Seawater carbonate chemistry and combined mechanistic effects of CO2 and light on the N2-fixing cyanobacterium Trichodesmium IMS101, 2010, supplement to: Levitan, Orly; Kranz, Sven A; Spungin, D; Prasil, O; Rost, Bjoern; Beran-Frank, Ilana (2010): Combined effects of CO2 and light on the N2-fixing cyanobacterium Trichodesmium IMS101: A mechanistic view. Plant Physiology, 154, 346-356

• Main Authors: Levitan, Orly, Kranz, Sven A, Spungin, D, Prasil, O, Rost, Bjoern, Beran-Frank, Ilana
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2010
• Subjects: Bacteria; Bottles or small containers/Aquaria <20 L; Cyanobacteria; Laboratory experiment; Laboratory strains; Light; Not applicable; Other metabolic rates; Pelagos; Phytoplankton; Primary production/Photosynthesis; Single species; Trichodesmium sp.; Comment; Time in hours; Radiation, photosynthetically active; Experimental treatment; Photosynthetic protein PsbA; Photosynthetic protein PsbA standard deviation; Photosynthetic protein PsbC; Photosynthetic protein PsbC standard deviation; Photosynthetic protein Rubisco; Photosynthetic protein Rubisco, standard deviation; CF1 subunit of ATP synthase protein; CF1 subunit of ATP synthase protein, standard deviation; Iron protein of nitrogenase; Iron protein of nitrogenase, standard deviation; GlnA subunit of Gln synthetase; GlnA subunit of Gln synthetase, standard deviation; Fluorescence, intrinsic; Fluorescence, intrinsic, standard deviation; Fluorescence, maximum; Fluorescence, maximum, standard deviation; Fluorescence, variable; Fluorescence, variable, standard deviation; Maximum photochemical quantum yield of photosystem II; Maximum photochemical quantum yield of photosystem II, standard deviation; Effective absorbance cross-section of photosystem II; Effective absorbance cross-section of photosystem II, standard deviation; Open photosystem II reaction centers; Open photosystem II reaction centers, standard deviation; Electron transport rate of photosystem II per cell; Electron transport rate of photosystem II, standard deviation; Carbonate system computation flag; Salinity; Temperature, water; pH; Carbon dioxide; Partial pressure of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Alkalinity, total; Carbon, inorganic, dissolved; Aragonite saturation state; Calcite saturation state; see references; Calculated using seacarb after Nisumaa et al. 2010; Alkalinity, Gran titration Gran, 1950; Calculated using CO2SYS; European network of excellence for Ocean Ecosystems Analysis EUR-OCEANS; European Project on Ocean Acidification EPOCA; Ocean Acidification International Coordination Centre OA-ICC; Sven; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.777431; https://doi.pangaea.de/10.1594/PANGAEA.777431

The marine diazotrophic cyanobacterium Trichodesmium responds to elevated atmospheric CO2 partial pressure (pCO2) with higher N2 fixation and growth rates. To unveil the underlying mechanisms, we examined the combined influence of pCO2(150 and 900 µatm) and light (50 and 200 µmol photons m-2 s-1) on TrichodesmiumIMS101. We expand on a complementary study that demonstrated that while elevated pCO2 enhanced N2 fixation and growth, oxygen evolution and carbon fixation increased mainly as a response to high light. Here, we investigated changes in the photosynthetic fluorescence parameters of photosystem II, in ratios of the photosynthetic units (photosystem I:photosystem II), and in the pool sizes of key proteins involved in the fixation of carbon and nitrogen as well as their subsequent assimilation. We show that the combined elevation in pCO2 and light controlled the operation of the CO2-concentrating mechanism and enhanced protein activity without increasing their pool size. Moreover, elevated pCO2 and high light decreased the amounts of several key proteins (NifH, PsbA, and PsaC), while amounts of AtpB and RbcL did not significantly change. Reduced investment in protein biosynthesis, without notably changing photosynthetic fluxes, could free up energy that can be reallocated to increase N2 fixation and growth at elevated pCO2 and light. We suggest that changes in the redox state of the photosynthetic electron transportchain and posttranslational regulation of key proteins mediate the high flexibility in resources and energy allocation in Trichodesmium. This strategy should enableTrichodesmium to flourish in future surface oceans characterized by elevated pCO2, higher temperatures, and high light. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI).