Release of active oxygen from phytopathogenic bacteria and their regulation

Some phytopathogenic bacteria including Xanthomonas oryzae pv. oryzae (a rice leaf bacterial blight pathogen) and its virulent gene mutant XooM3105, Xanthomonas campestris pv. campestris, Erwinia carotovora subsp. carotovora and so on, could release active oxygen such as O2 and H2O2 by themselves. Ca2+ , NADPH and O2 concentration regulated the response. The response is sensitive to heat and proteinase. These results show that the component releasing active oxygen in the bacterial plant pathogen may involve special protein and enzyme and be secreted to culture liquid. Various components of rice tissue can significantly induce the release of active oxygen in Xan-thomonas oryzae pv. oryzae.