Effects of Water and Turgor Potential on Malate Efflux from Leaf Slices of Kalanchoë daigremontiana
- 1 October 1977
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 60 (4), 521-523
- https://doi.org/10.1104/pp.60.4.521
Abstract
Malate efflux from leaf cells of the Crassulacean acid metabolism plant Kalanchoë daigremontiana Hamet et Perrier was studied using leaf slices submerged in experimental solutions. Leaves were harvested at the end of the dark phase and therefore contained high malate levels. Water potentials of solutions were varied between 0 and -5 bar using mannitol (a slowly permeating solute) and ethylene glycol (a rapidly permeating solute), respectively. Mannitol solutions of water potentials down to -5 bar considerably reduced malate efflux. The slowly permeating solute mannitol reduces both water potential and turgor potential of the cells. The water potential of a mannitol solution of -5 bar is just above plasmolyzing concentration. Malate efflux in ethylene glycol at -5 bar was only slightly smaller than at 0 bar, and much higher than in mannitol at -5 bar. Tissues in rapidly permeating ethylene glycol would have turgor potentials similar to tissues in 0.1 mm CaSO(4). The results demonstrate that malate efflux depends on turgor potential rather than on water potential of the cells.Keywords
This publication has 7 references indexed in Scilit:
- Turgor Pressure Sensing in Plant Cell MembranesPlant Physiology, 1976
- Effects of Osmotic Gradients on Vacuolar Malic Acid StoragePlant Physiology, 1975
- The pressure-dependence of the hydraulic conductivity, the membrane resistance and membrane potential during turgor pressure regulation inValonia utricularisThe Journal of Membrane Biology, 1974
- Effects of Rapidly and Slowly Permeating Osmotica on MetabolismPlant Physiology, 1970
- Salt Transport in Valonia : Inhibition of Potassium Uptake by Small Hydrostatic PressuresScience, 1968
- The permeability of the cell membranes of Nitella translucens to urea, and the effect of high concentrations of sucrose on this permeabilityBiochimica et Biophysica Acta (BBA) - Specialized Section on Biophysical Subjects, 1964
- Effect of Water Stress on Cell Wall Metabolism of Avena Coleoptile TissuePlant Physiology, 1960