Featured Research

from universities, journals, and other organizations

Dual role of carbon dioxide in photosynthesis: Pioneering findings

Date:
April 13, 2014
Source:
Ume universitet
Summary:
Carbon dioxide, in its ionic form bicarbonate, has a regulating function in the splitting of water in photosynthesis, researchers have found. This means that carbon dioxide has an additional role to being reduced to sugar. The pioneering work opens up a new research field where researchers can investigate possible biological and ecological consequences of the dual role of carbon dioxide.

Co-worker Sergey Koroidov is working in green light with the mass spectrometric experiments.
Credit: Image courtesy of Ume universitet

Researchers at Ume University in Sweden have found that carbon dioxide, in its ionic form bicarbonate, has a regulating function in the splitting of water in photosynthesis. This means that carbon dioxide has an additional role to being reduced to sugar.

The pioneering work is published in the latest issue of the Proceedings of the National Academy of Sciences.

It is well known that inorganic carbon in the form of carbon dioxide, CO2, is reduced in a light driven process known as photosynthesis to organic compounds in the chloroplasts. Less well known is that inorganic carbon also affects the rate of the photosynthetic electron transport and thus the rate of photosynthetic oxygen production. This result was first published by the Nobel Prize winner Otto Warburg and his collaborator in the late 50s.

Their explanation for the stimulating effect was logical at that time since they proposed that carbon dioxide was the source of the oxygen that plants produce. Their idea was proven to be incorrect many years later and instead we now know that water, H2O, is the source of oxygen in the atmosphere.

The observed stimulating effect by inorganic carbon on photosynthetic electron transport, has continued to cause an inflammatory debate among photosynthetic researchers around the world and resulted in hundreds of papers published on this issue.

"Our results will now put an end to this debate," says Johannes Messinger, Professor at the Department of Chemistry.

His research group has developed a very sensitive techniques based on "Membrane Inlet Mass Spectroscopy" that can be used to measure the production of gases in photosynthetic samples under analytically controlled conditions.

With this sensitive method they were able to test an earlier hypothesis that bicarbonate is acting as an acceptor for the protons that are produced when water is split in photosystem II. If so, a light driven production of carbon dioxide in addition to oxygen should be detected.

To their delight, the scientists could detect relatively large amounts of carbon dioxide in the mass spectrometric experiments.

"Therefore, it seems as if two different carbon species, both derived from the carbonic acid cycle, have got the optimal chemical properties to be used as terminal electron acceptor (CO2) in the very end of the photosynthetic reaction and at the same time as proton acceptor (HCO3-) in the very beginning of the photosynthetic reaction," says Johannes Messinger.

The results open up a new research field where researchers can investigate possible biological and ecological consequences of the dual role of carbon dioxide.


Story Source:

The above story is based on materials provided by Ume universitet. Note: Materials may be edited for content and length.


Journal Reference:

  1. S. Koroidov, D. Shevela, T. Shutova, G. Samuelsson, J. Messinger. Mobile hydrogen carbonate acts as proton acceptor in photosynthetic water oxidation. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1323277111

Cite This Page:

Ume universitet. "Dual role of carbon dioxide in photosynthesis: Pioneering findings." ScienceDaily. ScienceDaily, 13 April 2014. <www.sciencedaily.com/releases/2014/04/140413154053.htm>.
Ume universitet. (2014, April 13). Dual role of carbon dioxide in photosynthesis: Pioneering findings. ScienceDaily. Retrieved September 18, 2014 from www.sciencedaily.com/releases/2014/04/140413154053.htm
Ume universitet. "Dual role of carbon dioxide in photosynthesis: Pioneering findings." ScienceDaily. www.sciencedaily.com/releases/2014/04/140413154053.htm (accessed September 18, 2014).

Share This



More Earth & Climate News

Thursday, September 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Researchers Explore Shipwrecks Off Calif. Coast

Researchers Explore Shipwrecks Off Calif. Coast

AP (Sep. 16, 2014) Federal researchers are exploring more than a dozen underwater sites where they believe ships sank in the treacherous waters west of San Francisco in the decades following the Gold Rush. (Sept. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins