Photosystem adaptation and histone modification signatures are induced by cold priming in wheat

The objective of this study was to identify the mechanisms underlying the formation and maintenance of the photosystem as a stress-memory site. Profiling of transcriptome and genome-wide histone modifications in wheat across cold priming, a recovery phase, and subsequent chilling stress showed that priming installs an activating histone imprint that drives delayed stress-responsive gene expression, thereby increasing cold tolerance during recovery. This altered redox environment may be associated with the establishment of repressive epigenetic marks on photosystem repair genes, leading to a reduced demand for photosystem repair during subsequent chilling stress. Thus, dynamic shifts in histone modifications are associated with the maintenance of stress memory.