{"title":"Stomatal architecture and rapid jasmonate responses contribute to pear resistance against\u0000 Colletotrichum fructicola","authors":"Kexin Xu,Qingsong Yang,Zijuan Li,Zihan Miao,Xiaogang Li,Shutian Tao,Yiduo Wei,Jialiang Kan,Yongyue Ma,Jing Lin,Chaohui Li,Gang Liu,Bárbara Blanco-Ulate,Hong Wang","doi":"10.1093/hr/uhag420","DOIUrl":"https://doi.org/10.1093/hr/uhag420","url":null,"abstract":"Abstract Pear cultivars exhibit variation in resistance to anthracnose caused by Colletotrichum fructicola, yet the underlying mechanisms remain unclear. Through a two-step screening of 102 cultivars and 6,000 hybrid progenies, we identified a highly resistant genotype HR1 and a susceptible cultivar SC1. Field and controlled assays showed that HR1 maintains stable resistance regardless of environmental conditions, whereas SC1 exhibits humidity-dependent susceptibility. Microscopic analyses revealed that LCF-2 exhibited stomatal tropism and entered leaves of the susceptible cultivar SC1 through stomatal pores. HR1 possesses smaller stomata with restricted apertures and elevated peristomatal rims, where LCF-2 germ tubes frequently grew away from stomatal pores, and no successful stomatal penetration was detected. During early infection, HR1 showed rapid JA accumulation and strong induction of PpAOC, PpMYC3, PpPYL1, and PpOST1. Exogenous JA accelerated stomatal closure and reduced disease severity in SC1. PpMYC3 physically interacts with the ABA receptor PpPYL1. PpMYC3 overexpression promoted stomatal closure, reduced fungal accumulation, and enhanced resistance, whereas its silencing increased susceptibility. PpPYL1 overexpression increased PpOST1 expression and reduced stomatal aperture but did not confer resistance. Co-expression of PpMYC3 and PpPYL1 produced the strongest stomatal closure and reduced disease development relative to PpPYL1 overexpression alone, indicating that PpMYC3 provides a defense-associated context in which PpPYL1-mediated stomatal regulation contributes to resistance. Collectively, these findings support a proposed two-tiered defense combining preformed stomatal barriers with rapid JA-centered stomatal immunity, providing new insights into the multilevel regulatory network of tree-pathogen interactions and genetic resources for anthracnose resistance breeding in fruit trees.","PeriodicalId":13179,"journal":{"name":"Horticulture Research","volume":"16 1","pages":""},"PeriodicalIF":8.7,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149087981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}