ABSTRACT
Genetically modified plants manifest new traits via the expression of foreign proteins encoded by inserted transgenes. For example, cotton modified to contain a Bacillus thuringiensis (Bt) gene and expressing Bt toxin in its leaves and buds will be protected from bollworm attack. Since the protein products of many transgenes can be purified, these “active ingredients” of genetically modified plants can be used in experiments to assess the likely impacts of such plants on bees. Such tests have a number of advantages: they can be conducted prior to the lengthy process of plant modification, the effects of the proteins can be quantified and some tests may be conducted with bees outside strict quarantine conditions. The shortcomings of this approach are that indirect impacts of genetically modified plants on bees, such as pleiotropic effects resulting from changes in plant phenotype, cannot be assessed and that the test conditions may be somewhat artificial, for example keeping the bees in cages in an incubator. This chapter summarizes current results from bioassays with bees and purified transgene products. Effects of a range of proteins, Bt toxins, protease inhibitors, chitinases, glucanases, and biotin-binding proteins, on adult bee gut physiology, food consumption, olfactory learning behavior, and longevity are presented.
