Gravity induced, asymmetric unloading of indole-3-acetic acid from the stele of Zea mays into the mesocotyl cortex

Conference · Tue Mar 31 23:00:00 EST 1987 · Plant Physiol., Suppl.; (United States)

OSTI ID:5840475

Schulze, A; Bandurski, R S

Previous studies from this laboratory have demonstrated an increase within 3 min in both free and ester indole-3-acetic acid (IAA) on the lower side of the mesocotyl cortex of a gravity stimulated Zea mays seedling. Since both free and ester IAA are being transported from endosperm to shoot through the stele these results suggest that the gravity stimulus affects movement of IAA and/or its esters from stele to cortex. To test this postulate they injected 5-(/sup 3/H)-IAA into the endosperm and, after a 30 min period with the plants held vertically, severed the kernel from the shoot and placed the plants in a horizontal position. After 60 min the distribution of radioactivity in the mesocotyl cortex was 55 + 3% in the lower half and 45 + 3% in the upper half. These results support the working theory that a target for the gravity stimulus is the gating mechanism for the movement of hormone from stele to cortex.

• Research Organization: Michigan State Univ., East Lansing
• OSTI ID: 5840475
• Report Number(s): CONF-8707108-
• Journal Information: Plant Physiol., Suppl.; (United States), Journal Name: Plant Physiol., Suppl.; (United States) Vol. 83:4; ISSN PPYSA
• Country of Publication: United States
• Language: English

Related Subjects

550201 -- Biochemistry-- Tracer Techniques
551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AUXINS
BIOLOGICAL EFFECTS
BODY
CEREALS
ENDOSPERM
FOOD
GRASS
GRAVITATION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAIZE
PLANT GROWTH REGULATORS
PLANT TISSUES
PLANTS
SEEDLINGS
TISSUES
TRACER TECHNIQUES
TRANSLOCATION
TRITIUM COMPOUNDS
VEGETABLES