The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), is an introduced crop pest in North America that causes major damage to corn and reduces yield of food, feed, and biofuel materials. The Cry1F toxin from Bacillus thuringiensis (Bt) expressed in transgenic hybrid corn is highly toxic to O. nubilalis larvae and effective in minimizing feeding damage. A laboratory colony of O. nubilalis was selected for high levels of Cry1F resistance (>12,000-fold compared to susceptible larvae) and is capable of survival on transgenic hybrid corn. Genetic linkage maps with segregating AFLP markers show that the Cry1F resistance trait is controlled by a single quantitative trait locus (QTL) on linkage group 12. The map position of single nucleotide polymorphism (SNP) markers indicated that midgut Bt toxin-receptor genes, alkaline phosphatase, aminopeptidase N, and cadherin, are not linked with the Cry1F QTL. Evidence suggests that genes within this genome interval may give rise to a novel Bt toxin resistance trait for Lepidoptera that appears independent of known receptor-based mechanisms of resistance.
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http://dx.doi.org/10.1007/s10709-011-9590-0 | DOI Listing |
Pest Manag Sci
February 2025
Faculty of Science and Technology, University of Canberra, Canberra, Australia.
Background: Helicoverpa armigera is a highly polyphagous species that causes huge losses to agricultural and horticultural crops worldwide. In the cotton industry, H. armigera, including the Australian subspecies Helicoverpa armigera conferta, is largely managed using genetically modified crops that express insecticidal toxins, such as Cry1Ac.
View Article and Find Full Text PDFJ Agric Food Chem
September 2024
State Key Laboratory Cultivation Base, Ministry of Science and Technology─Jiangsu Key Laboratory for Food Quality and Safety, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
Synergistic factors can enhance the toxicity of Bt toxins and delay the development of Bt resistance. Previous research has demonstrated that a cadherin fragment (HaCad-TBR) increased the toxicity of Cry1Ac in larvae but did not have a synergistic effect on Cry1B, Cry1C, and Cry1F toxins. In this study, a fusion protein (HaCad-TBR-2D3 V) derived from HaCad-TBR and a Bt Cry1-specific antibody peptide was expressed in .
View Article and Find Full Text PDFPest Manag Sci
December 2024
Laboratório de Entomologia, Instituto Federal Goiano, Rio Verde, Brazil.
Background: Lepidopteran pest control in agriculture has become heavily dependent on cultivars that express Bacillus thuringiensis (Bt) toxins as 'plant-incorporated protectants'. However, populations of Spodoptera frugiperda (Smith) in Brazil appear resistant to the Bt traits currently available in commercial soybean cultivars.
Results: This study evaluated S.
Physiol Mol Biol Plants
July 2024
Bihar Agricultural University, Sabour, 813210 Bihar India.
Fall Armyworm imposes a major risk to agricultural losses. Insecticides have historically been used to manage its infestations, but it eventually becomes resistant to them. To combat the pest, a more recent strategy based on the use of transgenic maize that expresses Bt proteins such as Cry1F from the bacteria has been used.
View Article and Find Full Text PDFJ Econ Entomol
October 2024
Department of Mathematical Sciences, Clemson University, Clemson, SC, 29634, USA.
Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) has evolved resistance to insecticidal toxins from Bacillus thuringiensis (Bt) Berliner (Bacillales: Bacillaceae) expressed in genetically engineered corn, Zea mays L. This study provides an overview of field trials from Georgia, North Carolina, and South Carolina evaluating Bt and non-Bt corn hybrids from 2009 to 2022 to show changes in susceptibility in H. zea to Bt corn.
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