Comparative genomic and evolutionary analysis of stress-associated proteins in Prunus persica and distinct plant...

Stress-Associated Proteins (SAPs) are important zinc-finger proteins containing A20 and/or AN1 domains and are widely involved in plant stress responses and hormone signaling. However, the SAP gene family in peach (Prunus persica) has not yet been systematically characterized. In this study, we performed a genome-wide identification and comparative analysis of the PpSAP family to investigate its evolutionary relationships, structural features, promoter characteristics, and stress-responsive expression patterns. A total of nine PpSAPs (PpSAP1-PpSAP9) were identified and classified into four phylogenetic clades, providing a framework for understanding SAP family diversification in peach and other representative plant species. Comparative analysis showed that the SAP gene family is relatively conserved within Rosaceae species but exhibits greater divergence in more distantly related species, such as Arabidopsis thaliana and Oryza sativa, suggesting lineage-specific evolutionary differentiation. Promoter analysis revealed that PpSAPs contain abundant cis-regulatory elements associated with stress responses and hormone signaling, including ABA, GA, MYB, and anaerobic-responsive elements. RNA-seq expression profiling further demonstrated that PpSAPs exhibit diverse transcriptional responses under drought, salinity, ethylene, and cold stress conditions. In particular, different PpSAP members displayed distinct temporal expression patterns during cold treatment, indicating potential functional divergence within the family. Overall, this study provides the first comprehensive genomic and evolutionary characterization of the PpSAP gene family in peach and identifies several stress-responsive candidate genes for future functional validation and peach stress-resilience improvement.