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

Journal Article · Thu Mar 31 23:00:00 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]

---

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

Related Subjects

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