PbeVAMP724 Alleviates Cell Death and Enhances Resistance to Valsa Canker in Pyrus betulifolia

Valsa canker, caused by Valsa pyri (Vp), severely threatens global pear production. The VAMP72 family modulates plant immunity, but its role in Valsa canker resistance remains unclear. In this study, it was found that PbeVAMP724, encoding a membrane-localized SNARE protein, was significantly induced by Vp infection and Abscisic acid (ABA), salicylic acid (SA), and jasmonic acid (JA) in the resistant pear rootstock Pyrus betulaefolia. Transient overexpression of PbeVAMP724 in ‘Huangguan’ fruits reduced Vp-induced lesions, and the lesion diameter was reduced by 23.1% at 48 h and 20.0% at 72 h compared to the empty vector control (pFGC-5941), whereas VIGS silencing compromised the resistance. Stable overexpression in suspension cells ‘Duli-G03’ (P. betulifolia) enhanced tolerance to Vp metabolites (VpM), alleviated cell death, and induced ROS bursts and defense responses. Weighted gene co-expression network analysis (WGCNA) revealed that phloem/xylem histogenesis-related genes (GWHGAAYT028948, GWHGAAYT039435) are co-expressed with PbeVAMP724. In conclusion, we demonstrate that PbeVAMP724 integrates hormone signaling, triggers ROS bursts, and activates defense responses to positively regulate resistance to Valsa canker in pear, representing a promising candidate for breeding Valsa canker-resistant pear varieties.