Molecular Characterization of Peroxidase (PRX) Gene Family in Cucumber

Background: The Peroxidase (PRX) gene family is essential for plant growth and significantly contributes to defense against stresses. However, information about PRX genes in cucumber (Cucumis sativus L.) remains limited. Methods: In this present study, CsPRX genes were identified and characterized using bioinformatics analysis. The expression pattern analysis of CsPRX genes were examined utilizing the RNA-seq data of cucumber from public databases and real-time quantitative PCR (qRT-PCR) analysis. Results: Here, we identified 60 CsPRX genes and mapped them onto seven chromosomes of cucumber. The CsPRX proteins exhibited the presence of 10 conserved motifs, with motif 8, motif 2, motif 5, and motif 3 consistently appearing across all 60 CsPRX protein sequences, indicating the conservation of CsPRX proteins. Furthermore, RNA-seq analysis revealed that differential expression of CsPRX genes in various tissues. Notably, a majority of the CsPRX genes exhibited significantly higher expression levels in the root compared to the other plant tissues, suggesting a potential specialization of these genes in root function. In addition, qRT-PCR analysis for four selected CsPRX genes under different stress conditions indicated that these selected CsPRX genes demonstrated diverse expression levels when subjected to NaCl, CdCl₂, and PEG treatments, and the CsPRX17 gene was significantly induced by NaCl, CdCl₂, and PEG stresses, suggesting a vital role of the CsPRX17 gene in response to environmental stresses. Conclusions: These findings will contribute valuable insights for future research into the functions and regulatory mechanisms associated with CsPRX genes in cucumber.