Targeting novel metacaspase effector to develop antifungal strategies against rhizoctonia solani

Overview

Rice sheath blight, caused by the necrotrophic fungal pathogen Rhizoctonia solani, is a major threat to global rice production. This research addresses a critical gap in understanding how R. solani manipulates host plant defenses during infection. Through genome-wide analysis, seven novel effector proteins were identified, including RS107_6, a metacaspase that targets key components of rice defense pathways. By characterizing these effectors and their interactions with host proteins, this work enables the rational design of novel antifungal compounds that disrupt pathogen virulence mechanisms, offering a new strategy to protect rice crops from disease.

Technical specifications

• Genome-wide effector identification: Seven novel effectors were identified in R. solani based on characteristics of previously reported effector proteins, predicted to be non-classically secreted proteins with conserved functional domains.
• Metacaspase characterization: RS107_6, a metacaspase protein, was heterologously expressed in Escherichia coli and purified to approximately 36.5 kDa.
• Protein family confirmation: MALDI-TOF analysis confirmed RS107_6 belongs to the Peptidase_C14 protein family.
• Host target identification: Rice target proteins involved in regulating programmed cell death and defense mechanisms were identified, revealing the specific interaction points between pathogen effectors and host immunity.
• Antifungal compound design: The identified effector-host protein interactions provide molecular targets for designing novel antifungal molecules that prevent critical protein-protein interactions.
• Validation pipeline: Antifungal assays including time-kill assays and greenhouse trials are planned to confirm the potency of designed molecules.

Technology readiness level

The research is currently at an early-to-mid stage of development. Genome-wide identification and biochemical characterization of seven novel R. solani effectors has been completed, with RS107_6 successfully expressed, purified, and confirmed as a Peptidase_C14 family metacaspase. Host target proteins regulating programmed cell death have been identified. The next phase involves designing antifungal compounds targeting these effector-host interactions and validating their efficacy through in vitro antifungal assays and greenhouse trials. This represents a promising pathway toward developing novel antifungal strategies for controlling R. solani-induced diseases in rice, with potential applications in crop protection.