Photosynthetic characteristics of phycoerythrin-containing marine Synechococcus spp.

Marine Synechococcus spp. are sufficiently abundant to make a significant contribution to primary productivity in the ocean. They are characterized by containing high cellular levels of phycoerythrin which is highly fluorescent in vivo. We sought (Jan.–Apr., 1984) to determine the adaptive photosynthetic features of two clonal types of Synechococcus spp., and to provide a reliable physiological basis for interpreting remote sensing data in terms of the biomass and productivity of this group in natural assemblages. It was found that the two major clonal types optimize growth and photosynthesis at low photon flux densities by increasing the numbers of photosynthetic units per cell and by decreasing photosynthetic unit size. The cells of clone WH 7803 exhibited dramatic photoinhibition of photosynthesis and reduction in growth rate at high photon flux densities, accompanied by a large and significant increase in phycoerythrin fluorescence. Maximal photosynthesis of cells grown under 10–50 μE m-2 s-1 was reduced by 20 to 30% when the cells were exposed to photon flux densities greater than 150 μE m-2 s-1. However, steady-state levels of photosynthesis maintained for brief periods under these conditions were higher than those of cells grown continuously at high photon flux densities. No photoinhibition occurred in clone WH 8018 and rates of photosynthesis were greater than in WH 7803. Yields of in-vivo phycoerythrin fluorescence under all growth photon flux densities were lower in clone WH 8018 compared to clone WH 7803. Since significant inverse correlations were obtained between phycoerythrin fluorescence and Pmax and μ for both clones grown in laboratory culture, it may be possible to provide a reliable means of assessing the physiological state, photosynthetic capacity and growth rate of Synechococcus spp. in natural assemblages by remote sensing of phycoerythrin fluorescence. Poor correlations between phycoerythrin fluorescene and pigment content indicate that phycoerythrin fluorescence may not accurately estimate Synechococcus spp. biomass based on pigment content alone.

[1]  I. Morris,et al.  Physiology of photosynthesis by marine coccoid cyanobacteria-Some ecological implications , 1981 .

[2]  G. F. Humphrey,et al.  New spectrophotometric equations for determining chlorophylls a, b, c1 and c2 in higher plants, algae and natural phytoplankton , 1975 .

[3]  R. S. Alberte,et al.  Ecotypic differentiation in the marine diatom Skeletonema costatum: influence of light intensity on the photosynthetic apparatus , 1984 .

[4]  M. Tyler,et al.  Photoadaptation and diel periodicity of photosynthesis in the dinoflagellate Prorocentrum mariaelebouriae , 1983 .

[5]  P. Falkowski.  Light-Shade Adaptation in Marine Phytoplankton , 1980 .

[6]  W. Esaias,et al.  Spectral differences and temporal stability of phycoerythrin fluorescence in estuarine and coastal waters due to the domination of labile cryptophytes and stabile cyanobacteria , 1983 .

[7]  Paul W. Johnson,et al.  Chroococcoid cyanobacteria in the sea: A ubiquitous and diverse phototrophic biomass1 , 1979 .

[8]  L. Mets,et al.  PICOSECOND FLUORESCENCE STUDY OF PHOTOSYNTHETIC MUTANTS OF Chlamydomonas reinhardii: ORIGIN OF THE FLUORESCENCE DECAY KINETICS OF CHLOROPLASTS , 1985, Photochemistry and photobiology.

[9]  R. Guillard,et al.  Novel Phycoerythrins in Marine Synechococcus spp. : Characterization and Evolutionary and Ecological Implications. , 1984, Plant physiology.

[10]  J. E. Burris,et al.  Photoinhibition and P700 in the Marine Diatom Amphora sp. , 1981, Plant physiology.

[11]  E. Vierling,et al.  Functional organization and plasticity of the photosynthetic unit of the cyanobacterium Anacystis nidulans , 1980 .

[12]  C. Osmond,et al.  Photoinhibition of intact attached leaves of c(3) plants illuminated in the absence of both carbon dioxide and of photorespiration. , 1979, Plant physiology.

[13]  S. Powles,et al.  Effect of Light Intensity during Growth on Photoinhibition of Intact Attached Bean Leaflets. , 1980, Plant physiology.

[14]  B. Prézelin,et al.  Photosynthetic characteristics and organization of chlorophyll in marine dinoflagellates. , 1978, Proceedings of the National Academy of Sciences of the United States of America.

[15]  Trevor Platt,et al.  Mathematical formulation of the relationship between photosynthesis and light for phytoplankton , 1976 .

[16]  T. G. Owens,et al.  Light-Shade Adaptation : TWO STRATEGIES IN MARINE PHYTOPLANKTON. , 1980, Plant physiology.

[17]  T. A. Kursar,et al.  Photosynthetic Unit Organization in a Red Alga : Relationships between Light-Harvesting Pigments and Reaction Centers. , 1983, Plant physiology.

[18]  C. Critchley.  Studies on the Mechanism of Photoinhibition in Higher Plants: I. EFFECTS OF HIGH LIGHT INTENSITY ON CHLOROPLAST ACTIVITIES IN CUCUMBER ADAPTED TO LOW LIGHT. , 1981, Plant physiology.

[19]  T. A. Kursar,et al.  Morphology of a novel cyanobacterium and characterization of light-harvesting complexes from it: Implications for phycobiliprotein evolution. , 1981, Proceedings of the National Academy of Sciences of the United States of America.

[20]  B. Irwin,et al.  Photosynthesis of picoplankton in the oligotrophic ocean , 1983, Nature.

[21]  H. A. Matlick,et al.  Nutrient-dependent low-light adaptation in the dinoflagellate Gonyaulax polyedra , 1983 .

[22]  B. Prézelin,et al.  Time-course of photoadaptation in the photosynthesis-irradiance relationship of a dinoflagellate exhibiting photosynthetic periodicity , 1980 .

[23]  Y. Fujita,et al.  A probable lack of function of c-type cytochrome in the photosynthetic system of the blue-green alga Anabaena variabilis , 1979 .

[24]  J. Waterbury,et al.  Widespread occurrence of a unicellular, marine, planktonic, cyanobacterium , 1979, Nature.

[25]  P. Falkowski.  Light-shade adaptation and vertical mixing of marine phytoplankton : a comparative field study , 1983 .

[26]  R. Swift,et al.  Airborne dual laser excitation and mapping of phytoplankton photopigments in a Gulf Stream Warm Core Ring. , 1983, Applied optics.

[27]  Katherine Richardson,et al.  ADAPTATION OF UNICELLULAR ALGAE TO IRRADIANCE: AN ANALYSIS OF STRATEGIES , 1983 .

[28]  H. Seliger,et al.  Light-shade adaptation by the oceanic dinoflagellates Pyrocystis noctiluca and P. fusiformis , 1982 .

[29]  T. Platt,et al.  Photoadaptation of carboxylating enzymes and photosynthesis during a spring bloom , 1983 .

[30]  B. Prézelin,et al.  Mechanisms of photoadaptation in three strains of the symbiotic dinoflagellate Symbiodinium microadriaticum , 1983 .

[31]  K. Richardson,et al.  Photoinhibition at low quantum flux densities in a marine dinoflagellate (Amphidinium carterae) , 1982 .

[32]  J. Beardall,et al.  The concept of light intensity adaptation in marine phytoplankton: Some experiments with Phaeodactylum tricornutum , 1976 .

[33]  M. Mimuro,et al.  Quantitative relationship between two reaction centersin the photosynthetic system of blue-green algae , 1979 .

[34]  W. Doolittle,et al.  Phycocyanin synthesis and degradation in the blue-green bacterium Anacystis nidulans , 1977, Journal of bacteriology.

[35]  B. Prézelin,et al.  Photoadaptation of photosynthesis in Gonyaulax polyedra , 1978 .

[36]  R. Guillard,et al.  Studies of marine planktonic diatoms. I. Cyclotella nana Hustedt, and Detonula confervacea (cleve) Gran. , 1962, Canadian journal of microbiology.

[37]  T. Platt,et al.  Autotrophic Picoplankton in the Tropical Ocean , 1983, Science.

[38]  M. Perry,et al.  Photoadaption in marine phytoplankton: Response of the photosynthetic unit , 1981 .