Pathogen-inducible expression of the cytotoxic Barnase gene confers enhanced disease resistance in plants

Plant diseases pose a persistent threat to global food security, yet conventional disease-resistance breeding strategies often fail to provide durable and broad-spectrum protection. Plants rely on pattern-triggered immunity (PTI) for basal defense and effector-triggered immunity (ETI) for stronger, pathogen-specific resistance mediated by programmed cell death. However, effectively integrating these immune layers to achieve synergistic and enhanced resistance remains a major challenge. Here, we developed a pathogen-inducible defense system by coupling the TBF1 promoter and its upstream open reading frames (uORFs) with the cytotoxic ribonuclease Barnase, enabling stringent control of transgene expression with minimal basal leakage. In Arabidopsis thaliana , this system was precisely activated by pathogen-associated molecular patterns (PAMPs), including the bacterial flagellin epitope flg22, peptidoglycans (PGN), and fungal chitin, thereby triggering localized cell death and conferring significantly enhanced resistance to the hemibiotrophic pathogens Pseudomonas syringae pv. tomato DC3000 and Verticillium dahliae , but not to the necrotrophic fungus Botrytis cinerea . Remarkably, transgenic rice lines expressing this system exhibited robust resistance to both Xanthomonas oryzae pv. oryzae and Magnaporthe oryzae , while maintaining normal growth, development, and reproductive fitness. Taken together, our findings establish a safe, efficient, and broad-spectrum inducible resistance strategy, offering a scalable solution for crop protection.