Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins

Alteration of binding sites for Bacillus thuringiensis (Bt) toxins in insect midgut is the major mechanism of high-level resistance to Bt toxins in insects. The midgut cadherin is known to be a major binding protein for Bt Cry1A toxins and linkage of Bt-resistance to cadherin gene mutations has been...

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Main Authors:	Zhang, Xin, Tiewsiri, Kasorn, Kain, Wendy, Huang, Lihua, Wang, Ping
Format:	Online
Language:	English
Published:	Public Library of Science 2012
Online Access:	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351398/

id	pubmed-3351398
recordtype	oai_dc
spelling	pubmed-33513982012-05-17 Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins Zhang, Xin Tiewsiri, Kasorn Kain, Wendy Huang, Lihua Wang, Ping Research Article Alteration of binding sites for Bacillus thuringiensis (Bt) toxins in insect midgut is the major mechanism of high-level resistance to Bt toxins in insects. The midgut cadherin is known to be a major binding protein for Bt Cry1A toxins and linkage of Bt-resistance to cadherin gene mutations has been identified in lepidopterans. The resistance to Bt toxin Cry1Ac evolved in greenhouse populations of Trichoplusia ni has been identified to be associated with the down-regulation of an aminopeptidase N (APN1) gene by a trans-regulatory mechanism and the resistance gene has been mapped to the locus of an ABC transporter (ABCC2) gene. However, whether cadherin is also involved with Cry1Ac-resistance in T. ni requires to be understood. Here we report that the Cry1Ac-resistance in T. ni is independent of alteration of the cadherin. The T. ni cadherin cDNA was cloned and the cadherin sequence showed characteristic features known to cadherins from Lepidoptera. Various T. ni cadherin gene alleles were identified and genetic linkage analysis of the cadherin alleles with Cry1Ac-resistance showed no association of the cadherin gene with the Cry1Ac-resistance in T. ni. Analysis of cadherin transcripts showed no quantitative difference between the susceptible and Cry1Ac-resistant T. ni larvae. Quantitative proteomic analysis of midgut BBMV proteins by iTRAQ-2D-LC-MS/MS determined that there was no quantitative difference in cadherin content between the susceptible and the resistant larvae and the cadherin only accounted for 0.0014% (mol%) of the midgut BBMV proteins, which is 1/300 of APN1 in molar ratio. The cadherin from both the susceptible and resistant larvae showed as a 200-kDa Cry1Ac-binding protein by toxin overlay binding analysis, and nano-LC-MS/MS analysis of the 200-kDa cadherin determined that there is no quantitative difference between the susceptible and resistant larvae. Results from this study indicate that the Cry1Ac-resistance in T. ni is independent of cadherin alteration. Public Library of Science 2012-05-14 /pmc/articles/PMC3351398/ /pubmed/22606242 http://dx.doi.org/10.1371/journal.pone.0035991 Text en Zhang et al. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
repository_type	Open Access Journal
institution_category	Foreign Institution
institution	US National Center for Biotechnology Information
building	NCBI PubMed
collection	Online Access
language	English
format	Online
author	Zhang, Xin Tiewsiri, Kasorn Kain, Wendy Huang, Lihua Wang, Ping
spellingShingle	Zhang, Xin Tiewsiri, Kasorn Kain, Wendy Huang, Lihua Wang, Ping Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins
author_facet	Zhang, Xin Tiewsiri, Kasorn Kain, Wendy Huang, Lihua Wang, Ping
author_sort	Zhang, Xin
title	Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins
title_short	Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins
title_full	Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins
title_fullStr	Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins
title_full_unstemmed	Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins
title_sort	resistance of trichoplusia ni to bacillus thuringiensis toxin cry1ac is independent of alteration of the cadherin-like receptor for cry toxins
description	Alteration of binding sites for Bacillus thuringiensis (Bt) toxins in insect midgut is the major mechanism of high-level resistance to Bt toxins in insects. The midgut cadherin is known to be a major binding protein for Bt Cry1A toxins and linkage of Bt-resistance to cadherin gene mutations has been identified in lepidopterans. The resistance to Bt toxin Cry1Ac evolved in greenhouse populations of Trichoplusia ni has been identified to be associated with the down-regulation of an aminopeptidase N (APN1) gene by a trans-regulatory mechanism and the resistance gene has been mapped to the locus of an ABC transporter (ABCC2) gene. However, whether cadherin is also involved with Cry1Ac-resistance in T. ni requires to be understood. Here we report that the Cry1Ac-resistance in T. ni is independent of alteration of the cadherin. The T. ni cadherin cDNA was cloned and the cadherin sequence showed characteristic features known to cadherins from Lepidoptera. Various T. ni cadherin gene alleles were identified and genetic linkage analysis of the cadherin alleles with Cry1Ac-resistance showed no association of the cadherin gene with the Cry1Ac-resistance in T. ni. Analysis of cadherin transcripts showed no quantitative difference between the susceptible and Cry1Ac-resistant T. ni larvae. Quantitative proteomic analysis of midgut BBMV proteins by iTRAQ-2D-LC-MS/MS determined that there was no quantitative difference in cadherin content between the susceptible and the resistant larvae and the cadherin only accounted for 0.0014% (mol%) of the midgut BBMV proteins, which is 1/300 of APN1 in molar ratio. The cadherin from both the susceptible and resistant larvae showed as a 200-kDa Cry1Ac-binding protein by toxin overlay binding analysis, and nano-LC-MS/MS analysis of the 200-kDa cadherin determined that there is no quantitative difference between the susceptible and resistant larvae. Results from this study indicate that the Cry1Ac-resistance in T. ni is independent of cadherin alteration.
publisher	Public Library of Science
publishDate	2012
url	https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351398/
_version_	1611529335020191744

Resistance of Trichoplusia ni to Bacillus thuringiensis Toxin Cry1Ac Is Independent of Alteration of the Cadherin-Like Receptor for Cry Toxins

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