FLOWERING LOCUS C-mediated germination depends on dormancy status of Arabidopsis

LOGAN K BLAIR; GABRIELA A AUGE; KATHLEEN DONOHUE

Portland, Oregon

Conferencia; Plant Biology 2014; 2014

American Society of Plant Biology

Flowering Locus C (FLC) has a major regulatory role in the timing of flowering and germination in Arabidopsis thaliana. FLC's regulation of these two fundamental developmental transitions provides a good candidate system for studying pleiotropy, but major questions remain regarding its effects on germination. Here, we investigate theconditions under which FLC influences germination and demonstrate that its effect depends on the level of dormancy ? both primary and secondary. We tested germination of near isogenic lines containing different naturalalleles of FLC and germination of FLC-mutants over the course of after-ripening (AR) and after a secondary-dormancy inducing heat-stratification treatment. Genotypes with high FLC-expression showed increased germination; this response was greatest when seeds exhibited primary dormancy, cycled back into secondarydormancy, or were induced into secondary dormancy by hot stratification. The FLC effect was more evident at 22 °C than at 10 °C, in contrast to prior published results. Thus the temperature-dependent contribution of FLC to germination appears to be explained by its dependency on dormancy status and the observation that thetemperature range of germination also depends on dormancy. Finally, we document that the effect of FLC can depend on FRI and that FRI itself appears to influence germination.