title: Reactive oxygen production induced by near-infrared radiation in three strains of the Chl d-containing cyanobacterium Acaryochloris marina.
abstract: Cyanobacteria in the genus Acaryochloris have largely exchanged Chl a with Chl d, enabling them to harvest near-infrared-radiation (NIR) for oxygenic photosynthesis, a biochemical pathway prone to generate reactive oxygen species (ROS). In this study, ROS production under different light conditions was quantified in three Acaryochloris strains (MBIC11017, HICR111A and the novel strain CRS) using a real-time ethylene detector in conjunction with addition of 2-keto-4-thiomethylbutyric acid, a substrate that is converted to ethylene when reacting with certain types of ROS. In all strains, NIR was found to generate less ROS than visible light (VIS). More ROS was generated if strains MBIC11017 and HICR111A were adapted to NIR and then exposed to VIS, while strain CRS demonstrated the opposite behavior. This is the very first study of ROS generation and suggests that Acaryochloris can avoid a considerable amount of light-induced stress by using NIR instead of VIS for its photosynthesis, adding further evolutionary arguments to their widespread appearance.
authors.affiliation: Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, DK-3000, Denmark ; Section for Microbiology, Department of Biology, University of Copenhagen, Sølvgade, DK-1307, Denmark.
authors.forename: Lars
authors.initials: L
authors.lastname: Behrendt
authors.affiliation: Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, DK-3000, Denmark.
authors.forename: Marc
authors.initials: M
authors.lastname: Staal
authors.affiliation: Life Science Trace Gas Facility, Radboud University Nijmegen, Heyendaalseweg, 6525 AJ, Netherlands.
authors.forename: Simona M
authors.initials: SM
authors.lastname: Cristescu
authors.affiliation: Life Science Trace Gas Facility, Radboud University Nijmegen, Heyendaalseweg, 6525 AJ, Netherlands.
authors.forename: Frans Jm
authors.initials: FJ
authors.lastname: Harren
authors.affiliation: Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology Sydney, Sydney, NSW 2007, Australia.
authors.forename: Martin
authors.initials: M
authors.lastname: Schliep
authors.affiliation: Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology Sydney, Sydney, NSW 2007, Australia.
authors.forename: Anthony Wd
authors.initials: AW
authors.lastname: Larkum
authors.affiliation: Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, DK-3000, Denmark ; Plant Functional Biology and Climate Change Cluster, School of the Environment, University of Technology Sydney, Sydney, NSW 2007, Australia ; Singapore Centre on Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Nanyang, Singapore.
authors.forename: Michael
authors.initials: M
authors.lastname: Kühl