Interação de proteínas Vip3A e Cry1la10 de Bacillus thuringiensis com atividade inseticida a lepidópteros-praga

• Autor(a) principal: Marucci, Suzana Cristina [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/123778
• topic: Pragas agricolas; Lepidoptero; Proteinas de bacterias; Lagarta; Genetica vegetal; Bacterial proteins

Vip3Aa and Cry1Ia proteins have potential in control of Lepidopteran pest and emerge as a promising alternative in the pest resistance management the Cry1A proteins, which has been highly used in the formulation of commercial insecticides based on Bacillus thuringiensis (Bt) and in transgenic plants. Therefore, this study aimed to cloning and expression of Vip3Aa42, Vip3Aa43 and Cry1Ia10 proteins in Escherichia coli, in order to analyze the correlation between the binding to receptors through competition assays between the different Vip3Aa toxins and toxin Cry1Ia10, and toxicity to lepidopteran pests inferring up which combinations that could be used to produce transgenic plants containing multiple genes, which have been used to circumvent the development of insects resistance to Bt toxins. Therefore, vip3Aa and cry1Ia10 genes were cloned into the pET SUMO vector, expressed in E. coli and toxicity of proteins were tested in bioassays with neonate larvae of Spodoptera frugiperda, Anticarsia gemmatalis and Heliothis virescens. The BBMVs (Brush Border Membrane Vesicles) were prepared from the gut of the three species, and homologous and heterologous competition assays were performed. The Vip3Aa42 and Vip3Aa43 proteins were toxic to S. frugiperda and A. gemmatalis. Already Cry1Ia10 protein showed toxicity only for A. gemmatalis and proteins were not toxic to H. virescens. Binding assays to BBMVs demonstrated that Vip3Aa42, Vip3Aa43 and Cry1Ia10 proteins binding effectively to receptors present in the midgut in three species and, therefore, was correlation between toxicity and the binding to receptors for the populations of S. frugiperda and A. gemmatalis, but for H. virescens there was no relationship between toxicity and the binding to receptors. Thus, the combination of Cry1Ia10 and Vip3Aa42 or Vip3Aa43 proteins is indicated for the production of biological insecticidal, as well as for the production of transgenic plants to circumvent ...