Use of membrane vesicles as a simplified system for studying transport of auxin. Progress report
The accumulation of indoleacetic acid (IAA) inside microsomal vesicles depends on the presence of a pH gradient and is reversible when the ..delta..pH is collapsed by ionosphores. Accumulation is stimulated by either napthylphthalamic acid or TIBA. The accumulation of IAA by the vesicles can be saturated. At concentrations of 1 ..mu..M or less, IAA, synthetic auxins, or auxin antagonists do not affect the pH gradient, but decrease the accumulation of /sup 3/H-IAA, and therefore compete specifically for uptake. Concentrations of 10 ..mu..M and above, uptake of either the auxins or weak acids is sufficient to overcome the buffering capacity of the solution within the vesicles. The collapse of the pH gradient by such high concentrations affects uptake of either /sup 3/H-IAA or /sup 14/C-BA to similar extents and thus is nonspecific. 3 refs.
- Research Organization:
- Yale Univ., New Haven, CT (USA)
- DOE Contract Number:
- FG02-85ER13337
- OSTI ID:
- 5044442
- Report Number(s):
- DOE/ER/13337-1; ON: DE86002264
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AUXINS
BIOLOGICAL EFFECTS
MEMBRANE TRANSPORT
HERBICIDES
INDOLES
BIOCHEMICAL REACTION KINETICS
CARBON 14 COMPOUNDS
CELL MEMBRANES
LIPOSOMES
MICROSOMES
PH VALUE
PLANTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ULTRACENTRIFUGATION
AROMATICS
AZAARENES
AZOLES
CELL CONSTITUENTS
CENTRIFUGATION
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MEMBRANES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
PESTICIDES
PLANT GROWTH REGULATORS
PYRROLES
REACTION KINETICS
SEPARATION PROCESSES
550201* - Biochemistry- Tracer Techniques
550301 - Cytology- Tracer Techniques