The role of temperature in the regulation of the circadian rhythm of CO2 fixation in Bryophyllum fedtschenkoi

Carter, P. J., Wilkins, M. B., Nimmo, H. G. and Fewson, C. A. (1995) The role of temperature in the regulation of the circadian rhythm of CO2 fixation in Bryophyllum fedtschenkoi. Planta, 196(2), pp. 381-386. (doi: 10.1007/BF00201399)

Abstract

Detached leaves of Bryophyllum fedtschenkoi Hamet et Perrier kept in normal air show a single period of net CO2 fixation on transfer to constant darkness at temperatures in the range 0–25 °C. The duration of this initial fixation period is largely independent of temperature in the range 5–20 °C, but lengthens very markedly at temperatures below 4 °C, and is reduced at temperatures above 25 °C. The onset of net fixation of CO2 on transfer of leaves to constant darkness is immediate at low temperatures, but is delayed as the temperature is increased. The ambient temperature also determines whether or not a circadian rhythm of CO2 exchange occurs. The rhythm begins to appear at about 20 °C, is most evident at 30 °C and becomes less distinct at 35 °C. The occurrence of a distinct circadian rhythm in CO2 output at 30° C in the absence of a detectable rhythm in PEPCase kinase activity shows that the kinase rhythm is not a mandatory requirement for the rhythm of PEPCase activity. However, when it occurs, the kinase rhythm undoubtedly amplifies the PEPCase rhythm.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Nimmo, Professor Hugh
• Authors: Carter, P. J., Wilkins, M. B., Nimmo, H. G., and Fewson, C. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Planta
• Publisher: Springer
• ISSN: 0032-0935
• ISSN (Online): 1432-2048