Evolutionary insights and expression dynamics of the glutathione peroxidase (GPX) gene family in water lily (Nymphaea colorata) in response to multiple abiotic stresses

• Glutathione peroxidase ( GPX ) is a family of antioxidant enzymes that catalyze the reduction of hydrogen peroxide (H 2 O 2 ) and defend the cells from oxidative stress. • Identified the five GPX genes in the N. colorata genome and further divided into four main groups based on phylogenetic analyses. • NcGPX proteins have MW ranged 18.798–26.292 kDa and conserved exon-intron structures and motifs. • NcGPX exhibited segmental duplications and collinearity exists between N. thermarum. • RT-qPCR analysis revealed that all NcGPXs have dynamic expression especially NcGPX3 and NcGPX5 could be critical for abiotic stress improvement. The glutathione peroxidase ( GPX ) family in plants contains various isoenzymes, each with distinct subcellular localizations, tissue-specific expression patterns, and responses to environmental stress. In current study, we conducted genome-wide bioinformatics analyses of the GPX gene family in Nymphaea colorata , identifying five putative NcGPX genes dispersed across five of the fourteen chromosomes. Examination of the protein sequences revealed that NcGPXs comprehend three conserved cysteine residues, with predicted in-silico subcellular localizations in chloroplast, extracellular, or cytoplasm. We reported that NcGPX genes protein lengths and molecular weight (MW) ranged from 171 to 248 amino acids (aa) and 18.798–27.076 kDa, respectively. A comparative neighbor-joining phylogenetic study revealed that GPX genes were clustered into four main groups (Group A– D) from water lily and two closely related plant species, alongside with Arabidopsis thaliana . The universal analysis showed that segmental duplications occurred within the NcGPX gene family. Investigation of gene structure and motifs suggested that most NcGPX genes have relatively conserved exon-intron structures and motif arrangements. Promoter region exploration of NcGPX genes revealed numerous cis -acting regulatory elements associated with development, stress, and hormone responses. The identified 3D protein structures showed that water lily GPXs form conserved dimeric protein signatures. Finally, gene expression and enzymes accumulation of NcGPXs in response to different abiotic stresses, in leaves of N. colorata were analysed using real-time RT-qPCR and spectrophotometry. The results indicate that different members of the GPX gene family are co-ordinately regulated under specific environmental stress conditions, establishing a foundation for studying their gene functions and improving abiotic stress tolerance in water lily genetic breeding.