Abstract
Rosa rugosa is a representative aromatic species. Wild roses are known for their strong tolerance to highly salty environments, whereas cultivated varieties of roses exhibit lower salt stress tolerance, limiting their development and industrial expansion. Previous studies have shown that C2H2-type zinc finger proteins play a crucial role in plants' resistance to abiotic stresses. In this study, 102 C2H2-type zinc finger genes (RrC2H2s) were identified in R. rugosa via a comprehensive approach. These genes were categorized into three lineages, and their motif constitutions were grouped into four classes. RrC2H2s were distributed across all seven rose chromosomes, with 15 paralogous gene pairs identified within synteny regions. Additionally, 43 RrC2H2s showed differential expression across various tissues under salt stress, with RrC2H2-8 being the only gene consistently repressed in all tissues. Subcellular localization analysis revealed that the RrC2H2-8 protein was localized in the nucleus. The heterologous expression of RrC2H2-8 in Arabidopsis significantly improved its growth under salt stress compared to the wild-type (WT) plants. Furthermore, the malondialdehyde content in the roots of transgenic Arabidopsis was significantly lower than that in the WT, suggesting that RrC2H2-8 enhanced salt tolerance by reducing cellular damage. This study provides a systematic understanding of the RrC2H2 family and identifies RrC2H2-8 as a regulator of salt tolerance, laying a foundation for future research on the mechanisms of salt stress regulation by RrC2H2.