Structural and functional characterization of proteinous elicitor, harpin from Pseudomonas syringae

摘要

The hypersensitive response (HR) of higher plants is characterized by the raid and localized cell death at the site of pathogen invasion. Many Gram-negative phytopathogenic bacteria elicit the HR in non-host or resistant plants. Pseudomonas syringae produce HR inducing proteins, harpins that are glycine-rich, cysteine-lacking and heat stable extracellular ca. 35 kD proteins. To investigate their role on the host and nonhost plants, we isolated hrpZ genes from several pathovars of P. syringae that encode harpin proteins. In this study, we compared the structure of hrpZ genes and harpins. Furthermore HR inducing activity, oxidative burst and defense gene expression was investigated using recombinant harpin proteins.