A broad-range plant defense system employing thionins is disclosed. The invention protects various crop species and other plant species from attack by a wide range of phytopathogens, providing broad resistance to diverse plant diseases, using transgenes encoding a seed-derived thionin and a suitable signal peptide. Resistant crop varieties can not only prevent yield losses due to bacterial and fungal diseases, but can also expand the geographic boundaries of possible growing areas for economically important crops.
