ABSTRACT
Iron is an essential element for living organisms that plays critical roles in the process of bacterial growth and metabolism. However, it remains to be elucidated whether piuB encoding iron-uptake factor is involved in iron uptake and pathogenicity of Xanthomonas axonopodis pv. glycines (Xag). To investigate the function of piuB, we firstly generated a piuB deletion mutant (ΔpiuB) by homologous recombination. Compared with the wild-type, the piuB mutant exhibited significantly reduced growth and virulence in host soybean. The mutant displayed markedly increased siderophore secretory volume, and its sensitivity to Fe3+, Cu2+, Zn2+ and Mn2+ was significantly enhanced. Additionally, the H2O2 resistance, exopolysaccharide yield, biofilm formation, and cell mobility of ΔpiuB were significantly diminished compared to that of the wild-type. The addition of exogenous Fe3+ cannot effectively restore the above characteristics of ΔpiuB. However, expressing piuB in trans rescued the properties lost by ΔpiuB to the levels in the wild-type. Taken together, our results demonstrated that PiuB is a potential factor for Xag to assimilate Fe3+, and is necessary for Xag to be pathogenic in host soybean.
Subject(s)
Iron , Glycine max , Virulence , Xanthomonas axonopodis/genetics , Hydrogen PeroxideABSTRACT
Objective To investigate the family burden of patients with severe mental illness. Methods 148 patients with schizophrenia and bipolar disorder were assessed with Family Burden Scale of disease (FBS). Results Family burden broadly exists among those patients with schizophrenia and bipolar disorder, and the burden tends to involve several dimensions, including family relations (51%), home enter-tainment (50%), daily routine (45%), economic burden (43%), mental health of family members (36%) and physical health of family mem-bers (32%). Conclusion Integrated psychological and social intervention should be made to reduce the family burden of patients with schizo-phrenia and bipolar disorder.