Mechanisms of passive potassium influx in corn mitochondria

Journal Article · Thu Jan 01 04:00:00 EST 1981 · Plant Physiol.; (United States)

DOI:https://doi.org/10.1104/pp.68.2.267· OSTI ID:5403354

Fluegel, M J; Hanson, J B

Corn mitochondria in 100 millimolar KCl show accelerated passive swelling upon addition of uncoupler. This unusual response has been compared with swelling produced by valinomycin, tripropyltin, and nigericin. It is concluded that the driving force for swelling lies with the chloride gradient and a high P /sub cl/:P/sub k/ ratio, the chloride influx creating a negative membrane potential. The action of uncoupler is to facillitate K/sup +/ influx via the endogenous H/sup +//K/sup +/ antiporter. The antiporter is active over the pH range 6 to 8, is not sensitive to mg/sup 2 +/ concentration, and is not inactivated by aging. It is not clear why corn mitochondria show this exceptional activity of the H/sup +//K/sup +/ antiporter in K/sup +/ influx. It is speculated that during isolation the antiporter may be exposed or activated, and that it contributes to cyclic K/sup +/ transport and high State 4 respiration rates.

• Research Organization: Univ. of Illinois, Urbana
• OSTI ID: 5403354
• Journal Information: Plant Physiol.; (United States), Journal Name: Plant Physiol.; (United States) Vol. 68; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

551000* -- Physiological Systems
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALI METALS
ALKALINE EARTH METALS
CATIONS
CELL CONSTITUENTS
CEREALS
CHARGED PARTICLES
CHLORIDES
CHLORINE COMPOUNDS
ELEMENTS
GRAMINEAE
GRASS
HALIDES
HALOGEN COMPOUNDS
HYDROGEN
IONS
MAGNESIUM
MAIZE
METALS
MITOCHONDRIA
NONMETALS
ORGANOIDS
PERMEABILITY
PH VALUE
PLANTS
POTASSIUM
POTASSIUM CHLORIDES
POTASSIUM COMPOUNDS
SWELLING
UPTAKE