This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (34) Citing Articles via Google Scholar Google Scholar Articles by Palet, A. Articles by Azcón-Bieto, J. Search for Related Content PubMed PubMed Citation Articles by Palet, A. Articles by Azcón-Bieto, J. Agricola Articles by Palet, A. Articles by Azcón-Bieto, J.

Metabolism and Enzymology

Short-Term Effects of Carbon Dioxide on Carnation Callus Cell Respiration ¹

Departament de Biologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain, Departament de Bioquímica i Fisiologia, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain

The addition of potassium bicarbonate to the electrode cuvette immediately stimulated the rate of dark O₂ uptake of photomixotrophic and heterotrophic carnation (Dianthus caryophyllus L.) callus, of Elodea canadensis (Michx) leaves, and of other plant tissues. This phenomenon occurred at pH values lower than 7.2 to 7.8, and the stimulation depended on the concentration of gaseous CO₂ in the solution. These stimulatory responses lasted several minutes and then decreased, but additional bicarbonate or gaseous CO₂ again stimulated respiration, suggesting a reversible effect. Carbonic anhydrase in the solution increased the stimulatory effect of potassium bicarbonate. The CO₂/bicarbonate dependent stimulation of respiration did not occur in animal tissues such as rat diaphragm and isolated hepatocytes, and was inhibited by salicylhydroxamic acid in carnation callus cells and E. canadensis leaves. This suggested that the alternative oxidase was engaged during the stimulation in plant tissues. The cytochrome pathway was severely inhibited by CO₂/bicarbonate either in the absence or in the presence of the uncoupler carbonylcyanide m-chlorophenyl hydrazone. The activity of cytochrome c oxidase of callus tissue homogenates was also inhibited by CO₂/bicarbonate. The results suggested that high carbon dioxide levels (mainly free CO₂) partially inhibited the cytochrome pathway (apparently at the oxidase level), and this block in electron transport elicited a large transient engagement of the alternative oxidase when present uninhibited.

This article has been cited by other articles:

				R. Spicer and N. M. Holbrook Effects of carbon dioxide and oxygen on sapwood respiration in five temperate tree species J. Exp. Bot., April 1, 2007; 58(6): 1313 - 1320. [Abstract] [Full Text] [PDF]

				H. GREENWAY, W. ARMSTRONG, and T. D. COLMER Conditions Leading to High CO2 (>5 kPa) in Waterlogged-Flooded Soils and Possible Effects on Root Growth and Metabolism Ann. Bot., July 1, 2006; 98(1): 9 - 32. [Abstract] [Full Text] [PDF]