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Response to gravity by Zea mays seedlings. I. Time course of the responseGravistimulation induces an asymmetric distribution of free indole-3-acetic acid (IAA) in the cortex-epidermis of the Zea mays L. cv 'Stowells Evergreen' mesocotyl within 15 minutes, the shortest time tested. IAA was measured by an isotope dilution method as the pentaflurobenzyl ester. The per cent IAA in the lower half of the mescotyl cortex was 56 to 57% at 15, 30, and 90 minutes after stimulus initiation. Curvature is detectable in the mescotyl within 3 minutes after beginning gravitropic stimulation. The rate of curvature of the mesocotyl increases during the first 60 minutes to maximum of about 30 degrees per hour. Thus, the growth asymmetry continues to increase for 45 minutes after hormone asymmetry is established. Free IAA occurs predominantly in the stele of the mesocotyl whereas esterified IAA is mainly in the mesocotyl cortex-epidermis. This compartmentation may permit determining in which tissue the hormone asymmetry arises. Current data suggest the asymmetry originated in the stele.
Document ID
20040120808
Document Type
Reprint (Version printed in journal)
Authors
Bandurski, R. S. (Michigan State University East Lansing 48824-1312, United States)
Schulze, A.
Dayanandan, P.
Kaufman, P. B.
Date Acquired
August 22, 2013
Publication Date
January 1, 1984
Publication Information
Publication: Plant physiology
Volume: 74
ISSN: 0032-0889
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: NAGW-34
CONTRACT_GRANT: ORD 25796
CONTRACT_GRANT: NAGW-79
Distribution Limits
Public
Copyright
Other