An apoplastic Lasiodiplodia theobromae effector triggers plant immunity through a lectin receptor-like kinase in peach

Abstract Pathogen-associated molecular patterns (PAMPs) are recognized by plant pattern recognition receptors, activating PAMP-triggered immunity to restrict pathogen infection. The fungal pathogen Lasiodiplodia theobromae poses a major threat to global agriculture, yet its PAMPs and their interaction with plant pattern recognition receptors remain poorly understood. In this study, we identify LtSCRE11 as a key virulence factor of L. theobromae that also acts as a PAMP, inducing cell death and immune responses in Nicotiana benthamiana and peach (Prunus persica). In peach, LtSCRE11 is directly recognized by the L-type lectin receptor kinase PpLecRK-IX.1, which is essential for LtSCRE11-triggered cell death and immune activation. Remarkably, different plant lineages appear to have independently evolved distinct receptors to recognize LtSCRE11. PpLecRK-IX.1 binds LtSCRE11 through its extracellular lectin domain, forming a complex with the leucine-rich repeat receptor-like kinase PpBAK1 to mediate defense signaling. Our findings highlight the dual role of LtSCRE11 as both a virulence factor and a PAMP that activates plant immunity through PpLecRK-IX.1 in peach. This work provides insights into plant-fungal interactions and presents promising strategies for developing broad-spectrum disease resistance in peach.