Effects of bacterial populations, temperature and exogenous hydrogen peroxide on the induction of the hypersensitive response in Nicotiana tabacum against Xanthomonas perforans

The objective of this study was to investigate the effects of inoculum concentration, plant post-inoculation incubation temperature and exogenous hydrogen peroxide (H2O2) on the induction of the hypersensitive response (HR) in Nicotiana tabacum against Xanthomonas perforans. Inoculation of leaves with X. perforans at a concentration of 108 CFU · ml–1 and incubation of plants at 30°C resulted in the strongest HR elicitation. Furthermore, an exogenous supply of H2O2 accelerated X. perforans-induced HR, whereas in planta H2O2 removal by application of catalase led to a delay in HR development. Our data suggest that H2O2 has an important role in HR of N. tabacum against X. perforans.