Mechanisms of Resistance to Bacillus thuringiensis in the Diamondback Moth

Bruce, Mark J, Gatsi, Roxani, Crickmore, Neil and Sayyed, Ali H (2007) Mechanisms of Resistance to Bacillus thuringiensis in the Diamondback Moth. Biopesticides International, 3 (1). pp. 1-12. ISSN 0973-483X

Full text not available from this repository.


Plutella xylostella, the diamondback moth, has become a model organism for the study of resistance to Bacillus thuringiensis based insecticides, since it is the only insect that has readily acquired resistance to this agent in the field. A number of different mechanisms have been proposed that result in this resistance phenotype, including the loss of a midgut binding site and the reduced activation of protoxin to toxin. The latter mechanism has been proposed on the basis of resistant insects being more susceptible to toxin than protoxin. We investigated whether a reduction in proteolytic activity, and consequently toxin activity, could be the basis of the resistant phenotype. Our results suggest that there was no qualitative difference in the protease activity between gut extract from susceptible and resistant populations. In this paper we review the different resistant mechanism proposed for this insect and critically analyse the hypothesis that the preferential activity of toxin compared to protoxin is due to a defect in activation.

Item Type: Article
Schools and Departments: School of Life Sciences > Biochemistry
Depositing User: Mark Bruce
Date Deposited: 06 Feb 2012 20:17
Last Modified: 23 Mar 2012 08:50
📧 Request an update