Genome-Wide Identification and Expression Analysis of the YABBY Gene Family in Watermelon

The YABBY proteins are a type of transcription factor known to participate in the growth and development of plants. In this study, we analyzed a genome-wide identification of the YABBY gene family in watermelon (Citrullus Lanatus). A total of nine ClaYABBY genes were identified and classified into five subfamilies. Sequence and phylogenetic analyses revealed that segmental duplication contributed to the expansion of this family. Two paralogous gene pairs not only exhibited highly similar sequences but also had relatively consistent expression patterns. RT-qPCR results indicated that ClaYABBY genes exhibited specific expression in different tissues, and most members showed higher expression levels in reproductive organs. Among them, ClaYABBY2 maintained a consistently high expression throughout fruit development, suggesting its potential role in the stage of fruit development. Furthermore, under drought and salt stresses, the expressions of ClaYABBY2, 3, 4, and 9 were upregulated, indicating that they may be involved in abiotic stress in watermelon. This study provides insight for future research on the specific functions of the ClaYABBY gene in fruit development and environmental adaptation of watermelon.