WASHINGTON, June 14 (Xinhua) -- A study published on Thursday in the journal Science revealed a new type of photosynthesis that could tailor the way we hunt for alien life and lend insights into how we could engineer more efficient crops that make use of longer wavelengths of light.
The study showed that a new type of bacteria could use near-infrared light while the vast majority of life on Earth uses visible red light in the process of photosynthesis.
It was detected in a wide range of cyanobacteria (blue-green algae) when they grow in near-infrared light, found in shaded conditions like bacterial mats in Yellowstone and in beach rock in Australia.
The standard type of photosynthesis uses the green pigment, called chlorophyll-a, to collect light and use its energy to make useful biochemicals and oxygen.
Since chlorophyll-a is present in all plants, algae and cyanobacteria that we know of, it was considered that the energy of red light set the 'red limit' for photosynthesis, which is the minimum amount of energy needed to do the demanding chemistry that produces oxygen.
The red limit is now used in astrobiology to judge whether complex life could have evolved on planets in other solar systems.
However, when some cyanobacteria are grown under near-infrared light, the standard chlorophyll-a-containing systems shut down and different systems containing a different kind of chlorophyll, chlorophyll-f, takes over, using lower-energy infrared light to do the complex chemistry under shaded conditions.
"The new form of photosynthesis made us rethink what we thought was possible. It also changes how we understand the key events at the heart of standard photosynthesis. This is textbook changing stuff," said the lead researcher Professor Bill Rutherford at the Department of Life Sciences at Imperial College London.
According to the researches, the findings could be useful for engineering crops to perform more efficient photosynthesis by using a wider range of light.
