[The role of iron-uptake factor PiuB in pathogenicity of soybean pathogen pv. ].

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 encoding iron-uptake factor is involved in iron uptake and pathogenicity of pv. (). To investigate the function of , we firstly generated a deletion mutant (Δ) by homologous recombination. Compared with the wild-type, the mutant exhibited significantly reduced growth and virulence in host soybean. The mutant displayed markedly increased siderophore secretory volume, and its sensitivity to Fe, Cu, Zn and Mn was significantly enhanced. Additionally, the HO resistance, exopolysaccharide yield, biofilm formation, and cell mobility of Δ were significantly diminished compared to that of the wild-type. The addition of exogenous Fe cannot effectively restore the above characteristics of Δ. However, expressing rescued the properties lost by Δ to the levels in the wild-type. Taken together, our results demonstrated that PiuB is a potential factor for to assimilate Fe, and is necessary for to be pathogenic in host soybean.