Silencing of transposons in plant genomes: kick them when they're down Recent progress in understanding the silencing of transposable elements in the model plant Arabidopsis has revealed an interplay between DNA methylation, histone methylation and small interfering RNAs. DNA and histone methylation are not always sufficient to maintain silencing, and RNA-based reinforcement can be needed to maintain as well as initiate it. 5 12 Springer Nature 1