The CaMV 35S enhancer has a function to change the histone modification state at insertion loci in Arabidopsis thaliana

Abstract

Chromatin regions with different states usually harbor distinct epigenetic information, through which gene expression is regulated. Recent studies using mammalian cells showed that a chromatin state signature is associated with active developmental enhancers, defined by high levels of histone H3 lysine 27 acetylation (H3K27ac) and strong depletion of H3K27 trimethylation (H3K27me3). These findings also imply that active enhancers may play a role in creating a chromatin state by changing histone modification markers, which in turn affects gene expression. To explore whether an active enhancer in plants affect histone modifications, we investigated the cauliflower mosaic virus 35S enhancer (35Senh) for understanding its action model in Arabidopsis. We report that the 35Senh has a function to change the histone modification pattern at its presenting loci, by characterization of the 35Senh activated BREVIPEDICELLUS (BP) silencing lines and the randomly selected 35Senh activation tagging lines. By analyzing histone modification markers reflecting the plant chromatin state, we show that the 35Senh is generally correlated with the reduced level of H3K27me3 and the increased level of H3K4me3 at the insertion loci. Our data are consistent with those in mammals and suggest that the enhancer sequence correlating with the active chromatin state signature may be generally present in the eukaryotic kingdom.