EXTRA-EPIGENIC PATHWAY. “Zhang et al., found that H3K27me3 regulates an unexpectedly large number of genes in Arabidopsis (∼4400), suggesting that this is a major silencing mechanism in plants that acts independently of other epigenetic pathways, such as small RNAs (smRNAs) or DNA methylation.”
http://jxb.oxfordjournals.org/content/62/11/3713.full