Center for Molecular Agriculture

Raffi V. Aroian

Understanding Bt toxin action and resistance: Bt toxins are currently the most widely used naturally occurring agricultural pesticide. These organic insecticides are safer and more benign than the chemical pesticides they are replacing and are used extensively both by organic farmers and in transgenic crops to provide safe protection against insect pests. Despite the widespread use and importance of Bt toxins, little is known about how Bt toxins act at the molecular level in the target organisms and how resistance develops. We are examining Bt toxin action in C. elegans in order to study toxicity in an organism with good molecular genetics. Our laboratory has demonstrated for the first time that a single Bt toxin can be toxic to a nematode. We have isolated and characterized mutations in five genes that confer resistance in C. elegans to Bt toxicity. We have cloned several of these genes and are characterizing the pathways that define Bt toxicity and that can mutate to resistance. This information is expanding our knowledge of how Bt toxins operate and should help protect this invaluable resource in the long term. We have also found some Bt toxins have broad nematicidal properties and are testing these for effectiveness against parasitic nematodes.

For a discussion of our work on polarity, see the Aroian homepage.

Technologies developed in the Aroian laboratory:

• Genes that encode Bt resistance. 

Link to: Recent publications