Journal article
Seed Germination of GA-Insensitive sleepy1 Mutants Does Not Require RGL2 Protein Disappearance in Arabidopsis[W]
The Plant cell, Vol.19(3), pp.791-804
03/2007
Handle:
https://hdl.handle.net/2376/115504
PMCID: PMC1867373
PMID: 17384169
Abstract
We explore the roles of gibberellin (GA) signaling genes
SLEEPY1
(
SLY1
) and
RGA-LIKE2
(
RGL2
) in regulation of seed germination in
Arabidopsis thaliana
, a plant in which the hormone GA is required for seed germination. Seed germination failure in the GA biosynthesis mutant
ga1-3
is rescued by GA and by mutations in the DELLA gene
RGL2
, suggesting that RGL2 represses seed germination. RGL2 protein disappears before wild-type seed germination, consistent with the model that GA stimulates germination by causing the SCF
SLY1
E3 ubiquitin ligase complex to trigger ubiquitination and destruction of RGL2. Unlike
ga1-3
, the GA-insensitive
sly1
mutants show variable seed dormancy. Seed lots with high seed dormancy after-ripened slowly, with stronger alleles requiring more time. We expected that if RGL2 negatively controls seed germination,
sly1
mutant seeds that germinate well should accumulate lower RGL2 levels than those failing to germinate. Surprisingly, RGL2 accumulated at high levels even in after-ripened
sly1
mutant seeds with 100% germination, suggesting that RGL2 disappearance is not a prerequisite for seed germination in the
sly1
background. Without GA, several GA-induced genes show increased accumulation in
sly1
seeds compared with
ga1-3
. It is possible that the RGL2 repressor of seed germination is inactivated by after-ripening of
sly1
mutant seeds.
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Details
- Title
- Seed Germination of GA-Insensitive sleepy1 Mutants Does Not Require RGL2 Protein Disappearance in Arabidopsis[W]
- Creators
- Tohru Ariizumi - Department of Crop and Soil Science, Washington State University, Pullman, Washington 99164-6420Camille M Steber - Department of Crop and Soil Science, Washington State University, Pullman, Washington 99164-6420
- Publication Details
- The Plant cell, Vol.19(3), pp.791-804
- Academic Unit
- Crop and Soil Sciences, Department of
- Publisher
- American Society of Plant Biologists
- Identifiers
- 99900547773401842
- Language
- English
- Resource Type
- Journal article