Identification of Rhythmic Subsystems in the Circadian Cycle of Crassulacean Acid Metabolism under Thermoperiodic Perturbations
-
A. Bohn
Abstract
Leaves of the Crassulacean acid metabolism (CAM) plant Kalanchoë daigremontiana Hamet et Perrier de la Bâthie show overt circadian rhythms in net CO2 uptake, leaf conductance to water and intercellular CO2 concentration, which are entrained by periodic temperature cycles. To probe their sensitivity to thermoperiodic perturbations, intact leaves were exposed to continuous light intensity and temperature cycles with a period of 16 h, applying a set of different baseline temperatures and thermodriver amplitudes. All three overt rhythms were analyzed with respect to their frequency spectra and their phase relations with the thermodriver. For most stimulation protocols, stomatal conductance and net CO2 change were fully or partially entrained by the temperature pulses, while the internal CO2 concentration remained dominated by oscillations in the circadian range. Prolonged time series recorded for up to 22 d in continuous light underline the robustness of these circadian oscillations. This suggests that the overt circadian rhythm of net CO2 uptake in CAM results from the interaction of two coupled original systems: (i) an endogenous cycle of CO2 fixation in the mesophyll, showing very robust periodic activity, and (ii) stomatal movements that respond to environmental stimuli independently of rhythmic processes in the mesophyll, and thus modulate the gas exchange amplitude.
Copyright © 2003 by Walter de Gruyter GmbH & Co. KG
Artikel in diesem Heft
- The Circadian Clock of the Unicellular Eukaryotic Model Organism Chlamydomonas reinhardtii
- Cardiovascular Control by the Suprachiasmatic Nucleus: Neural and Neuroendocrine Mechanisms in Human and Rat
- Synchronization of the Molecular Clockwork by Light- and Food-Related Cues in Mammals
- Identification of Rhythmic Subsystems in the Circadian Cycle of Crassulacean Acid Metabolism under Thermoperiodic Perturbations
- Age-Dependent Effects of Conditioning on Cholinergic and Vasopressin Systems in the Rat Suprachiasmatic Nucleus
- The Magnetofection Method: Using Magnetic Force to Enhance Gene Delivery
- The Protease Inhibitor Bikunin, a Novel Anti-Metastatic Agent
- Transcriptional Regulation of the Urokinase Receptor (u-PAR) – A Central Molecule of Invasion and Metastasis
- Identification and Characterization of KAT, a Novel Gene Preferentially Expressed in Several Human Cancer Cell Lines
- Trichostatin A and Structurally Related Histone Deacetylase Inhibitors Induce 5-Lipoxygenase Promoter Activity
- Treatment of Tumor Cells with Histone Deacetylase Inhibitors Results in Altered Recruitment of Methyl-CpG Binding Proteins to a Methylated CpG Island
- Intra- and Interspecies Interactions between Prion Proteins and Effects of Mutations and Polymorphisms
- Contribution of the Absolutely Conserved B8Gly to the Foldability of Insulin
- Fabin, a Novel Calcyon-Like and Glucanase-Like Protein with Mitogenic, Antifungal and Translation-Inhibitory Activities from Broad Beans
- Quantification of Elastase-Like Activity in 13 Human Cancer Cell Lines and in an Immortalized Human Epithelial Cell Line by RP-HPLC
- Differences in the Activation Mechanism between the α and β Subunits of Human Meprin
Artikel in diesem Heft
- The Circadian Clock of the Unicellular Eukaryotic Model Organism Chlamydomonas reinhardtii
- Cardiovascular Control by the Suprachiasmatic Nucleus: Neural and Neuroendocrine Mechanisms in Human and Rat
- Synchronization of the Molecular Clockwork by Light- and Food-Related Cues in Mammals
- Identification of Rhythmic Subsystems in the Circadian Cycle of Crassulacean Acid Metabolism under Thermoperiodic Perturbations
- Age-Dependent Effects of Conditioning on Cholinergic and Vasopressin Systems in the Rat Suprachiasmatic Nucleus
- The Magnetofection Method: Using Magnetic Force to Enhance Gene Delivery
- The Protease Inhibitor Bikunin, a Novel Anti-Metastatic Agent
- Transcriptional Regulation of the Urokinase Receptor (u-PAR) – A Central Molecule of Invasion and Metastasis
- Identification and Characterization of KAT, a Novel Gene Preferentially Expressed in Several Human Cancer Cell Lines
- Trichostatin A and Structurally Related Histone Deacetylase Inhibitors Induce 5-Lipoxygenase Promoter Activity
- Treatment of Tumor Cells with Histone Deacetylase Inhibitors Results in Altered Recruitment of Methyl-CpG Binding Proteins to a Methylated CpG Island
- Intra- and Interspecies Interactions between Prion Proteins and Effects of Mutations and Polymorphisms
- Contribution of the Absolutely Conserved B8Gly to the Foldability of Insulin
- Fabin, a Novel Calcyon-Like and Glucanase-Like Protein with Mitogenic, Antifungal and Translation-Inhibitory Activities from Broad Beans
- Quantification of Elastase-Like Activity in 13 Human Cancer Cell Lines and in an Immortalized Human Epithelial Cell Line by RP-HPLC
- Differences in the Activation Mechanism between the α and β Subunits of Human Meprin
