Apigenin and quercetin promote. Delta. pH-dependent accumulation of IAA in membrane vesicles

Conference · Tue May 01 04:00:00 EDT 1990 · Plant Physiology, Supplement; (USA)

OSTI ID:5851059

Woolard, D D; Clark, K A ^[1]

---

1. Southern Illinois Univ., Carbondale (USA)

Flavonoids may act as regulators of polar auxin transport. In the presence of a pH gradient (pH 8{sub in}/6{sub out}) the flavonoids quercetin and apigenin, as well as the synthetic herbicide napthylphthalamic acid (NPA), promote the accumulation of IAA in membrane vesicles from dark-grown zucchini hypocotyls. Simultaneous accumulation of {sup 3}H-IAA (10 nM) and {sup 14}C-butyric acid (5 {mu}M; included as a pH probe) was determined by a filtration assay after incubating the vesicles with 3 nM to 100 {mu}M quercetin, apigenin, NPA or unlabeled IAA. Maximal stimulation (% of Control) was observed with 3 {mu}M NPA (130%), 1 {mu}M quercetin (120%), or 3 {mu}M apigenin (115%); {Delta}pH was not affected by these concentrations. As reported by others, IAA uptake was saturable: 1 {mu}M unlabeled IAA eliminated {Delta}pH-dependent uptake of {sup 3}H-IAA without altering {Delta}pH. However, at 30 to 100 {mu}M, every compound tested collapsed the imposed pH gradient and therefore abolished specific {sup 3}H-IAA uptake.

• OSTI ID: 5851059
• Report Number(s): CONF-9007196--
• Conference Information: Journal Name: Plant Physiology, Supplement; (USA) Journal Volume: 93:1
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
553004 -- Agriculture & Food Technology-- Food Protection & Preservation-- (1987-)
59 BASIC BIOLOGICAL SCIENCES
60 APPLIED LIFE SCIENCES
AUXINS
BIOCHEMICAL REACTION KINETICS
CARBON 14 COMPOUNDS
FLAVENOIDS
FOOD
HERBICIDES
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PESTICIDES
PH VALUE
PLANT GROWTH REGULATORS
PLANTS
REACTION KINETICS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VEGETABLES