Histone H3K37 acetylation regulates salt stress response by promoting gene transcription in rice

Histone acetylation is a well-known chromatin mark that associated with gene transcriptional activation. In plants, histone acetylation modification mainly occurs at the N-terminal lysine residues of histone H3 and H4. The acetylation status of specific Lys residues on histone proteins is reversibly modulated by histone acetyltransferases and histone deacetylases. These enzymes play essential roles in plant growth, development, and responses to abiotic stresses by regulating gene transcription. Many HDACs have been reported to be involved in modulating plants tolerance to abiotic stresses highlighting the pivotal roles of histone acetylation in modulating the transcriptional programs underlying plant abiotic stresses tolerance. However, our understanding of the full repertoire of histone Lys acetylation sites and their specific functions remains incomplete. Herein, we identified an unexplored histone Lys acetylation in rice, Lys 37 of histone H3, we found this acetylation modification is highly conserved across plants species. Notably, the level of H3K37 acetylation in rice is strongly induced by salinity stress. Furthermore, we have identified a histone deacetylase, OsHDA705, that is responsible for removing the acetylation mark from H3K37, and mutation of HDA705 significantly improved the salt tolerance of rice plants.