Growing Hyphae of Achlya bisexualis Generate a Longtitudinal pH Gradient in the Surrounding Medium Free

Abstract

Growing hyphae of were found to generate a longitudinal pH gradient in the surrounding medium; the medium adjacent to the tip was slightly more alkaline than the bulk phase, while that near distal parts was acidic. The profile of external pH paralleled that of electric current, as measured with a vibrating probe; the apical alkaline zone corresponded to the region of current inflow. In organisms grown in complete medium, both current flow and apical alkalinization were inhibited when amino acid uptake was blocked, either by removing amino acids from the medium or by raising the external pH to 8·5. could, however, adapt to a medium deficient in organic nutrients; elongating hyphae again generated both the pH profile and the transcellular electric current. It is proposed that both the pH profile and the electric current are manifestations of a transcellular proton current, which arises from the segregation of proton pumps from proton leaks. Symport of protons with amino acids may be one mechanism by which protons enter the hyphal apex.

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1984-11-01
2024-03-28
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References

  1. Armbruster B.L., Weisensebl M.H. 1983; Ionic currents traverse growing hyphae and sporangia of the mycelial water mold Achyladebaryana. Protoplasma 115:65–69
    [Google Scholar]
  2. Cabib E., Duran A., Bowers B. 1979; Localized activation of chitin synthetase in the initiation of yeast septum formation. In Fungal Walls and Hyphal Growth pp. 189–201 Edited by Burnett J.H., Trinci St A.P.J. Cambridge: Cambridge University Press;
    [Google Scholar]
  3. Eddy A.A. 1982; Mechanisms of solute transport in microorganisms. Advances in Microbial Physiology 23:1–78
    [Google Scholar]
  4. Goffeau A., Slayman C.W. 1981; The proton- translocating ATPase of the fungal plasma membrane. Biochimica et biophysicaacta 639:197–223
    [Google Scholar]
  5. Gooday G.W. 1978; The enzymology of hyphal growth. In The Filamentous Fungi 3 pp. 51–77 Smith J.E., Berry D.R. Edited by London: Edward Arnold;
    [Google Scholar]
  6. Gooday G.W. 1983; The hyphal tip. In Recent Advances in Fungal Morphogenesis pp. 315–356 Smith J.E. New York: Marcel Dekker;
    [Google Scholar]
  7. Gooday G.W., Trinci A.P.J. 1980; Wall structure and biosynthesis in fungi. Symposia of the Society for General Microbiology 30:207–251
    [Google Scholar]
  8. Gow N.A.R. 1984; Transhyphal electrical currents in fungi. Journal of General Microbiology in the Press
    [Google Scholar]
  9. Grovb S.N., Bracker C.E. 1980; Protoplasmic organization of hyphal tips among fungi; vesicles and Spitzenkdrper. Journal of Bacteriology 104:989–1009
    [Google Scholar]
  10. Harold F.M. 1982; Pumps and currents; a biological perspective. Current Topics in Membranes and Transport 16:485–516
    [Google Scholar]
  11. Hill T.W., Mullins J.T. 1980; Hyphal tip growth in Achlya. I.Cytoplasmic organization. Canadian Journal of Microbiology 26:1132–1140
    [Google Scholar]
  12. Howard R.J. 1981; Ultrastructural analysis of hyphal tip cell growth in fungi; Spitzenkdrper. Journal of Cell Science 48:89–103
    [Google Scholar]
  13. Jaffe L.F. 1979; Control of development by ionic currents. In Membrane Transduction Mechanisms.Society for General Physiologists Series 33 pp. 199–231 Edited by Cone R.A., Dowling J.E. New York: Raven Press;
    [Google Scholar]
  14. Jaffe L.F. 1981; The role of ionic currents in establishing developmental pattern. Philosophical Transactions of the Royal Society of London B295:553–566
    [Google Scholar]
  15. Jaffe L.F., Nuccitelli R. 1974; An ultrasensitive vibrating probe for measuring steady extracellular currents. Journal of Cell Biology 63:614–628
    [Google Scholar]
  16. Jaffe L.F., Nuccitelli R. 1977; Electrical controls of development. Annual Review of Biophysics and Bioengineering 6:445–476
    [Google Scholar]
  17. Kropf D.L., Lupa M.D.A., Caldwell J.H., Harold F.M. 1983; Cell polarity: Endogenous ion currents precede and predict branching in the water mold Achlya. Science 220:1385–1387
    [Google Scholar]
  18. Kropf D.L., Caldwell J.H., Gow N.A.R., Harold F.M. 1984; Symport of protons with amino acids carries transcellular current into hyphal tips. Journal of Cell Biology 99:486–496
    [Google Scholar]
  19. Mitchell P. 1976; Vectorial chemistry and molecular mechanics of chemiosmotic coupling: power transmission by proticity. Biochemical Society Transactions 4:399–439
    [Google Scholar]
  20. Sanders D.L., Slayman C.L. 1982; Control of intracellular pH.Predominant role of oxidative metabolism, not proton transport, in the eukaryotic microorganism Neurospora. Journal of General Physiology 80:377–402
    [Google Scholar]
  21. Slevers A., Schnepf E. 1981; Morphogenesis and polarity of tubular cells with tip growth. In Cytomorphogenesis in Plants 8 pp. 265–299 Edited by Kicmager O. Vienna: Springer Verlag;
    [Google Scholar]
  22. Smith F.A., Raven J.A. 1979; Intracellular pH and its regulation. Annual Review of Plant Physiology 30:289–311
    [Google Scholar]
  23. Stump R.F., Robinson K.R., Harold R.L., Harold F.M. 1980; Endogenous electrical currents in the water mold Blastocladiellaemersoniiduring growth and sporulation. Proceedings of the National Academy of Sciences of the United States of America 77:6673–6677
    [Google Scholar]
  24. Turian G. 1979; Cytochemical gradients and mitochondrial exclusion in the apices of vegetative hyphae. Experientia 35:1164–1166
    [Google Scholar]
  25. Turian G. 1981; Low pH in fungal bud initials. Experientia 37:1278–1279
    [Google Scholar]
  26. Zalokar M. 1959; Enzyme activity and cell differentiation in Neurospora. American Journal of Botany 46:555–559
    [Google Scholar]
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