Bt Toxin Resistance from Loss of a Putative Carbohydrate-Modifying Enzyme

The development of resistance is the main threat to the long-term use of toxins from Bacillus thuringiensis (Bt) in transgenic plants. Here we report the cloning of a Bt toxin resistance gene,Caenorhabditis elegans bre-5, which encodes a putative β-1,3-galactosyltransferase. Lack of bre-5 in the intestine led to resistance to the Bt toxin Cry5B. Wild-type but notbre-5 mutant animals were found to uptake toxin into their gut cells, consistent with bre-5 mutants lacking toxin-binding sites on their apical gut. bre-5 mutants displayed resistance to Cry14A, a Bt toxin lethal to both nematodes and insects; this indicates that resistance by loss of carbohydrate modification is relevant to multiple Bt toxins.

[1]  R. D. de Maagd,et al.  How Bacillus thuringiensis has evolved specific toxins to colonize the insect world. , 2001, Trends in genetics : TIG.

[2]  R. Plasterk,et al.  The silence of the genes. , 2000, Current opinion in genetics & development.

[3]  L. Marroquin,et al.  Bacillus thuringiensis (Bt) toxin susceptibility and isolation of resistance mutants in the nematode Caenorhabditis elegans. , 2000, Genetics.

[4]  S. Cohen,et al.  Glycosyltransferase activity of Fringe modulates Notch–Delta interactions , 2000, Nature.

[5]  A. Fire,et al.  Identification and molecular-genetic characterization of a LAMP/CD68-like protein from Caenorhabditis elegans. , 2000, Journal of cell science.

[6]  H. Clausen,et al.  Identification and characterization of large galactosyltransferase gene families: galactosyltransferases for all functions. , 1999, Biochimica et biophysica acta.

[7]  M. Adang,et al.  Binding of Bacillus thuringiensis Cry1Ac toxin to Manduca sexta aminopeptidase‐N receptor is not directly related to toxicity , 1999, FEBS letters.

[8]  D. Derbyshire,et al.  N-acetylgalactosamine on the putative insect receptor aminopeptidase N is recognised by a site on the domain III lectin-like fold of a Bacillus thuringiensis insecticidal toxin. , 1999, Journal of molecular biology.

[9]  K. Irvine,et al.  Modulators of Notch signaling. , 1998, Seminars in cell & developmental biology.

[10]  Min Han,et al.  A new marker for mosaic analysis in Caenorhabditis elegans indicates a fusion between hyp6 and hyp7, two major components of the hypodermis. , 1998, Genetics.

[11]  B. Tabashnik.  Delaying insect adaptation to transgenic plants: seed mixtures and refugia reconsidered , 1994, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[12]  B. Spangler,et al.  Structure and function of cholera toxin and the related Escherichia coli heat-labile enterotoxin. , 1992, Microbiological reviews.

[13]  F. Gould.  Sustainability of transgenic insecticidal cultivars: integrating pest genetics and ecology. , 1998, Annual review of entomology.