NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Ethylene plays multiple nonprimary roles in modulating the gravitropic response in tomatoEthylene is known to interact with auxin in regulating stem growth, and yet evidence for the role of ethylene in tropic responses is contradictory. Our analysis of four mutants of tomato (Lycopersicon esculentum) altered in their response to gravity, auxin, and/or ethylene revealed concentration-dependent modulation of shoot gravitropism by ethylene. Ethylene inhibitors reduce wild-type gravicurvature, and extremely low (0.0005-0.001 microliter L-1) ethylene concentrations can restore the reduced gravitropic response of the auxin-resistant dgt (diageotropica) mutant to wild-type levels. Slightly higher concentrations of ethylene inhibit the gravitropic response of all but the ethylene-insensitive nr (never-ripe) mutant. The gravitropic responses of nr and the constitutive-response mutant epi (epinastic) are slightly and significantly delayed, respectively, but otherwise normal. The reversal of shoot gravicurvature by red light in the lz-2 (lazy-2) mutant is not affected by ethylene. Taken together, these data indicate that, although ethylene does not play a primary role in the gravitropic response of tomato, low levels of ethylene are necessary for a full gravitropic response, and moderate levels of the hormone specifically inhibit gravicurvature in a manner different from ethylene inhibition of overall growth.
Document ID
20040141905
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Madlung, A.
(Oregon State University Corvallis 97331-2902, United States)
Behringer, F. J.
Lomax, T. L.
Davies, E.
Date Acquired
August 22, 2013
Publication Date
July 1, 1999
Publication Information
Publication: Plant physiology
Volume: 120
Issue: 3
ISSN: 0032-0889
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Plant Biology

Available Downloads

There are no available downloads for this record.
No Preview Available