Imperial College of London published a research in the journal Science on June 15 which claims that they have discovered a new form of photosynthesis. Although the research was led by the Imperial College of London, it also involved the BBSRC, ANU from Canberra, the CNRS from Paris and the CNR in Milan. The press release portal of the College reports, “The discovery changes our understanding of the basic mechanism of photosynthesis and should rewrite the textbooks”. According to scientists this will change the way we search for alien life and could provide useful information about how we could engineer more efficient crops which use longer wavelengths of light.
Most of the living organisms on Earth utilise red light for the process of photosynthesis, but this new form of photosynthesis utilizes near-infrared light instead. It was observed in a wide range of cyanobacteria, also known as the blue green algae. When the blue green algae grows in near infrared light it shows this type of photosynthesis. Quite interesting is that the cyanobacteria performs this type of photosynthesis in a cupboard fitted with infrared LEDs at the Imperial College of London. Dr Andrea Fantuzzi, co-author and researcher at the Department of Life Sciences at Imperial said, “Finding a type of photosynthesis that works beyond the red limit changes our understanding of the energy requirements of photosynthesis. This provides insights into light energy use and into mechanisms that protect the systems against damage by light.”
The photosynthesis process used by almost every species that relies on it uses chlorophyll-a, a green pigment, to collect light and turn it into chemical energy. Chlorophyll-a absorbs light from the red spectrum of sunlight and then uses it for photosynthesis. Chlorophyll-a is present in all plants, algae and cyanobacteria and it was thought that red light set the ‘red limit’ for photosynthesis- the minimum amount of energy required to produce oxygen. But now scientists have observed that when some blue green algae is exposed to near-infrared light, it chooses to activate chlorophyll-f instead of chlorophyll-a. In the past, Chlorophyll-f was thought to be just harvesting the light. Now we know that chlorophyll-f plays the main hero in the process of photosynthesis under shaded conditions. This type of photosynthesis is said to be “beyond the red limit”.