Abstract
31P-Nuclear-magnetic-resonance spectra of maize (Zea mays L.) root tips, that had been induced to extrude large amounts of H+ in response to fusicoccin (FC) in the presence of potassium salts, indicate that the cytoplasmic pH does not become higher than that of controls. In fact, the cytoplasmic pH may become slightly (approx. 0.1 pH unit) lower in cells extruding H+. Estimations of the buffer capacity of the cells show that without active intracellular pH regulation, H+ extrusion caused by FC would cause the intracellular pH to rise by at least 0.6 pH unit h-1. Our results indicate that intracellular pH is tightly regulated even during extreme rates of acid extrusion, and that a rise in cytoplasmic pH is not the signal linking H+ extrusion with enhanced organic-acid synthesis or other intracellular responses to H+ pumping.
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Abbreviations
- FC:
-
fusicoccin
- Pi :
-
inorganic phosphate
- NMR:
-
nuclear magnetic resonance
- δ:
-
chemical shift
- MDP:
-
methylene diphosphonic acid
References
Abdul-Baki, A.A., Ray, P.M. (1971) Regulation by auxin of carbohydrate metabolism involved in cell wall synthesis by pea stem tissue. Plant Physiol. 47, 537–544
Bassham, J.A., Calvin, M. (1957) The path of carbon in photosynthesis. Prentice-Hall Inc., Englewood Cliffs, N.J.
Burt, C.T., Cohen, S.M., Bárány, M. (1979) Analysis of intact tissue with 31P NMR. Annu. Rev. Biophys. Bioeng. 8, 1–25
Davies, D.D. (1973) Control of and by pH. Symp. Soc. Exp. Biol. 27, 513–529
Davies, D.D. (1979) The central role of phosphoenolpyruvate in plant metabolism. Annu. Rev. Plant Physiol. 30, 131–158
Hiatt, A.G. (1967) Reactions in vitro of enzymes involved in CO2 fixation accompanying salt uptake by barley roots. Z. Pflanzenphysiol. 56, 233–245
Jackson, P.C., Adams, H.R. (1963) Cation-anion balance during potassium and sodium absorption by barley roots. J. Gen. Physiol. 46, 369–386
Jacoby, B., Laties, G.G. (1971) Bicarbonate fixation and malate compartmentation in relation to salt-induced stoichiometric synthesis of organic acid. Plant Physiol. 47, 525–531
Johnson, K.D., Rayle, D.L. (1976) Enhancement of CO2 uptake in Avena coleoptiles by fusicoccin. Plant Physiol. 57, 806–811
Lado, P., De Michelis, M.I., Cerana, R., Marrè, E. (1976) Fusicoccin-induced, K+-stimulated proton secretion and acid growth of apical root segments. Plant Sci. Lett. 6, 5–20
Marrè, E. (1979) Fusicoccin: a tool in plant physiology. Annu. Rev. Plant Physiol. 30, 273–288
Matile, Ph. (1978) Biochemistry and function of vacuoles. Annu. Rev. Plant Physiol. 29, 193–213
Moon, R.B., Richards, J.H. (1973) Determination of intracellular pH by 31p magnetic resonance. J. Biol. Chem. 248, 7276–7278
Osmond, C.B. (1976) Ion absorption and carbon metabolism in cells of higher plants. In: Encyclopedia of plant physiology, [N.S.], vol. 2A, pp. 347–372, Lüttge, U., Pitman, M.G., eds., Springer, Berlin
Raven, J.A., Smith, F.A. (1976) Cytoplasmic pH regulation and electrogenic H+ extrusion. Curr. Adv. Plant Sci. 8, 649–660
Raven, J.A., De Michelis, M.I. (1979) Acid-base regulation during nitrate assimilation in Hydrodictyon africanum. Plant, Cell and Environment 2, 245–257
Raven, J.A., De Michelis, M.I. (1980a) Acid-base regulation during ammonium assimilation in Hydrodictyon africanum. Plant, Cell and Environment 3, 325–338
Raven, J.A., De Michelis, M.I. (1980b) Acid-base regulation during ammonium and nitrate assimilation in Hydrodictyon africanum. In. Plant Membrane Transport, 579–600, Spanswich, R.M., Lucas, W.J., Dainty, J., eds.. Elsevier/North-Holland, Amsterdam
Rayle, D.L., Cleland, R.E. (1977) Control of plant cell enlargement by hydrogen ions. Curr. Top. Dev. Biol. 11, 187–214
Roberts, J.K.M., Ray, P.M., Wade-Jardetzky, N., Jardetzky, O. (1980) Estimation of cytoplasmic and vacuolar pH in higher plant cells by 31P NMR. Nature (London) 283, 870–872
Smith, F.A., Raven, J.A. (1979) Intracellular pH and its regulation. Annu. Rev. Plant Physiol. 30, 289–311
Torii, K., Laties, G.G. (1966) Organic acid synthesis in response to excess cation absorption in vacuolate and non-vacuolate sections of corn and barley roots. Plant Cell Physiol. 7 395–403
Ulrich, A. (1941) Metabolism of non-volatile organic acids in excised barley roots as related to cation-anion balance during salt accumulation. Am. J. Bot. 28, 526–537
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Roberts, J.K.M., Ray, P.M., Wade-Jardetzky, N. et al. Extent of intracellular pH changes during H+ extrusion by maize root-tip cells. Planta 152, 74–78 (1981). https://doi.org/10.1007/BF00384988
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DOI: https://doi.org/10.1007/BF00384988