Publication Date:
2024-03-15
Description:
The combination of elevated CO2 and the increased acidity in surface oceans is likely to have an impact on photosynthesis via its effects on inorganic carbon speciation and on the overall energetics of phytoplankton. Exposure to UV radiation (UVR) may also have a role in the response to elevated CO2 and acidification, due to the fact that UVR may variously impact on photosynthesis and because of the energy demand of UVR defense. The cell may gain energy by down-regulating the CO2 concentrating mechanism, which may lead to a greater ability to cope with UVR and/or higher growth rates. In order to clarify the interplay of cell responses to increasing CO2 and UVR, we investigated the photosynthetic response of the marine and estuarine diatom Cylindrotheca closterium f. minutissima cultured at either 390 (ambient) or 800 (elevated) ppmv CO2, while exposed to solar radiation with or without UVR (UVR, 280-400 nm). After a 6 day acclimation period, the growth rate of cells was little affected by elevated CO2 and no obvious correlation with the radiation dose (for both PAR and PAR + UV treatments) could be detected. However, the relative electron transport rate was reduced and was more sensitive to UVR in cells main - tained at elevated CO2 as compared to cells cultured at ambient CO2. The CO2 concentrating mechanism was down regulated at 800 ppmv CO2, but was apparently not completely switched off. These data are discussed with respect to their significance in the context of global climate change.
Keywords:
Alkalinity, total; Alkalinity, total, standard deviation; Aragonite saturation state; Bicarbonate ion; Bicarbonate ion, reciprocal of photosynthetic affinity value; Bicarbonate ion, reciprocal of photosynthetic affinity value, standard deviation; Bicarbonate ion, standard deviation; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calculated; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, reciprocal of photosynthetic affinity value; Carbon, inorganic, dissolved, reciprocal of photosynthetic affinity value, standard deviation; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, reciprocal of photosynthetic affinity value; Carbon dioxide, reciprocal of photosynthetic affinity value, standard deviation; Cell density; Cell density, standard deviation; Chromista; Cylindrotheca closterium; Effective quantum yield; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; Growth rate, standard deviation; Identification; Incubation duration; Initial slope of rapid light curve; Laboratory experiment; Laboratory strains; Light; Light saturation; Linear slope, photosynthesis/dissolved organic carbon curve; Linear slope, photosynthesis/dissolved organic carbon curve, standard deviation; Maximal electron transport rate, relative; Maximum potential capacity of photosynthesis; Maximum potential capacity of photosynthesis, standard deviation; Myzozoa; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Ochrophyta; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; pH, standard deviation; Phytoplankton; Potentiometric; Primary production/Photosynthesis; Radiation, photosynthetically active, dose daily; Salinity; Single species; Species; Temperature, water; Time of day; Treatment; Ultraviolet-a radiation, dose daily; Ultraviolet-b radiation, dose daily
Type:
Dataset
Format:
text/tab-separated-values, 3736 data points
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