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Wu S, Luo Y, Zeng Z, Yu Y, Zhang S, Hu Y, Chen L. Determination of internal controls for quantitative gene expression of Spodoptera litura under microbial pesticide stress. Sci Rep 2024; 14:6143. [PMID: 38480844 PMCID: PMC10937984 DOI: 10.1038/s41598-024-56724-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 03/10/2024] [Indexed: 03/17/2024] Open
Abstract
Quantitative real-time polymerase chain reaction (qRT-PCR) has become a commonly used method for the quantification of gene expression. However, accurate qRT-PCR analysis requires a valid internal reference for data normalization. To determine the valid reference characterized with low expression variability among Spodoptera litura samples after microbial pesticide treatments, nine housekeeping genes, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), arginine kinase, ubiquitin C, actin-5C (ACT5C), actin, ribosomal protein S13 (RPS13), tubulin, acidic ribosomal protein P0 (RPLP0) and ubiquinol-cytochrome c reductase, were evaluated for their suitability using geNorm, Normfinder, BestKeeper, RefFinder and the comparative delta CT methods in this study. S. litura larvae after direct treatment (larvae were immersed in biopesticides), indirect treatment (larvae were fed with biopesticide immersed artificial diets) and comprehensive treatment (larvae were treated with the first two treatments in sequence), respectively with Metarhizium anisopliae, Empedobacter brevis and Bacillus thuringiensis, were investigated. The results indicated that the best sets of internal references were as follows: RPLP0 and ACT5C for direct treatment conditions; RPLP0 and RPS13 for indirect treatment conditions; RPS13 and GAPDH for comprehensive treatment conditions; RPS13 and RPLP0 for all the samples. These results provide valuable bases for further genetic researches in S. litura.
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Affiliation(s)
- Shuang Wu
- Institute of Vegetable and Flower Research, Chongqing Academy of Agricultural Sciences, Chongqing, 401329, China
| | - Yunmi Luo
- Institute of Vegetable and Flower Research, Chongqing Academy of Agricultural Sciences, Chongqing, 401329, China
| | - Zhihong Zeng
- Institute of Vegetable and Flower Research, Chongqing Academy of Agricultural Sciences, Chongqing, 401329, China
| | - Ying Yu
- Institute of Vegetable and Flower Research, Chongqing Academy of Agricultural Sciences, Chongqing, 401329, China
| | - Shicai Zhang
- Institute of Vegetable and Flower Research, Chongqing Academy of Agricultural Sciences, Chongqing, 401329, China
| | - Yan Hu
- Institute of Vegetable and Flower Research, Chongqing Academy of Agricultural Sciences, Chongqing, 401329, China
| | - Lei Chen
- Institute of Vegetable and Flower Research, Chongqing Academy of Agricultural Sciences, Chongqing, 401329, China.
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Dávila-Orozco G, Cruz-Salazar B, Ruiz-Montoya L. How Does the Application of Beauveria bassiana and Compost on Corn Crops Affect the Survival and Genetic Diversity of Phyllophaga obsoleta (Coleoptera: Melolonthinae)? ENVIRONMENTAL ENTOMOLOGY 2021; 50:1227-1240. [PMID: 34164658 DOI: 10.1093/ee/nvab054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Indexed: 06/13/2023]
Abstract
The knowledge of the diversity and genetic structure of pest insects under management contributes to the improvement of control strategies. An experiment was run to investigate whether the addition of the fungus Beauveria bassiana (Balsamo) Vuillemin (Hypocreales: Cordycipitaceae) (BB) and compost to soil affects the presence and genetic diversity of adults and larvae of Phyllophaga obsoleta Blanch (Coleoptera: Melolonthinae) larvae in maize crops. We collected adults in and used mating pairs under four treatments (BB, compost, soil, blank). Genetic diversity and structure were determined through five allo/iso-enzymatic loci. Beauveria bassiana affected the presence and mortality of P. obsoleta in the laboratory but not under field conditions. The genetic diversity of P. obsoleta ranged from moderate to high (Ho = 0.26-0.31), with a low genetic differentiation among localities or treatments (Phi < 0.05), indicating high levels of gene flow. Our results showed a weak effect of B. bassiana on P. obsoleta in the field. Still, our laboratory observations suggest that the fungus may be a suitable alternative for biological control.
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Affiliation(s)
- Guillermo Dávila-Orozco
- Programa de Pós-Graduação em Biologia Animal, Universidade Federal de Pelotas, Pelotas RS, Brazil
| | - Bárbara Cruz-Salazar
- Centro Tlaxcala de Biología de la Conducta, CONACYT-Universidad Autónoma de Tlaxcala, Tlaxcala, Mexico
| | - Lorena Ruiz-Montoya
- Departamento de Conservación de la Biodiversidad, El Colegio de la Frontera Sur, San Cristóbal de Las Casas, Chiapas, Mexico
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3
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Horikoshi RJ, Vertuan H, de Castro AA, Morrell K, Griffith C, Evans A, Tan J, Asiimwe P, Anderson H, José MOMA, Dourado PM, Berger G, Martinelli S, Head G. A new generation of Bt maize for control of fall armyworm (Spodoptera frugiperda). PEST MANAGEMENT SCIENCE 2021; 77:3727-3736. [PMID: 33624355 PMCID: PMC8360028 DOI: 10.1002/ps.6334] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 02/19/2021] [Accepted: 02/24/2021] [Indexed: 05/25/2023]
Abstract
BACKGROUND The pyramided genetically modified maize (Zea mays [L.]) event MON 95379, expressing the Cry1B.868 and Cry1Da_7 proteins, was designed to protect against larval feeding damage by the fall armyworm, Spodoptera frugiperda (FAW). Here, we conducted laboratory, greenhouse, and field studies to assess the dose and field efficacy of MON 95379 against FAW and inform the development of insect resistance management plans. RESULTS The Cry1B.868 and Cry1Da_7 proteins were active against susceptible FAW neonates in diet-incorporation bioassays: median lethal concentration [LC50 ] (95% CI) = 62.8 (42.6-87.6) μg/ml diet for Cry1B.868 and 9.4 (5.3-18.6) μg/ml diet for Cry1Da_7. In laboratory leaf disc bioassays, MON 95379 maize and experimental maize lines expressing the individual components were effective in controlling susceptible FAW. In whole-plant assays, MON 95379 controlled FAW resistant to the Cry1A.105 and Cry2Ab2 proteins. Likewise, under field conditions, MON 95379 maize expressing Cry1B.868 and Cry1Da_7 was highly effective at protecting plants against the larval feeding of FAW. CONCLUSIONS The expression of Cry1B.868 and Cry1Da_7 in MON 95379 consistently protected maize plants against larval feeding by FAW and represents an alternative to manage trait resistance issues in South America. © 2021 Bayer Crop Science-US. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
| | | | | | | | - Cara Griffith
- Plant Biotechnology, Bayer Crop Science USChesterfieldMOUSA
| | - Adam Evans
- Plant Biotechnology, Bayer Crop Science USChesterfieldMOUSA
| | - Jianguo Tan
- Regulatory Science, Bayer Crop Science USChesterfieldMOUSA
| | - Peter Asiimwe
- Regulatory Science, Bayer Crop Science USChesterfieldMOUSA
| | | | | | | | | | | | - Graham Head
- Regulatory Science, Bayer Crop Science USChesterfieldMOUSA
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4
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Gong M, Zhang H, Wu D, Zhang Z, Zhang J, Bao D, Yang Y. Key metabolism pathways and regulatory mechanisms of high polysaccharide yielding in Hericium erinaceus. BMC Genomics 2021; 22:160. [PMID: 33676419 PMCID: PMC7937317 DOI: 10.1186/s12864-021-07480-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 02/25/2021] [Indexed: 12/23/2022] Open
Abstract
Background Hericium erinaceus, a rare edible and medicine fungus, is widely used in the food and medical field. Polysaccharides from H. erinaceus are the main bioactive compound that exert high bioactive value in the medical and healthcare industries. Results The genome of H. erinaceus original strain HEA was reported 38.16 Mb, encoding 9780 predicted genes by single-molecule, real-time sequencing technology. The phylogenomic analysis showed that H. erinaceus had the closest evolutionary affinity with Dentipellis sp. The polysaccharide content in the fermented mycelia of mutated strains HEB and HEC, which obtained by ARTP mutagenesis in our previous study, was improved by 23.25 and 47.45%, and a new β-glucan fraction with molecular weight 1.056 × 106 Da was produced in HEC. Integrative analysis of transcriptome and proteomics showed the upregulation of the carbohydrate metabolism pathway modules in HEB and HEC might lead to the increased production of glucose-6P and promote the repeating units synthesis of polysaccharides. qPCR and PRM analysis confirmed that most of the co-enriched and differentially co-expressed genes involved in carbohydrate metabolism shared a similar expression trend with the transcriptome and proteome data in HEB and HEC. Heatmap analysis showed a noticeably decreased protein expression profile of the RAS-cAMP-PKA pathway in HEC with a highly increased 47.45% of polysaccharide content. The S phase progression blocking experiment further verified that the RAS-cAMP-PKA pathway’s dysfunction might promote high polysaccharide and β-glucan production in the mutant strain HEC. Conclusions The study revealed the primary mechanism of the increased polysaccharide synthesis induced by ARTP mutagenesis and explored the essential genes and pathways of polysaccharide synthesis. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07480-x.
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Affiliation(s)
- Ming Gong
- Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, the People's Republic of China, No.1000, Jinqi Road, Shanghai, 201403, China
| | - Henan Zhang
- Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, the People's Republic of China, No.1000, Jinqi Road, Shanghai, 201403, China
| | - Di Wu
- Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, the People's Republic of China, No.1000, Jinqi Road, Shanghai, 201403, China
| | - Zhong Zhang
- Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, the People's Republic of China, No.1000, Jinqi Road, Shanghai, 201403, China
| | - Jinsong Zhang
- Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, the People's Republic of China, No.1000, Jinqi Road, Shanghai, 201403, China
| | - Dapeng Bao
- Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, the People's Republic of China, No.1000, Jinqi Road, Shanghai, 201403, China
| | - Yan Yang
- Institute of Edible Fungi, Shanghai Academy of Agricultural Sciences, National Engineering Research Center of Edible Fungi, Key Laboratory of Edible Fungi Resources and Utilization (South), Ministry of Agriculture, the People's Republic of China, No.1000, Jinqi Road, Shanghai, 201403, China.
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5
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Singh D, Samiksha, Thayil SM, Sohal SK, Kesavan AK. Exploration of insecticidal potential of Cry protein purified from Bacillus thuringiensis VIID1. Int J Biol Macromol 2021; 174:362-369. [PMID: 33493564 DOI: 10.1016/j.ijbiomac.2021.01.143] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/25/2022]
Abstract
Insect pests are a threat to agriculture as they cause a loss of 15-22% to economically important crops every year. Bacillus thuringiensis produces parasporal crystal inclusions that have insecticidal 'Cry' proteins which are toxic to insect larvae of the order Lepidoptera, Coleoptera and Diptera, etc. In the present study, 40 different soil samples from Amritsar and its surrounding areas were selected for isolation of B. thuringiensis. The rod shaped, gram-positive bacterial isolates were further analyzed for characteristic crystal formation using phase contrast and scanning electron microscopy. 6 Bacillus samples containing cry genes were identified using the universal primers for cry genes, of which one isolate exhibited a protein band of ~95 kDa. This protein was purified using a Sephadex G-75 column. The insecticidal assays conducted with purified Cry protein on insect larvae of lepidopteran and dipteran orders viz. Spodoptera litura, Galleria malonella, Bactrocera cucurbitae and Culex pipens revealed considerable detrimental effects. A significant increase in larval mortality was observed for the larvae of all insects in a concentration dependent manner when treated with Cry protein purified from B. thuringenisis VIID1. The purified Cry protein did not have any significant effect on honey bee larvae.
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Affiliation(s)
- Drishtant Singh
- Molecular Microbiology Lab, Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Samiksha
- Insect Physiology Lab, Department of Zoology, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Seema Madhumal Thayil
- Molecular Microbiology Lab, Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Satwinder Kaur Sohal
- Insect Physiology Lab, Department of Zoology, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Anup Kumar Kesavan
- Molecular Microbiology Lab, Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, Punjab, India.
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Yang X, Chen W, Song X, Ma X, Cotto-Rivera RO, Kain W, Chu H, Chen YR, Fei Z, Wang P. Mutation of ABC transporter ABCA2 confers resistance to Bt toxin Cry2Ab in Trichoplusia ni. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 112:103209. [PMID: 31422154 DOI: 10.1016/j.ibmb.2019.103209] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 07/22/2019] [Accepted: 07/24/2019] [Indexed: 05/29/2023]
Abstract
Insecticidal proteins from Bacillus thuringiensis (Bt) are the primary recombinant proteins expressed in transgenic crops (Bt-crops) to confer insect resistance. Development of resistance to Bt toxins in insect populations threatens the sustainable application of Bt-crops in agriculture. The Bt toxin Cry2Ab is a major insecticidal protein used in current Bt-crops, and resistance to Cry2Ab has been selected in several insects, including the cabbage looper, Trichoplusia ni. In this study, the Cry2Ab resistance gene in T. ni was mapped to Chromosome 17 by genetic linkage analyses using a whole genome resequencing approach, and was then finely mapped using RNA-seq-based bulked segregant analysis (BSA) and amplicon sequencing (AmpSeq)-based fine linkage mapping to a locus containing two genes, ABCA1 and ABCA2. Mutations in ABCA1 and ABCA2 in Cry2Ab resistant T. ni were identified by both genomic DNA and cDNA sequencing. Analysis of the expression of ABCA1 and ABCA2 in T. ni larvae indicated that ABCA2 is abundantly expressed in the larval midgut, but ABCA1 is not a midgut-expressed gene. The mutation in ABCA2 in Cry2Ab resistant T. ni was identified to be an insertion of a transposon Tntransib in ABCA2. For confirmation of ABCA2 as the Cry2Ab-resistance gene, T. ni mutants with frameshift mutations in ABCA1 and ABCA2 were generated by CRISPR/Cas9 mutagenesis. Bioassays of the T. ni mutants with Cry2Ab verified that the mutations of ABCA1 did not change larval susceptibility to Cry2Ab, but the ABCA2 mutants were highly resistant to Cry2Ab. Genetic complementation test of the ABCA2 allele in Cry2Ab resistant T. ni with an ABCA2 mutant generated by CRISPR/Cas9 confirmed that the ABCA2 mutation in the Cry2Ab resistant strain confers the resistance. The results from this study confirmed that ABCA2 is essential for the toxicity of Cry2Ab in T. ni and mutation of ABCA2 confers the resistance to Cry2Ab in the resistant T. ni strain derived from a Bt resistant greenhouse population.
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Affiliation(s)
- Xiaowei Yang
- Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA
| | - Wenbo Chen
- Boyce Thompson Institute, Ithaca, NY, 14853, USA
| | - Xiaozhao Song
- Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA
| | - Xiaoli Ma
- Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA
| | - Rey O Cotto-Rivera
- Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA
| | - Wendy Kain
- Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA
| | - Hannah Chu
- Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA; Department of Science, John Jay College of Criminal Justice-City University of New York, New York, NY, 10019, USA
| | - Yun-Ru Chen
- Boyce Thompson Institute, Ithaca, NY, 14853, USA
| | - Zhangjun Fei
- Boyce Thompson Institute, Ithaca, NY, 14853, USA; USDA-Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY, 14853, USA
| | - Ping Wang
- Department of Entomology, Cornell University, New York State Agricultural Experiment Station, Geneva, NY, 14456, USA.
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7
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Reisig DD, Huseth AS, Bacheler JS, Aghaee MA, Braswell L, Burrack HJ, Flanders K, Greene JK, Herbert DA, Jacobson A, Paula-Moraes SV, Roberts P, Taylor SV. Long-Term Empirical and Observational Evidence of Practical Helicoverpa zea Resistance to Cotton With Pyramided Bt Toxins. JOURNAL OF ECONOMIC ENTOMOLOGY 2018; 111:1824-1833. [PMID: 29668958 DOI: 10.1093/jee/toy106] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Indexed: 06/08/2023]
Abstract
Evidence of practical resistance of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) to Bt cotton in the United States is debatable, supported with occasional reports of boll damage in the field. Our objective was to provide both empirical and long-term observational evidence of practical resistance by linking both in-season and end-of-season measurements of H. zea damage to pyramided Bt cotton bolls and to provide Cry1Ac diet-based bioassay data in support of these damage estimates. In-season boll damage from H. zea was highly correlated to end-of-season damaged bolls. Across North Carolina, Bt cotton fields with end-of-season bolls damaged by H. zea increased during 2016 compared to previous years. Elevated damage was coupled with an increase in field sprays targeting H. zea during 2016, but not related to an increase in H. zea abundance. Bioassay data indicated that there was a range of Cry1Ac susceptibility across the southeastern United States. Given the range of susceptibility to Cry1Ac across the southeastern United States, it is probable that resistant populations are common. Since H. zea is resistant to cotton expressing pyramided Cry toxins, the adoption of new cotton varieties expressing Vip3Aa will be rapid. Efforts should be made to delay resistance of H. zea to the Vip3Aa toxin to avoid foliar insecticide use.
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Affiliation(s)
- Dominic D Reisig
- Department of Entomology and Plant Pathology, North Carolina State University, Vernon G. James Research and Extension Center, Plymouth, NC
| | - Anders S Huseth
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
| | - Jack S Bacheler
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
| | - Mohammad-Amir Aghaee
- Department of Entomology and Plant Pathology, North Carolina State University, Vernon G. James Research and Extension Center, Plymouth, NC
| | - Lewis Braswell
- Department of Entomology and Plant Pathology, North Carolina State University, Vernon G. James Research and Extension Center, Plymouth, NC
| | - Hannah J Burrack
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC
| | - Kathy Flanders
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL
| | - Jeremy K Greene
- Department of Agricultural and Environmental Sciences, Edisto Research & Education Center, Clemson University, Blackville, SC
| | - D Ames Herbert
- Department of Entomology, Tidewater Agricultural Research and Extension Center, Virginia Polytechnic Institute and State University, Suffolk, VA
| | - Alana Jacobson
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL
| | | | - Phillip Roberts
- Department of Entomology, University of Georgia, Tifton Campus, Tifton, GA
| | - Sally V Taylor
- Department of Entomology, Tidewater Agricultural Research and Extension Center, Virginia Polytechnic Institute and State University, Suffolk, VA
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8
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Farinós GP, Hernández-Crespo P, Ortego F, Castañera P. Monitoring of Sesamia nonagrioides resistance to MON 810 maize in the European Union: lessons from a long-term harmonized plan. PEST MANAGEMENT SCIENCE 2018; 74:557-568. [PMID: 28925554 DOI: 10.1002/ps.4735] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/11/2017] [Accepted: 09/11/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Use of MON 810 maize (Zea mays), which expresses the insecticidal protein Cry1Ab from Bacillus thuringiensis (Bt maize), is a highly effective method to control Sesamia nonagrioides (Lefèbvre), a key maize pest in Mediterranean countries. Monitoring programs to assess the potential development of resistance of target pests to Bt maize are mandatory in the European Union (EU). Here we report the results of the S. nonagrioides resistance monitoring plan implemented for MON 810 maize in the EU between 2004 and 2015 and reassess the different components of this long-term harmonized plan. RESULTS No major shifts in the susceptibility of S. nonagrioides to the Cry1Ab protein have occurred over time. The reassessment of this long-term program has identified some practical and technical constraints, allowing us to provide specific recommendations for improvement: use reference strains instead of susceptibility baselines as comparators for field-collected populations; shift from dose-response bioassays to diagnostic concentrations; and focus monitoring on areas with high adoption rates, such as the Ebro basin in Spain. CONCLUSION There are no signs of field resistance of S. nonagrioides to the Cry1Ab protein of MON 810 maize. Specific recommendations for improvement are provided, based on the knowledge and experience accumulated through the implementation of this unique EU-wide harmonized plan. © 2017 Society of Chemical Industry.
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Affiliation(s)
- Gema P Farinós
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Pedro Hernández-Crespo
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Félix Ortego
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
| | - Pedro Castañera
- Department of Environmental Biology, Centro de Investigaciones Biológicas, CSIC, Madrid, Spain
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9
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Molecular characterization of indigenous Bacillus thuringiensis strains isolated from Kashmir valley. 3 Biotech 2017; 7:143. [PMID: 28597156 DOI: 10.1007/s13205-017-0756-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 01/30/2017] [Indexed: 10/19/2022] Open
Abstract
Bacillus thuringiensis (Bt) being an eco-friendly bioinsecticide is effectively used in pest management strategies and, therefore, isolation and identification of new strains effective against a broad range of target pests is important. In the present study, new indigenous B. thuringiensis strains were isolated and investigated so that these could be used as an alternative and/or support the current commercial strains/cry proteins in use. For this, 159 samples including soil, leaf and spider webs were collected from ten districts of Kashmir valley (India). Of 1447 bacterial strains screened, 68 Bt strains were identified with 4 types of crystalline inclusions. Crystal morphology ranking among the Bt strains was spherical (69.11%) > spore attached (8.82%) > rod (5.88%) = bipyramidal (5.88%) > spherical plus rod (4.41%) > spherical plus bipyramidal (2.94%) = cuboidal (2.94%). SDS-PAGE investigation of the spore-crystal mixture demonstrated Bt strains contained proteins of various molecular weights ranging from 150 to 28 kDa. Insecticidal activity of the 68 indigenous Bt strains against Spodoptera litura neonates showed that Bt strain SWK1 strain had the highest mortality. Lepidopteron active genes (cry1, cry2Ab, cry2Ab) were present in six Bt strains. Further, analysis of a full-length cry2A gene (~1.9 kb) by PCR-RFLP in strain SWK1 revealed that it was a new cry2A gene in Bt strain SWK1 and was named as cry2Al1 (GenBank Accession No. KJ149819.1) using the Bt toxin nomenclature ( http://www.btnomenclature.info ). Insect bioassays with neonate larvae of S. litura and H. armigera showed that the purified Cry2Al1 is toxic to S. litura with LC50 2.448 µg/ml and H. armigera with LC50 3.374 µg/ml, respectively. However, it did not produce any mortality in third instar larvae of Aedes aegypti, Culex quinquefasciatus and Anopheles stephensi larvae/pupae insects (100 µg/ml) at 28 ± 2 °C and 75 to 85% relative humidity under a photoperiod of 14L:10D.
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10
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Cloning, characterization and expression of a novel haplotype cry2A-type gene from Bacillus thuringiensis strain SWK1, native to Himalayan valley Kashmir. J Invertebr Pathol 2016; 136:1-6. [DOI: 10.1016/j.jip.2016.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/17/2016] [Accepted: 02/18/2016] [Indexed: 11/21/2022]
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11
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Von Kanel MB, Gore J, Catchot A, Cook D, Musser F, Caprio M. Influence of Dual-Bt Protein Corn on Bollworm, Helicoverpa zea (Boddie), Survivorship on Bollgard II Cotton. JOURNAL OF ECONOMIC ENTOMOLOGY 2016; 109:860-864. [PMID: 26809264 PMCID: PMC4821456 DOI: 10.1093/jee/tov401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 12/16/2015] [Indexed: 06/05/2023]
Abstract
Similar Cry proteins are expressed in both Bt corn, Zea mays L., and cotton, Gossypium hirsutum (L.), commercial production systems. At least one generation of corn earworm, Helicoverpa zea (Boddie), completes development on field corn in the Mid-South before dispersing across the landscape into other crop hosts like cotton. A concern is that Bt corn hybrids may result in selection for H. zea populations with a higher probability of causing damage to Bt cotton. The objective of this study was to determine the susceptibility of H. zea offspring from moths that developed on non-Bt and VT Triple Pro (VT3 PRO) field corn to lyophilized Bollgard II cotton tissue expressing Cry1Ac and Cry2Ab. Offspring of individuals reared on VT3 PRO expressing Cry1A.105 and Cry2Ab had a significantly higher LC50 two out of the three years this study was conducted. Excess larvae were placed on artificial diet and allowed to pupate to determine if there were any inheritable fitness costs associated with parental development on VT3 PRO corn. Offspring resulting from males collected from VT3 PRO had significantly lower pupal weight and longer pupal duration compared with offspring of individuals collected from non-Bt corn. However, offspring from females collected from VT3 PRO were not different from non-Bt offspring. Paternal influence on offspring in insects is not commonly observed, but illustrates the side effects of development on a transgenic plant expressing less than a high dose, 25 times the concentration needed to kill susceptible larvae.
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Affiliation(s)
- M. B. Von Kanel
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, 100 Old Hwy 12, Mississippi State, MS 39762 (; ; ; )
| | - J. Gore
- Delta Research and Extension Center, Mississippi State University, P.O. Box 197, Stoneville, MS 38776 (; ), and
| | - A. Catchot
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, 100 Old Hwy 12, Mississippi State, MS 39762 (; ; ; )
| | - D. Cook
- Delta Research and Extension Center, Mississippi State University, P.O. Box 197, Stoneville, MS 38776 (; ), and
| | - F. Musser
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, 100 Old Hwy 12, Mississippi State, MS 39762 (; ; ; )
| | - M. Caprio
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, 100 Old Hwy 12, Mississippi State, MS 39762 (; ; ; )
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12
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Nair R, Kamath SP, Mohan KS, Head G, Sumerford DV. Inheritance of field-relevant resistance to the Bacillus thuringiensis protein Cry1Ac in Pectinophora gossypiella (Lepidoptera: Gelechiidae) collected from India. PEST MANAGEMENT SCIENCE 2016; 72:558-565. [PMID: 25864528 DOI: 10.1002/ps.4023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 04/02/2015] [Accepted: 04/02/2015] [Indexed: 05/29/2023]
Abstract
BACKGROUND The inheritance and phenotypic expression of resistance to Bacillus thuringiensis Cry1Ac insecticidal protein were studied in selected populations of pink bollworm, Pectinophora gossypiella (Saunders), that were collected from Bollgard cotton in India. The individual populations in the pool were Cry1Ac resistant and sourced from Cry1Ac-containing Bt cotton (Bollgard) hybrids in 2010. RESULTS Laboratory selection on diet with 1.0 µg Cry1Ac protein mL(-1) increased the percentage reaching at least third instar from 7% in the F3 generation to 94% in the F15 generation, a 257-fold increase in median lethal concentration relative to the susceptible strain. Analysis of reciprocal genetic crosses between the Cry1Ac-resistant strain NKJ and a susceptible laboratory strain MRC showed a dominance of 0.22, indicating that the inheritance of Cry1Ac resistance is partially recessive at Cry1Ac concentrations comparable with those in Bollgard. Analyses of backcrosses of F1 hybrid moths with NKJ and MRC indicated that resistance is autosomal. The Cry1Ac-resistant strain exhibited little or no cross-resistance to the Cry2Ab2 protein. CONCLUSION This is the first study of the dominance of Cry1Ac field resistance in P. gossypiella. The results provide the basis for refining resistance management strategies for Bt cotton.
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Affiliation(s)
- Rupa Nair
- Monsanto Research Centre, Bangalore, Karnataka, India
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13
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Andow DA, Pueppke SG, Schaafsma AW, Gassmann AJ, Sappington TW, Meinke LJ, Mitchell PD, Hurley TM, Hellmich RL, Porter RP. Early Detection and Mitigation of Resistance to Bt Maize by Western Corn Rootworm (Coleoptera: Chrysomelidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2016; 109:1-12. [PMID: 26362989 DOI: 10.1093/jee/tov238] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/17/2015] [Indexed: 05/25/2023]
Abstract
Transgenic Bt maize that produces less than a high-dose has been widely adopted and presents considerable insect resistance management (IRM) challenges. Western corn rootworm, Diabrotica virgifera virgifera LeConte, has rapidly evolved resistance to Bt maize in the field, leading to local loss of efficacy for some corn rootworm Bt maize events. Documenting and responding to this resistance has been complicated by a lack of rapid diagnostic bioassays and by regulatory triggers that hinder timely and effective management responses. These failures are of great concern to the scientific and agricultural community. Specific challenges posed by western corn rootworm resistance to Bt maize, and more general concerns around Bt crops that produce less than a high-dose of Bt toxin, have caused uncertainty around current IRM protocols. More than 15 years of experience with IRM has shown that high-dose and refuge-based IRM is not applicable to Bt crops that produce less than a high-dose. Adaptive IRM approaches and pro-active, integrated IRM-pest management strategies are needed and should be in place before release of new technologies that produce less than a high-dose. We suggest changes in IRM strategies to preserve the utility of corn rootworm Bt maize by 1) targeting local resistance management earlier in the sequence of responses to resistance and 2) developing area-wide criteria to address widespread economic losses. We also favor consideration of policies and programs to counteract economic forces that are contributing to rapid resistance evolution.
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Affiliation(s)
- David A Andow
- Department of Entomology, University of Minnesota, St. Paul, MN 55108 ,
| | - Steven G Pueppke
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Arthur W Schaafsma
- University of Guelph Ridgetown Campus, Ridgetown, Ontario, Canada N0P 2C0
| | | | | | - Lance J Meinke
- Department of Entomology, University of Nebraska, Lincoln, NE 68583
| | - Paul D Mitchell
- Department of Agricultural and Applied Economics, University of Wisconsin, Madison, WI 53706
| | - Terrance M Hurley
- Department of Applied Economics, University of Minnesota, St. Paul, MN 55108 , and
| | - Richard L Hellmich
- USDA-ARS, Corn Insects & Crop Genetics Research Unit, Ames, IA 50011 (; )
| | - R Pat Porter
- Texas A&M Agrilife Research and Extension Center, Lubbock, TX 79403
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14
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Burkness EC, Cira TM, Moser SE, Hutchison WD. Bt Maize Seed Mixtures for Helicoverpa zea (Lepidoptera: Noctuidae): Larval Movement, Development, and Survival on Non-transgenic Maize. JOURNAL OF ECONOMIC ENTOMOLOGY 2015; 108:2761-2769. [PMID: 26318006 DOI: 10.1093/jee/tov253] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/06/2015] [Indexed: 06/04/2023]
Abstract
In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins-Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2-16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts.
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Affiliation(s)
- Eric C Burkness
- Department of Entomology, University of Minnesota, 1980 Folwell Avenue, St. Paul, MN 55108-6125.
| | - T M Cira
- Department of Entomology, University of Minnesota, 1980 Folwell Avenue, St. Paul, MN 55108-6125
| | - S E Moser
- DuPont Pioneer, 7250 NW 62nd Ave., Johnston, IA 50131
| | - W D Hutchison
- Department of Entomology, University of Minnesota, 1980 Folwell Avenue, St. Paul, MN 55108-6125
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15
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Resistance to Bacillus thuringiensis Toxin Cry2Ab in Trichoplusia ni Is Conferred by a Novel Genetic Mechanism. Appl Environ Microbiol 2015; 81:5184-95. [PMID: 26025894 DOI: 10.1128/aem.00593-15] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 05/18/2015] [Indexed: 01/06/2023] Open
Abstract
The resistance to the Bacillus thuringiensis (Bt) toxin Cry2Ab in a greenhouse-originated Trichoplusia ni strain resistant to both Bt toxins Cry1Ac and Cry2Ab was characterized. Biological assays determined that the Cry2Ab resistance in the T. ni strain was a monogenic recessive trait independent of Cry1Ac resistance, and there existed no significant cross-resistance between Cry1Ac and Cry2Ab in T. ni. From the dual-toxin-resistant T. ni strain, a strain resistant to Cry2Ab only was isolated, and the Cry2Ab resistance trait was introgressed into a susceptible laboratory strain to facilitate comparative analysis of the Cry2Ab resistance with the susceptible T. ni strain. Results from biochemical analysis showed no significant difference between the Cry2Ab-resistant and -susceptible T. ni larvae in midgut proteases, including caseinolytic proteolytic activity and zymogram profile and serine protease activities, in midgut aminopeptidase and alkaline phosphatase activity, and in midgut esterases and hemolymph plasma melanization activity. For analysis of genetic linkage of Cry2Ab resistance with potential Cry toxin receptor genes, molecular markers for the midgut cadherin, alkaline phosphatase (ALP), and aminopeptidase N (APN) genes were identified between the original greenhouse-derived dual-toxin-resistant and the susceptible laboratory T. ni strains. Genetic linkage analysis showed that the Cry2Ab resistance in T. ni was not genetically associated with the midgut genes coding for the cadherin, ALP, and 6 APNs (APN1 to APN6) nor associated with the ABC transporter gene ABCC2. Therefore, the Cry2Ab resistance in T. ni is conferred by a novel but unknown genetic mechanism.
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16
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Wangila DS, Gassmann AJ, Petzold-Maxwell JL, French BW, Meinke LJ. Susceptibility of Nebraska Western Corn Rootworm (Coleoptera: Chrysomelidae) Populations to Bt Corn Events. JOURNAL OF ECONOMIC ENTOMOLOGY 2015; 108:742-51. [PMID: 26470186 DOI: 10.1093/jee/tou063] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 12/03/2014] [Indexed: 05/16/2023]
Abstract
Transgenic plants have been widely adopted by growers to manage the western corn rootworm, Diabrotica virgifera virgifera LeConte, in field corn. Because of reduced efficacy in some Nebraska fields after repeated use of Cry3Bb1-expressing hybrids, single plant bioassays were conducted in 2012 and 2013 to characterize the susceptibility of western corn rootworm populations to the rootworm-active proteins Cry3Bb1, mCry3A, and Cry34/35Ab1. Results demonstrate that there are heritable differences in susceptibility of Nebraska western corn rootworm populations to rootworm-active Bt traits. Proportional survival and corrected survival data coupled with field histories collectively support the conclusion that a level of field resistance to Cry3Bb1 has evolved in some Nebraska populations in response to selection pressure and that cross-resistance exists between Cry3Bb1 and mCry3A. There was no apparent cross-resistance between Cry34/35Ab1 and either Cry3Bb1 or mCry3A. The potential implications of these results on current and future corn rootworm management strategies are discussed.
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Affiliation(s)
- David S Wangila
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE 68583
| | - Aaron J Gassmann
- Department of Entomology, Iowa State University, 18 Insectary, Ames, IA 50011
| | - Jennifer L Petzold-Maxwell
- Department of Entomology, Iowa State University, 18 Insectary, Ames, IA 50011. Current address: Department of Biology, 100 Wartburg Blvd., Wartburg College, Waverly, IA 50677
| | - B Wade French
- North Central Agricultural Research Laboratory, USDA-ARS, Brookings, SD 57006
| | - Lance J Meinke
- Department of Entomology, University of Nebraska-Lincoln, Lincoln, NE 68583. Corresponding author, e-mail:
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17
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Resistance of Trichoplusia ni populations selected by Bacillus thuringiensis sprays to cotton plants expressing pyramided Bacillus thuringiensis toxins Cry1Ac and Cry2Ab. Appl Environ Microbiol 2014; 81:1884-90. [PMID: 25480752 DOI: 10.1128/aem.03382-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Two populations of Trichoplusia ni that had developed resistance to Bacillus thuringiensis sprays (Bt sprays) in commercial greenhouse vegetable production were tested for resistance to Bt cotton (BollGard II) plants expressing pyramided Cry1Ac and Cry2Ab. The T. ni colonies resistant to Bacillus thuringiensis serovar kurstaki formulations were not only resistant to the Bt toxin Cry1Ac, as previously reported, but also had a high frequency of Cry2Ab-resistant alleles, exhibiting ca. 20% survival on BollGard II foliage. BollGard II-resistant T. ni strains were established by selection with BollGard II foliage to further remove Cry2Ab-sensitive alleles in the T. ni populations. The BollGard II-resistant strains showed incomplete resistance to BollGard II, with adjusted survival values of 0.50 to 0.78 after 7 days. The resistance to the dual-toxin cotton plants was conferred by two genetically independent resistance mechanisms: one to Cry1Ac and one to Cry2Ab. The 50% lethal concentration of Cry2Ab for the resistant strain was at least 1,467-fold that for the susceptible T. ni strain. The resistance to Cry2Ab in resistant T. ni was an autosomally inherited, incompletely recessive monogenic trait. Results from this study indicate that insect populations under selection by Bt sprays in agriculture can be resistant to multiple Bt toxins and may potentially confer resistance to multitoxin Bt crops.
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18
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Huang F, Qureshi JA, Meagher RL, Reisig DD, Head GP, Andow DA, Ni X, Kerns D, Buntin GD, Niu Y, Yang F, Dangal V. Cry1F resistance in fall armyworm Spodoptera frugiperda: single gene versus pyramided Bt maize. PLoS One 2014; 9:e112958. [PMID: 25401494 PMCID: PMC4234506 DOI: 10.1371/journal.pone.0112958] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 10/16/2014] [Indexed: 11/24/2022] Open
Abstract
Evolution of insect resistance to transgenic crops containing Bacillus thuringiensis (Bt) genes is a serious threat to the sustainability of this technology. However, field resistance related to the reduced efficacy of Bt maize has not been documented in any lepidopteran pest in the mainland U.S. after 18 years of intensive Bt maize planting. Here we report compelling evidence of field resistance in the fall armyworm, Spodoptera frugiperda (J.E. Smith), to Cry1F maize (TC 3507) in the southeastern region of the U.S. An F2 screen showed a surprisingly high (0.293) Cry1F resistance allele frequency in a population collected in 2011 from non-Bt maize in south Florida. Field populations from non-Bt maize in 2012-2013 exhibited 18.8-fold to >85.4-fold resistance to purified Cry1F protein and those collected from unexpectedly damaged Bt maize plants at several locations in Florida and North Carolina had >85.4-fold resistance. In addition, reduced efficacy and control failure of Cry1F maize against natural populations of S. frugiperda were documented in field trials using Cry1F-based and pyramided Bt maize products in south Florida. The Cry1F-resistant S. frugiperda also showed a low level of cross-resistance to Cry1A.105 and related maize products, but not to Cry2Ab2 or Vip3A. The occurrence of Cry1F resistance in the U.S. mainland populations of S. frugiperda likely represents migration of insects from Puerto Rico, indicating the great challenges faced in achieving effective resistance management for long-distance migratory pests like S. frugiperda.
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Affiliation(s)
- Fangneng Huang
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America
| | - Jawwad A. Qureshi
- Department of Entomology and Nematology, University of Florida, Institute of Food and Agricultural Sciences, Southwest Florida Research and Education Center, Immokalee, Florida, United States of America
| | - Robert L. Meagher
- Insect Behavior and Biocontrol Unit, USDA-ARS CMAVE, Gainesville, Florida, United States of America
| | - Dominic D. Reisig
- Department of Entomology, North Carolina State University, Vernon G. James Research and Extension Center, Plymouth, North Carolina, United States of America
| | - Graham P. Head
- Monsanto Company, St. Louis, Missouri, United States of America
| | - David A. Andow
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Xinzi Ni
- USDA, Agricultural Research Service, Crop Genetics and Breeding Research Unit, Tifton, Georgia, United States of America
| | - David Kerns
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America
| | - G. David Buntin
- UGA-Griffin Campus, Department of Entomology, the University of Georgia, Griffin, Georgia, United States of America
| | - Ying Niu
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America
| | - Fei Yang
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America
| | - Vikash Dangal
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, United States of America
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19
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Park Y, González-Martínez RM, Navarro-Cerrillo G, Chakroun M, Kim Y, Ziarsolo P, Blanca J, Cañizares J, Ferré J, Herrero S. ABCC transporters mediate insect resistance to multiple Bt toxins revealed by bulk segregant analysis. BMC Biol 2014; 12:46. [PMID: 24912445 PMCID: PMC4071345 DOI: 10.1186/1741-7007-12-46] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/02/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Relatively 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. RESULTS We 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. CONCLUSIONS The 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.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Salvador Herrero
- Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain.
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