Main conclusion <p>This study identified a <i>PbrCAR1</i> gene in pear, which promotes pollen tube growth by mediating vesicle transport, and Ca²⁺ treatment enhances <i>PbrCAR1</i> expression and promotes its plasma membrane accumulation.</p> Abstract <p>The C2-domain abscisic acid-related (CAR) proteins bind to diverse signaling protein complexes and play essential roles in numerous biological processes, including blue light tropism, gravitropism, iron nutrition, and responses to biotic and abiotic stresses. However, the functions of <i>CAR</i> gene family members in pear pollen development within the Rosaceae family remain inadequately explored. In this study, we identified a total of 33 <i>CAR</i> genes across four Rosaceae species. Phylogenetic and structural analyses classified these genes into three distinct subfamilies (I to III). Evolutionary analyses indicated that purifying selection significantly influenced the evolution of the Rosaceae <i>CAR</i> gene family, while whole-genome duplication and tandem duplication contributed substantially to its expansion. Transcriptomic data combined with quantitative real-time PCR (qRT-PCR) analysis revealed tissue-specific expression patterns of <i>PbrCAR</i> genes, with <i>PbrCAR1</i> showing high expression during pollen development and mainly localizing in the cytoplasm. Exogenous calcium ion (Ca²⁺) treatment was shown to enhance the expression of <i>PbrCAR1</i> and promote its accumulation at the plasma membrane. Moreover, knocking down <i>PbrCAR1</i> in pear pollen tubes significantly inhibited vesicle trafficking at the pollen tube tip, thereby suppressing pollen tube growth. These findings indicate that PbrCAR1 regulates pear pollen tube growth by mediating vesicle transport and provide valuable insights along with a theoretical foundation for studying the evolution, expression patterns, and functions of the <i>CAR</i> gene family in plants.</p>