Relative insectcidal activities of Bacillus thuringiensis subsp. kurstaki toxins CryIA(b) and CryIA(c), produced in Escherichia coli

Abstract

及 thuringiensis produced insecticidal toxin proteins during sporulation. A toxin gene from

B. thuringiensis subsp. kurstaki HD-1 was cloned, and based on the restriction map it was identified as a clone for cryIA(b). Toxin gene clones, cryIA(b) and cryIA(c) that were reported previously, were carried by an E. coli expression vector pT6HB and introduced into E. coli. Truncated cryIA(b) and cryIA(c) were also introduced into E. coli to identify the putative functional domains in the toxins. Production of toxins in E. coli was confirmed by Western blot with a polyclonal antibody against B. thuringiensis subsp. HD-73 toxin. Insecticidal activities of these toxins were compared against Korean bom tobacco cut worm, tobacco budworm, silk worm, diamond back ficities of the toxins were identified. moth and fall webworm. Potencies and speci-