Discovery of functional PRRs for the fungal elicitor Xyn11/eix in Prunus fruit trees

• The fungal elicitor, Xyn11/eix, triggers characteristic defense responses in Prunus persica (peach) and Prunus avium (sweet cherry) species: increased production of ethylene, and induction of cell death. • Functional orthologues of LeEIX2, a known Xyn11/eix receptor in Solanum lycopersicum , were identified in both Prunus persica (PpEIX2–2) and Prunus avium (PaEIX2). • Our findings indicate a similar PTI response for Xyn11/six recognition and signaling across Rosaceae and Solanaceae plant families. Pattern-triggered immunity (PTI) is a critical defense mechanism employed by plants against pathogen attacks. This study explores the role of PTI induced by the Xyn11/eix fungal elicitor in two commercially valuable Rosaceae species, Prunus persica (peach) and Prunus avium (sweet cherry). Our findings demonstrate that Xyn11/eix triggers two specific defense responses: the increase in ethylene production and the induction of cell death. Furthermore, Xyn11/eix-mediated PTI significantly reduces the susceptibility to Botrytis cinerea infection in both species. The study reveals changes in gene expression patterns after Xyn11/eix treatment. Notably, ACO1 and SARDEF1 genes, involved in ethylene and salycilic acid biosynthesis, respectively, are upregulated in P. persica , but not in P. avium at the time point analyzed. This result suggests a potential role for the ethylene and salicylic acid signaling in Xyn11/mix-mediated PTI in P. persica . Additionally, the research identified functional orthologues of LeEIX2, the receptor for Xyn11/eix in Solanum lycopersicum , within both Prunes genomes. Altogether, these results suggest a remarkable functional convergence between Rosaceae and Solanaceae plants in the Xyn11/eix mediated defense responses although not at the transcriptional level, and opens new avenues for developing novel disease control strategies for stone fruits.