Abstract
BACKGROUND/OBJECTIVES: The Suppressor of Female Function (SOFF) and Shy Girl (SyGI) gene families play vital roles in sex determination in dioecious plants. However, their evolutionary dynamics and functional characteristics remain largely unexplored. METHODS: Through this study, a systematic bioinformatics analysis of SOFF and SyGI families was performed in plants to explore their evolutionary relationships, gene structures, motif synteny and functional predictions. RESULTS: Phylogenetic analysis showed that the SOFF family expanded over time and was divided into two subfamilies and seven groups, while SyGI was a smaller family made of compact molecules with three groups. Synteny analysis revealed that 125 duplicated gene pairs were identified in Kiwifruit where WGD/segmental duplication played a major role in duplicating these events. Structural analysis predicted that SOFF genes have a DUF 247 domain with a transmembrane region, while SyGI sequences have an REC-like conserved domain, with a "barrel-shaped" structure consisting of five α-helices and five β-strands. Promoter region analysis highlighted their probable regulatory roles in plant development, hormone signaling and stress responses. Protein interaction analysis exhibited only four SOFF genes with a close interaction with other genes, while SyGI genes had extensive interactions, particularly with cytokinin signal transduction pathways. CONCLUSIONS: The current study offers a crucial understanding of the molecular evolution and functional characteristics of SOFF and SyGI gene families, providing a foundation for future functional validation and genetic studies on developmental regulation and sex determination in dioecious plants. Also, this research enhances our insight into plant reproductive biology and offers possible targets for breeding and genetic engineering approaches.