Localization changes of endogenous hydrogen peroxide during cell division cycle of Xanthomonas.

Production and localization of endogenous hydrogen peroxide (H2O2) were investigated in strains of Xanthomonas by histochemical analysis under electron microscopy. Even though the levels of endogenous H2O2 production were different among various strains, the produced H2O2 was localized in the cell wall of all Xanthomonas strains tested. The impairment of the level of endogenous H2O2 accumulation resulted in a significantly decreased growth rate of bacteria, regardless if the difference of the H2O2 level is originally present between wild type strains or caused by mutation of the ahpC gene of Xanthomonas. The endogenous accumulation of H2O2 positively correlates with the cell division. Interestingly, the accumulated H2O2 was also localized in the mesosome-like structure and nucleoids during the cell division cycle. Furthermore, results revealed quantitative and dimensional changes of H2O2 accumulation in the two additional locations. These findings indicated that the additional locations of the accumulated H2O2 were closely associated with the process of cell division. Together, these results suggest that the endogenous H2O2 production plays an important role in cell proliferation of Xanthomonas.