Lectins and dirigent proteins are both thought to be involved in plant defense; lectins due to their ability to recognize cell surface carbohydrates highly specifically, and dirigent proteins because of their crucial role in controlling free radical coupling of monolignols to yield lignans and lignins. We identified a rice gene (OsJAC1) encoding for a protein with a lectin and dirigent domain which conferred broad-spectrum disease resistance in transgenic rice plants overexpressing the gene. This type of modular protein has exclusively developed within the Poaceae family. FRET analysis revealed that both domains physically interact with each other and transient overexpression showed that both domains are required for full pathogen resistance.