The Arabidopsis NPR1 is a key regulator in the signal transduction pathway that leads to SAR (Kinkema et al., 2000), and npr1 mutant fails to respond to various SAR-inducing agents (SA, INA, and avirulent pathogens), displaying little expression of PR genes (PR5 was 5-fold lower and PR1 was 20-fold lower than the wild type), and exhibiting increased susceptibility to bacterial and fungal infections (Cao et al., 1994). This evidence concerns the gene NPR1 and fungal infectious disease.