The differential strain virulence of the candidate toxins of can be correlated with their inter-strain gene sequence diversity.

is an insect-parasitic bacterium that symbiotically associates with the nematode, . The bacterium possesses several pathogenicity islands that aids in conferring toxicity to different insects. Herein, we constructed the plasmid clones of coding sequences of four toxin genes (, , and ; each was isolated from four strains IARI-SGMG3, IARI-SGGJ2, IARI-SGHR2 and IARI-SGMS1) in and subsequently, their biological activity were investigated against the fourth-instar larvae of the model insect, via intra-hemocoel injection. Bioinformatics analyses indicated inter-strain amino acid sequence difference at several positions of the candidate toxins. In corroboration, differential insecticidal activity of the identical toxin protein (PirA, TcaA, TccA and TccC conferred 15-59, 27-100, 25-100 and 33-98% insect mortality, respectively, across the strains) derived from the different bacterial strains was observed, suggesting that the diverse gene pool in Indian strains of leads to strain-specific virulence in this bacterium. These toxin candidates appear to be an attractive option to deploy them in biopesticide development for managing the insect pests globally.