Acetylation as a dynamic regulatory interface between plant stress memory, cross-tolerance, and crop resilience...

Plants are increasingly exposed to recurrent, combined, and fluctuating environmental stresses, making it essential to understand how transient stress signals are converted into durable adaptive states. Stress memory and cross-tolerance represent two interconnected strategies that enable plants to respond more rapidly or effectively to subsequent stresses, yet the regulatory mechanisms linking short-term responses with long-term adaptive potential remain incompletely understood. Acetylation has emerged as a dynamic regulatory interface in this process owing to its reversibility, rapid responsiveness, broad substrate range, and close coupling with cellular metabolic status. In this review, we summarize recent progress in acetylation-mediated plant stress adaptation, focusing on transcriptional bookmarking at the chromatin level, non-histone acetylation of signaling and metabolic proteins, acetyl-CoA-dependent and NAD⁺-dependent metabolic coupling, and regulation in different subcellular compartments, including chloroplasts, mitochondria, and the cytoplasm. We further discuss the conservation, divergence, and evidence hierarchy of key HAT/HDAC regulatory nodes in model plants and crops, highlighting that their functional outputs depend on target identity, stress context, and crop background rather than on their enzymatic identity alone. Finally, we evaluate the potential and limitations of acetylation-based crop strategies for improving crop stress resilience, including priority target selection, small-molecule regulation, epigenome editing, synthetic regulatory modules, and molecular design breeding. Overall, acetylation should not be viewed simply as a transcriptional "on/off" switch, but as a multilayered regulatory hub linking environmental signals, metabolic states, chromatin plasticity, and adaptive phenotypes. Future advances will depend on causal validation of non-histone substrates, time-resolved acetylation maps, multi-stress network dissection, and validation in crop systems under complex field conditions.