Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists clarify light harvesting in green algae

28.11.2019

Algae are indispensable because they generate about 50% of primary organic matter and account for about 50% of all oxygen on Earth. They produce oxygen through oxygenic photosynthesis -a biological process that "harvests" light and turns it into chemical energy.

A new study by Chinese and Japanese researchers has now characterized the light-harvesting system of Chlamydomonas reinhardtii, a common unicellular green alga. This research enhances understanding of the molecular basis for efficient light harvesting as well as photoprotection in green algae under variable light conditions.


Structures of C2S2M2L2 and C2S2 -type PSII-LHCII supercomplex from a green algae

Credit: Dr. LIU Zhenfeng's group

The study was conducted by Dr. LIU Zhenfeng's group from the Institute of Biophysics (IBP) of the Chinese Academy of Sciences and Dr. Jun Minagawa from Japan's National Institute for Basic Biology. Results were published online in Nature Plants on Nov. 25, 2019 in an article entitled "Structural insights into light harvesting for photosystem II in green algae."

Oxygenic photosynthesis in algae and plants relies on photosystem II (PSII) molecules and light-harvesting complex II (LHCII) molecules, and their associated supercomplexes, to convert light energy into chemical energy. For example, PSII catalyzes the splitting of water molecules into oxygen and protons. PSII also assembles with LHCII at the peripheral region to absorb photon energy efficiently.

C. reinhardtii has been an important model for photosynthesis research over the past few decades as well as a platform for the production of high-value products such as biofuel and pharmaceutical compounds. Its LHCII molecules join with PSII molecules to form the C2S2M2L2 supercomplex - the largest known algae or plant PSII-LHCII supercomplex, in addition to the smaller C2S2-type supercomplex.

The researchers solved the structures of both C2S2M2L2 and C2S2 by using cryo-electron microscopy (cryo-EM). They also deciphered in great detail the assembly mechanisms and energy transfer pathways of the two supercomplexes.

Their research shows that the LHCII trimer strongly associated with the PSII core (C) contains three distinct subunits, namely, LhcbM1, LhcbM2 and LhcbM3. Two special lipid molecules mediate the interactions between LhcbM1 and the PSII core antenna CP43.

Furthermore, they discovered that one pair of moderately associated LHCII trimers (M-LHCII) and an additional pair of loosely associated LHCII trimers (L-LHCII) attach at the peripheral region of the C2S2 supercomplex, leading to the formation of the C2S2M2L2 > supercomplex.

By analyzing the structure of C2S2M2L2 supercomplex, the scientists found that the minor antenna complexes CP29 and CP26 contain several green algae-specific regions that are absent in homologs from land plants. They discovered that these special regions on CP29 play a crucial role in linking L-LHCII and M-LHCII and stabilizing the resulting assembly, whereas those of CP26 strengthen its own interactions with S-LHCII (LHCII strongly-associated with PSII).

In addition, using quantitative analysis of chlorophyll-chlorophyll relationships, the team unraveled multiple energy transfer routes from L-LHCII, M-LHCII and S-LHCII to PSII, thus explaining the fundamental steps of the light-harvesting process in green algae.

###

The project was funded by the National Key R&D Program of China, the National Natural Science Foundation of China, the Strategic Priority Research Program and the Key Research Program of Frontier Sciences of CAS, among others.

Media Contact

LIU Zhenfeng
liuzf@ibp.ac.cn

http://english.cas.cn/ 

LIU Zhenfeng | EurekAlert!

More articles from Life Sciences:

nachricht When plants bloom
29.11.2019 | Max-Planck-Institut für Molekulare Pflanzenphysiologie

nachricht Harnessing the power of CRISPR in space and time
29.11.2019 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How do scars form? Fascia function as a repository of mobile scar tissue

Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.

Fibroblasts kit - ready to heal wounds

Im Focus: McMaster researcher warns plastic pollution in Great Lakes growing concern to ecosystem

Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.

In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...

Im Focus: Machine learning microscope adapts lighting to improve diagnosis

Prototype microscope teaches itself the best illumination settings for diagnosing malaria

Engineers at Duke University have developed a microscope that adapts its lighting angles, colors and patterns while teaching itself the optimal...

Im Focus: Small particles, big effects: How graphene nanoparticles improve the resolution of microscopes

Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.

Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...

Im Focus: Atoms don't like jumping rope

Nanooptical traps are a promising building block for quantum technologies. Austrian and German scientists have now removed an important obstacle to their practical use. They were able to show that a special form of mechanical vibration heats trapped particles in a very short time and knocks them out of the trap.

By controlling individual atoms, quantum properties can be investigated and made usable for technological applications. For about ten years, physicists have...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

High entropy alloys for hot turbines and tireless metal-forming presses

05.11.2019 | Event News

 
Latest News

When plants bloom

29.11.2019 | Life Sciences

Harnessing the power of CRISPR in space and time

29.11.2019 | Life Sciences

New evolutionary insights into the early development of songbirds

29.11.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>