RRC ID 48684
著者 Shimakawa G, Matsuda Y, Nakajima K, Tamoi M, Shigeoka S, Miyake C.
タイトル Diverse strategies of O2 usage for preventing photo-oxidative damage under CO2 limitation during algal photosynthesis.
ジャーナル Sci Rep
Abstract Photosynthesis produces chemical energy from photon energy in the photosynthetic electron transport and assimilates CO2 using the chemical energy. Thus, CO2 limitation causes an accumulation of excess energy, resulting in reactive oxygen species (ROS) which can cause oxidative damage to cells. O2 can be used as an alternative energy sink when oxygenic phototrophs are exposed to high light. Here, we examined the responses to CO2 limitation and O2 dependency of two secondary algae, Euglena gracilis and Phaeodactylum tricornutum. In E. gracilis, approximately half of the relative electron transport rate (ETR) of CO2-saturated photosynthesis was maintained and was uncoupled from photosynthesis under CO2 limitation. The ETR showed biphasic dependencies on O2 at high and low O2 concentrations. Conversely, in P. tricornutum, most relative ETR decreased in parallel with the photosynthetic O2 evolution rate in response to CO2 limitation. Instead, non-photochemical quenching was strongly activated under CO2 limitation in P. tricornutum. The results indicate that these secondary algae adopt different strategies to acclimatize to CO2 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 CO2 limitation in cyanobacterial and algal photosynthesis.
巻・号 7
ページ 41022
公開日 2017-1-20
DOI 10.1038/srep41022
PII srep41022
PMID 28106164
PMC PMC5247695
MeSH Carbon Dioxide / metabolism* Diatoms / metabolism* Electron Transport Energy Metabolism Euglena gracilis / metabolism* Oxidative Stress* Oxygen / metabolism* Photosynthesis*
IF 3.998
引用数 14
WOS 分野 PLANT SCIENCES
リソース情報
藻類 NIES-48