Expression of the Insecticidal Protein Gene crylC of Bacillus thuringiensis in Plant-Colonizing Nitrogen-Fixing Bacteria

摘要

The NMO 10 bacterial isolate was isolated from the rhizosphere of cotton plants. This isolate showed high potentiality to fix nitrogen and a high ability to colonize the phyllosphere of cotton plants. Based on this, plasmid pHTNC3 harboring the cry 1Cgene was used to transform NMO10. The transformed bacterial isolate (tNMOlO) had a dual action both in the biocontrol of the Lepidopteron insect Spodoptera littoralis and as a bio-fertilizer. The presence of an expressed 135 kDa CrylC protein in the protein pattern of tNMOlO, microscopic examination of the bipyramidal crystals that characterize the CrylC protein and immuonoblot analysis indicated efficient expression of the cry 1C gene in the heterologous host NMO10. Bioassays against the neonate larvae of the cotton leaf worm S. littoralis revealed that the protein preparations from the tNMO 10 were toxic.