Data Description

Levitan, O et al. (2010): Seawater carbonate chemistry and combined mechanistic effects of CO2 and light on the N2-fixing cyanobacterium Trichodesmium IMS101, 2010. doi:10.1594/PANGAEA.777431,
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, doi:10.1104/pp.110.159285
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).
#NameShort NameUnitPrincipal InvestigatorMethodComment
1Comment *CommentLevitan, Orly *
2Time in hours *TimehLevitan, Orly *
3Radiation, photosynthetically active *PARµE/m2/sLevitan, Orly *
4Experimental treatment *Exp trtmLevitan, Orly *
5Photosynthetic protein PsbA *PsbApmol/µgLevitan, Orly *see reference(s) *
6Photosynthetic protein PsbA standard deviation *PsbA std dev±Levitan, Orly *
7Photosynthetic protein PsbC *PsaCpmol/µgLevitan, Orly *see reference(s) *
8Photosynthetic protein PsbC standard deviation *PsaC std dev±Levitan, Orly *
9Photosynthetic protein Rubisco *RbcLpmol/mgLevitan, Orly *see reference(s) *
10Photosynthetic protein Rubisco, standard deviation *RbcL std dev±Levitan, Orly *
11CF1 subunit of ATP synthase protein *AtpBpmol/mgLevitan, Orly *see reference(s) *
12CF1 subunit of ATP synthase protein, standard deviation *AtpB std dev±Levitan, Orly *
13Iron protein of nitrogenase *NifHpmol/mgLevitan, Orly *see reference(s) *
14Iron protein of nitrogenase, standard deviation *NifH std dev±Levitan, Orly *
15GlnA subunit of Gln synthetase *GlnApmol/mgLevitan, Orly *see reference(s) *
16GlnA subunit of Gln synthetase, standard deviation *GlnA std dev±Levitan, Orly *
17Fluorescence, intrinsic *FoLevitan, Orly *see reference(s) *
18Fluorescence, intrinsic, standard deviation *Fo std dev±Levitan, Orly *
19Fluorescence, maximum *FmLevitan, Orly *see reference(s) *
20Fluorescence, maximum, standard deviation *Fm std dev±Levitan, Orly *
21Fluorescence, variable *FvLevitan, Orly *see reference(s) *
22Fluorescence, variable, standard deviation *Fv std dev±Levitan, Orly *
23Maximum photochemical quantum yield of photosystem II *Fv/FmLevitan, Orly *see reference(s) *
24Maximum photochemical quantum yield of photosystem II, standard deviation *Fv/Fm std dev±Levitan, Orly *
25Effective absorbance cross-section of photosystem II *sigma PSIIA2/quantaLevitan, Orly *see reference(s) *
26Effective absorbance cross-section of photosystem II, standard deviation *sigma PSII std dev±Levitan, Orly *
27Open photosystem II reaction centers *PSIIopen#Levitan, Orly *see reference(s) *
28Open photosystem II reaction centers, standard deviation *PSIIopen std dev±Levitan, Orly *
29Electron transport rate of photosystem II per cell *ETR PSII#/#/sLevitan, Orly *see reference(s) *
30Electron transport rate of photosystem II, standard deviation *ETR PSII std dev±Levitan, Orly *
31Carbonate system computation flag *CSC flagNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *
32Salinity *SalLevitan, Orly *
33Temperature, water *Temp°CLevitan, Orly *
34pH *pHNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *Total scale
35Carbon dioxide *CO2µmol/kgNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *
36Partial pressure of carbon dioxide (water) at sea surface temperature (wet air) *pCO2water_SST_wetµatmNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *
37Fugacity of carbon dioxide (water) at sea surface temperature (wet air) *fCO2water_SST_wetµatmNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *
38Bicarbonate ion *[HCO3]-µmol/kgNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *
39Carbonate ion *[CO3]2-µmol/kgNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *
40Alkalinity, total *ATµmol/kgLevitan, Orly *Alkalinity, Gran titration (Gran, 1950) *
41Carbon, inorganic, dissolved *DICµmol/kgLevitan, Orly *Calculated using CO2SYS *
42Aragonite saturation state *Omega ArgNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *
43Calcite saturation state *Omega CalNisumaa, Anne-Marin *Calculated using seacarb after Nisumaa et al. (2010) *
608 data points

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