Display options
Cite
Thibaud JB, Soler A, Grignon C. H and k electrogenic exchanges in corn roots. Plant Physiol. 1986;81(3):847-53doi: 10.1104/pp.81.3.847.
Thibaud, J. B., Soler, A., & Grignon, C. (1986). H and k electrogenic exchanges in corn roots. Plant physiology, 81(3), 847-53. https://doi.org/10.1104/pp.81.3.847
Thibaud, J B, et al. "H and k electrogenic exchanges in corn roots." Plant physiology vol. 81,3 (1986): 847-53. doi: https://doi.org/10.1104/pp.81.3.847
Thibaud JB, Soler A, Grignon C. H and k electrogenic exchanges in corn roots. Plant Physiol. 1986 Jul;81(3):847-53. doi: 10.1104/pp.81.3.847. PMID: 16664913; PMCID: PMC1075438.
Copy Download .nbib Format: NLM
Share it on

Plant Physiol. 1986 Jul;81(3):847-53. doi: 10.1104/pp.81.3.847.

H and k electrogenic exchanges in corn roots.

Plant physiology

J B Thibaud, A Soler, C Grignon

Affiliations

  1. Biochimie et Physiologie Végétales, Institut National de la Recherche Agronomique (Centre National de la Recherche Scientifique, UA 573), Ecole Nationale Supérieure Agronomique, 34060 Montpellier Cedex, France.

PMID: 16664913 PMCID: PMC1075438 DOI: 10.1104/pp.81.3.847

Abstract

The membrane potential difference, the net H(+) exchange rate, the K(+) net flux, and the K(+) ((86)Rb(+)) influx were measured in excised corn roots as functions of the K(+) concentration in the medium at various pH values, in the presence of poorly permeant anions. The roots behaved as a K(+)/H(+) exchange system. By comparing the results in normal or hypoxic conditions, or in the presence of vanadate, it was possible to distinguish the active components of membrane potential and transports from the passive ones. The magnitude of the electrogenic potential was not related to the active H(+) extrusion rate. At pH 6, the variations of the electrogenic potential resulted from variations of the stoichiometry of the active H(+)/K(+) exchange. The same relationship between this stoichiometry and the K(+) concentration was observed in conditions ensuring different membrane polarizations (pH 6, pH 4, or pH 6 with fusicoccin). Both metabolic and Mg-ATPase specific inhibitors stopped the active H(+) transport and the net K(+) influx. Nevertheless, the tracer influx in the presence of vanadate remained higher than the passive influx calculated from the permeability coefficient determined in hypoxia. It is proposed that vanadate uncouples the K(+) moiety of the H(+)/K(+) antiport and allows it to mediate isotopic exchanges.

References

  1. Plant Physiol. 1979 Nov;64(5):842-5 - PubMed
  2. Plant Physiol. 1980 Jun;65(6):1139-45 - PubMed
  3. Biophys J. 1969 Mar;9(3):447-63 - PubMed
  4. Plant Physiol. 1980 Dec;66(6):1095-8 - PubMed
  5. Plant Physiol. 1982 Jun;69(6):1344-7 - PubMed

Publication Types