ABCC transporters mediate insect resistance to multiple Bt toxins revealed by bulk segregant analysis

BMC Biology

Research Article

Yonggyun Kim¹  Youngjin Park¹  Gloria Navarro-Cerrillo²  Juan Ferré²  Rosa M González-Martínez²  Maissa Chakroun²  Salvador Herrero²  Jose Blanca³  Pello Ziarsolo³  Joaquin Cañizares³ 

[1] Department of Bioresource Sciences, Andong National University, 760-749, Andong, Korea;Department of Genetics, Universitat de València, Dr Moliner 50, 46100, Burjassot, Spain;Institute for Conservation & Improvement of Valentian Agrodiversity (COMAV), Polytechnic University of Valencia, Valencia, Spain;

关键词: Bt resistance;    ABCC2 transporter;    Cry toxins;   

DOI  :  10.1186/1741-7007-12-46

 received in 2014-02-28, accepted in 2014-06-02,  发布年份 2014

来源: Springer

【 摘 要 】

BackgroundRelatively recent evidence indicates that ABCC2 transporters play a main role in the mode of action of Bacillus thuringiensis (Bt) Cry1A-type proteins. Mapping of major Cry1A resistance genes has linked resistance to the ABCC2 locus in Heliothis virescens, Plutella xylostella, Trichoplusia ni and Bombyx mori, and mutations in this gene have been found in three of these Bt-resistant strains.ResultsWe have used a colony of Spodoptera exigua (Xen-R) highly resistant to a Bt commercial bioinsecticide to identify regions in the S. exigua genome containing loci for major resistance genes by using bulk segregant analysis (BSA). Results reveal a region containing three genes from the ABCC family (ABBC1, ABBC2 and ABBC3) and a mutation in one of them (ABBC2) as responsible for the resistance of S. exigua to the Bt commercial product and to its key Spodoptera-active ingredients, Cry1Ca. In contrast to all previously described mutations in ABCC2 genes that directly or indirectly affect the extracellular domains of the membrane protein, the ABCC2 mutation found in S. exigua affects an intracellular domain involved in ATP binding. Functional analyses of ABBC2 and ABBC3 support the role of both proteins in the mode of action of Bt toxins in S. exigua. Partial silencing of these genes with dsRNA decreased the susceptibility of wild type larvae to both Cry1Ac and Cry1Ca. In addition, reduction of ABBC2 and ABBC3 expression negatively affected some fitness components and induced up-regulation of arylphorin and repat5, genes that respond to Bt intoxication and that are found constitutively up-regulated in the Xen-R strain.ConclusionsThe current results show the involvement of different members of the ABCC family in the mode of action of B. thuringiensis proteins and expand the role of the ABCC2 transporter in B. thuringiensis resistance beyond the Cry1A family of proteins to include Cry1Ca.

【 授权许可】

Unknown   
© Park et al.; licensee BioMed Central Ltd. 2014. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.