A hormonal regulatory module that provides flexibility to tropic responses.

Details

Serval ID
serval:BIB_180F6421AAD5
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
A hormonal regulatory module that provides flexibility to tropic responses.
Journal
Plant Physiology
Author(s)
Gallego-Bartolomé J., Kami C., Fankhauser C., Alabadí D., Blázquez M.A.
ISSN
1532-2548 (Electronic)
ISSN-L
0032-0889
Publication state
Published
Issued date
2011
Volume
156
Number
4
Pages
1819-1825
Language
english
Abstract
Plants orient their growth depending on directional stimuli such as light and gravity, in a process known as tropic response. Tropisms result from asymmetrical accumulation of auxin across the responding organ relative to the direction of the stimulus, which causes differential growth rates on both sides of the organ. Here, we show that gibberellins (GAs) attenuate the gravitropic reorientation of stimulated hypocotyls of dark-grown Arabidopsis (Arabidopsis thaliana) seedlings. We show that the modulation occurs through induction of the expression of the negative regulator of auxin signaling INDOLE-3-ACETIC ACID INDUCIBLE19/MASSUGU2. The biological significance of this regulatory mechanism involving GAs and auxin seems to be the maintenance of a high degree of flexibility in tropic responses. This notion is further supported by observations that GA-deficient seedlings showed a much lower variance in the response to gravity compared to wild-type seedlings and that the attenuation of gravitropism by GAs resulted in an increased phototropic response. This suggests that the interplay between auxin and GAs may be particularly important for plant orientation under competing tropic stimuli.
Keywords
Arabidopsis/drug effects, Arabidopsis/genetics, Arabidopsis Proteins/genetics, Arabidopsis Proteins/metabolism, Gene Expression Regulation, Plant/drug effects, Gibberellins/pharmacology, Gravitropism/drug effects, Gravitropism/physiology, Hypocotyl/drug effects, Hypocotyl/physiology, Mutation/genetics, Repressor Proteins/metabolism
Pubmed
Web of science
Open Access
Yes
Create date
09/05/2011 7:25
Last modification date
20/08/2019 12:48
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