Long-term photoacclimation of Haslea ostrearia (Bacillariophyta): effect of irradiance on growth rates, pigment content and photosynthesis

Mouget, Jean‐Luc; Tremblin, Gérard; Morant-Manceau, Annick; Morançais, Michèle; Robert, Jean Michel

doi:10.1017/s0967026299002073

Cited by 28 publications

(46 citation statements)

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“…The species-specific effects observed during the succession of the diatom community, agree with previous observations on periphyton communities colonising artificial substratum (Bothwell et al 1993;Santas et al 1997). UVBR treatment effects-Interestingly, the clearest UVBR effect on species level in our experiment was the decreased abundance of one of the commonest species, H. ostrearia, a taxon known to adapt well to high PAR levels (Mouget et al 1999). H. ostrearia is known for its blue water-soluble pigment marennine, which functions as a light-shield in the long-wavelength region (Schubert et al 1995), but apparently has no shielding function for UVBR.…”

Section: Discussionmentioning

confidence: 75%

Effects of UVB radiation on a marine microphytobenthic community growing on a sand‐substratum under different nutrient conditions

Wulff

Wängberg

Sundbäck

et al. 2000

Limnology & Oceanography

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The effect of ultraviolet-B radiation (UVBR) on a microphytobenthic community, dominated by diatoms, was studied under different nutrient conditions in a 9 day outdoor experiment on the Swedish west coast. The microalgal assemblage was isolated from the sediment and resettled onto acid-cleaned sand placed in petridishes. The experimental treatments were: ''ambient'' or ''enhanced'' UVBR with no nutrient addition, ''ambient'' or ''enhanced'' UVBR with nutrient addition (N, P, Si). Enhanced UVBR (ϩ15%) was provided by a computer-controlled system. Primary productivity, carbon allocation, chlorophyll a (Chl a) concentrations, composition of algae and pigments and intra-and extracellular carbohydrate fractions were measured. Most UVBR effects were seen in treatments without nutrient addition. Exposure to enhanced UVBR resulted in statistically significant decreases in primary productivity, Chl a and in the biomass of Haslea ostrearia and Nitzschia spp. The relative amount of carbon allocated to proteins increased when exposed to enhanced UVBR. The effect of enhanced UVBR on microalgae subjected to nutrient addition was less pronounced, and observed for Chl a, algal intracellular storage of carbohydrates (glucans) and concentration of extracellular ''colloidal'' carbohydrates. Enhanced UVBR ϩ nutrients resulted in a significantly greater ratio between glucan and total carbohydrates and a decreased concentration of colloidal carbohydrates compared to the ambient UVBR ϩ nutrients treatment. These results indicate that availability of inorganic nutrients acts to mitigate the negative effects of UVBR on microphytobenthic communities and that UVBR acts as a selective force during early growth and succession.

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Section: Discussionmentioning

confidence: 75%

Effects of UVB radiation on a marine microphytobenthic community growing on a sand‐substratum under different nutrient conditions

Wulff

Wängberg

Sundbäck

et al. 2000

Limnology & Oceanography

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“…Descriptions of photoacclimation processes are often based on data interpretation from photosynthesis-irradiance response curves, which usually involve short-term responses of some expression of photosynthetic rates and a notion of an achievable steady-state photosynthetic rate that is within the time constraints of the experiment. For example, Mouget et al (1999) found that the diatom Haslea ostrearia acclimated to high irradiance and had lower maximum photosynthetic rate and maximum light utilization coefficient when expressed on a per cell basis; however, these assertions were reversed when the same data were normalized on a Chl a basis. Different normalization currencies and physiological steady states have been extensively used in the literature with little precision in their definition and the practical work involved.…”

Section: Discussionmentioning

confidence: 99%

Physiological steady state of phytoplankton in the field? An example based on pigment profile of Emiliania huxleyi (Haptophyta) during a light shift

Leonardos

2008

Limnology & Oceanography

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A calcifying strain of Emiliania huxleyi was used to study the photoacclimation process during a shift from low (LL) to high (HL) photon flux density (PFD) under nutrient-replete and pH-and [CO 2 ]-controlled continuous cultures. Physiological steady states were obtained after culturing the alga in each PFD for more than a month, and pigment profiles and cell volume changes were monitored for 25 d after the light shift. Fucoxanthin was the major carotenoid in LL, while under HL this role was assumed by 199hexanoyloxyfucoxanthin (19Hex). The photoprotective pigments diadinoxanthin and diatoxanthin (Dd+Dt), normalized to chlorophyll a (Chl a), increased with increasing PFD, while Chl a content per cell and Chl c's and fucoxanthin, normalized to Chl a, decreased with increasing PFD. The sum of all carotenoids normalized to Chl a and the 19Hex+Fuco : Chl c ratio were remarkably constant from LL to HL conditions. The results confirm that the total amount of carotenoids was synthesized/catabolized in tandem with Chl a to a genetically predefined level independent of PFD. When normalized to a per cell basis, Chl a content reached the long-term HL steady state after 17-20 d, while Chl c, Fuco, and Dd+Dt, normalized to Chl a, reached the long-term HL steady state after 5-7 d. Growth rate adjustment was completed within 3 d after the transition to HL. When Chl a was normalized to cellular volume, the transition to a fully acclimated HL state was complete within 3 d. The results highlight the need for the critical evaluation of the normalization ''currency'' (i.e., cell number, volume, Chl a) to which mass is expressed during the photoacclimation process and suggest that natural phytoplankton populations are unlikely to ever be in true physiological steady state.

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“…Phytoplankton are noted for their ability to adjust their intracellular concentrations of light-harvesting and xanthophyll cycle pigments in response to ambient light conditions (Mouget et al 1999). An important protection mechanism against increased light intensity is the thermal dissipation of excess energy by xanthophyll cycle pigments in their de-epoxidated state.…”

Section: Introductionmentioning

confidence: 99%

Photosynthetic activation of the dark-acclimated diatom <i>Thalassiosira weissflogii</i> upon light exposure

Katayama

Murata

Taguchi

2015

Plankton Benthos Res

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Abstract:The photoresponse of chlorophyll a (Chl a) fluorescence and xanthophyll pigments to light was studied in the diatom Thalassiosira weissflogii with respect to various durations of dark storage. The light-limited slope (α) obtained from the electron transport rate (ETR) versus the irradiance curve remained steady, whereas the light-saturated rate (ETR max ) decreased gradually during dark storage. Consequently the light-saturation index (E k =ETR max /α) decreased with time, suggesting that cells acclimate to dark conditions. Dark-acclimated cells were exposed to light-dark conditions with varied silicate availability. The maximum quantum yield of PSII (F v /F m ), as well as the changes in the α and the ETR max , increased immediately to the maximum on the first day and decreased for the second half of the light exposure period. The ratio of diatoxanthin (DT) to the xanthophyll pigment diadinoxanthin (DD) and DT (DT/ [DD+DT]) represents thermal dissipation behavior through non-photochemical quenching (NPQ). This study indicates that F v /F m and E k are a good index to follow photoacclimation during a transition from continuous dark conditions to the L-D cycle of saturated light. This study also indicates that dark-acclimated T. weissflogii can acclimate to the growth irradiance by the enhancement of photosynthetic activity with changes in xanthophyll pigments, in relation to the dark duration and silicate availability. Such a response to light suggests that the vegetative cells of T. weissflogii could possibly proliferate at ports in the coastal zone on a global scale after ejection into high light environments from the darkness of a ship s ballast water tank.

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Long-term photoacclimation of Haslea ostrearia (Bacillariophyta): effect of irradiance on growth rates, pigment content and photosynthesis

Cited by 28 publications

References 0 publications

Effects of UVB radiation on a marine microphytobenthic community growing on a sand‐substratum under different nutrient conditions

Effects of UVB radiation on a marine microphytobenthic community growing on a sand‐substratum under different nutrient conditions

Physiological steady state of phytoplankton in the field? An example based on pigment profile of Emiliania huxleyi (Haptophyta) during a light shift

Photosynthetic activation of the dark-acclimated diatom <i>Thalassiosira weissflogii</i> upon light exposure

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