Adaptive epigenetic changes in histone variants and modifications rescue the fitness of Arabidopsis plants with dysfunctional histone chaperones

The aim was to characterize histone variants and PTMs in mutant plants with histone chaperone dysfunction using mass spectrometry-based approach. We found that the maintenance of genome stability via chromatin remodelling depends on a two-tiered process. The first level relies on a highly flexible mechanism that involves alterations in histone marks while the second adaptive level requires assistance of histone chaperones for the replacement of specific histone variants which is a more time-consuming process.

本研究旨在通过基于质谱（mass spectrometry）的分析方法，对组蛋白伴侣（histone chaperone）功能异常的突变植株中的组蛋白变体与翻译后修饰（post-translational modifications，PTMs）进行表征。研究发现，通过染色质重塑（chromatin remodelling）维持基因组稳定性的过程依赖于双层级调控机制：第一层级依赖于一种高度灵活的机制，该机制涉及组蛋白修饰标记（histone marks）的改变；第二层级的适应性调控过程则需要组蛋白伴侣协助替换特定组蛋白变体，这一过程相对更为耗时。