2025-09-05 理化学研究所,科学技術振興機構
非モデル植物からの免疫受容体(LRR-RLKK-XII)の同定法と受容体改変による認識範囲の拡大
<関連情報>
- https://www.riken.jp/press/2025/20250905_1/index.html
- https://www.science.org/doi/10.1126/science.adx2508
植物における合成免疫受容体の体系的発見と設計 Systematic discovery and engineering of synthetic immune receptors in plants
Bruno Pok Man Ngou, Michele Wyler, Marc W. Schmid, Takehiro Suzuki, […] , and Ken Shirasu
Science Published:4 Sep 2025
DOI:https://doi.org/10.1126/science.adx2508
Editor’s summary
A vast array of receptors at the plant cell surface perceive fragments of pathogens and elicit immune responses. Each receptor binds to specific pathogenic ligands. Ngou et al. analyzed thousands of plant pattern recognition receptors and identified distantly related receptors with similar ligand-binding regions that convergently evolved to detect bacterial cold shock proteins. By identifying key features of the protein required for binding and altering critical amino acids, the authors engineered receptor proteins with an expanded repertoire of cold shock proteins. The research demonstrates a pipeline for the discovery and optimization of immune recognition mechanisms by using information from diverse species and systems. —Madeleine Seale
Structured Abstract
INTRODUCTION
Plants, like most organisms, sense external stimuli through cell surface–localized receptors composed of an ectodomain, transmembrane domain, and cytosolic domain. Environmental cues are typically detected by the ectodomain, triggering activation of the cytosolic domain and downstream signaling. Pathogen-associated molecules are recognized by a class of receptors known as pattern recognition receptors (PRRs), which initiate defense responses against pathogens and pests. Among these, leucine-rich repeat receptor-like kinases (LRR-RLKs) form one of the largest PRR families in plants.
RATIONALE
LRR-RLKs have diversified in a lineage-specific manner throughout land plant evolution. These lineage-specific PRRs can be transferred across crop species to confer broad-spectrum resistance against pathogens. Although genetic tools facilitate the identification of PRRs in model plants, characterizing them in nonmodel species, such as trees and perennial crops, remains challenging. This study aimed to map the pathogen recognition landscape of LRR-RLKs and identify uncharacterized PRRs that can be engineered to enhance disease resistance in crop species.
RESULTS
To characterize subgroup XII of LRR-RLKs (LRR-RLK-XIIs), 13,185 receptors from 285 angiosperm genomes were clustered on the basis of conserved residues in their LRR ectodomains, yielding 210 subgroups, which represent 31.7% of all identified receptors. To identify those responsive to pathogens, we expressed chimeric receptors in Nicotiana benthamiana, each comprising a subgroup-specific LRR ectodomain fused to the cytosolic kinase domain of a brassinosteroid receptor, enabling specific detection of PRR activation in response to pathogens. Of the 210 chimeras screened, seven were activated by Agrobacterium, including receptor 181 from Citrus maxima (pomelo), which responded to multiple bacterial species. Biochemical analysis revealed that receptor 181 recognizes cold shock proteins (CSPs), specifically the conserved peptide csp15, and was designated SCORE (selective cold shock protein receptor). SCORE differs in ligand recognition specificity from the previously characterized CSP receptor CORE. In addition, SCORE and its orthologs—primarily found in Sapindales, Malvids, and Magnoliids—exhibit diverse specificity toward csp15 variants owing to sequence polymorphisms. Protein structure predictions and domain swapping experiments identified the 10th LRR motif in SCORE as key to csp15 recognition specificity, with three variable residues modulating specificity through surface charge interactions. Guided by these insights, we engineered synthetic SCORE variants to detect CSPs from a broader range of pathogens. Several variants gained responsiveness to Ralstonia, Xanthomonas, Candidatus Liberibacter asiaticus (causative pathogen for citrus greening disease), and root-knot nematodes, which cannot be detected by the wild-type (WT) SCORE.
CONCLUSION
This study demonstrates a scalable approach to identifying functional immune receptors across plant lineages by integrating bioinformatics, synthetic biology, and biochemical approaches. We characterized SCORE, a receptor that evolved independently from CORE to detect CSPs and exhibits natural variation in ligand specificity. Structural insights enabled the engineering of synthetic SCORE variants capable of recognizing previously undetectable pathogens. These findings highlight the evolutionary and functional diversity of PRRs and offer a promising strategy for developing disease-resistant crops, particularly in nonmodel and perennial species, for which conventional genetic approaches remain limited. Future work may expand this platform to systematically mine and reprogram PRRs for broad-spectrum resistance across diverse crops.
Pipeline for systematic discovery and engineering of plant immune receptors.
A total of 13,185 LRR-RLK-XIIs were clustered into 210 subgroups. These receptors were expressed as chimeras and screened for Agrobacterium-induced activation. SCORE was identified as a cold shock protein (CSP) receptor, with orthologs showing polymorphic recognition of the conserved CSP peptide. Guided by structural and phylogenomic insights, we engineered SCORE variants to detect diverse crop pathogens and pests. RCM, repeat conservation mapping; WT, wild type.
Abstract
Plants deploy a diverse array of pattern recognition receptors (PRRs), which perceive microbe-associated molecular patterns to activate immune responses. Leucine-rich repeat receptor-like kinase subgroup XII (LRR-RLK-XII) represents one of the largest PRR families owing to lineage-specific diversification. Through bioinformatics and synthetic biology approaches, we characterized LRR-RLK-XIIs from 285 plant species and identified a receptor, “SCORE,” that perceives cold shock protein (CSP) peptides. SCORE orthologs from multiple angiosperm lineages exhibit CSP recognition polymorphisms, indicating recurrent selection for pathogen recognition through substitutions at key amino acid residues. Through functional phylogenomics and protein structure predictions, we engineered SCORE variants capable of detecting multiple phytopathogen CSP peptides, thus revealing the diverse PRR recognition landscape in plants. Our strategy holds promise for engineering plant immune receptors, particularly for perennial crops.
