Cloning of phenazine carboxylic acid genes of <em>Fusarium fujikuroi</em> antagonists bacteria

Abstract

Bakanae disease caused by Fusarium fujikuroi is an important diseases on rice. Pseudomonas fluorescens produces the broad-spectrum antibiotic phenazine-carboxylic acid (PCA), which is active against a variety of fungal root pathogens. In this study two genes from seven gene locus of phenazine were cloned in Escherichia coli DH5α. The contaminated rice samples were collected from infected farms of Guilan. 238 bacteria were isolated from the rhizosphere. The antagonistic ability of 12 of which, was demonstrated with dual culture method. From the biochemical and culture results, 8 isolated were identified as P. fluorescens. The two genes from seven gene locus of phenazine were cloned into E. coli DH5α. We speculate that P. fluorescens that produce 2,4-diacetylphloroglucinol (Phl) play an important role in the natural suppressiveness of this soil to causal agent of collar and root rot of rice.