Genome-wide identification of sugarcane HAT gene family and functional analysis of ScHAT1 in stress response

Sugarcane (Saccharum spp.) is a globally important crop for sugar production, but its growth and development are affected by various biotic and abiotic stresses. Histone acetyltransferases (HATs) are key regulators in plant stress responses, yet their functions and mechanisms remain largely unexplored in sugarcane. Here, we identified 44, 62, and 13 HAT gene family members from R570 (S. spp. hybrid), LA-purple (S. officinarum), and AP85-441 (S. spontaneum), respectively. They were assigned to four well-defined subfamilies, including HAG, HAC, HAM, and HAF. Notably, stress-responsive elements were significantly enriched in the promoter regions of the HAM subfamily. Expression pattern analysis revealed that several sugarcane HAT genes responded to smut (Sporisorium scitamineum) and drought stress, with ShHAT24 showing significant upregulation under both stress conditions. Furthermore, a homolog of ShHAT24, named ScHAT1, was successfully cloned from the sugarcane variety ROC22. Its expression was significantly upregulated in the smut-susceptible ROC22 variety post smut pathogen infection. Additionally, ScHAT1 gene conferred enhanced tolerance to salt and drought stress. Interestingly, overexpression of ScHAT1 inhibited the transcription of genes involved in the salicylic acid (SA) and jasmonic acid (JA) signaling cascades, thereby increasing plant susceptibility to pathogens. This study provides insights into the evolutionary characteristics of sugarcane HAT gene family and reveals the dual role of ScHAT1 during plant interactions with biotic and abiotic stresses, presenting a potential target for improving stress resistance in sugarcane breeding.