title: Synthetic fusion-protein containing domains of Bt Cry1Ac and Allium sativum lectin (ASAL) conferred enhanced insecticidal activity against major lepidopteran pests.
abstract: Different transgenic crop plants, developed with δ-endotoxins of Bacillus thuringiensis (Bt) and mannose-specific plant lectins, exhibited significant protection against chewing and sucking insects. In the present study, a synthetic gene (cry-asal) encoding the fusion-protein having 488 amino acids, comprising DI and DII domains from Bt Cry1Ac and Allium sativum agglutinin (ASAL), was cloned and expressed in Escherichia coli. Ligand blot analysis disclosed that the fusion-protein could bind to more number of receptors of brush border membrane vesicle (BBMV) proteins of Helicoverpa armigera. Artificial diet bioassays revealed that 0.025 μg/g and 0.50 μg/g of fusion-protein were sufficient to cause 100% mortality in Pectinophora gossypiella and H. armigera insects, respectively. As compared to Cry1Ac, the fusion-protein showed enhanced (8-fold and 30-fold) insecticidal activity against two major lepidopteran pests. Binding of fusion-protein to the additional receptors in the midgut cells of insects is attributable to its enhanced entomotoxic effect. The synthetic gene, first of its kind, appears promising and might serve as a potential candidate for engineering crop plants against major insect pests.
authors.affiliation: Centre for Plant Molecular Biology, Osmania University, Hyderabad 500 007, India.
authors.forename: Sunita
authors.initials: S
authors.lastname: Tajne
authors.affiliation: Centre for Plant Molecular Biology, Osmania University, Hyderabad 500 007, India.
authors.forename: Dayakar
authors.initials: D
authors.lastname: Boddupally
authors.affiliation: Centre for Plant Molecular Biology, Osmania University, Hyderabad 500 007, India.
authors.forename: Vijayakumar
authors.initials: V
authors.lastname: Sadumpati
authors.affiliation: Centre for Plant Molecular Biology, Osmania University, Hyderabad 500 007, India.
authors.forename: Dashavantha Reddy
authors.initials: DR
authors.lastname: Vudem
authors.affiliation: Centre for Plant Molecular Biology, Osmania University, Hyderabad 500 007, India. Electronic address: rao_kv1@rediffmail.com.
authors.forename: Venkateswara Rao
authors.initials: VR
authors.lastname: Khareedu
mesh_terms: D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004731:Endotoxins / Q000235:genetics* / Q000378:metabolism; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000187:drug effects; D007915:Lepidoptera / Q000187:drug effects*; D037241:Mannose-Binding Lectins / Q000235:genetics* / Q000378:metabolism; D010572:Pest Control, Biological; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism* / Q000494:pharmacology*
chemical_list: C422947:ASAI protein, Allium sativum; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D037241:Mannose-Binding Lectins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis
keywords: Bacillus thuringiensis; Fusion-protein; Garlic lectin; Insecticidal activity; Ligand blot