Characterization of the WD40 gene family in Pyrus bretschneideri and functional analysis of PbrWD40–60 in pollen tube growth

• Identified 330 PbrWD40 genes in the pear genome, categorized into eight subfamilies. • WGD duplication events and dispersed duplication contributes to driving the expansion of the WD40 gene family in pear. • The PbrWD40 genes exhibit pronounced differential expression across diverse tissues and developmental stages, underscoring their crucial and varied roles in pear growth and development. • PbrWD40–60 controls pear pollen tube growth. WD40 proteins represent a large gene family within the plant kingdom and play crucial roles at various stages of plant growth and development. However, their function in pear remains poorly characterized. In this study, we performed a genome-wide analysis of the WD40 gene family in pear. A total of 330 members of the WD40 family were meticulously identified and categorized into eight distinct subfamilies. Chromosomal mapping revealed a random distribution of 290 WD40 family members across 17 chromosomes, demonstrating significant variation in the representation of these members. Intriguingly, members of the same subfamily exhibited similar gene structures and conserved motif arrangements, highlighting their functional relatedness. Whole-genome duplication events and dispersed replication contributed to the expansion of the WD40 gene family in pear. Furthermore, expression analysis revealed tissue-specific, constitutive, and developmentally dynamic patterns, suggesting stage- and tissue-dependent regulatory roles. Among them, PbrWD40–60 showed specific expression in pollen and a continuous increase in transcript abundance during pollen tube growth, and was therefore selected for functional validation. Antisense oligonucleotides (As-ODNs) confirmed the role of PbrWD40–60 in pear pollen tube growth. This study provides an overview of the WD40 family within the pear genome and establishes a foundation for future functional research.