Journal article
Proteolysis-Independent Downregulation of DELLA Repression in Arabidopsis by the Gibberellin Receptor GIBBERELLIN INSENSITIVE DWARF1[W]
The Plant cell, Vol.20(9), pp.2447-2459
09/2008
Handle:
https://hdl.handle.net/2376/105012
PMCID: PMC2570730
PMID: 18827182
Abstract
This article presents evidence that DELLA repression of gibberellin (GA) signaling is relieved both by proteolysis-dependent and -independent pathways in
Arabidopsis thaliana
. DELLA proteins are negative regulators of GA responses, including seed germination, stem elongation, and fertility. GA stimulates GA responses by causing DELLA repressor degradation via the ubiquitin-proteasome pathway. DELLA degradation requires GA biosynthesis, three functionally redundant GA receptors
GIBBERELLIN INSENSITIVE DWARF1
(
GID1a
,
b
, and
c
), and the
SLEEPY1
(
SLY1
) F-box subunit of an SCF E3 ubiquitin ligase. The
sly1
mutants accumulate more DELLA proteins but display less severe dwarf and germination phenotypes than the GA biosynthesis mutant
ga1-3
or the
gid1abc
triple mutant. Interestingly,
GID1
overexpression rescued the
sly1
dwarf and infertility phenotypes without decreasing the accumulation of the DELLA protein REPRESSOR OF
ga1-3
. GID1 rescue of
sly1
mutants was dependent on the level of GID1 protein, GA, and the presence of a functional DELLA motif. Since DELLA shows increasing interaction with GID1 with increasing GA levels, it appears that GA-bound GID1 can block DELLA repressor activity by direct protein–protein interaction with the DELLA domain. Thus, a SLY1-independent mechanism for GA signaling may function without DELLA degradation.
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Details
- Title
- Proteolysis-Independent Downregulation of DELLA Repression in Arabidopsis by the Gibberellin Receptor GIBBERELLIN INSENSITIVE DWARF1[W]
- Creators
- Tohru Ariizumi - Department of Crop and Soil Science, Washington State University, Pullman, Washington 99164-6420Kohji Murase - Department of Biology, Duke University, Durham, North Carolina 27708Tai-ping Sun - Department of Biology, Duke University, Durham, North Carolina 27708Camille M Steber - Department of Crop and Soil Science, Washington State University, Pullman, Washington 99164-6420
- Publication Details
- The Plant cell, Vol.20(9), pp.2447-2459
- Academic Unit
- Crop and Soil Sciences, Department of
- Publisher
- American Society of Plant Biologists
- Identifiers
- 99900546710301842
- Language
- English
- Resource Type
- Journal article