Construction of Pseudomonas syringae pv. tomato DC3000 Mutant and Polymutant Strains

Redundancy between Pseudomonas syringae pv. tomato DC3000 virulence factors has made their characterization difficult. One method to circumvent redundancy for phenotypic characterization is to simultaneously delete all redundant factors through the generation of polymutant strains. Described here are methods by which single and polymutant strains of DC3000 can be generated through the use of the small mobilizable sucrose counter-selection vector pK18mobsacB , FRT-flanked antibiotic marker cassettes, and Flp recombination.