Abstract
Superoxide dismutase (SOD) serves as a critical enzyme that is involved in plant development and abiotic stresses by effectively detoxifying reactive oxygen species (ROS). Though the SOD gene family has been reported across various plant species, its specific members and functional roles in litchi (Litchi chinensis Sonn.) remain poorly understood. In this study, a total of seven SOD (christened LcSOD) genes were identified from the litchi genome and classified into three groups across six chromosomes. Notably, genes from the same evolutionary branch had more similar structures and motif distributions. The LcSOD genes were confirmed to have a stronger collinearity with dicotyledons than with monocotyledons. Cis-acting elements analysis indicated that the LcSOD gene family was deeply involved in orchestrating growth, development, and responses to multiple phytohormones and diverse stresses. Expression patterns of the LcSOD genes across different tissues revealed universal and specific expressions. In leaves, expression levels of the LcSOD genes were induced by cold, heat, drought, and salt stresses, and transcript levels correlated positively with concomitant changes in key physiological parameters under the same conditions. In addition, the LcSOD genes were characterized for their physicochemical properties, subcellular localizations, secondary and tertiary structures, gene ontology (GO) annotations, and protein-protein interactions. Our findings offer comprehensive insights into the LcSOD gene family, enriching genetic resources. They provide a framework for functional characterization and the development of stress-resistant cultivars, driving both basic research and applied breeding programs in litchi.