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 7 (Page no: 69)

Roles of insect midgut cadherin in Bt intoxication and resistance.

Genetically engineered crops producing Bacillus thuringiensis (Bt) proteins for insect control target major insect pests. Bt crops have improved yields and their use reduces the risks associated with the application of conventional insecticides. However, the evolution of resistance to Bt toxins by target pests threatens the long-term success of such transgenic crops. Insects resistant to Bt Cry toxins have been selected in the laboratory and field-evolved resistance has been reported for economically important insects in several regions of the world. Although the mechanisms of resistance have not been reported for all cases, the most common mechanism involves changes in larval midgut target sites that probably reduce binding to Bt toxins. The binding of Cry toxins to midgut cadherin represents an important step in Bt intoxication for many insects and mutations in the cadherin gene can result in resistance to Bt toxins. Here, we highlight the roles that insect midgut cadherins play in Bt Cry intoxication and review cases where changes in cadherin are involved with resistance to Cry toxins. Furthermore, we emphasize the importance of understanding the underlying molecular basis of Bt intoxication and resistance to Bt, and the implications of fundamental knowledge for resistance management strategies.

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: 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: 10 (Page no: 107) The role of proteolysis in the biological activity of Bt insecticidal crystal proteins. Author(s): Zalunin, I. A., Elpidina, E. N., Oppert, B.
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.