An international team of researchers led by scientists at Virginia Tech and the University of California, Berkeley has discovered that a process that turns on photosynthesis（光合作用） in plants likely developed on Earth in ancient microbes 2.5 billion years ago, long before oxygen became available. The research offers new perspective on evolutionary biology, microbiology, and the production of natural gas, and may shed light on climate change, agriculture, and human health.

"By looking at this one mechanism that was not previously studied, we will be able to develop new basic information that potentially has broad impact on contemporary issues ranging from climate change to obesity," said Biswarup Mukhopadhyay, an associate professor of biochemistry at the Virginia Tech College of Agriculture and Life Sciences, and the senior author of the study. He is also a faculty member at the Virginia Bioinformatics Institute. Plant and microbial biology professor emeritus（退休的） Bob B. Buchanan co-led the research and co-authored the paper.

The findings were described this week in an early online edition of the Proceedings of the National Academy of Sciences.

This research concerns methane-forming archaea, a group of microbes known as methanogens（产甲烷菌）, which live in areas where oxygen is absent. Methane is the main component of natural gas and a potent greenhouse gas.

"This innovative work demonstrates the importance of a new global regulatory system in methanogens," said William Whitman, a professor of microbiology at the University of Georgia who is familiar with the study, but not connected to it. "Understanding this system will provide the tools to use these economically important microorganisms better."