Growth, photosynthesis and carbon metabolism in the temperate marine diatom Skeletonema costatum adapted to low temperature and low photon-flux density

Mortain‐Bertrand, Anne; Descolas-Gros, C.; Jupin, Henri

doi:10.1007/bf00392963

Cited by 58 publications

(29 citation statements)

References 37 publications

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“…P-carboxylation may be a compensatory mechanism. High rates of P-carboxylation have previously been observed in S. costatum with suboptimal conditions of light and temperature (Mortain-Bertrand et al 1988b) and by Guy et al (1989) during NH,' assimilation by N-limited green algae. For autotrophic cells, such as diatoms and cyanobacteria grown in light, P-carboxylation occurs using a substrate (phosphoenolpyruvate) derived from the Calvin-Benson cycle; in the dark, phosphoenolpyruvate is obtained from the dissimilation of reserve carbohydrate as is also the case in brown macroalgae (Kremer 1981, Mortain-Bertrand et al 1988a.…”

Section: Discussionmentioning

confidence: 72%

Variations in carboxylase activity in marine phytoplankton cultures, ß-carbolxylation in carbon flux studies

Descolas-Gros¹,

Oriol²

1992

Mar. Ecol. Prog. Ser.

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Inorganic carbon may be assimilated through the Calvin-Benson cycle via the enzyme ribulose-1.5-bisphosphate carboxylase (Rubisco) andlor by 0-carboxylation [via the enzymes phosphoenolpyruvate carboxylase (PEPC), phosphoenolpyruvate carboxykinase (PEPCK) or pyruvate carboxylase]. Here, carboxylase activity measurements for marine phytoplankton are described. Two indices measuring carboxylase activity in marine phytoplankton were used. The first measures Rubisco activity per unit chlorophyll [R/Chl; nmol CO2 (pg chl a+b+c)-' h-'] while the second is the ratio of P-carboxylase activity to Rubisco activity, expressed as % (PC/R), which reflects the proportion of inorganic carbon fixed by these 2 groups of carboxylases. These ratios were studied in (1) different algal species in culture, (2) dunng the different growth phases of a culture, and (3) after a light-dark transition to measure the time response of carboxylase activities. These indices were different from one species to another at the same stage of growth. In autotrophic cells, P-carboxylation remained low (PC/R<40). The PCIR ratio increased significantly when R/Chl began to decrease at the end of the growth phase of a culture of Skeletonerna costaturn. The heterotrophic dinoflagellate Crypthecodinjurn cohnii, grown on an organic medium, incorporated inorganic carbon in the dark through PEPCK activity. The wlde range in PC/R ratio observed among the species confirm that in phytoplankton there may exist a continuum between autotrophy and heterotrophy. From a carbon budget point of view the 2 mechanisms are not equivalent. Rubisco fixation uses light as an energy source and results in gross production; 0-carboxylation also fixes inorganic carbon but as energy source uses metabolites synthesized by other pathways in the cell or from the external medium.

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Section: Discussionmentioning

confidence: 72%

Variations in carboxylase activity in marine phytoplankton cultures, ß-carbolxylation in carbon flux studies

Descolas-Gros¹,

Oriol²

1992

Mar. Ecol. Prog. Ser.

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“…Our experiment further showed an effect of temperature on the fractions of total C, intracellular C and attached C in the light-limited part of the P/E curve (highest fixation/production efficiency at 25°C). This disagrees with the fact that the effect of short-term changes in temperature on the initial slope of a P/E curve is relatively minor (Mortain-Bertrand et al 1988, Falkowski & Raven 1997. In all fractions, highest production rates were normally measured at 25°C, followed by those obtained at 10°C.…”

Section: Discussionmentioning

confidence: 89%

Production of extracellular polymeric substances (EPS) by benthic diatoms: effect of irradiance and temperature

Wolfstein¹,

Stal²

2002

Mar. Ecol. Prog. Ser.

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“…induce structural and functional alterations to the photosynthetic apparatus, such as changes in photosynthetic unit size (Ley, 1986) or alterations in Rubisco activity (Mortain-Bertrand et al, 1988), to maintain the energy balance.…”

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confidence: 99%

“…Sudden imbalances in the energy budget are countered by altering the efficiency of PSII photochemistry via alterations in the trans-thylakoid pH gradient (Foyer et al, 1990). In addition, environmental changes may induce structural and functional alterations to the photosynthetic apparatus, such as changes in photosynthetic unit size (Ley, 1986) or alterations in Rubisco activity (Mortain-Bertrand et al, 1988), to maintain the energy balance.…”

mentioning

confidence: 99%

Growth at Low Temperature Mimics High-Light Acclimation in Chlorella vulgaris

et al. 1994

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Structural and functional alterations to the photosynthetic apparatus after growth at low temperature (5°C) were investigated in the green alga Chlorella vulgaris Beijer. Cells grown at 5'C had a 2-fold higher ratio of chlorophyll a/b, 5-fold lower chlorophyll content, and an increased xanthophyll content compared to cells grown at 27°C even though growth irradiance was kept constant at 150 pmol m-'s-l. Concomitant with the increase in the chlorophyll a/b ratio was a lower abundance of light-harvesting polypeptides in 5'C-grown cells as observed by sodium dodecyl sulfatepolyacrylamide gel electrophoresis and confirmed by western blotting. The differences in pigment composition were found to be alleviated within 12 h of transferring 5°C-grown cells to 27'C.Furthermore, exposure of 5°C-grown cells to a 30-fold lower growth irradiance (5 pmol m-'s-') resulted in pigment content and composition similar to that in cells grown at 27°C and 150 pmol temperature effects on COz-saturated Oz evolution, 5'C-grown cells exhibited light-saturated rates of O2 evolution that were 2.8-and 3.9-fold higher than 27'C-grown cells measured at 27°C and 5'C, respectively. Steady-state chlorophyll a fluorescence indicated that the yield of photosystem 11 electron transport of 5°C-grown cells was less temperature sensitive than that of 27°C-grown cells. This appears to be dueto an increased capacity to keep the primary, stable quinone electron acceptor of photosystem li (OA) oxidized at low temperature in 5°C-compared with 27°C-grown cells regardless of irradiance. We conclude that Chlorella acclimated to low temperature adjusts its photosynthetic apparatus in response to the excitation pressure on photosystem 11 and not to the absolute externa1 irradiance. We suggest that the redox state of Q,, may act as a signal for this photosynthetic acclimation to low temperature in Chlorella. m-2 s -1 . Although both cell types exhibited similar measuringUnder a given set of environmental conditions, photosynthetic organisms attempt to maintain a balance between energy supply through electron transport and energy consumption through carbon fixation. This balance is required to protect the organism from the detrimental effects of excess light while maintaining sufficient pools of ATP and NADPH for cellular metabolism. Sudden imbalances in the energy budget are countered by altering the efficiency of PSII photochemistry via alterations in the trans-thylakoid pH gradient (Foyer et al., 1990). In addition, environmental changes may 535induce structural and functional alterations to the photosynthetic apparatus, such as changes in photosynthetic unit size (Ley, 1986) or alterations in Rubisco activity (Mortain-Bertrand et al., 1988), to maintain the energy balance.A major environmental variable that can perturb the equilibrium between energy input and energy consumption and induce photosynthetic alterations is low temperature. Any phenotypic adjustment of functional or structural properties of the photosynthetic apparatus that can be modulated by envi...

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Growth, photosynthesis and carbon metabolism in the temperate marine diatom Skeletonema costatum adapted to low temperature and low photon-flux density

Cited by 58 publications

References 37 publications

Variations in carboxylase activity in marine phytoplankton cultures, ß-carbolxylation in carbon flux studies

Variations in carboxylase activity in marine phytoplankton cultures, ß-carbolxylation in carbon flux studies

Production of extracellular polymeric substances (EPS) by benthic diatoms: effect of irradiance and temperature

Growth at Low Temperature Mimics High-Light Acclimation in Chlorella vulgaris

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