Convergent evolution of immune receptors underpins distinct elicitin recognition in closely related Solanaceous plants

Citations Over TimeTop 1% of 2023 papers

Abstract

Elicitins are a large family of secreted proteins in Phytophthora. Clade 1 elicitins were identified decades ago as potent elicitors of immune responses in Nicotiana species, but the mechanisms underlying elicitin recognition are largely unknown. Here we identified an elicitin receptor in Nicotiana benthamiana that we named REL for Responsive to ELicitins. REL is a receptor-like protein (RLP) with an extracellular leucine-rich repeat (LRR) domain that mediates Phytophthora resistance by binding elicitins. Silencing or knocking out REL in N. benthamiana abolished elicitin-triggered cell death and immune responses. Domain deletion and site-directed mutagenesis revealed that the island domain (ID) located within the LRR domain of REL is crucial for elicitin recognition. In addition, sequence polymorphism in the ID underpins the genetic diversity of REL homologs in various Nicotiana species in elicitin recognition and binding. Remarkably, REL is phylogenetically distant from the elicitin response (ELR) protein, an LRR-RLP that was previously identified in the wild potato species Solanum microdontum and REL and ELR differ in the way they bind and recognize elicitins. Our findings provide insights into the molecular basis of plant innate immunity and highlight a convergent evolution of immune receptors towards perceiving the same elicitor.

Related Papers

• → Harpin, Elicitor of the Hypersensitive Response Produced by the Plant Pathogen Erwinia amylovora(1992)794 cited
• → Genome-Wide Identification Reveals That Nicotiana benthamiana Hypersensitive Response (HR)-Like Lesion Inducing Protein 4 (NbHRLI4) Mediates Cell Death and Salicylic Acid-Dependent Defense Responses to Turnip Mosaic Virus(2021)14 cited
• → A novel protein elicitor ( PeSy1 ) from Saccharothrix yanglingensis induces plant resistance and interacts with a receptor‐like cytoplasmic kinase in Nicotiana benthamiana(2023)13 cited
• → Mutational analysis of the Verticillium dahliae protein elicitor PevD1 identifies distinctive regions responsible for hypersensitive response and systemic acquired resistance in tobacco(2013)16 cited
• → A marine bacterium elicits the type III secretion-dependent nonhost hypersensitive response in a land plant(2023)