Abstract：Erwinia amylovora causes fire blight on many plants of the Rosaceae family such as apple and pear. The Twin-arginine translocation(Tat) pathway plays a crucial role in transporting the proteins which are related to virulence. In this study, a tatC disruption mutant EaΔtatC was successfully constructed by homologous recombination as well as the complement strain EaΔtatC(pME-tatC). The results showed that the tatC mutant EaΔtatC displayed the reduced virulence, extracellular polysaccharide production, chemotaxis, motility, flagella assembly and growth in vitro. However, compared to wild type strain NCPPB1665(Ea1665), the induction of hypersensitive response in nonhost tobacco, biofilm synthesis and cellulose production of the tatC mutant EaΔtatC didn't show significant difference. These findings demonstrate that tatC gene in Erwinia amylovora is involved in growth, and motility and play an important role in virulence.
