Embryonic epigenetic reprogramming by a pioneer transcription factor in plants ($)

Pioneer transcription factors are a special type of transcription factor that are able to access their target sequences in condensed chromatin. They are often associated with changes in cell fate and developmental switching. Tao et al. showed that the seed-specific transcription factor LEAFY COTYLEDON1 (LEC1) acts as a pioneer transcription factor. In Arabidopsis, prolonged cold leads to the epigenetic silencing of the flowering suppressor FLC, thus enabling the plant to flower, but FLC is reset to an active state during embryogenesis. This new work shows that LEC1 is necessary for FLC resetting during embryo formation and is necessary for the increase in activating histone marks at the FLC locus. Nature 10.1038/nature24300