Abstract
Ethylene plays a crucial role in plant growth, development, and stress responses, with 1-aminocyclopropane-1-carboxylate synthase (ACS) being a key enzyme in its biosynthetic pathway. However, the ACS gene family of Myrica rubra has not yet been systematically identified and characterized. In this study, we identified and characterized seven ACS genes (MrACS) in Myrica rubra through genome-wide analysis. Phylogenetic analysis revealed that these genes belong to three major subfamilies, with certain members clustering closely with ACS genes from Rosaceae species, suggesting a conserved evolutionary relationship. Gene structure and the conserved motif analyses confirmed functional conservation, while chromosomal localization indicated an uneven distribution across the genome. Collinearity analysis revealed strong homologous relationships between Myrica rubra and other plant species, particularly Solanum lycopersicum, Vitis vinifera, and Prunus persica. Furthermore, the transcriptome data demonstrated distinct temporal and tissue-specific expression patterns, with MrACS5 showing fruit-specific expression, suggesting its potential role in fruit ripening. These findings provide comprehensive insights into the ACS gene family in Myrica rubra, offering a valuable foundation for further functional studies on ethylene biosynthesis and its regulatory mechanisms in fruit development.