Expression of Serratia and Pseudomonas Chitinase Genes in Rhizobium Via Horizontal Gene Transfer

Abstract

This study aimed to transfer chitinase genes into Rhizobium leguminosarum bv. vicia in order to enhance the defense of faba bean plants against soil pathogens, in addition to , improving symbiotic nitrogen fixation, as well. Toward this target, 12 transconjugants resulted from conjugation between Pseudomonas flurocescens and Serratia marcescence as a donors against four strains of Rhizobium leguminosarum. The donar strains were tested for chitinolytic activity depending on chitin hydrolysis zone appeared on chitin agar medium. Six out of eight matings between Pseudomonas and Serratia against Rhizobium were successeded. Some recombinants expressed significant amount of IAA production in both complete and minimal media. Some of Rhizobium transcojugants showed significant performance for chitinase activity above the mid-parent. Cell culture and cellfree filterate of some Rhizobium transconjugants showed higher antagonistic activity against Rhizoctonia solani in relation to the mid-parent, because they were able to produce higher amounts of antifungal metabolites. These transcojugants may inhibit the growth of various soil-born pathogens with a higher efficiency than their parents.