Bacillus thuringiensis kurstaki bioinsecticide induces growth defects and developmental delay by disturbing protein metabolism

Abstract

Bt bioinsecticides are the bioinsecticide best sale worldwide. Because of the governmental policies and the public opinion, the use of such bioinsecticides has been exponentially increased during this last decade and this trend is continuing. Although many data have demonstrated the short-term safety of Bt products on non-target animals, only scarce data are available on the unintended long-term effects of those products. Therefore, using the non-target animal Drosophila melanogaster model, we investigated the putative impacts of the ingestion of environmental doses of Bt products on both growth and developmental time. We then identified the physiological processes impacted by Bt products. We showed that Bt products impairs growth and developmental time by disturbing protein metabolism of the larvae. We further demonstrated that these effects are mediated by the synergism between Bt bacteria and Bt insecticidal toxins, which induce a significant apoptosis of enterocytes. We assume that this death of enterocytes may decrease the capacity of the intestine to digest and absorb proteins resulting in a growth defect and developmental delay.