Role of Nitric Oxide, Ethylene, Hydrogen Sulfide and Their Interplay With Histone Acetylation in Plants.

Histone acetylation is an essential epigenetic modification that regulates chromatin structure and gene expression by opposing the actions of histone acetyltransferases (HATs) and deacetylases (HDACs). Gas signaling molecules are endogenous gaseous compounds that can freely diffuse across biological membranes. They mediate interplant communications and plant signaling transductions, with representative members including nitric oxide (NO), ethylene (Eth), hydrogen sulfide (H2S), and methane (CH4). Multiple studies have revealed that gas signaling molecules and histone acetylation can interact to dynamically regulate plant growth and stress responses. This review examines the current knowledge on the role of gas signaling molecules, as well as their synergistic effects with histone acetylation in plants. Specifically, NO can regulate flowering by S-nitrosylating HDACs and influence fruit ripening by inhibiting HDACs. In addition, both NO and Eth can affect seed germination, seedling growth, and pathogen resistance by regulating acetylation levels. Additionally, H2S can modulate root development in plants by regulating histone deacetylation. However, the interactive relationships among NO, Eth, and H2S, as well as the interplay of other gas signaling molecules and histone acetylation in plants warrant further in-depth research. The existing problems and future research directions are also discussed.