Insecticidal activity of scorpion toxin (ButaIT) and snowdrop lectin (GNA) containing fusion proteins towards pest species of different orders.
BACKGROUND
The toxicity of a fusion protein, ButalT/GNA, comprising a venom toxin (ButaIT) derived from the red scorpion, Mesobuthus tamulus (F.), and Galanthus nivalis agglutinin (GNA), was evaluated under laboratory conditions against several pest insects. Insecticidal activity was compared with SFI1/GNA, a fusion comprising a venom toxin (SFI1) derived from the European spider Segestria florentina (Rossi) and GNA, which has been previously demonstrated to be effective against lepidopteran and hemipteran pests, and to GNA itself.


RESULTS
Injection assays demonstrated that both fusion proteins were toxic to lepidopteran larvae, dipteran adults, coleopteran adults and larvae and dictyopteran nymphs. ButalT/GNA was more toxic than SFI1/GNA in all cases. GNA itself made a minor contribution to toxicity. Oral toxicity of ButalT/GNA towards lepidopteran pests was confirmed against neonate Spodoptera littoralis (Boisd.), where incorporation at 2% dietary protein resulted in 50% mortality and > 85% reduction in growth compared with controls. ButaIT/GNA was orally toxic to Musca domestica L. adults, causing 75% mortality at 1 mg mL(-1) in aqueous diets and, at 2 mg g(-1) it was orally toxic to Tribolium castaneum (Herbst.), causing 60% mortality and a 90% reduction in growth.


CONCLUSIONS
Toxicity of the ButaIT/GNA recombinant fusion protein towards a range of insect pests from different orders was demonstrated by injection bioassays. Feeding bioassays demonstrated the potential use of the ButaIT/GNA fusion protein as an orally active insecticide against lepidopteran, dipteran and coleopteran pests. These experiments provide further evidence that the development of fusion protein technology for the generation of new, biorational, anti-insect molecules holds significant promise.
Fitches
Elaine C
EC
Food and Environment Research Agency, Sand Hutton, York, UK. elaine.fitches@fera.gsi.gov.uk
Bell
Howard A
HA
Powell
Michelle E
ME
Back
Emma
E
Sargiotti
Chiara
C
Weaver
Robert J
RJ
Gatehouse
John A
JA
D000818:Animals; D006793:Houseflies / Q000187:drug effects; D007267:Injections; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D037241:Mannose-Binding Lectins / Q000494:pharmacology*; D037121:Plant Lectins / Q000494:pharmacology*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000302:isolation & purification; D012604:Scorpion Venoms / Q000494:pharmacology*; D018411:Spodoptera / Q000187:drug effects; D018675:Toxicity Tests; D014231:Tribolium / Q000187:drug effects
C469905:Buthus tamulus insect toxin; D007306:Insecticides; D037241:Mannose-Binding Lectins; D037121:Plant Lectins; D011993:Recombinant Fusion Proteins; D012604:Scorpion Venoms; C063117:snowdrop lectin