Change in Nucleosome Dynamics During Stress Responses in Plants.

Abstract

The dynamic nature of chromatin is the basis for the regulation of various biological processes in eukaryotic organisms. Nucleosome, the basic unit of chromatin in eukaryotes, undergo various reversible posttranslational modifications (PTM) in response to both external and internal cues. This PTM is recognized by different reader molecules, which facilitates the recruitment of various chromatin remodeling proteins that modulate the chromatin structure. In plants, the promoters of active genes are associated with higher lysine acetylation of histones H3 and H4, and these modifications are recognized by Bromo-domain (BRM) containing chromatin remodelers. This leads to the remodeling of the nucleosome at promoter regions, thereby increasing accessibility of the transcription machinery. It also plays a role in transcriptional repression when enriched in repressed genes. Lysine methylation recruits methyl-binding domain-containing proteins such as LIKE HETEROCHROMATIN PROTEIN1 (LHP1), which facilitates a more condensed chromatin structure that further inhibits access by the transcriptional machinery. In this article, protocols to study the regulation of chromatin conformations and nucleosome dynamics in plants in response to different stress signals are provided.