Abstract
H2B mono-ubiquitination (ub1) is an important histone modification attaching a ubiquitin moiety to the small histone H2B and changing the biochemical features of the chromatin. The dynamic equilibrium between H2B ub1 and deubiquitination (deub1) has been shown to affect nucleosome stability, nucleosome reassembly and higher chromatin structure. The above changes mediated by H2B ub1 regulate transcription activation and elongation, and play key roles in multiple molecular and biological processes including growth, development, pathogenesis and aging. In this review, we summarize our current knowledge in regulation of H2B ub1/deub1 equilibrium, and how this modification affects chromatin dynamics and gene expressions. We also discuss the roles of H2B ub1/deub1 cycle in plant-pathogen interactions, and point out the questions that remain to be resolved in future studies.