title: Temperature-Induced Remodeling of the Photosynthetic Machinery Tunes Photosynthesis in the Thermophilic AlgaCyanidioschyzon merolae.
abstract: The thermophilic algaC. merolaethrives in extreme environments (low pH and temperature between 40°C and 56°C). In this study, we investigated the acclimation process of the alga to a colder temperature (25°C). A long-term cell growth experiment revealed an extensive remodeling of the photosynthetic apparatus in the first 250 h of acclimation, which was followed by cell growth to an even higher density than the control (grown at 42°C) cell density. Once the cells were shifted to the lower temperature, the proteins of the light-harvesting antenna were greatly down-regulated and the phycobilisome composition was altered. The amount of PSI and PSII subunits was also decreased, but the chlorophyll to photosystems ratio remained unchanged. The 25°C cells possessed a less efficient photon-to-oxygen conversion rate and require a 2.5 times higher light intensity to reach maximum photosynthetic efficiency. With respect to chlorophyll, however, the photosynthetic oxygen evolution rate of the 25°C culture was 2 times higher than the control. Quantitative proteomics revealed that acclimation requires, besides remodeling of the photosynthetic apparatus, also adjustment of the machinery for protein folding, degradation, and homeostasis. In summary, these remodeling processes tuned photosynthesis according to the demands placed on the system and revealed the capability ofC. merolaeto grow under a broad range of temperatures.
authors.affiliation: Institute of Plant Biology and Biotechnology (D.N., D.W., M.S., T.B., M.H.), Institute for Evolution and Biodiversity (J.P.S.), University of Münster, 48143 Münster, Germany.
authors.forename: Denitsa
authors.initials: D
authors.lastname: Nikolova
authors.affiliation: Institute of Plant Biology and Biotechnology (D.N., D.W., M.S., T.B., M.H.), Institute for Evolution and Biodiversity (J.P.S.), University of Münster, 48143 Münster, Germany.
authors.forename: Dieter
authors.initials: D
authors.lastname: Weber
authors.affiliation: Institute of Plant Biology and Biotechnology (D.N., D.W., M.S., T.B., M.H.), Institute for Evolution and Biodiversity (J.P.S.), University of Münster, 48143 Münster, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Scholz
authors.affiliation: Institute of Plant Biology and Biotechnology (D.N., D.W., M.S., T.B., M.H.), Institute for Evolution and Biodiversity (J.P.S.), University of Münster, 48143 Münster, Germany.
authors.forename: Till
authors.identifier: http://orcid.org/0000-0001-5341-0079
authors.initials: T
authors.lastname: Bald
authors.affiliation: Institute of Plant Biology and Biotechnology (D.N., D.W., M.S., T.B., M.H.), Institute for Evolution and Biodiversity (J.P.S.), University of Münster, 48143 Münster, Germany.
authors.forename: Jörn Peter
authors.identifier: http://orcid.org/0000-0003-4291-6853
authors.initials: JP
authors.lastname: Scharsack
authors.affiliation: Institute of Plant Biology and Biotechnology (D.N., D.W., M.S., T.B., M.H.), Institute for Evolution and Biodiversity (J.P.S.), University of Münster, 48143 Münster, Germany mhippler@uni-muenster.de.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0001-9670-6101
authors.initials: M
authors.lastname: Hippler
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D020418:Algal Proteins / Q000378:metabolism; D006706:Homeostasis / Q000528:radiation effects; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000378:metabolism; D010788:Photosynthesis / Q000502:physiology*; D045331:Photosystem I Protein Complex / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism; D045524:Phycobilisomes / Q000378:metabolism; D000461:Rhodophyta / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects; D013696:Temperature; D020524:Thylakoids / Q000378:metabolism / Q000528:radiation effects
chemical_list: D020418:Algal Proteins; D045342:Light-Harvesting Protein Complexes; D045331:Photosystem I Protein Complex; D045332:Photosystem II Protein Complex; D045524:Phycobilisomes