Genome-wide identification of histone acetyltransferase members and functional dissection of histone acetylation-mediated desiccation tolerance in Syntrichia caninervis.

Desiccation tolerance (DT) has contributed greatly to the adaptation of land plants to severe water-deficient conditions. Despite substantial progress in physiological, transcriptomic and genomic research achieved in recent years, the role of histone acetylation in regulating DT remains largely unexplored. Syntrichia caninervis (S. caninervis) is an emerging model for DT plants that possesses the remarkable ability to survive near complete dehydration and rapidly recover within seconds upon rehydration. In this study, eight Histone Acetyltransferases (HATs) were identified and classified into six groups based on conserved gene structures and motif compositions. These HATs exhibit distinct gene expression patterns in response to desiccation stress. Following treatment with the histone deacetylase inhibitor MB-3, S. caninervis exhibited compromised DT during dehydration-rehydration process. Transcriptome analysis revealed that, during the dehydration-rehydration process, various biological processes including photosynthesis, antioxidant pathways, diverse metabolic activities, ATP synthesis, as well as the activity of transcription factors, are all adversely affected by inhibiting the function of histone acetylation. Taken together, our work identified the HAT family members in S. caninervis and proposed that histone acetylation plays a crucial role in regulating DT through versatile mechanisms.