Submitted to: Society of Nematology Meeting
Publication Type: Proceedings
Publication Acceptance Date: August 25, 2001
Publication Date: N/A
Bacillus thuringiensis (Bt) delta-endotoxins, a family of crystal (Cry) proteins, are widely used as insecticides in agriculture. Recently, we described that Bt toxins may be also effective nematocides. To more fully address the potential of Cry toxins as nematocides to control plant-parasitic-nematodes (PPNs), we analyzed the toxicities of eight Cry proteins (Cry 5A, 5B, 6A, 6B, 12A, 13A, 14A, and 21A) on five free-living nematodes (C. elegans, Pristionchus pacificus, Panagrellus redivivus, Acrobeloides, and Distolabrellus veechi). The results of general toxicity assays, morphology, and brood size indicated that indeed some of these Cry proteins are potent nematocidal toxins. However, some had little effect on nematodes. One nematode species was resistant to all toxins. We found that one Bt toxin could be trimmed to a small 42 kD active core that was toxic to almost all these diverse nematodes. We believe that Bt toxins show good potential to control PPNs.