Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New type of photosynthesis discovered

18.06.2018

The discovery changes our understanding of the basic mechanism of photosynthesis and should rewrite the textbooks.

It will also tailor the way we hunt for alien life and provide insights into how we could engineer more efficient crops that take advantage of longer wavelengths of light.


Colony of Chroococcidiopsis-like cells where the different colours represent photosynthesis driven by chlorophyll-a (magenta) and chlorophyll-f (yellow).

Credit: Dennis Nuernberg

The discovery, published today in Science, was led by Imperial College London, supported by the BBSRC, and involved groups from the ANU in Canberra, the CNRS in Paris and Saclay and the CNR in Milan.

The vast majority of life on Earth uses visible red light in the process of photosynthesis, but the new type uses near-infrared light instead. 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.

As scientists have now discovered, it also occurs in a cupboard fitted with infrared LEDs in Imperial College London.

Photosynthesis beyond the red limit

The standard, near-universal type of photosynthesis uses the green pigment, chlorophyll-a, both to collect light and use its energy to make useful biochemicals and oxygen. The way chlorophyll-a absorbs light means only the energy from red light can be used for photosynthesis.

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; that is, the minimum amount of energy needed to do the demanding chemistry that produces oxygen. The red limit is 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.

Until now, it was thought that chlorophyll-f just harvested the light. The new research shows that instead chlorophyll-f plays the key role in photosynthesis under shaded conditions, using lower-energy infrared light to do the complex chemistry. This is photosynthesis 'beyond the red limit'.

Lead researcher Professor Bill Rutherford, from the Department of Life Sciences at Imperial, said: "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."

Preventing damage by light

Another cyanobacterium, Acaryochloris, is already known to do photosynthesis beyond the red limit. However, because it occurs in just this one species, with a very specific habitat, it had been considered a 'one-off'. Acaryochloris lives underneath a green sea-squirt that shades out most of the visible light leaving just the near-infrared.

The chlorophyll-f based photosynthesis reported today represents a third type of photosynthesis that is widespread. However, it is only used in special infrared-rich shaded conditions; in normal light conditions, the standard red form of photosynthesis is used.

It was thought that light damage would be more severe beyond the red limit, but the new study shows that it is not a problem in stable, shaded environments.

Co-author Dr Andrea Fantuzzi, from 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."

These insights could be useful for researchers trying to engineer crops to perform more efficient photosynthesis by using a wider range of light. How these cyanobacteria protect themselves from damage caused by variations in the brightness of light could help researchers discover what is feasible to engineer into crop plants.

Textbook-changing insights

More detail could be seen in the new systems than has ever been seen before in the standard chlorophyll-a systems. The chlorophylls often termed 'accessory' chlorophylls were actually performing the crucial chemical step, rather than the textbook 'special pair' of chlorophylls in the centre of the complex.

This indicates that this pattern holds for the other types of photosynthesis, which would change the textbook view of how the dominant form of photosynthesis works.

Dr Dennis Nürnberg, the first author and initiator of the study, said: "I did not expect that my interest in cyanobacteria and their diverse lifestyles would snowball into a major change in how we understand photosynthesis. It is amazing what is still out there in nature waiting to be discovered."

Peter Burlinson, lead for frontier bioscience at BBSRC - UKRI says, "This is an important discovery in photosynthesis, a process that plays a crucial role in the biology of the crops that feed the world. Discoveries like this push the boundaries of our understanding of life and Professor Bill Rutherford and the team at Imperial should be congratulated for revealing a new perspective on such a fundamental process."

Hayley Dunning | EurekAlert!
Further information:
https://www.imperial.ac.uk/news/186732/new-type-photosynthesis-discovered/
http://dx.doi.org/10.1126/science.aar8313

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>