Researchers found bacteria growing in almost full darkness use a previously-unknown process for harvesting energy from sunlight.
The discovery could lead to innovations in improving plant growth and harnessing energy from the Sun, Penn State reported.
We have shown that some cyanobacteria, also called blue-green algae, can grow in far-red wavelengths of light, a range not seen well by most humans," said Donald A. Bryant, the Ernest C. Pollard Professor of Biotechnology and a professor of biochemistry and molecular biology at Penn State. "Most cyanobacteria can't 'see' this light either. But we have found a new subgroup that can absorb and use it, and we have discovered some of the surprising ways they manipulate their genes in order to grow using only these wavelengths,"
The team found a bacteria strain called Leptolyngbya change its photosynthesis apparatus to use far-red light. In order to do this the cyanobacteria replace seventeen proteins in three major light-using complexes and produce new chlorophyll pigments that can absorb the far red light. The bacteria also turn off several genes to modify cellular metabolism and turn off other genes in a process called Far-Red Light Photoacclimation (FaRLiP).
"Our studies reveal that the particular cyanobacterium that we studied can massively change its physiology and metabolism, and its photosynthetic apparatus," Bryant said. "It changes the core components of the three major photosynthetic complexes, so one ends up with a very differentiated cell that is then capable of growing in far-red light. The impact is that they are better than other strains of cyanobacteria at producing oxygen in far-red light, and they are better even than themselves.
The findings could lead to a method of introducing into plants the ability to absorb far red light and use these wavelengths for photosynthesis.
"We now have clearly established that photosynthesis can occur in far-red light, in a wavelength range where people previously did not think that oxygenic photosynthesis could take place, and we have provided details about many of the processes involved. Now there are a whole set of associated scientific questions that need to be answered about more of the details before we can begin to investigate any applications that may or may not be possible," Bryant said. "Our research has opened up many new questions for basic scientific research."
