title: FLUORESCENCE EMISSION SPECTRA OF MARINE AND BRACKISH-WATER ECOTYPES OF FUCUS VESICULOSUS AND FUCUS RADICANS (PHAEOPHYCEAE) REVEAL DIFFERENCES IN LIGHT-HARVESTING APPARATUS(1).
abstract: The Bothnian Sea in the northerly part of the Baltic Sea is a geologically recent brackish-water environment, and rapid speciation is occurring in the algal community of the Bothnian Sea. We measured low-temperature fluorescence emission spectra from the Bothnian Sea and the Norwegian Sea ecotypes of Fucus vesiculosus L., a marine macroalga widespread in the Bothnian Sea. Powdered, frozen thallus was used to obtain undistorted emission spectra. The spectra were compared with spectra measured from the newly identified species Fucus radicans Bergström et L. Kautsky, which is a close relative of F. vesiculosus and endemic to the Bothnian Sea. The spectrum of variable fluorescence was used to identify fluorescence peaks originating in PSI and PSII in this chl c-containing alga. The spectra revealed much higher PSII emission, compared to PSI emission, in the Bothnian Sea ecotype of F. vesiculosus than in F. radicans or in the Norwegian Sea ecotype of F. vesiculosus. The results suggest that more light-harvesting chl a/c proteins serve PSII in the Bothnian Sea ecotype of F. vesiculosus than in the two other algal strains. Treatment of the Bothnian Sea ecotype of F. vesiculosus in high salinity (10, 20, and 35 practical salinity units) for 1 week did not lead to spectral changes, indicating that the measured features of the Bothnian Sea F. vesiculosus are stable and not simply a direct result of exposure to low salinity.
authors.affiliation: Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, SwedenMolecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, FinlandDepartment of Natural Sciences, Engineering and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, SwedenMolecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Maria Gylle
authors.affiliation: Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, SwedenMolecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, FinlandDepartment of Natural Sciences, Engineering and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, SwedenMolecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, Finland.
authors.forename: Susanne
authors.initials: S
authors.lastname: Rantamäki
authors.affiliation: Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, SwedenMolecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, FinlandDepartment of Natural Sciences, Engineering and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, SwedenMolecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, Finland.
authors.forename: Nils G A
authors.initials: NG
authors.lastname: Ekelund
authors.affiliation: Department of Natural Sciences, Engineering and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, SwedenMolecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, FinlandDepartment of Natural Sciences, Engineering and Mathematics, Mid Sweden University, SE-851 70 Sundsvall, SwedenMolecular Plant Biology, Department of Biochemistry and Food Chemistry, University of Turku, FI-20014 Turku, Finland.
authors.forename: Esa
authors.initials: E
authors.lastname: Tyystjärvi
keywords: 77 K emission; Fucus radicans; Fucus vesiculosus; brown algae; chl a/c proteins; fluorescence spectrum; light harvesting; photosystem