Bt resistance: characterization and strategies for GM crops producing Bacillus thuringiensis toxins.

Chapter 11 (Page no: 119)

The lessons that Caenorhabditis elegans has taught us about the mechanism of action of crystal proteins.

Caenorhabditis elegans is susceptible to three domain crystal proteins similar to those that intoxicate insects. Investigations of this organism have several important strengths, for example, ease of forward genetic screens, range of molecular genetic tools available and ease of carrying out RNAi (RNA interference) studies. These have been exploited to study cellular responses known as cellular non-immune defences (CNIDs) to the crystal proteins of Bacillus thuringiensis (Bt) and pore-forming toxins in general. We will discuss what we have learned through genetics and RNAi (including genome-wide RNAi) to elucidate the pathways that allow cells to respond productively to crystal protein attack. In addition, key results will be discussed from investigations with mammalian pore-forming proteins to highlight the conservation of cellular responses to crystal proteins with cellular responses to pore-forming proteins in general.