Biology Reference
In-Depth Information
Figure 4.
wrky2 mutants are hypersensitive to ABA responses during postgermination growth Seeds were
germinated.
Postgermination growth
efficiencies (green cotyledons) were scored for 7 d after stratification. Three independent
experiments are shown, and above 100 seeds were used in each experiment.
To analyze the role of WRKY2 during the seedling growth stages, we first
germinated the wild-type and wrky2 mutant seeds on MS medium for 4 d and
then transferred the seedlings onto MS medium containing 0 µM, 0.5 µM, 1.0
µM, 1.5 µM, 2.0 µM, 5.0 µM, 10 µM, 20 µM, 40 µM and 80 µM ABA. No
significant difference was observed between the wild type and wrky2 mutants 10
days after the transfer (data not shown).
When the germination experiments were carried out in dark, wrky2 mutants
are again more sensitive to ABA responses than wild type (Figure 3). Taken to-
gether, these observations suggest that wrky2 mutants are hypersensitive to ABA
responses only during seed germination and early seedling growth.
Response of WRKY2 Mutants to ABA Defines a Limited
Developmental Window
The transcription factors ABI3 and ABI5 are known to be important regulators
of ABA-dependent growth arrest during germination [14,15]. ABI3 and ABI5 are
