PICKLE is a CHD3 chromatin-remodeling factor that regulates the transition from embryonic to vegetative development in <i>Arabidopsis</i>

The life cycle of angiosperms is punctuated by a dormant phase that separates embryonic and postembryonic development of the sporophyte. In the pickle ( pkl ) mutant of Arabidopsis , embryonic traits are expressed after germination. The penetrance of the pkl phenotype is strongly enhanced by inhibitors of gibberellin biosynthesis. Map-based cloning of the PKL locus revealed that it encodes a CHD3 protein. CHD3 proteins have been implicated as chromatin-remodeling factors involved in repression of transcription. PKL is necessary for repression of LEC1 , a gene implicated as a critical activator of embryo development. We propose that PKL is a component of a gibberellin-modulated developmental switch that functions during germination to prevent reexpression of the embryonic developmental state.