Claim · model-written summary
Reversal-potential measurements ranked ion selectivity K(+) ≫ Rb(+) > NH(+)(4) > Na(+) ≫ Cl(-).
- Taxon
- barley
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Hordeum vulgaret0 - Outcome
- K(+) ≫ Rb(+) > NH(+)(4) > Na(+) ≫ Cl(-)e0
Not reportedMaterialGeneCompoundOrgan / stageInteractorInteractor roleSecond interactorSecond interactor roleTreatmentComparatorSettingDirectionValueQualifier
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
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Verbatim
e0“K(+) ≫ Rb(+) > NH(+)(4) > Na(+) ≫ Cl(-)”
t0“barley”
Title
A. Amtmann; S. Laurie; R. Leigh; et al. Journal of Experimental Botany 1997. doi:10.1093/jxb/48.special_issue.481
Other claims from this paper (19)
- Observation About half the barley cells in both media had resting potentials below passive diffusion potentials.
- Observation Membrane hyperpolarization activated large inward currents.
- Observation Instantaneous current components did not discriminate K(+) from Na(+).
- Observation Time-dependent inward current was selective for potassium over sodium.
- Observation I(in) exhibited double exponential activation with 0.03 s and 0.3 s time constants.
- Observation I(in) half activation potential was - 171 mV.
- Observation I(in) showed no inactivation.
- Intervention effect Ba(2+) completely blocked I(in).
- Intervention effect TEA(+) partly blocked I(in), up to 50%.
- Association I(in) depended on millimolar cytoplasmic ATP.
- Observation External or cytoplasmic sodium did not block I(in).
- Observation Steady-state current measurements ranked ion selectivity K(+) ≫ NH(+)(4) > Na(+) > Rb(+).
- Observation Sodium to potassium permeability ratio was 0.07 ± 0.02.
- Observation Sodium to potassium current ratio was 0.17 + 0.05.
- Mechanism Variable permeability ratios suggested contributions from multiple channels.
- Observation Single channel experiments identified a 12 pS voltage-gated potassium-selective channel.
- Observation Single channel experiments identified a 7 pS ATP-activated nonselective cation channel.
- Observation Single channel experiments identified a 150 pS inward rectifying anion channel.
- Intervention effect High salt adaptation caused no significant difference in whole-cell currents or single-channel characteristics.