Insecticidal toxins from the bacterium Photorhabdus luminescens: gene cloning and toxin histopathology
نویسندگان
چکیده
Four toxin complexes, Tca, Tcb, Tcc and Tcd from the culture broth of Photorhabdus luminescens have been puri®ed and the four toxin complex encoding loci, tca, tcb, tcc and tcd, cloned. Genetic knockout of either tca or tcd reduced oral toxicity to Manduca sexta, and knockout of both loci eliminated activity. Puri®ed Tca speci®cally affected the insect midgut, despite its putative normal delivery directly into the insect haemocel. These Photorhabdus toxins may form useful alternatives to other orally active bacterial protein toxins such as those from Bacillus thuringiensis.
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