Abstract
The electrochemical potential differences \(\left( {\Delta \overline \mu _{{\rm K}^ + } } \right)\) for potassium, between excised barley (Hordeum vulgare L.) roots and external media containing 0.05 mM KCl+0.5 mM CaSO4, were determined over a 4-h period during which initially low-K+ roots accumulated K+ by pretreatment in 50 mM KCl plus 0.5 mM CaCl2. This pretreatment resulted in increased internal [K+], decreased K+ influx (as measured from 0.05 mM KCl+0.5 mM CaSO4) and decreased values of \(\Delta \overline \mu _{{\rm K}^ + }\). These observations indicate that the decline of K+ influx associated with increased internal K+ concentration cannot be accounted for by passive adjustment to the electrochemical gradient for this ion.
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References
Bange, G.G.J.: Ionic equilibration of the symplast of low-salt barley roots. Acta Bot. Neerl. 27, 183–198 (1978)
Broyer, T.C., Hoagland, D.R.: Metabolic activities of roots and their bearing on the relation on upward movement of salts and water in plants. Am. J. Bot. 30, 261–283 (1943)
Cornish-Bowden, A., Koshland, D.E.: Diagnostic uses of the Hill (Logit and nernst) plots. J. Mol. Biol. 95, 201–212 (1975)
Cram, W.J.: Relationships between chloride transport and electrical potential differences in carrot root cells. Aust. J. Plant Physiol. 2, 301–310 (1975)
Cram, W.J.: Negative feedback regulation of transport in cells. The maintainance of turgor, volume and nutrient supply. In: Encyclopedia of Plant Physiology, N.S., vol. 2, Transport in Plants, vol. IIA, Cells, pp. 284–316, Lüttge, U., Pitman, M.G., eds. Berlin, Heidelberg, New York: Springer 1976
Cram, W.J., Laties, G.C.: Use of short term and quasi-steady influx in estimating plasmalemma and tonoplast influx in barley root cells at various external and internal chloride concentrations. Aust. J. Biol. Sci. 24, 633–646 (1971)
Dunlop, J.: The electrical potential difference across the tonoplast of root cells. J. Exp. Bot. 27, 908–915 (1976)
Elbrink, J., Bihler, I.: Membrane Transport: its relation to cellular metabolic rates. Science 188, 1177–1184 (1975)
Glass, A.D.M.: The regulation of potassium absorption in barley roots. Plant Physiol. 56, 377–380 (1975)
Glass, A.D.M.: Regulation of potassium absorption in barley roots: an allosteric model. Plant Physiol. 58, 33–37 (1976)
Glass, A.D.M.: Regulation of K+ influx in barley roots. Evidence for direct control by internal K+. Aust. J. Plant Physiol. 4, 313–318 (1977)
Jensen, P., Pettersson, S.: Allosteric regulation of potassium uptake in plant roots. Physiol. Plant. 42, 207–213 (1978)
Johansen, C., Edwards, D.G., Loneragan, J.F.: Potassium fluxes during potassium adsorption by intact barley plants of increasing potassium content. Plant Physiol. 45, 601–603 (1970)
Pitman, M.G., Mertz, S.M., Graves, J.S., Pierce, W.S., Higinbotham, N.: Electrical potential difference in cells of barley roots and their relation to ion uptake. Plant Physiol. 47, 76–80 (1970)
Pitman, M.G., Cram, W.J.: Regulation of ion content in whole plants. Proc. Soc. Exp. Biol. 31, 391–424 (1978)
Post, R.L., Albright, C.D., Dayani, K.: Resolution of pump and leak components of sodium and potassium ion transport in human erythrocytes. J. Gen. Physiol. 50, 1201–1220 (1967)
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Glass, A.D.M., Dunlop, J. The regulation of K+ influx in excised barley roots. Planta 145, 395–397 (1979). https://doi.org/10.1007/BF00388368
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DOI: https://doi.org/10.1007/BF00388368