Genome-wide analysis of the superoxide dismutase (SOD) gene family in Zostera marina and expression profile analysis under temperature stress

Superoxide dismutases (SODs) serve as the first line of defense in the plant antioxidant enzyme system, and play a primary role in the removal of reactive oxygen species (ROS). However, our understanding of the functions of the SOD family in is limited. In this study, a systematic analysis was conducted on the characteristics of the SOD genes in at the whole-genome level. Five SOD genes were identified, consisting of two , two , and one . Phylogenetic analysis showed that proteins could be divided into two major categories ( and ). Sequence motifs, gene structure, and the 3D-modeled protein structures further supported the phylogenetic analysis, with each subgroup having similar motifs, exon-intron structures, and protein structures. Additionally, several cis-elements were identified that may respond to biotic and abiotic stresses. Transcriptome analysis revealed expression diversity of in various tissues. Moreover, qRT-PCR analysis showed that the expression level of most genes trended to decreased expression with the increase of temperature, indicating that heat stress inhibits expression of and may result in reduced ability of to scavenge ROS. Our results provide a basis for further functional research on the SOD gene family in , which will help to determine the molecular mechanism of genes in response to environmental stress.