RT Journal Article
T1 Toxicity and mode of action of Bacillus thuringiensis Cry proteins in the Mediterranean corn borer, Sesamia nonagrioides (Lefebvre).
A1 González-Cabrera, Joel
A1 Farinós, Gema
A1 Caccia, Silvia
A1 Díaz Mendoza, María Mercedes
A1 Castañera, Pedro
A1 Giovanna Leonardi, Maria
A1 Giordana, Barbara
A1 Ferré, Juan
AB Sesamia nonagrioides is one of the most damaging pests of corn in Spain and other Mediterranean countries. Bt corn expressing the Bacillus thuringiensis Cry1Ab toxin is being grown on about 58,000 ha in Spain. Here we studied the mode of action of this Cry protein on S. nonagrioides (binding to specific receptors, stability of binding, and pore formation) and the modes of action of other Cry proteins that were found to be active in this work (Cry1Ac, Cry1Ca, and Cry1Fa). Binding assays were performed with 125I- or biotin-labeled toxins and larval brush border membrane vesicles (BBMV). Competition experiments indicated that these toxins bind specifically and that Cry1Aa, Cry1Ab, and Cry1Ac share a binding site. Cry1Ca and Cry1Fa bind to different sites. In addition, Cry1Fa binds to Cry1A's binding site with very low affinity and vice versa. Binding of Cry1Ab and Cry1Ac was found to be stable over time, which indicates that the observed binding is irreversible. The pore-forming activity of Cry proteins on BBMV was determined using the voltage-sensitive fluorescent dye DiSC3(5). Membrane permeability increased in the presence of the active toxins Cry1Ab and Cry1Fa but not in the presence of the nonactive toxin Cry1Da. In terms of resistance management, based on our results and the fact that Cry1Ca is not toxic to Ostrinia nubilalis, we recommend pyramiding of Cry1Ab with Cry1Fa in the same Bt corn plant for better long-term control of corn borers.
PB American Society for Microbiology
SN 0099-2240
YR 2006
FD 2006
LK https://hdl.handle.net/20.500.14352/94273
UL https://hdl.handle.net/20.500.14352/94273
LA eng
NO González-Cabrera J, Farinós GP, Caccia S, Díaz-Mendoza M, Castañera P, Leonardi MG, Giordana B, Ferré J 2006. Toxicity and Mode of Action of Bacillus thuringiensis Cry Proteins in the Mediterranean Corn Borer, Sesamia nonagrioides (Lefebvre). Appl Environ Microbiol 72:.https://doi.org/10.1128/AEM.72.4.2594-2600.2006
NO This work was supported by European Union project QLRT-2001-01969.
NO European Commission
DS Docta Complutense
RD 7 abr 2025