The leucine-rich repeat receptor-like kinase PpLRR1 enhances peach resistance to <i>Xanthomonas arboricola</i> pv. <i>pruni</i>

Plants have evolved sophisticated defense mechanisms to counter pathogen infections, among which the hypersensitive response (HR) mediated by leucine-rich repeat receptor-like kinases (LRR-RLKs) plays a key role in limiting pathogen spread. However, whether LRR-RLKs mediate HR to confer resistance against <italic>Xanthomonas arboricola</italic> pv. <italic>pruni</italic> (Xap) in peach (<italic>Prunus persica</italic>) remains unclear. This study identified the LRR-RLK gene family member, <italic>PpLRR1</italic>, which was significantly upregulated in response to Xap infection. Functional analysis revealed that <italic>PpLRR1</italic> is essential for HR signaling and enhances resistance to pathogen attack. Transient overexpression of <italic>PpLRR1</italic> significantly reduced disease symptoms, whereas its silencing aggravated infection. Further studies demonstrated that the MYB transcription factor PpLIMYB directly binds to the <italic>PpLRR1</italic> promoter and activates its transcription. These findings highlight the important role of the PpLIMYB-<italic>PpLRR1</italic> regulatory module in peach disease resistance. This study advances the understanding of disease resistance mechanisms in woody plants and identifies a potential target for breeding disease-resistant cultivars.