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Poster: Molecular & Cellular Plant-Microbe Interactions: MPMI


Biological functional Analysis of tatB in Acidovorax citrulli
T. ZHAO (1) (1) Chinese academy of agricultrual sciences, institute of plant protection, China

Acidovorax citrulli causes bacterial fruit blotch of cucubits world wide. In order to explore the relationship between Twin-arginine Translocation system (Tat) and pathogenicity of A. citrulli, a tatB disruption mutant (?tatB) and its complement strains were constructed by homologous recombination. The virulence, motility, growth ability, extracellular polysaccharide and cellulase producing ability and biofilm formation of the wild type, mutant and the complement strains were tested to illustrate the influence of Tat system on A. citrulli. By comparing the expression of trbC, hrcN, Aave_1810, Aave_0034 and hrpE gene with real-time fluorescent quantitative PCR, we explored the relationship between tatB genes associated with type III secretion system, Tat system related genes and cell toxicity related genes. The results showed the deficiency of tatB weakened the virulence, motility and growth ability of A. citrulli, while had no effect on the production of extracellular polysaccharide (EPS)?extracellular cellulase and biofilm formation. Real-time fluorescent quantitative analysis showed that the deficiency of tatB made the expressions of trbC and hrcN genes in mutant strain significantly increase, while the expressions of other genes notably decreased. Consequently, the deficiency of functional gene tatB in Tat affects some biological characteristics of A. citrulli, and ultimately weakens pathogenic ability.