Abstract
Valsa canker, a destructive necrotrophic disease caused by Valsa species (V. mali and V. pyri), threatens global apple and pear production. Resistance breeding has gained much attention because of its environmental friendliness and effectiveness, making it extremely critical to obtain key disease resistance genes. In this study, we identified that the expression of PbeSTOP2, a C2H2-type transcription factor in 'Duli-G03' (Pyrus betulifolia, rootstock of pear), was induced in response to signals from Vp and Vp metabolites (VpM). Transient expression in fruits and stable overexpression in suspension cells demonstrated that PbeSTOP2 enhances resistance to Vp. In overexpressing cells, genes associated with jasmonic acid (JA) and pattern-triggered immunity (PTI) signaling were upregulated, and endogenous JA and auxin (IAA) levels increased. These results revealed that JA signaling was involved in the enhanced Valsa canker resistance conferred by PbeSTOP2 overexpression. This finding on host disease resistance should facilitate the breeding efforts for Valsa canker resistance.