Uncovering Convergent Pattern Recognition Receptors Recognising Phytophthora Across Plant Lineages.

Abstract

Pattern recognition receptors (PRRs) are pivotal for plant immunity, yet their discovery in crops is hindered by lineage-specific divergence. We demonstrate that microbe-associated molecular patterns (MAMPs) often activate immunity through phylogenetically unrelated, convergently evolved PRRs across plant lineages. Using the Phytophthora-derived MAMP RLK6 as a prototype, we identified two leucine-rich repeat receptor-like proteins (LRR-RLPs), NbRKR1 and NbRKR2, that redundantly perceive RLK6 in the model plant Nicotiana benthamiana. Strikingly, soybean retained RLK6 responsiveness despite lacking NbRKR1/2 orthologs. By integrating AlphaFold3 structural prediction with functional screening in N. benthamiana receptor mutants, we uncovered GmRLP30 as the convergent RLK6 receptor in soybean. Phylogenetic analysis revealed RKR1/2 conservation in Solanaceae but their absence in Capsicum annuum, which encodes a truncated RKR1 variant incapable of activating RLK6 immunity. Critically, heterologous expression of NbRKR1 or GmRLP30 in pepper restored RLK6 perception, confirming functional equivalence. These results establish a direct receptor-mediated communication between pathogen and host surfaces, an ortholog-independent pipeline for rapid PRR mining across crops, and a foundation for engineering synthetic immune interfaces with durable disease resistance.