The chitinase encoding Tn7-based chiA gene endows Pseudomonas fluorescens with the capacity to control plant pathogens in soil.

A transposon system based on Tn7 carrying the chiA gene (encoding chitinase) of Serratia marcescens was established. The transposon was introduced by conjugation into Pseudomonas fluorescens as a stable integrate expressing and secreting the active chitinase enzyme. The resulting strain was shown to control the plant pathogen Rhizoctonia solani in soil.