Send to:

Choose Destination
See comment in PubMed Commons below
Plant Physiol. 1980 Jun;65(6):1139-45.

Effect of ATPase inhibitors on cell potential and k influx in corn roots.

Author information

  • 1Department of Botany, University of Illinois, Urbana, Illinois 61801.


Experiments were performed to determine the effect of plasmalemma ATPase inhibitors on cell potentials (Psi) and K(+) ((86)Rb) influx of corn root tissue over a wide range of K(+) activity. N,N'Dicyclohexylcarbodiimide (DCCD), oligomycin, and diethylstilbestrol (DES) pretreatment greatly reduced active K(+) influx and depolarized Psi at low, but not at high, K(+) activity (K degrees ). More comprehensive studies with DCCD and anoxia showed nearly complete inhibition of the active component of K(+) influx over a wide range of K degrees , with no effect on the apparent permeability constant. DCCD had no effect on the electrogenic component of the cell potential (Psi(p)) above 0.2 millimolar K degrees . Net proton efflux was rapidly reduced 80 to 90% by DCCD. Since tissue ATP content and respiration were only slightly affected by the DCCD-pretreatment, the inhibitions of active K(+) influx and Psi(p) at low K degrees can be attributed to inhibition of the plasmalemma ATPase.It is concluded that by DCCD treatment, the energy-linked electrogenic system at high K degrees is separated from the energy-linked K(+) influx system at low K degrees . The results are analyzed in terms of electrical analogue models of the membrane. The presence of two, algebraically additive electrogenic components is indicated; one is better modeled as a current source (system I) and one as a voltage source (system II). No K(+) stimulation of system II is required to produce the observed K degrees dependence of Psi(p).

Free PMC Article
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk