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Auxin and ethylene regulate elongation responses to neighbor proximity signals independent of gibberellin and della proteins in Arabidopsis.
Auxin and ethylene regulate elongation responses to neighbor proximity signals independent of gibberellin and della proteins in Arabidopsis.
- Source :
-
Plant physiology [Plant Physiol] 2009 Apr; Vol. 149 (4), pp. 1701-12. Date of Electronic Publication: 2009 Feb 11. - Publication Year :
- 2009
-
Abstract
- Plants modify growth in response to the proximity of neighbors. Among these growth adjustments are shade avoidance responses, such as enhanced elongation of stems and petioles, that help plants to reach the light and outgrow their competitors. Neighbor detection occurs through photoreceptor-mediated detection of light spectral changes (i.e. reduced red:far-red ratio [R:FR] and reduced blue light intensity). We recently showed that physiological regulation of these responses occurs through light-mediated degradation of nuclear, growth-inhibiting DELLA proteins, but this appeared to be only part of the full mechanism. Here, we present how two hormones, auxin and ethylene, coregulate DELLAs but regulate shade avoidance responses through DELLA-independent mechanisms in Arabidopsis (Arabidopsis thaliana). Auxin appears to be required for both seedling and mature plant shoot elongation responses to low blue light and low R:FR, respectively. Auxin action is increased upon exposure to low R:FR and low blue light, and auxin inhibition abolishes the elongation responses to these light cues. Ethylene action is increased during the mature plant response to low R:FR, and this growth response is abolished by ethylene insensitivity. However, ethylene is also a direct volatile neighbor detection signal that induces strong elongation in seedlings, possibly in an auxin-dependent manner. We propose that this novel ethylene and auxin control of shade avoidance interacts with DELLA abundance but also controls independent targets to regulate adaptive growth responses to surrounding vegetation.
- Subjects :
- Arabidopsis radiation effects
Cryptochromes
Flavoproteins
Gibberellins metabolism
Hypocotyl growth & development
Hypocotyl metabolism
Hypocotyl radiation effects
Light
Mutation genetics
Photoreceptors, Plant metabolism
Phytochrome B metabolism
Plant Leaves cytology
Plant Leaves growth & development
Plant Leaves metabolism
Arabidopsis growth & development
Arabidopsis metabolism
Arabidopsis Proteins metabolism
Ethylenes metabolism
Indoleacetic Acids metabolism
Signal Transduction radiation effects
Subjects
Details
- Language :
- English
- ISSN :
- 0032-0889
- Volume :
- 149
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Plant physiology
- Publication Type :
- Academic Journal
- Accession number :
- 19211699
- Full Text :
- https://doi.org/10.1104/pp.108.133496