A dynamic model of photoadaptation in phytoplankton

We present a new dynamic model that uses a small number of prescribed parameters to predict the chlorophyll a:carbon ratio and growth rate of phytoplankton in both constant and varying irradiance. The model provides a self-contained description of energy and mass fluxes and regulation of partitioning of photosynthate during phytoplankton adaptation to irradiance. The kinetics and steady-state outcomes of photoadaptation are described in terms of changes in the rates of synthesis of three intracellular carbon pools. These pools account for the distribution of cell material between light-harvesting components, the biosynthetic apparatus, and energy storage compounds. Regulation of the flow of recent photosynthate to these pools is controlled by the ratio of realized to potential photosynthetic electron flow at a given instant. The responses of growth rate and Chl a:C to static and dynamic irradiance regimes can be adequately described by specifying four parameters: the initial slope of the photosynthesis-irradiance curve, the maximum growth rate, the maximum Chl a:C observed under light limitation, and the maintenance metabolic rate. The model predictions compared favorably with observations of the diatoms Thalassiosira pseudonana and Phaedactylum tricornutum.

[1]  C. Lancelot,et al.  Biochemical fractionation of primary production by phytoplankton in Belgian coastal waters during short- and long-term incubations with 14C-bicarbonate , 1985 .

[2]  J. Marra.  Phytoplankton photosynthetic response to vertical movement in a mixed layer , 1978 .

[3]  T. Zohary,et al.  Ultraphytoplankton in the eastern Mediterranean Sea: towards deriving phytoplankton biomass from flow cytometric measurements of abundance, fluorescence and light scatter , 1993 .

[4]  B. Shuter,et al.  A model of physiological adaptation in unicellular algae. , 1979, Journal of theoretical biology.

[5]  E. Laws,et al.  A theoretical and experimental examination of the predictions of two recent models of phytoplankton growth , 1983 .

[6]  T. Piatt,et al.  A mechanistic model of photoadaptation in microalgae , 1986 .

[7]  G. Janowitz,et al.  An Eulerian Model of Phytoplankton Photosynthetic Response in the Upper Mixed Layer , 1991 .

[8]  G. Evans,et al.  Towards a model of ocean biogeochemical processes , 1993 .

[9]  Paul G. Falkowski,et al.  Light-saturated photosynthesis — Limitation by electron transport or carbon fixation? , 1987 .

[10]  P. Falkowski,et al.  Light intensity regulation of cab gene transcription is signaled by the redox state of the plastoquinone pool. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[11]  C. Langdon.  On the causes of interspecific differences in the growth-irradiance relationship for phytoplankton. II. A general review , 1988 .

[12]  P. Glibert,et al.  Effect of irradiances up to 2000 μE m−2 s−1 on marine Synechococcus WH7803—II. Photosynthetic responses and mechanisms , 1987 .

[13]  A. T. Chan.  COMPARATIVE PHYSIOLOGICAL STUDY OF MARINE DIATOMS AND DINOFLAGELLATES IN RELATION TO IRRADIANCE AND CELL SIZE. I. GROWTH UNDER CONTINUOUS LIGHT 1, 2 , 1978 .

[14]  T. Platt,et al.  Turbulent motions may control phytoplankton photosynthesis in the upper ocean , 1984, Nature.

[15]  John J. Cullen,et al.  The deep chlorophyll maximum comparing vertical profiles of chlorophyll a , 1982 .

[16]  J. Raven.  A COST‐BENEFIT ANALYSIS OF PHOTON ABSORPTION BY PHOTOSYNTHETIC UNICELLS , 1984 .

[17]  Paul G. Falkowski,et al.  Growth‐irradiance relationships in phytoplankton1 , 1985 .

[18]  T. Platt.  DISTRIBUTION OF CARBON AMONG PHOTOSYNTHETIC END‐PRODUCTS IN PHYTOPLANKTON OF THE EASTERN CANADIAN ARCTIC 1 , 1982 .

[19]  A. Bergmann,et al.  RHYTHMIC REGULATION OF THE LIGHT‐HARVESTING CHLOROPHYLL alb PROTEIN and THE SMALL SUBUNIT OF RIBULOSE‐1,5‐BISPHOSPHATE CARBOXYLASE mRNA IN RYE SEEDLINGS , 1990, Photochemistry and photobiology.

[20]  J. Raven,et al.  LIGHT DEPENDENCE OF GROWTH AND PHOTOSYNTHESIS IN PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE) 1 , 1985 .

[21]  T. G. Owens.  Light-Harvesting Function in the Diatom Phaeodactylum tricornutum: II. Distribution of Excitation Energy between the Photosystems. , 1986, Plant physiology.

[22]  R. S. Alberte,et al.  A diatom light-harvesting pigment-protein complex : purification and characterization. , 1984, Plant physiology.

[23]  C. Gallegos,et al.  Vertical advection of phytoplankton and productivity estimates: a dimensional analysis , 1985 .

[24]  W. G. Harrison,et al.  Carbon flow into the end-products of photosynthesis in short and long incubations of a natural phytoplankton population , 1982 .

[25]  D. Lean,et al.  Night synthesis of protein by algae1 , 1984 .

[26]  P. Falkowski,et al.  Photoregulation of the Light-Harvesting Chlorophyll Protein Complex Associated with Photosystem II in Dunaliella tertiolecta: Evidence that Apoprotein Abundance but Not Stability Requires Chlorophyll Synthesis. , 1990, Plant physiology.

[27]  J. Cullen,et al.  The kinetics of algal photoadaptation in the context of vertical mixing , 1988 .

[28]  H. Wittmann.  Components of bacterial ribosomes. , 1982, Annual review of biochemistry.

[29]  T. G. Owens,et al.  Light-Harvesting Function in the Diatom Phaeodactylum tricornutum: I. Isolation and Characterization of Pigment-Protein Complexes. , 1986, Plant physiology.

[30]  P. Falkowski,et al.  Light Intensity-Induced Changes in cab mRNA and Light Harvesting Complex II Apoprotein Levels in the Unicellular Chlorophyte Dunaliella tertiolecta. , 1991, Plant physiology.

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

[32]  M. Perry,et al.  An immunoprobe to measure Rubisco concentrations and maximal photosynthetic rates of individual phytoplankton cells , 1992, Limnology and oceanography.

[33]  Z. Dubinsky,et al.  Changes in the Levels of Ribulose-l,5-bisphosphate Carboxylase/Oxygenase (Rubisco) in Tetraedron minimum (Chlorophyta) during Light and Shade Adaptation , 1989 .

[34]  C. Thurston,et al.  Protein Turnover in Chlorella fusca var. vacuolata: Measurement of the Overall Rate of Intracellular Protein Degradation using Isotope Exchange with Water , 1980 .

[35]  R. Geider.  Respiration: Taxation Without Representation? , 1992 .

[36]  J. Raven,et al.  Temperature and algal growth , 1988 .

[37]  G. Lorimer,et al.  Ribulose-1,5-bisphosphate carboxylase-oxygenase. , 1983, Annual review of biochemistry.

[38]  A. T. Chan.  COMPARATIVE PHYSIOLOGICAL STUDY OF MARINE DIATOMS AND DINOFLAGELLATES IN RELATION TO IRRADIANCE AND CELL SIZE. II. RELATIONSHIP BETWEEN PHOTOSYNTHESIS, GROWTH, AND CARBON/CHLOROPHYLL a RATIO 1, 2 , 1980 .

[39]  W. F. Thompson,et al.  Physiological and Molecular Studies of Light-Regulated Nuclear Genes in Higher Plants , 1991 .

[40]  D. Kiefer,et al.  A steady state description ofgrowth and light absorption in the marine planktonic diatom Skeletonema costatum , 1989 .

[41]  J. Frenette,et al.  Photoadaptation to intermittent light across the St. Lawrence Estuary freshwater-saltwater transition zone , 1994 .

[42]  R. Foy,et al.  The role of carbohydrate accumulation in the growth of planktonic Oscillatoria species , 1980 .

[43]  W. Richard,et al.  TEMPERATURE AND PHYTOPLANKTON GROWTH IN THE SEA , 1972 .