A plant exhibiting resistance to at least one disease is provided. The plant includes an expression cassette including a thionin gene, which is capable of expressing the thionin gene. A method for producing the plant is also provided. The method includes the steps of constructing an expression vector containing an expression cassette including a thionin gene, which is capable of expressing the thionin gene, transforming a plant cell with the expression vector, and regenerating a plant from the transformed plant cell. The plant exhibits resistance to at least one disease such as a disease caused by a plant pathogenic bacterium (e.g., a bacterium causing bacterial leaf blight of rice or a bacterium causing bacterial seedling blight of rice) or a plant pathogenic filamentous fungus (e.g., a fungus causing late blight of potato). A seed obtained from the above disease resistant plant is also provided. <IMAGE>