Thus, while infection by the pathogen increased apoplastic glutathione reductase (GR) activity and decreased superoxide dismutase (SOD) and diamine oxidase (DAO) activities in the susceptible and resistant cultivars, that occurred earlier (i.e., GR and SOD) or in higher quantities (i.e., DAO) in the resistant (‘WR-315’) than in the susceptible (‘JG-62’) cultivar. The gene discussed is GSR; the disease is infection.