Site specific mutagenesis in nodulation genes of Mesorhizobium ciceri strain Me 18-7 using in vitro transposition in a heterologous cloned DNA

Abstract

Mesorhizobium eieeri strain MC18-7, nodulating chickpea was used to generate nod-mutants to study primary nodulation responses. Transposon insertion was carried out in pRmSL-26 using in vitro transposition by EZ:: TN less than KAN 2 greater than insertion system. Transposon insertion sites in nod ABC and nod 0 genes in pRmSL-26 were used for marker exchanging in M. eieeri strain MC 18-7. In total three mutants, one nod ABC- mutant and two nod 0mutants were obtained. The common nod ABC- mutant showed complete lack of root hair infection/deformation, while nod 0- mutants showed delayed/reduced primary modulation responses.