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. 1985 Jan;77(1):136–141. doi: 10.1104/pp.77.1.136

Effect of pH on Orthophosphate Uptake by Corn Roots 1

Hervé Sentenac 1, Claude Grignon 1
PMCID: PMC1064471  PMID: 16663996

Abstract

Orthophosphate (Pi) influx in washed corn roots was studied with experimental conditions allowing a distinction of pH effects on Pi ionization in the medium and on the transport system itself. There appeared to be no relationship between the pH dependencies of membrane potential, H+ secretion, and 32Pi influx. The Pi uptake versus pH curves were compared to the calculated ones describing the concentrations of the different ionized Pi forms in the medium and in the cell walls; the latter were obtained using the theoretical model described by Sentenac and Grignon (1981) Plant Physiol 68: 415-419). The conclusion was that the transported form is H2PO4− and the concentration sensed by the transport system is the local one. The ionic compositions of experimental media were manipulated to ensure constant pH and various H2PO4− concentrations, or constant H2PO4− concentration and various pH values in the walls. The kinetic analysis of the results in the micromolar range showed that the transport system has an intrinsic sensitivity to pH, and is switched from a low activity state at pH > 6 to a high activity one at pH < 4 (pH in the walls). This change could be triggered by the protonation of a group with pK 5.5.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Arnon D. I., Fratzke W. E., Johnson C. M. HYDROGEN ION CONCENTRATION IN RELATION TO ABSORPTION OF INORGANIC NUTRIENTS BY HIGHER PLANTS. Plant Physiol. 1942 Oct;17(4):515–524. doi: 10.1104/pp.17.4.515. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. CRESTFIELD A. M., STEIN W. H., MOORE S. Alkylation and identification of the histidine residues at the active site of ribonuclease. J Biol Chem. 1963 Jul;238:2413–2419. [PubMed] [Google Scholar]
  3. Carter O. G., Lathwell D. J. Effects of temperature on orthophosphate absorption by excised corn roots. Plant Physiol. 1967 Oct;42(10):1407–1412. doi: 10.1104/pp.42.10.1407. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Hagen C. E., Hopkins H. T. Ionic Species in Orthophosphate Absorption by Barley Roots. Plant Physiol. 1955 May;30(3):193–199. doi: 10.1104/pp.30.3.193. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Leggett J. E., Galloway R. A., Gauch H. G. Calcium Activation of Orthophosphate Absorption by Barley Roots. Plant Physiol. 1965 Sep;40(5):897–902. doi: 10.1104/pp.40.5.897. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Leonard R. T., Hanson J. B. Induction and development of increased ion absorption in corn root tissue. Plant Physiol. 1972 Mar;49(3):430–435. doi: 10.1104/pp.49.3.430. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Lin W. Corn Root Protoplasts: ISOLATION AND GENERAL CHARACTERIZATION OF ION TRANSPORT . Plant Physiol. 1980 Oct;66(4):550–554. doi: 10.1104/pp.66.4.550. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Lin W., Hanson J. B. Cell potentials, cell resistance, and proton fluxes in corn root tissue: effects of dithioerythritol. Plant Physiol. 1976 Sep;58(3):276–282. doi: 10.1104/pp.58.3.276. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Lin W., Hanson J. B. Phosphate absorption rates and adenosine 5'-triphosphate concentrations in corn root tissue. Plant Physiol. 1974 Sep;54(3):250–256. doi: 10.1104/pp.54.3.250. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Lin W. Potassium and Phosphate Uptake in Corn Roots: Further Evidence for an Electrogenic H/K Exchanger and an OH/Pi Antiporter. Plant Physiol. 1979 May;63(5):952–955. doi: 10.1104/pp.63.5.952. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Sentenac H., Grignon C. A model for predicting ionic equilibrium concentrations in cell walls. Plant Physiol. 1981 Aug;68(2):415–419. doi: 10.1104/pp.68.2.415. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Ullrich-Eberius C. I., Novacky A., Fischer E., Lüttge U. Relationship between Energy-dependent Phosphate Uptake and the Electrical Membrane Potential in Lemna gibba G1. Plant Physiol. 1981 Apr;67(4):797–801. doi: 10.1104/pp.67.4.797. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Weimberg R., Lerner H. R., Poljakoff-Mayber A. Kinetics of toluene-induced leakage of low molecular weight solutes from excised sorghum tissues. Plant Physiol. 1981 Dec;68(6):1433–1438. doi: 10.1104/pp.68.6.1433. [DOI] [PMC free article] [PubMed] [Google Scholar]

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