Affordable Access

Temperature Dependence of Carbon Isotope Fractionation in CAM Plants.

Authors
  • Deleens, E
  • Treichel, I
  • O'leary, M H
Type
Published Article
Journal
PLANT PHYSIOLOGY
Publisher
American Society of Plant Biologists
Publication Date
Sep 01, 1985
Volume
79
Issue
1
Pages
202–206
Identifiers
PMID: 16664371
Source
Medline
License
Unknown

Abstract

The carbon isotope fractionation associated with nocturnal malic acid synthesis in Kalanchoë daigremontiana and Bryophyllum tubiflorum was calculated from the isotopic composition of carbon-4 of malic acid, after appropriate corrections. In the lowest temperature treatment (17 degrees C nights, 23 degrees C days), the isotope fractionation for both plants is -4 per thousand (that is, malate is enriched in (13)C relative to the atmosphere). For K. daigremontiana, the isotope fractionation decreases with increasing temperature, becoming approximately 0 per thousand at 27 degrees C/33 degrees C. Detailed analysis of temperature effects on the isotope fractionation indicates that stomatal aperture decreases with increasing temperature and carboxylation capacity increases. For B. tubiflorum, the temperature dependence of the isotope fractionation is smaller and is principally attributed to the normal temperature dependences of the rates of diffusion and carboxylation steps. The small change in the isotopic composition of remaining malic acid in both species which is observed during deacidification indicates that malate release, rather than decarboxylation, is rate limiting in the deacidification process.

Report this publication

Statistics

Seen <100 times