Recombinant Bacillus thuringiensis strain shows high insecticidal activity against Plutella xylostella and Leptinotarsa decemlineata without affecting nontarget species in the field

• Published in: Journal of applied microbiology 2008-11, Vol.105 (5), p.1536-1543
• Main Authors: Wang, G, Zhang, J, Song, F, Gu, A, Uwais, A, Shao, T, Huang, D
• Format: Article
• Language: English
• Subjects: Animals; Bacillus thuringiensis; Bacillus thuringiensis - genetics; Bacillus thuringiensis - metabolism; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacterial Toxins - genetics; Bacterial Toxins - metabolism; bioassay; bioassays; Biological and medical sciences; Coleoptera - drug effects; Endotoxins; Fundamental and applied biological sciences. Psychology; Hemolysin Proteins; Insecticides - pharmacology; Lepidoptera - drug effects; Leptinotarsa decemlineata; Lethal Dose 50; microbial population variation; Microbiology; nontarget organisms; Pest Control, Biological - methods; Plasmids; Plutella xylostella; recombinant strain
• ISSN: 1364-5072; 1365-2672
• DOI: 10.1111/j.1365-2672.2008.03866.x

To construct a recombinant Bacillus thuringiensis (Bt) strain with broad insecticidal spectrum and investigate its impact on nontarget organisms in field. The cry-type gene of wild Bt strain UV17 was identified and a novel cry1Ba gene was cloned. The cry3Aa7 gene, which was highly toxic to coleopteran pests, was introduced into UV17, and a recombinant strain designated as UV173A was obtained. Bioassay results showed that UV173A was not only highly toxic against Plutella xylostella (50% lethal concentration [LC₅₀] = 18·03 μg ml⁻¹), but also against coleopteran Leptinotarsa decernlineata (LC₅₀ = 0·19 mg ml⁻¹). The recombinant strain was then tested in field trials to monitor its spatial variation of population and to investigate the impact on nontarget invertebrates. A recombinant Bt stain UV173A with broad insecticidal spectrum was obtained, and it did not cause adverse effects on the population of nontarget organisms. The results obtained here indicated that cry1Ba3 gene may be useful for the resistance management of P. xylostella, and the recombinant stain UV173A was potential for field application against some crucifer vegetable pests as well as L. decemlineata.