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Snowdrop Lectin (snowdrop + lectin)
Selected AbstractsSnowdrop lectin (Galanthus nivalis agglutinin) in aphid honeydew negatively affects survival of a honeydew- consuming parasitoidAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2009Petra A. M. Hogervorst Abstract 1,Insecticidal proteins can be excreted in the honeydew when sap-sucking insects feed on insect-resistant transgenic plants. Honeydew can be an important source of carbohydrates, thus potentially exposing a broad range of honeydew-feeding insects to transgene products. 2,Snowdrop lectin (Galanthus nivalis agglutinin; GNA) dissolved in a 2 m sucrose solution had no antifeedant effect on female aphid parasitoids (Aphidius ervi) but had a direct negative effect on their longevity. 3,When feeding on honeydew from Rhopalosiphum padi feeding on a GNA-containing artificial diet, Aphidius ervi suffered a longevity reduction that was more pronounced than was to be expected based on the detected GNA concentration in the honeydew. 4,Analysis of carbohydrate and amino acid composition revealed that a change in honeydew composition caused by a GNA-effect on the aphids could be a possible explanation for the additional reduction in parasitoid longevity. 5,When comparing the effect of honeydew from Sitobion avenae and R. padi feeding on GNA-expressing or nontransformed wheat plants on A. ervi longevity, aphid species was found to have a significant effect, whereas the wheat variety had no effect. The latter result was probably due to low GNA expression levels in the plants. Differences in nutritional suitability between honeydew from R. padi and S. avenae could be explained by differences in carbohydrate and amino acid composition. 6,This is the first study to demonstrate that GNA ingested by aphids and transported into the honeydew can negatively affect the parasitoids consuming this honeydew. 7,We recommend that honeydew should be considered as a route of exposure to transgene products in future risk assessment studies. [source] Are fecundity and longevity of female Aphelinus abdominalis affected by development in GNA-dosed Macrosiphum euphorbiae?PHYSIOLOGICAL ENTOMOLOGY, Issue 4 2001A. Couty Abstract. Snowdrop lectin (Galanthus nivalis agglutinin, GNA) confers partial resistance to several aphid species when incorporated into an artificial diet and/or expressed in transgenic potato. First-tier laboratory-scale experiments were conducted to assess the potential effect of GNA on the longevity and fecundity of female parasitoid Aphelinus abdominalis (Dalman) that had developed in Macrosiphum euphorbiae (Thomas) fed artificial diet containing 0.1% GNA (w/v). In a previous study it was shown that GNA ingested by A. abdominalis larvae is not acutely toxic. It was also shown that GNA has a host-size mediated effect on parasitoid sex ratio and larval development, but no apparent direct effect. In this study, we report that A. abdominalis larvae that developed in GNA-dosed aphids that were smaller than control aphids of the same age, produced smaller adults with a reduced longevity and fecundity. Aphelinus abdominalis larvae that developed in GNA-dosed aphids older than the control but of the same size, produced adults of similar size that lived as long as the control but had a reduced fecundity. Our results suggest that GNA fed to aphids in artificial diet has both a host-mediated effect (via aphid-size) and a direct effect on adult parasitoid fecundity. It is not known how GNA affects parasitoid larval development and subsequently adult fecundity, but it is hypothesized that GNA acted as an antifeedant to parasitoid larvae, thus disturbing nutrient assimilation and conversion necessary for egg maturation. [source] An evaluation of garlic lectin as an alternative carrier domain for insecticidal fusion proteinsINSECT SCIENCE, Issue 6 2008Elaine Fitches Abstract The mannose-binding lectin GNA (snowdrop lectin) is used as a "carrier" domain in insecticidal fusion proteins which cross the insect gut after oral ingestion. A similar lectin from garlic bulb, ASAII, has been evaluated as an alternative "carrier". Recombinant ASAII delivered orally to larvae of cabbage moth (Mamestra brassica; Lepidoptera) was subsequently detected in haemolymph, demonstrating transport. Fusion proteins comprising an insect neurotoxin, ButaIT (Buthus tamulus insecticidal toxin; red scorpion toxin) linked to the C-terminal region of ASAII or GNA were produced as recombinant proteins (GNA/ButaIT and ASA/ButaIT) by expression in Pichia pastoris. In both cases the C-terminal sequence of the lectin was truncated to avoid post-translational proteolysis. The GNA-containing fusion protein was toxic by injection to cabbage moth larvae (LD50, 250 ,g/g), and when fed had a negative effect on survival and growth. It also decreased the survival of cereal aphids (Sitobion avenae; Homoptera) from neonate to adult by >70% when fed. In contrast, the ASA-ButaIT fusion protein was non-toxic to aphids, and had no effect on lepidopteran larvae, either when injected or when fed. However, intact ASA-ButaIT fusion protein was present in the haemolymph of cabbage moth larvae following ingestion, showing that transport of the fusion had occurred. The stabilities of GNA/ButaIT and ASA/ButaIT to proteolysis in vivo after injection or ingestion differed, and this may be a factor in determining insecticidal activities. [source] Insecticidal activity of scorpion toxin (ButaIT) and snowdrop lectin (GNA) containing fusion proteins towards pest species of different ordersPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 1 2010Elaine C Fitches Abstract 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. © Crown Copyright 2009. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd. [source] Insecticidal spider venom toxin fused to snowdrop lectin is toxic to the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae) and the rice brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 1 2006Rachel E Down Abstract The SFI1/GNA fusion protein, comprising of snowdrop lectin (Galanthus nivalis agglutinin, GNA) fused to an insecticidal spider venom neurotoxin (Segestria florentina toxin 1, SFI1) was tested for toxicity against the rice brown planthopper Nilaparvata lugens (Stål) and the peach-potato aphid Myzus persicae (Sulzer) by incorporation into artificial diets. Significant effects on the mortality of N. lugens were observed, with 100% of the insects fed on the SFI1/GNA fusion protein diet dead by day 7. The survival of the aphid M. persicae was also reduced when fed on the SFI1/GNA fusion protein. After 14 days, only 49% of the aphids that were fed on the fusion protein were still alive compared with approximately 90% of the aphids fed on the control diet or on diet containing GNA only. The SFI1/GNA fusion protein also slowed the development of M. persicae, and the reproductive capacity of the aphids fed on the SFI1/GNA fusion protein was severely reduced. The ability of GNA to act as a carrier protein, and deliver the SFI1 neurotoxin to the haemolymph of N. lugens, following oral ingestion, was investigated. The successful delivery of intact SFI1/GNA fusion protein to the haemolymph of these insects was shown by western blotting. Haemolymph taken from the insects that were fed on the fusion protein contained two GNA-immunoreactive proteins of molecular weights corresponding to GNA and to the SFI1/GNA fusion protein. © 2005 British Crown Copyright. Published for SCI by John Wiley & Sons, Ltd. [source] | ||||||||||