Cis- and trans-determinants of epigenetic silencing by Polycomb Repressive Complex 2 in Arabidopsis.

Compared to normal Arabidopsis plants, polycomb mutants form leaves that curl upward and flower early. The same is true for mutants in the 2 transcription factor families (TFs) that recruit the PRC2 Polycomb Complex. Members of the BPC and ZnF transcription factors bind to the cis motifs shown below in plant PREs to recruit  PRC2 for gene silencing.