Diverse strategies of O2 usage for preventing photo-oxidative damage under CO2 limitation during algal photosynthesis

• Shimakawa, Ginga

• Matsuda, Yusuke

• Nakajima, Kensuke

• Tamoi, Masahiro

• Shigeoka, Shigeru

• Miyake, Chikahiro

Abstract

Photosynthesis produces chemical energy from photon energy in the photosynthetic electron transport and assimilates CO 2 using the chemical energy. Thus, CO 2 limitation causes an accumulation of excess energy, resulting in reactive oxygen species (ROS) which can cause oxidative damage to cells. O 2 can be used as an alternative energy sink when oxygenic phototrophs are exposed to high light. Here, we examined the responses to CO 2 limitation and O 2 dependency of two secondary algae, Euglena gracilis and Phaeodactylum tricornutum . In E. gracilis , approximately half of the relative electron transport rate (ETR) of CO 2 -saturated photosynthesis was maintained and was uncoupled from photosynthesis under CO 2 limitation. The ETR showed biphasic dependencies on O 2 at high and low O 2 concentrations. Conversely, in P. tricornutum , most relative ETR decreased in parallel with the photosynthetic O 2 evolution rate in response to CO 2 limitation. Instead, non-photochemical quenching was strongly activated under CO 2 limitation in P. tricornutum . The results indicate that these secondary algae adopt different strategies to acclimatize to CO 2 limitation, and that both strategies differ from those utilized by cyanobacteria and green algae. We summarize the diversity of strategies for prevention of photo-oxidative damage under CO 2 limitation in cyanobacterial and algal photosynthesis.

Journal

• Scientific Reports

  Scientific Reports 7 41022-41022, 2017-01-20

  Nature Publishing Group

Keywords

• Multidisciplinary

Details

• CRID: 1050575520347565696
• NII Article ID: 120005972980
• DOI: 10.1038/srep41022
• ISSN: 20452322
• HANDLE: 20.500.14094/90003824
• Web Site: https://www.nature.com/articles/srep41022.pdf
• Web Site: https://www.nature.com/articles/srep41022
• Text Lang: en
• Article Type: journal article
• Data Source:
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN