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

Document Type : Original Article

Authors

1 معهد بحوث الأراضى والمياه والبيئة – مرکز البحوث الزراعية بالجيزة

2 قسم الوراثة – کلية الزراعة – جامعة المنصورة .

3 قسم الوراثة – کلية الزراعة – جامعة المنصورة

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 cell – free 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.

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