CGC Bibliography Paper 4916

Are Bt toxins nematicides?

Wei J-Z, Hale K, Carta LK, Aroian RV

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Citation:

Phytopathology 91: S145- 2001

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ARTICLE

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Abstract:

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 nematicides. To more fully address the potential of Cry toxins as nematicides 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 nematicidal 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.