The role of CRWN nuclear proteins in chromatin-based regulation of stress response genes.

The periphery in animal nuclei is generally considered to be a transcriptionally repressive environment. Recent studies indicate that chromatin-based mechanisms establish a similar situation in plant nuclei. We demonstrated recently that the loss of CRWN nuclear lamina proteins in Arabidopsis leads to the misregulation of a group of genes involved in plant defense. How this defense response is triggered is largely unknown. Here, we briefly review recent findings that identify several layers of chromatin-based regulation responsible for this response. Further, we introduce new data suggesting that histone H3 lysine 27 tri-methylation levels are reduced in the absence of CRWNs near genes encoding transcription factors regulating SA biosynthesis, providing an explanation for SA induction. These discoveries begin to uncover the interplay between nuclear architecture and stress response in plants.