Article

Activity of wild-type and hybrid Bacillus thuringiensis δ-endotoxins against Agrotis ipsilon

Plant Research International B.V., P.O. Box 16, 6700 AA, Wageningen, The Netherlands.
Archives of Microbiology (Impact Factor: 1.86). 06/2003; 179(5):363-7. DOI: 10.1007/s00203-003-0543-6
Source: PubMed

ABSTRACT Twelve Cry1 and two Cry9 delta-endotoxins from Bacillus thuringiensis were tested for their activity against black cutworm ( Agrotis ipsilon). A. ipsilon was not susceptible to many toxins, but three toxins had significant activity. Cry9Ca was the most toxic, followed by Cry1Aa and Cry1Fb. Hybrids between these three active proteins were made by in vivo recombination and analyzed for activity against A. ipsilon. Analysis of hybrids between Cry1Aa and Cry1Fb indicated that domain I of Cry1Aa protein was involved in its higher activity.

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    • "Domain II, the middle domain, is a b-prism that is implicated in receptor interactions and insect specificity (Rajamohan et al. 1996; Wu and Dean 1996; G omez et al. 2003; Fernández et al. 2008). Domain III, the C-terminus domain, is a b-sandwich that affects receptor interactions, insect specificity (Schnepf et al. 1998; de Maagd et al. 2003), and stabilization of molecular structure (Grochulski et al. 1995). Cry toxins are thought to bind cadherin-like receptors via loop a8 (Gó mez et al. 2003), loop 1 (Wu and Dean 1996), loop 2 (Gó mez et al. 2001), and loop 3 (Xie et al. 2005) of domain II. "
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