P-025 - Deciphering the molecular basis of PERU-mediated ligand recognition and functional diversification

Plant cell surface pattern recognition receptors (PRRs) have evolved at an accelerated rate, with their diversity and repertoire largely shaped by the pathogen pressure. Our recent research has revealed that the potato PRR Pep-13 receptor unit (PERU) is a leucine-rich repeat receptor kinase that recognizes Pep-13, a conserved immunogenic peptide pattern derived from the transglutaminase secreted by pathogenic Phytophthora species. PERU perceives Pep-13, enhancing potato resistance to the late blight pathogen Phytophthora infestans. Ligand-sensitivity analysis, conducted on a large population within Solanum section Petota, demonstrated that active PERU alleles are present in approximately 26% of the population and primarily belong to sections Tuberosa or Piurana and are predominantly located in the Andean region of Bolivia and Peru. This geographic pattern suggests that the PERU receptor family originated in this region. Intriguingly, these potato populations exhibit different PERU ligand specificities. The mode of PERU evolution and its ligand specificities under the pressure of pathogens and environment remain unclear. In this study, we investigate the ligand specificity of PERU alleles between two potato genotypes and identify the specific residues responsible for ligand recognition and functional diversification, providing insights into the evolutionary mechanism shaping PRR diversity and strengthening our understanding of plant-pathogen coevolution.