Dissipation of pH gradients in tonoplast vesicles and liposomes by mixtures of acridine orange and anions. [Avena sativa L. ; Beta vulgaris]

Journal Article · Fri Apr 01 00:00:00 EST 1988 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.86.4.1315· OSTI ID:7025807

Pope, A J; Leigh, R A ^[1]

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1. AFRC Institute of Arable Crops Research, Harpenden (England)

Acridine orange altered the response to anions of both ATP and inorganic pyrophosphate-dependent pH gradient formation in tonoplast vesicles isolated from oat (Avena sativa L.) roots and red beet (Beta vulgaris L.) storage tissue. When used as a fluorescent pH probe in the presence of I{sup {minus}}, ClO{sub 3}{sup {minus}}, NO{sub 3}{sup {minus}}, Br{sup {minus}}, or SCN{sup {minus}}, acridine orange reported lower pH gradients than either quinacrine or ({sup 14}C)methylamine. Acridine orange, but not quinacrine, reduced ({sup 14}C)methylamine accumulation when NO{sub 3}{sup {minus}} was present indicating that the effect was due to a real decrease in the size of the pH gradient, not a misreporting of the gradient by acridine orange. Other experiments indicated that acridine orange and NO{sub 3}{sup {minus}} increased the rate of pH gradient collapse both in tonoplast vesicles and in liposomes of phosphatidylcholine and that the effect in tonoplast vesicles was greater at 24{degree}C than at 12{degree}C. It is suggested that acridine orange and certain anions increase the permeability of membranes to H{sup +}, possibly because protonated acridine orange and the anions form a lipophilic ion pair within the vesicle which diffuses across the membrane thus discharging the pH gradient.

• OSTI ID: 7025807
• Journal Information: Plant Physiology; (USA), Vol. 86:4; ISSN 0032-0889
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CELL MEMBRANES
PERMEABILITY
LIPOSOMES
BIOCHEMICAL REACTION KINETICS
PHYSIOLOGY
ACRIDINE ORANGE
ANIONS
BEETS
BROMIDES
CARBON 14 COMPOUNDS
CELL FLOW SYSTEMS
CHLORATES
IODIDES
LECITHINS
NITRATES
OATS
PH VALUE
RESPONSE MODIFYING FACTORS
ROOTS
TEMPERATURE DEPENDENCE
THIOCYANATES
TRACER TECHNIQUES
ACRIDINES
AMINES
ANTITHYROID DRUGS
AROMATICS
AZAARENES
AZINES
BROMINE COMPOUNDS
CARBONIC ACID DERIVATIVES
CELL CONSTITUENTS
CEREALS
CHARGED PARTICLES
CHLORINE COMPOUNDS
DRUGS
DYES
ESTERS
FOOD
GRASS
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
HORMONE ANTAGONISTS
IODINE COMPOUNDS
IONS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LILIOPSIDA
LIPIDS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MEMBRANES
NITROGEN COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANOIDS
OXYGEN COMPOUNDS
PHOSPHOLIPIDS
PLANTS
PYRIDINES
REACTION KINETICS
VEGETABLES
551001* - Physiological Systems- Tracer Techniques