Raimundo W. de Souza Aguiar¹ , Erica Soares Martins^2,4 , Bergmann Morais Ribeiro³ , Rose Gomes Monnerat⁴

1. Fundacao Universidade Federal do Tocantins, Campus Universitario de Gurupi,Gurupi, TO, Brazil;
2. Faculdades Promove de Brasilia, Campus Aguas Claras, Brasilia, DF;
3. Universidade de Brasilia, Departamento de Biologia Celular, Campus Universitario, Asa Norte, Brasilia, DF, Brazil;
4. Embrapa Recursos Geneticos e Biotecnologia, Controle biologico, Asa Norte, Brasilia 70770-900, Brazil
Author    Correspondence author
Bt Research, 2012, Vol. 3, No. 4   doi: 10.5376/bt.2012.03.0004
Received: 22 May, 2012    Accepted: 19 Jul., 2012    Published: 20 Jul., 2012

This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

de Souza Aguiar et al., 2012, Cry10Aa Protein is Highly Toxic to Anthonomus grandis Boheman (Coleoptera: Curculionidae), an Important Insect Pest in Brazilian Cotton Crop Fields, Bt Research, Vol.3, No.4 20-28 (doi: 10.5376/bt.2012.03.0004)

The cry10Aa gene from the Brazilian Bacillus thuringiensis subsp israelensis S1804 strain was introduced into the genome of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) in order to evaluate its expression in insect cells and its toxicity to A. grandis. The recombinant virus (vSyncry10Aa) was amplified in Trichoplusia ni (BTI-Tn5B1-4) cells and used to infect Spodoptera frugiperda larvae. Total extracts from S. frugiperda infected with the recombinant viruses were analysed by SDS-PAGE and showed the presence of a polypeptide around 85 kD. Cuboid-shaped protein crystals were observed in insect extracts by light and scanning electron microscopy. Bioassays, using the recombinant virus infected-insect extracts showed high toxicity to A. grandis larvae, with a LC₅₀ of 7.12 µg/mL. Furthermore, a competition binding assay with the recombinant biotin-labeled Cry10A protein and brush border membrane vesicles (BBMV) from A. grandis indicated that the toxin binds specifically to BBMVs. Therefore, the Cry10A protein has a potential to be used in transgenic cotton plants for the control of this important insect pest.

 

Bacillus thuringiensis (Bt); Toxicity; Recombinant protein