Collaboration between scientists in Spain, Holland, and Auburn University has developed a means to maintain a green plant pest control regimen.
The results were published at the Public Library of Science website on September 17, 2010.
Bacillus thuringiensis is the most effective microbial control agent for controlling numerous species from different insect orders. The main threat for the long term use of B. thuringiensis in pest control is the ability of insects to develop resistance. Thus, the identification of insect genes involved in conferring resistance is of paramount importance.
With the goal to find genes contributing to the resistance to B. thuringiensis containing multiple S. exigua-active compounds, we measured differential gene expression between a susceptible S. exigua colony and a colony that had developed high levels of resistance to a B. thuringiensis-based formulated product (Xentari). Although neonate selection was discontinued after five days, resistance ratios obtained using both neonates and late instar larvae show that resistance was maintained during the entire larval stage, including the larval instar used in the macroarray analyses.
In summary, we have found a significant overlap between genes that are differentially expressed in Xen-R and genes that are up-regulated after exposure of susceptible insects to Xentari. Results also show possible associations between REPAT and arylphorin expression (or the genes governing their expression) and resistance to Xentari, and demonstrate that exposure of larvae to Xentari does not have an effect on the midgut epithelium renewal. Additional studies would contribute to identifying the mutation(s) in genes involved in the midgut response to pathogens and to clarify the role of REPAT and arylphorin in response to pathogens.
Constitutive Activation of the Midgut Response to Bacillus thuringiensis in Bt-Resistant Spodoptera exigua
Patricia Hernández-Martínez 1, Gloria Navarro-Cerrillo 1, Silvia Caccia 1, Ruud A. de Maagd 2, William J. Moar 3, Juan Ferré1, Baltasar Escriche 1, Salvador Herrero 1
1 Department of Genetics, Universitat de València, Burjassot, Spain,
2 Plant Research International B.V., Wageningen University and Research Centre, Wageningen, The Netherlands,
3 Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America
Citation: Hernández-Martínez P, Navarro-Cerrillo G, Caccia S, de Maagd RA, Moar WJ, et al. (2010) Constitutive Activation of the Midgut Response to Bacillus thuringiensis in Bt-Resistant Spodoptera exigua. PLoS ONE 5(9): e12795. doi:10.1371/journal.pone.0012795