TRANSPOSON MUTAGENESIS FOR ENHANCEMENT OF NITROGEN FIXING ABILITY OF RHIZOBIUM JAPONICUM INFECTING VIGNA RADIATAAbhay Ghatage, Rachna Pandey and G.R PathadeAbstract This study developed mutant library of 800 mutants with transposition frequency of 3.7 x 10- 6. Transposon mutagenesis is an easy and highly effective method for generating bacteria with improved characteristics and gene knockouts. The slow growing Rhizobium japonicum isolated from root nodules of locally grown mung bean plant. The isolated strain was subjected for transposon mutagenesis to produce 800 mutants. These 800 mutants were screened for nodulation. After screening of these 800 mutants, the100 mutants showed pink coloured nodulation to mung bean plant. Out of 100 mutants 10 were promising for nodulation and nitrogen fixation. Bacterial surface polysaccharides including Exopolysaccharides (EPS) and Lipopolysaccharides (LPS) are constituents of the bacterial cell wall. They have been reported in numerous studies as symbiotically important; defects in EPS production tend to result in arrest at the infection thread stage which is the early stage of nodulation. EPS and LPS were isolated from wild variety and mutant variety. The polysaccharides production in mutant and wild variety were compared. This study was aimed to investigate the role of EPS and LPS on nodulation and enhancement of nitrogen fixation of Rhizobium japonicum infecting Vigna radiata. |