State University's School of Life Sciences.

Oxygen, one of the by-products of photosynthesis by microbes such as cyanobacteria and their descendants (including algae and higher plants), transformed the Precambrian Earth and made possible the evolution of more complex organisms. With an $867,000 award from the National Science Foundation and the USDA National Institute of Food and Agriculture, Touchman works to illuminate large gaps in the available genetic data for photosynthetic microbes through the study of phototrophic extremophiles (organisms living in unusually harsh and exotic environments). His research is focused on genome sequencing and molecular analyses of heliobacteria, proteobacteria and a cyanobacterium with the ability to shift into anoxygenic (oxygen-free) photosynthesis in the presence of sulfide, a possible evolutionary "missing link" between anoxygenic and oxygenic photosynthetic organisms.

"Knowing how photosynthesis originated and evolved is essential to obtaining the deep understanding required to yield improvements in bioenergy, agriculture and the environment," Touchman says.

Touchman, who is also an adjunct investigator at The Translational Genomics Research Institute (TGen), has chosen his photosynthetic, microbial partners carefully; each bears a unique metabolism, physiology or ecology and differs in fundamental ways from sequenced genomes of any other phototroph. Hidden in these organisms' various genetic codes may be hallmarks: traces of early evolutionary innovations pointing to the origin of oxygen-evolving high-energy photosynthesis.

There are important linkages between Touchman's work on earthbound origins and astrobiology as well. Phototrophic extremophiles are excellent model microbes for studies of interplanetary photosynthetic exchange, Touchman says. That is, exchange that might come about in stellar systems that have terrestrial-type rocky planets that could be capable of exchanging gneiss and rocky material. The arrival of oxygenic photosynthesis via transport of materials by external means, such as meteorites, could profoundly change the direction of biological evolution on a planet's surface.

Transpermia or rocky panspermia is the possibility of the exchange of micro-organisms between planets via impact material. Paul Davies, director of ASU's Beyond Center for Fundamental Concepts in Science, developed some of the thinking upon which Touchman's extraterrestrial pursuits are based: "some microorganisms can survive interplanetary journeys cocooned inside rocks blasted off planets by comet and asteroid impacts. That rocky panspermia is an effective mechanism for spreading life within a planetary system."

"Oxygen is a central biosignature or fingerprint of life sought in the atmospheric spectra of planets beyond our solar system," Touchman says. "Detailed molecular understanding of how photosynthetic microbes can push the boundaries of extreme-environment existence on our own planet will also fill important gaps in our current understanding of extra-terrestrial potential for oxygen-evolving photosynthesis."

Touchman's research is part of a suite of innovative genetic and genetic engineering studies being conducted with cyanobacteria by School of Life Sciences faculty in coordination with the Center for Bioenergy and Photosynthesis in the College of Liberal Arts and Sciences. Most notable of these are translational life science studies to advance bioenergy biodiesel and biohydrogen studies supported by Department of Energy's Advanced Research Projects Agency-Energy (ARPA-E) program funding, headed by professor Willem Vermaas and work on natural sunscreens by professor Ferran Garcia-Pichel.


'/>"/>

Contact: Margaret Coulombe
margaret.coulombe@asu.edu
480-727-8934
Arizona State University
Source:Eurekalert

Related biology news :

1. Common aquatic animals show extreme resistance to radiation
2. Answering challenges of life in extreme environments research
3. Extreme nausea and vomiting varies among pregnant women from different countries
4. Instances of mass die-offs in wild lions precipitated by extreme climate change
5. Vegetation hardly affected by extreme flood events
6. Extreme nature helps scientists design nano materials
7. Extreme weather postpones the flowering time of plants
8. Geoscientists discuss sea level rise, extreme storm events and more
9. Genome projects launched for three extreme-environment animals
10. Treatment for extreme nausea, vomiting during pregnancy
11. Scientists track chemical changes in cells as they endure extreme conditions
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/16/2017)... , May 16, 2017  Veratad Technologies, LLC ( ... online age and identity verification solutions, announced today they ... Conference 2017, May 15 thru May 17, 2017, in ... and International Trade Center. Identity impacts ... and in today,s quickly evolving digital world, defining identity ...
(Date:4/18/2017)... April 18, 2017  Socionext Inc., a global expert in SoC-based ... edge server, the M820, which features the company,s hybrid codec technology. ... by Tera Probe, Inc., will be showcased during the upcoming Medtec ... show at the Las Vegas Convention Center ... Click here ...
(Date:4/11/2017)... -- Research and Markets has announced the addition of ... offering. ... market to grow at a CAGR of 30.37% during the period ... has been prepared based on an in-depth market analysis with inputs ... growth prospects over the coming years. The report also includes a ...
Breaking Biology News(10 mins):
(Date:8/15/2017)... NC (PRWEB) , ... August 15, 2017 , ... ... 2017, celebrating 10 years of successes helping medical technology companies and inventors develop and ... to a renowned full-service national engineering firm with a portfolio of clients in the ...
(Date:8/15/2017)... ... 15, 2017 , ... The Conference Forum and The Trout ... a series of upcoming panels and events. The partnership culminates with the 4th ... in New York City. , “With our experience in producing the Immuno-Oncology 360° NYC ...
(Date:8/14/2017)... ... 14, 2017 , ... The Conference Forum has confirmed the one-day ... on September 6, 2017 at the Marriott Copley Place in Boston, MA. , Returning ... and Regulatory Strategy, Pfizer Innovative Research Lab, Pfizer, who leads 19 industry speakers in ...
(Date:8/10/2017)... , ... August 09, 2017 , ... ... help the agriculture industry reach its ideal customers with the right message. Their ... , “As a Midwest company, we realize how crucial the agriculture industry is,” ...
Breaking Biology Technology: