Dark respiration causes an increase in leaf CO2 concentration (Ci), and the continuing increases in atmospheric [CO2] further increases Ci. Elevated leaf CO2 concentration causes stomatal pores to close. Here, we demonstrate that high intracellular CO2/HCO3 (-) enhances currents mediated by the Arabidopsis thaliana guard cell S-type anion channel SLAC1 upon coexpression of any one of the Arabid...

[This corrects the article DOI: 10.1186/s40425-015-0086-9.].

The rate of active H+ secretion (JH) across the luminal cell membrane of the turtle bladder decreases linearly with the chemical (delta pH) or electrical potential gradient (delta psi) against which secretion occurs. To examine the control of JH from the cell side of the pump, acid-base changes were imposed on the cellular compartment by increasing serosal[HCO3-] at constant PCO2 or by varying ...

Acid-base regulation in rainbow trout acclimated to about 3, 100 and SOOmmolP Na and Cl~, at constant water [HCO3~], was assessed during 24h of exposure to 1 % CO2 and during recovery. The respiratory acidosis induced by a rise in plasma Pco2 to about 1.15kPa (8.5mmHg, Smmoll" ), 1.33kPa (lOmmHg, lOOmmoir) or 1.5 kPa (11.2 mmHg, SOOmmoll") was partially compensated for by accumulation of plasma...

Applications of speleothem calcite geochemistry in climate change studies require the evaluation of the accuracy and sensitivity of speleothem proxies to correctly infer paleoclimatic information. The present study of Harrison’s Cave, Barbados, uses the analysis of the modern climatology and groundwater system to evaluate controls on the C and O isotopic composition of modern speleothems. This ...

Fast Reaction Kinetics, Pulse Conductometry, Peroxyl Radicals, Radiation Chemistry The kinetics of the reactions of CO2 + OH -»HCO3 (i) and barbituric acid ^barbiturate anion -jH+ (ii) have been remeasured using as a new approach the pulse radiolysis technique with optical and conductivity detection. The rate constants obtained in the present study, ki (21 °C) = 6900 ± 700 M^s"1 and ku (19 °C) ...

Eubacterium acidaminophilum combines the oxidation of amino acids such as alanine or valine with the reduction of glycine to acetate in a two-substrate fermentation (Stickland reaction). In the absence of glycine, dense cell suspensions oxidized alanine or valine only to a small extent, with limited production of hydrogen and acetate. Experiments with 14C-labeled carbonate revealed that acetate...

We describe an enzymatic method, requiring only 10 mul of serum, for determining CO2 as bicarbonate or dissolved gas. Phosphoenolpyruvate carboxylase catalyzes the reaction of HCO3- with phosphoenolypyruvate to give oxalacetate. The resulting NADH, in the presence of malate dehydrogenase, is oxidized to NAD+, and the decrease in absorbance at 340 nm is directly proportional to the amount of CO2...

In cyanobacteria, the CO2-concentrating mechanism (CCM) is a vital biological process that provides effective photosynthetic CO2 fixation by elevating the CO2 level near the active site of Rubisco. This process enables the adaptation of cyanobacteria to various habitats, particularly in CO2-limited environments. Although CCM of freshwater and marine cyanobacteria are well studied, there is limi...

The processes of CO2 acquisition were characterized for the acid-tolerant, free-living chlorophyte alga, CPCC 508. rDNA data indicate an affiliation to the genus Coccomyxa, but distinct from other known members of the genus. The alga grows over a wide range of pH from 3.0 to 9.0. External carbonic anhydrase (CA) was detected in cells grown above pH 5, with the activity increasing marginally fro...