Active Oxygen Production During a Bacteria-Induced Hypersensitive Reaction in Tobacco Suspension Cells

Keppler, L. D., Baker, C. J., and Atkinson, M. M. 1989. Active oxygen production during a bacteria-induced hypersensitive reaction in tobacco suspension cells. Phytopathology 79:974-978. In tobacco cell suspensions, onset of the hypersensitive reaction induced syringae (wild-type, a pathogen of wheat) was used to induce a hyperby phytopathogenic bacteria can be monitored as increased extracellular sensitive reaction in tobacco cell suspensions. P. s. syringae B7, a Tn5 pH. Previous reports suggested that active oxygen-initiated lipid insertion mutant that does not induce a hypersensitive reaction, and peroxidation preceded this increased extracellular pH. Here, we investi- P. s. tabaci, a pathogen of tobacco, were used as controls. All bacterial gated the timing of active oxygen production and increased extracellular treatments induced transient increases in both active oxygen and extrapH during the onset of the hypersensitive reaction. Active oxygen levels cellular pH between 0 and 1 hr. Concomitant increases of extracellular were monitored by measuring light production (chemiluminescence), in pH and active oxygen levels were observed between 2 and 4 hr only the presence of luminol. Increase in active oxygen levels over time in tobacco cell suspensions undergoing the hypersensitive reaction correlated with increased extracellular pH. Pseudomonas syringae pv. (inoculated with wild-type bacteria).