Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

CABI Book Chapter

Bt resistance: characterization and strategies for GM crops producing Bacillus thuringiensis toxins.

Book cover for Bt resistance: characterization and strategies for GM crops producing <i xmlns="http://www.w3.org/1999/xhtml">Bacillus thuringiensis</i> toxins.

Description

This book focuses on descriptions of the extent of use of Bacillus thuringiensis (Bt) crops and the emerging problem of resistance, recent progress in elucidating the mechanism of action of Bt toxins and describing the different resistance mechanisms and strategies for coping with resistance in the field. There are four sections. In the first section ('The extent of use of Bt crops and the emergin...

Chapter 10 (Page no: 107)

The role of proteolysis in the biological activity of Bt insecticidal crystal proteins.

The crystal toxins (Cry) produced by the bacterium Bacillus thuringiensis (Bt) have been successfully used in both spray formulations and transgenic crops to control some of the most problematic insect pests, as has been discussed in previous chapters. The δ-endotoxins of Bt are functionally active in the insect gut and interact with and are processed by proteolytic enzymes. The structure of Cry proteins has specific features that not only permit them to retain their biological activity in the hostile environment of the insect gut, but also to use the process of proteolysis in the solubilization and activation of Cry protoxins. Because the proteolysis of Cry proteins is critical to their biological activity, we review the literature on studies related to insect and mammalian proteases and their effects on toxin structure and toxicity.

Other chapters from this book

Chapter: 1 (Page no: 1) Successes and failures of transgenic Bt crops: global patterns of field-evolved resistance. Author(s): Tabashnik, B. E., Carrière, Y.
Chapter: 2 (Page no: 15) Status of resistance to Bt cotton in China: cotton bollworm and pink bollworm. Author(s): Gao YuLin, Liu ChenXi, Wu YiDong, Wu KongMing
Chapter: 3 (Page no: 26) Insect resistance to Bt toxins in Brazil and Latin America. Author(s): Monnerat, R., Martins, E., Queiroz, P., Praça, L., Soares, C. M.
Chapter: 4 (Page no: 36) Resistance of Busseola fusca to Cry1Ab Bt maize plants in South Africa and challenges to insect resistance management in Africa. Author(s): Berg, J. van den, Campagne, P.
Chapter: 5 (Page no: 49) Resistance of cabbage loopers to Btk in a greenhouse setting: occurrence, spread and management. Author(s): Janmaat, A., Franklin, M., Myers, J. H.
Chapter: 6 (Page no: 56) Different models of the mode of action of Bt 3d-Cry toxins. Author(s): Bravo, A., Gómez, I., Mendoza, G., Gaytán, M., Soberón, M.
Chapter: 7 (Page no: 69) Roles of insect midgut cadherin in Bt intoxication and resistance. Author(s): Fabrick, J. A., Wu YiDong
Chapter: 8 (Page no: 87) Mechanism of Cry1Ac resistance in cabbage loopers - a resistance mechanism selected in insect populations in an agricultural environment. Author(s): Wang, P.
Chapter: 9 (Page no: 98) Roles of ABC proteins in the mechanism and management of Bt resistance. Author(s): Heckel, D. G.
Chapter: 11 (Page no: 119) The lessons that Caenorhabditis elegans has taught us about the mechanism of action of crystal proteins. Author(s): Sitaram, A., Aroian, R. V.
Chapter: 12 (Page no: 126) The development and prospect of discovery of Bt toxin genes. Author(s): Zhang Jie, Shu ChangLong, Wang ZeYu
Chapter: 13 (Page no: 138) Cry toxin binding site models and their use in strategies to delay resistance evolution. Author(s): Jakka, S., Ferré, J., Jurat-Fuentes, J. L.
Chapter: 14 (Page no: 150) Countering pest resistance with genetically modified Bt toxins. Author(s): Soberón, M., García-Gómez, B. I., Pacheco, S., Sánchez, J., Tabashnik, B. E., Bravo, A.
Chapter: 15 (Page no: 162) RNA interference strategy for crop protection against insect pests. Author(s): Sneha Yogindran, Rajam, M. V.
Chapter: 16 (Page no: 173) Resistance management for Bt maize and above-ground lepidopteran targets in the USA: from single gene to pyramided traits. Author(s): Huang, F. N.
Chapter: 17 (Page no: 186) Insect resistance management and integrated pest management for Bt crops: prospects for an area-wide view. Author(s): Hutchison, W. D.