Phenotypic changes in the fluidity of the tonoplast membrane of crassulacean-acid-metabolism plants in response to temperature and salinity stress

Abstract

Electron paramagnetic resonance-spectroscopic studies on spin-labeled purified tonoplast membranes showed that in the obligate crassulacean-acid-metabolism (CAM) plant Kalanchoë daigremontiana Hamet et Perr. the fluidity of the tonoplast decreased during acclimation to higher temperatures. This phenotypic change in tonoplast fluidity was paralleled by a decrease in the mobilization of malic acid from the vacuoles during CAM in the light. The shift from the C3 to the CAM mode of photosynthesis in the facultative CAM plant Mesembryanthemum crystallinum L. also led to a decrease in the fluidity of the tonoplast membrane. The results are consistent with the hypothesis that the ability to store malic acid during CAM in the vacuoles depends largely on the actual fluidity of the tonoplast membrane.

Effects of High Night Temperature on Crassulacean Acid Metabolism (CAM) Photosynthesis ofKalanchoë pinnataandAnanas comosus

“…It is conceivable that at night, higher effl ux rates of malate can be counter-balanced by a higher rate of active malate transport into the vacuole, and the change in tonoplast fl uidity would alter the resistance to the diffusion of the relative lipophilic undissociated malate out of the vacuole, thus allowing malate accumulation. In addition, the acclimation of CAM to higher temperatures is accompanied with an alteration of tonoplast fl uidity (Kliemchen et al, 1993). These fi ndings are consistent with this study, indicating that malate accumulation is not only dependent on the cytoplasmic enzyme, but also is infl uenced by the properties of tonoplast.…”

Generation of rhythmic and arrhythmic behaviour of Crassulacean acid metabolism in Kalancho� daigremontiana under continuous light by varying the irradiance or temperature: Measurements in vivo and model simulations

“…This would affect the rate of passive effiux of malic acid from the vacuole to the cytoplasm, and thus determine the capacity for malate accumulation in the vacuole, as shown by Friemert et al (1988). Kliemchen et al (1993) demonstrated that plants of K. daigremontiana grown at higher temperatures had developed tonoplast membranes with a higher state of order than plants grown at lower temperatures. The vacuoles of the former could keep higher malate levels at higher temperatures than those of the latter.…”

Chlorophyll Fluorescence and Organic Acid Oscillations during Transition from CAM to C3-photosynthesis inClusia minor L. (Clusiaceae)

“…3) while rates of CO 2 uptake during the middle to the end of the light period increased. It has been shown that temperature aects nocturnal accumulation and diurnal decarboxylation of malic acid due to changes in the permeability of the tonoplast membrane, which determines the rate of passive eux of malic acid from the vacuole (Friemert et al, 1988;Kluge et al, 1991;Kliemchen et al, 1993). High temperatures increase tonoplast permeability and thus may reduce the vacuolar capacity for nocturnal storage of organic acids.…”