Current models of the mode of action of Bacillus thuringiensis insecticidal crystal proteins: A critical review

Specificity determinants for Cry insecticidal proteins: Insights from their mode of action

“…Interaction between Cry toxin and midgut receptors is considered the main step dictating specificity of the toxin, although there are cases of high affinity binding not being associated with toxicity (Wolfersberger, 1990). While the specific mechanism responsible for enterocyte death by Cry toxins is still a matter of debate (Vachon et al, 2012), it is generally accepted that the toxin forms a pore that kills the cell by osmotic shock. Massive enterocyte death disrupts integrity of the midgut epithelial layer, allowing Bt and potentially other resident gut bacteria to invade the nutrient-rich hemocoel where they proliferate leading to septicemia and death of the insect (Raymond et al, 2010).…”

Structural classification of insecticidal proteins – Towards an in silico characterisation of novel toxins

“…Similarly, while there are a lot of data available on the target specificity of individual toxins (Palma et al, 2014a;van Frankenhuyzen, 2009), many of these are contradictory, thus compounding efforts to derive meaningful associations. The area where least information is known concerns the interaction of the toxin with the target cell (Vachon et al, 2012). As discussed above, even when putative receptors are identified, determining which interactions are crucial for toxicity is far from straightforward.…”

Is there a transgenerational inheritance of host resistance against pathogens? Lessons from the Galleria mellonella-Bacillus thuringiensis interaction model

“…alkaline-phosphatase, amino-peptidase, lipoproteins), resulting in cell intoxication and osmotic lysis. 11,12 Some Cry toxins can kill the insect on their own, as shown in transgenic Bt-crops expressing cry genes. 13 The lethal effect depends on the ingested amount of toxin and the size of the larva.…”