Meristem specific expression of epigenetic regulators facilitates inactivation of transposable elements in Arabidopsis thaliana

Due to their potential risk for the genome integrity and thus the viability of an organism, transposable elements are kept inactive. Among others, the mechanism of RNA-directed DNA methylation facilitates this inactivation in plants. Recent investigations discovered a new shoot apical meristem specific function of this mechanism. It reinforces silencing of these elements during the early phase of vegetative growth and counteracts their drug-induced activation. It furthermore provides a checkpoint for correct epigenetic inheritance during the transition from vegetative to reproductive phase.