In a landmark discovery that could revolutionize plant immunity and agricultural sustainability, a team of researchers at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan has identified an ancient immune receptor protein capable of recognizing an unprecedented range of bacterial and pathogen signals. This receptor, dubbed “SCORE” (Selective COld shock protein Receptor), exhibits remarkable specificity for a conserved segment of cold-shock proteins prevalent in over 85% of known bacterial species, fungi, and even insects. Such a finding heralds a new era in engineering crop resilience, offering a sophisticated molecular toolkit to bolster plant defenses against rapidly evolving pathogens.
The discovery came through an extensive comparative genomic survey involving over 1,300 receptor candidates extracted from the genomes of 350 diverse plant species. Initially isolated from the pomelo (Citrus maxima), SCORE demonstrated a unique ability to recognize variations of cold-shock proteins, a category of small, highly conserved proteins that bacteria produce in response to abrupt temperature changes or environmental stresses. By isolating SCORE’s interaction with a specific 15-amino acid sequence segment termed “csp15,” the team delineated how slight alterations in either the receptor or the protein segment could modulate pathogen recognition.
Cold-shock proteins serve as vital molecular markers across a wide range of pathogens, making them ideal targets for plant immune systems. However, what makes SCORE exceptional is its evolutionary refinement—specific amino acid positions within csp15 and the receptor structure itself show significant variability across different plant lineages. Particularly, the residues at positions 6, 7, 14, and 15 in the csp15 segment contain a breadth of variation that dictates the binding affinity and specificity of the receptor. This intrinsic plasticity implies that SCORE has undergone repeated evolutionary tuning, enabling plants to adapt their immune surveillance to distinct microbial threats across ecological niches.
The manipulation of SCORE’s amino acid composition unlocks an avenue for custom-designing immune receptors tailored to recognize pathogens that currently evade natural plant defenses. Notably, the team engineered synthetic variants of pomelo SCORE that gained the ability to detect cold-shock proteins from notorious agricultural pathogens such as Ralstonia, Erwinia, and Xanthomonas species. These engineered receptors not only extend the defensive repertoire of the host plants but also hold promise for durable resistance by focusing on a conserved pathogen epitope unlikely to mutate without loss of function.
SCORE’s ancient origin dates back to the last common ancestor of all flowering plants, implying it is widely distributed across agronomically important species including rice, wheat, olives, and bamboo. This broad phylogenetic conservation offers an extensive genetic resource pool to mine for functional variants and facilitate cross-lineage receptor transfer. Unlike traditional genetic engineering approaches limited to model plants with well-studied genomes, SCORE-based strategies open possibilities for enhancing immunity in perennial crops and non-model species that often lack advanced molecular tools.
Current challenges in plant immune receptor research stem from the immense combinatorial diversity of microbe-receptor interactions—there are hundreds of thousands of potential pairs, yet fewer than ten have been definitively characterized. SCORE’s identification and modular engineering represent a paradigm shift, providing a rational framework to predict and tailor receptor specificity based on amino acid charges and structural motifs. This approach transcends conventional trial-and-error methods, enabling precision design of plant immune surveillance systems based on deep evolutionary and biochemical insights.
The implications for sustainable agriculture are profound. Pathogen infection is a leading cause of yield reduction and crop loss worldwide, threatening global food security and farmer livelihoods. By introducing engineered SCORE variants into target crops, it may become feasible to buffer plants against a broad spectrum of pathogens, reducing reliance on chemical pesticides and fostering resilient agroecosystems. Furthermore, the modularity of the receptor system suggests a flexible platform adaptable to emergent microbial threats in the face of climate change and evolving biodiversity.
Ken Shirasu, the lead investigator, emphasizes, “Our findings compose a new blueprint for discovering and designing immune receptors in a long-neglected category of plants, particularly woody perennials that have traditionally resisted genetic intervention.” This breakthrough also suggests that evolutionary principles can guide synthetic biology frameworks to enhance immunity with minimal unintended trade-offs. The precise tuning of receptor-ligand interactions showcases nature’s ingenuity and offers a powerful template for human-directed crop improvement.
Complementing this, co-author Yasuhiro Kodata highlights the evolutionary depth of SCORE: “The extensive natural variation in CSP recognition across orthologs reflects repeated adaptive fine-tuning to diverse pathogen environments across plant lineages. This evolutionary plasticity underpins SCORE’s versatile functionality.” These insights reiterate the importance of integrating evolutionary biology with molecular engineering to address pressing challenges in agriculture and ecosystem health.
The next frontier involves translating these synthetic variants into economically vital crops via genomic integration and field trials. Lead author Bruno Pok Man Ngou envisions a future where engineered SCORE receptors bestow durable, broad-spectrum resistance with minimal fitness costs. Such innovations would mark a sustainable paradigm in crop protection, decreasing agrochemical inputs and enhancing yield stability. As global populations surge and climate unpredictability rises, resilient plant immunity systems like SCORE are indispensable tools in securing food supplies.
Ultimately, the discovery and engineering of SCORE represent a confluence of evolutionary biology, structural biochemistry, and synthetic engineering that could transform agricultural practices. This protein receptor exemplifies how ancient natural systems can be harnessed and tailored to meet modern challenges, reaffirming the value of fundamental research in enabling technological breakthroughs with substantial societal benefits.
Subject of Research: Plant immune receptors and synthetic engineering of pathogen recognition
Article Title: Systematic discovery and engineering of synthetic immune receptors in plants
News Publication Date: 4-Sep-2025
Web References: DOI link
Image Credits: By Ivar Leidus – Own work, CC BY-SA 4.0
Keywords: plant immunity, cold-shock protein, immune receptor engineering, pathogen recognition, synthetic biology, crop protection, plant evolution, agriculture, disease resistance, plant sciences, microbiology, sustainable agriculture
