RECOMBINANT BACILLUS-THURINGIENSIS CRYSTAL PROTEINS WITH NEW PROPERTIES - POSSIBILITIES FOR RESISTANCE MANAGEMENT

To obtain Bacillus thuringiensis crystal proteins with new properties and to identify the regions involved in insecticidal activity, we gene rated hybrid genes composed of cryIC and cryIE by in vivo recombinatio n. Analysis of the hybrid proteins showed that domain III of CryIC is involved in the toxicity towards Spodoptera exigua and Mamestra brassi cae. Transfer of this domain to CryIE, which is not active against the se insects, resulted in a new protein with a broader activity. This hy brid protein binds to different receptors than CryIC, suggesting its u se as an alternative for CryIC in resistance management programs.