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Liu L, Bulla LA. Commentary: Analyzing invertebrate bitopic cadherin G protein-coupled receptors that bind Cry toxins of Bacillus thuringiensis. Comp Biochem Physiol B Biochem Mol Biol 2024; 272:110963. [PMID: 38431088 DOI: 10.1016/j.cbpb.2024.110963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/05/2024]
Affiliation(s)
- Li Liu
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX 75083, USA.
| | - Lee A Bulla
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, TX 75083, USA.
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Chung T, Salazar A, Harm G, Johler S, Carroll LM, Kovac J. Comparison of the performance of multiple whole-genome sequence-based tools for the identification of Bacillus cereus sensu stricto biovar Thuringiensis. Appl Environ Microbiol 2024; 90:e0177823. [PMID: 38470126 PMCID: PMC11026089 DOI: 10.1128/aem.01778-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Accepted: 02/19/2024] [Indexed: 03/13/2024] Open
Abstract
The Bacillus cereus sensu stricto (s.s.) species comprises strains of biovar Thuringiensis (Bt) known for their bioinsecticidal activity, as well as strains with foodborne pathogenic potential. Bt strains are identified (i) based on the production of insecticidal crystal proteins, also known as Bt toxins, or (ii) based on the presence of cry, cyt, and vip genes, which encode Bt toxins. Multiple bioinformatics tools have been developed for the detection of crystal protein-encoding genes based on whole-genome sequencing (WGS) data. However, the performance of these tools is yet to be evaluated using phenotypic data. Thus, the goal of this study was to assess the performance of four bioinformatics tools for the detection of crystal protein-encoding genes. The accuracy of sequence-based identification of Bt was determined in reference to phenotypic microscope-based screening for the production of crystal proteins. A total of 58 diverse B. cereus sensu lato strains isolated from clinical, food, environmental, and commercial biopesticide products underwent WGS. Isolates were examined for crystal protein production using phase contrast microscopy. Crystal protein-encoding genes were detected using BtToxin_Digger, BTyper3, IDOPS (identification of pesticidal sequences), and Cry_processor. Out of 58 isolates, the phenotypic production of crystal proteins was confirmed for 18 isolates. Specificity and sensitivity of Bt identification based on sequences were 0.85 and 0.94 for BtToxin_Digger, 0.97 and 0.89 for BTyper3, 0.95 and 0.94 for IDOPS, and 0.88 and 1.00 for Cry_processor, respectively. Cry_processor predicted crystal protein production with the highest specificity, and BtToxin_Digger and IDOPS predicted crystal protein production with the highest sensitivity. Three out of four tested bioinformatics tools performed well overall, with IDOPS achieving high sensitivity and specificity (>0.90).IMPORTANCEStrains of Bacillus cereus sensu stricto (s.s.) biovar Thuringiensis (Bt) are used as organic biopesticides. Bt is differentiated from the foodborne pathogen Bacillus cereus s.s. by the production of insecticidal crystal proteins. Thus, reliable genomic identification of biovar Thuringiensis is necessary to ensure food safety and facilitate risk assessment. This study assessed the accuracy of whole-genome sequencing (WGS)-based identification of Bt compared to phenotypic microscopy-based screening for crystal protein production. Multiple bioinformatics tools were compared to assess their performance in predicting crystal protein production. Among them, identification of pesticidal sequences performed best overall at WGS-based Bt identification.
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Affiliation(s)
- Taejung Chung
- Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Abimel Salazar
- Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Grant Harm
- Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Sophia Johler
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Laura M. Carroll
- Department of Clinical Microbiology, SciLifeLab, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- Integrated Science Lab (IceLab), Umeå University, Umeå, Sweden
| | - Jasna Kovac
- Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania, USA
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Wang Y, Yao Y, Zhang Y, Qian X, Guo D, Coates BS. A chromosome-level genome assembly of the soybean pod borer: insights into larval transcriptional response to transgenic soybean expressing the pesticidal Cry1Ac protein. BMC Genomics 2024; 25:355. [PMID: 38594617 PMCID: PMC11005160 DOI: 10.1186/s12864-024-10216-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 03/12/2024] [Indexed: 04/11/2024] Open
Abstract
BACKGROUND Genetically modified (GM) crop plants with transgenic expression of Bacillus thuringiensis (Bt) pesticidal proteins are used to manage feeding damage by pest insects. The durability of this technology is threatened by the selection for resistance in pest populations. The molecular mechanism(s) involved in insect physiological response or evolution of resistance to Bt is not fully understood. RESULTS To investigate the response of a susceptible target insect to Bt, the soybean pod borer, Leguminivora glycinivorella (Lepidoptera: Tortricidae), was exposed to soybean, Glycine max, expressing Cry1Ac pesticidal protein or the non-transgenic parental cultivar. Assessment of larval changes in gene expression was facilitated by a third-generation sequenced and scaffolded chromosome-level assembly of the L. glycinivorella genome (657.4 Mb; 27 autosomes + Z chromosome), and subsequent structural annotation of 18,197 RefSeq gene models encoding 23,735 putative mRNA transcripts. Exposure of L. glycinivorella larvae to transgenic Cry1Ac G. max resulted in prediction of significant differential gene expression for 204 gene models (64 up- and 140 down-regulated) and differential splicing among isoforms for 10 genes compared to unexposed cohorts. Differentially expressed genes (DEGs) included putative peritrophic membrane constituents, orthologs of Bt receptor-encoding genes previously linked or associated with Bt resistance, and those involved in stress responses. Putative functional Gene Ontology (GO) annotations assigned to DEGs were significantly enriched for 36 categories at GO level 2, respectively. Most significantly enriched cellular component (CC), biological process (BP), and molecular function (MF) categories corresponded to vacuolar and microbody, transport and metabolic processes, and binding and reductase activities. The DEGs in enriched GO categories were biased for those that were down-regulated (≥ 0.783), with only MF categories GTPase and iron binding activities were bias for up-regulation genes. CONCLUSIONS This study provides insights into pathways and processes involved larval response to Bt intoxication, which may inform future unbiased investigations into mechanisms of resistance that show no evidence of alteration in midgut receptors.
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Affiliation(s)
- Yangzhou Wang
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Yao Yao
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Yunyue Zhang
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Xueyan Qian
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China
| | - Dongquan Guo
- Jilin Academy of Agricultural Sciences, Changchun, 130033, China.
| | - Brad S Coates
- United States Department of Agriculture, Agricultural Research Service, Corn Insects & Crop Genetics Research Unit, 532 Science II, 2310 Pammel Dr., Ames, IA, 50011, USA.
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Takahashi H, Asakura M, Ide T, Hayakawa T. Mutational analysis of the transmembrane α4-helix of Bacillus thuringiensis mosquito-larvicidal Cry4Aa toxin. Curr Microbiol 2024; 81:80. [PMID: 38281302 PMCID: PMC10822788 DOI: 10.1007/s00284-023-03602-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/26/2023] [Indexed: 01/30/2024]
Abstract
Cry4Aa, produced by Bacillus thuringiensis subsp. israelensis, exhibits specific toxicity to larvae of medically important mosquito genera. Cry4Aa functions as a pore-forming toxin, and a helical hairpin (α4-loop-α5) of domain I is believed to be the transmembrane domain that forms toxin pores. Pore formation is considered to be a central mode of Cry4Aa action, but the relationship between pore formation and toxicity is poorly understood. In the present study, we constructed Cry4Aa mutants in which each polar amino acid residues within the transmembrane α4 helix was replaced with glutamic acid. Bioassays using Culex pipiens mosquito larvae and subsequent ion permeability measurements using symmetric KCl solution revealed an apparent correlation between toxicity and toxin pore conductance for most of the Cry4Aa mutants. In contrast, the Cry4Aa mutant H178E was a clear exception, almost losing its toxicity but still exhibiting a moderately high conductivity of about 60% of the wild-type. Furthermore, the conductance of the pore formed by the N190E mutant (about 50% of the wild-type) was close to that of H178E, but the toxicity was significantly higher than that of H178E. Ion selectivity measurements using asymmetric KCl solution revealed a significant decrease in cation selectivity of toxin pores formed by H178E compared to N190E. Our data suggest that the toxicity of Cry4Aa is primarily pore related. The formation of toxin pores that are highly ion-permeable and also highly cation-selective may enhance the influx of cations and water into the target cell, thereby facilitating the eventual death of mosquito larvae.
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Affiliation(s)
- Hirokazu Takahashi
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, 3-1-1 Tsushima-Naka, Kita-Ku, Okayama, 700-8530, Japan
| | - Mami Asakura
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, 3-1-1 Tsushima-Naka, Kita-Ku, Okayama, 700-8530, Japan
| | - Toru Ide
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, 3-1-1 Tsushima-Naka, Kita-Ku, Okayama, 700-8530, Japan
| | - Tohru Hayakawa
- Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, 3-1-1 Tsushima-Naka, Kita-Ku, Okayama, 700-8530, Japan.
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He X, Yang Y, Soberón M, Bravo A, Zhang L, Zhang J, Wang Z. Bacillus thuringiensis Cry9Aa Insecticidal Protein Domain I Helices α3 and α4 Are Two Core Regions Involved in Oligomerization and Toxicity. J Agric Food Chem 2024; 72:1321-1329. [PMID: 38175929 DOI: 10.1021/acs.jafc.3c08070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Bacillus thuringiensis Cry9 proteins show high insecticidal activity against different lepidopteran pests. Cry9 could be a valuable alternative to Cry1 proteins because it showed a synergistic effect with no cross-resistance. However, the pore-formation region of the Cry9 proteins is still unclear. In this study, nine mutations of certain Cry9Aa helices α3 and α4 residues resulted in a complete loss of insecticidal activity against the rice pest Chilo suppressalis; however, the protein stability and receptor binding ability of these mutants were not affected. Among these mutants, Cry9Aa-D121R, Cry9Aa-D125R, Cry9Aa-D163R, Cry9Aa-E165R, and Cry9Aa-D167R are unable to form oligomers in vitro, while the oligomers formed by Cry9Aa-R156D, Cry9Aa-R158D, and Cry9Aa-R160D are unstable and failed to insert into the membrane. These data confirmed that helices α3 and α4 of Cry9Aa are involved in oligomerization, membrane insertion, and toxicity. The knowledge of Cry9 pore-forming action may promote its application as an alternative to Cry1 insecticidal proteins.
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Affiliation(s)
- Xiang He
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui Province 230036, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yanchao Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Apdo. Postal 510-3, Morelos 62250, Mexico
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Apdo. Postal 510-3, Morelos 62250, Mexico
| | - Lihong Zhang
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui Province 230036, China
| | - Jie Zhang
- Anhui Province Engineering Laboratory for Green Pesticide Development and Application, School of Plant Protection, Anhui Agricultural University, Hefei, Anhui Province 230036, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zeyu Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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Gatica-Arias A, Villalta-Villalobos J, Pereira LF. Coffee Cell Suspensions as a Platform for Transient Gene Expression Analysis. Methods Mol Biol 2024; 2788:209-226. [PMID: 38656516 DOI: 10.1007/978-1-0716-3782-1_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Coffea arabica L. is a crucial crop globally, but its genetic homogeneity leads to its susceptibility to diseases and pests like the coffee berry borer (CBB). Chemical and cultural control methods are difficult due to the majority of the CBB life cycle taking place inside coffee beans. One potential solution is the use of the gene cyt1Aa from Bacillus thuringiensis as a biological insecticide. To validate candidate genes against CBB, a simple, rapid, and efficient transient expression system is necessary. This study uses cell suspensions as a platform for expressing the cyt1Aa gene in the coffee genome (C. arabica L. var. Catuaí) to control CBB. The Agrobacterium tumefaciens strain GV3101::pMP90 containing the bar and cyt1Aa genes are used to genetically transform embryogenic cell suspensions. PCR amplification of the cyt1Aa gene is observed 2, 5, and 7 weeks after infection. This chapter describes a protocol that can be used for the development of resistant varieties against biotic and abiotic stresses and CRISPR/Cas9-mediated genome editing.
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Affiliation(s)
- Andrés Gatica-Arias
- School of Biology, University of Costa Rica, San José, Costa Rica.
- School of Biology and Programa de Posgrado en Biología, University of Costa Rica, San José, Costa Rica.
| | - Jimmy Villalta-Villalobos
- School of Biology, University of Costa Rica, San José, Costa Rica
- School of Biology and Programa de Posgrado en Biología, University of Costa Rica, San José, Costa Rica
| | - Luiz Filipe Pereira
- Rural Development Institute of Parana (IAPAR-EMATER), Londrina, Paraná, Brazil
- Empresa Brasileira de Pesquisa Agropecuária, Embrapa Café, Brasília, Brazil
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Fonseca SS, Santos ALZ, Pinto CPG, Marques L, Santos AC, Bing J, Nowatzki T, Sethi A, Rossi GD. A soybean trypsin inhibitor reduces the resistance to transgenic maize in a population of Spodoptera frugiperda (Lepidoptera: Noctuidae). J Econ Entomol 2023; 116:2146-2153. [PMID: 37816687 PMCID: PMC10711543 DOI: 10.1093/jee/toad188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/14/2023] [Accepted: 09/27/2023] [Indexed: 10/12/2023]
Abstract
Lepidopteran pests have been successfully managed by the adoption of insect resistant transgenic plants expressing Cry and/or Vip insecticidal proteins derived from Bacillus thuringiensis (Bt plants). Among such pests, Spodoptera frugiperda (Smith, 1797) (Lepidoptera: Noctuidae) is highlighted for its destructive potential in maize crops and for cases of field-evolved resistance to Bt plants. Cry insecticidal proteins expressed in Bt plants are known for their interaction with insect midgut receptors and subsequent midgut cell disruption that leads to target pest death. In the midgut of lepidopteran larval pests such as S. frugiperda, serine proteases are important in dietary protein digestion and activation or degradation of insecticidal proteins. This work was conducted to evaluate if the use of a soybean trypsin inhibitor (SBTI) could disrupt the development of a Bt-susceptible and a Bt-resistant population of S. frugiperda ingesting Bt (expressing Cry1F, Cry1A.105, and Cry2Ab2 Cry proteins) and non-Bt maize plants. The SBTI was produced and purified using recombinant expression in E. coli followed by purification in Ni-Sepharose. Bioassays using non-Bt maize leaves indicated that the development of susceptible and resistant populations of S. frugiperda was not influenced by the ingestion of SBTI. However, when the resistant population consumed Bt maize plants amended with SBTI, high mortality along with a reduction in larval weight and reduced activity of digestive trypsins were observed. Although the mode of action was not elucidated, it is possible that the consumption of SBTI increased susceptibility to Bt maize in the resistant population of S. frugiperda.
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Affiliation(s)
- Sandy Sousa Fonseca
- São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal, SP 14884-900, Brazil
| | - Ana Leticia Zero Santos
- São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal, SP 14884-900, Brazil
| | - Ciro Pedro Guidotti Pinto
- São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal, SP 14884-900, Brazil
| | - Luiz Marques
- Corteva Agriscience, Avenida Tamboré, 267, Alphaville, Barueri, SP 06460-000, Brazil
| | - Antonio Cesar Santos
- Corteva Agriscience, Avenida Tamboré, 267, Alphaville, Barueri, SP 06460-000, Brazil
| | - James Bing
- Corteva Agriscience, 7000 NW 62nd Avenue, Johnston, IA 50131, USA
| | - Timothy Nowatzki
- Corteva Agriscience, 7000 NW 62nd Avenue, Johnston, IA 50131, USA
| | - Amit Sethi
- Corteva Agriscience, 7000 NW 62nd Avenue, Johnston, IA 50131, USA
| | - Guilherme Duarte Rossi
- São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal, SP 14884-900, Brazil
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Torres J, Surya W, Boonserm P. Channel Formation in Cry Toxins: An Alphafold-2 Perspective. Int J Mol Sci 2023; 24:16809. [PMID: 38069132 PMCID: PMC10705909 DOI: 10.3390/ijms242316809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 11/23/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
Bacillus thuringiensis (Bt) strains produce pore-forming toxins (PFTs) that attack insect pests. Information for pre-pore and pore structures of some of these Bt toxins is available. However, for the three-domain (I-III) crystal (Cry) toxins, the most used Bt toxins in pest control, this crucial information is still missing. In these Cry toxins, biochemical data have shown that 7-helix domain I is involved in insertion in membranes, oligomerization and formation of a channel lined mainly by helix α4, whereas helices α1 to α3 seem to have a dynamic role during insertion. In the case of Cry1Aa, toxic against Manduca sexta larvae, a tetrameric oligomer seems to precede membrane insertion. Given the experimental difficulty in the elucidation of the membrane insertion steps, we used Alphafold-2 (AF2) to shed light on possible oligomeric structural intermediates in the membrane insertion of this toxin. AF2 very accurately (<1 Å RMSD) predicted the crystal monomeric and trimeric structures of Cry1Aa and Cry4Ba. The prediction of a tetramer of Cry1Aa, but not Cry4Ba, produced an 'extended model' where domain I helices α3 and α2b form a continuous helix and where hydrophobic helices α1 and α2 cluster at the tip of the bundle. We hypothesize that this represents an intermediate that binds the membrane and precedes α4/α5 hairpin insertion, together with helices α6 and α7. Another Cry1Aa tetrameric model was predicted after deleting helices α1 to α3, where domain I produced a central cavity consistent with an ion channel, lined by polar and charged residues in helix α4. We propose that this second model corresponds to the 'membrane-inserted' structure. AF2 also predicted larger α4/α5 hairpin n-mers (14 ≤n ≤ 17) with high confidence, which formed even larger (~5 nm) pores. The plausibility of these models is discussed in the context of available experimental data and current paradigms.
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Affiliation(s)
- Jaume Torres
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Wahyu Surya
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Panadda Boonserm
- Institute of Molecular Biosciences, Mahidol University, Salaya, Phuttamonthon, Nakhon Pathom 73170, Thailand;
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Berçot MR, Queiroz PRM, Grynberg P, Togawa R, Martins ÉS, Rocha GT, Monnerat RG. Distribution and Genetic Diversity of Genes from Brazilian Bacillus thuringiensis Strains Toxic to Agricultural Insect Pests Revealed by Real-Time PCR. Microb Ecol 2023; 86:2515-2526. [PMID: 37392204 DOI: 10.1007/s00248-023-02255-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 06/06/2023] [Indexed: 07/03/2023]
Abstract
Bacillus thuringiensis is a Gram-positive aerobic bacterium and the most used biopesticide worldwide. Given the importance of B. thuringiensis strain characterization for the development of new bioinsecticides or transgenic events and the identification and classification of new B. thuringiensis genes and strains to understand its distribution and diversity, this work is aimed at creating a gene identification system based on qPCR reactions utilizing core B. thuringiensis genes cry1, cry2, cry3, cry4, cry5, app6, cry7, cry8, cry9, cry10, cry11, vpb1, vpa2, vip3, cyt1, and cyt2 for the characterization of 257 strains of B. thuringiensis. This system was based on the Invertebrate Bacteria Collection from Embrapa Genetic Resources and Biotechnology and analyzed (a) the degree of correlation between the distribution of these strains and the origin of the substrate from which the strain was isolated and (b) between its distribution and geoclimatic conditions. This study made it possible to observe that the cry1, cry2, and vip3A/B genes occur homogeneously in the Brazilian territory, and some genes are found in specific regions. The biggest reservoir of variability is within B. thuringiensis strains in each region, and it is suggested that both geoclimatic conditions and regional crops interfere with the genetic diversity of the B. thuringiensis strains present in the region, and B. thuringiensis strains can constantly exchange genetic information.
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Affiliation(s)
- Marcelo Rodrigues Berçot
- Entompathogenic Bacteria Laboratory, Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB, Av. W5 Norte (Final) Caixa Postal 02372, Brasília, DF-CEP, 70770-917, Brazil
| | | | - Priscila Grynberg
- Bioinformatics Laboratory, Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB, Av. W5 Norte (Final) Caixa Postal 02372, Brasília, DF-CEP, 70770-917, Brazil
| | - Roberto Togawa
- Bioinformatics Laboratory, Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB, Av. W5 Norte (Final) Caixa Postal 02372, Brasília, DF-CEP, 70770-917, Brazil
| | - Érica Soares Martins
- Distrito Federal State Department of Education (SEEDF), SBN Quadra 02 Bloco C, Edifício Phenícia, CEP: 70040-020, Brazil
| | - Gabriela Teodoro Rocha
- Entompathogenic Bacteria Laboratory, Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB, Av. W5 Norte (Final) Caixa Postal 02372, Brasília, DF-CEP, 70770-917, Brazil
| | - Rose Gomes Monnerat
- Entompathogenic Bacteria Laboratory, Embrapa Genetic Resources and Biotechnology, Parque Estação Biológica, PqEB, Av. W5 Norte (Final) Caixa Postal 02372, Brasília, DF-CEP, 70770-917, Brazil
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Carrière Y, Degain B, Unnithan GC, Tabashnik BE. Inheritance and fitness cost of laboratory-selected resistance to Vip3Aa in Helicoverpa zea (Lepidoptera: Noctuidae). J Econ Entomol 2023; 116:1804-1811. [PMID: 37555261 DOI: 10.1093/jee/toad145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/22/2023] [Accepted: 07/10/2023] [Indexed: 08/10/2023]
Abstract
The polyphagous pest Helicoverpa zea (Lepidoptera: Noctuidae) has evolved practical resistance to transgenic corn and cotton producing Cry1 and Cry2 crystal proteins from Bacillus thuringiensis (Bt) in several regions of the United States. However, the Bt vegetative insecticidal protein Vip3Aa produced by Bt corn and cotton remains effective against this pest. To advance knowledge of resistance to Vip3Aa, we selected a strain of H. zea for resistance to Vip3Aa in the laboratory. After 28 generations of continuous selection, the resistance ratio was 267 for the selected strain (GA-R3) relative to a strain not selected with Vip3Aa (GA). Resistance was autosomal and almost completely recessive at a concentration killing all individuals from GA. Declines in resistance in heterogeneous strains containing a mixture of susceptible and resistant individuals reared in the absence of Vip3Aa indicate a fitness cost was associated with resistance. Previously reported cases of laboratory-selected resistance to Vip3Aa in lepidopteran pests often show partially or completely recessive resistance at high concentrations and fitness costs. Abundant refuges of non-Bt host plants can maximize the benefits of such costs for sustaining the efficacy of Vip3Aa against target pests.
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Affiliation(s)
- Yves Carrière
- Department of Entomology, University of Arizona, Tucson, AZ, USA
| | - Ben Degain
- Department of Entomology, University of Arizona, Tucson, AZ, USA
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Chen SWW, Teulon JM, Pellequer JL. Cry11Aa and Cyt1Aa exhibit different structural orders in crystal topography. J Mol Recognit 2023; 36:e3047. [PMID: 37474122 DOI: 10.1002/jmr.3047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/22/2023]
Abstract
Cry11Aa and Cyt1Aa are two pesticidal toxins produced by Bacillus thuringiensis subsp. israelensis. To improve our understanding of the nature of their oligomers in the toxic actions and synergistic effects, we performed the atomic force microscopy to probe the surfaces of their natively grown crystals, and used the L-weight filter to enhance the structural features. By L-weight filtering, molecular sizes of the Cry11Aa and Cyt1Aa monomers obtained are in excellent agreement with the three-dimensional structures determined by x-ray crystallography. Moreover, our results show that the layered feature of a structural element distinguishes the topographic characteristics of Cry11Aa and Cyt1Aa crystals, suggesting that the Cry11Aa toxin has a better chance than Cyt1Aa for multimerization and therefore cooperativeness of the toxic actions.
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Affiliation(s)
- Shu-Wen W Chen
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
- Rue Cyprien Jullin, Vinay, France
| | - Jean-Marie Teulon
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Jean-Luc Pellequer
- Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France
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12
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Morwool P, Dimitriu T, Crickmore N, Raymond B. Group Selection as a Basis for Screening Mutagenized Libraries of Public Goods (Bacillus thuringiensis Cry Toxins). Appl Environ Microbiol 2023; 89:e0051223. [PMID: 37358425 PMCID: PMC10370297 DOI: 10.1128/aem.00512-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 05/26/2023] [Indexed: 06/27/2023] Open
Abstract
The pesticidal toxins of Bacillus thuringiensis (Bt) supply the active proteins for genetically modified insect-resistant crops. There is therefore keen interest in finding new toxins, or improving known toxins, in order to increase the mortality of various targets. The production and screening of large libraries of mutagenized toxins are among the means of identifying improved toxins. Since Cry toxins are public goods, and do not confer advantages to producers in competition, conventional directed evolution approaches cannot be used here. Instead, thousands of individual mutants have to be sequenced and assayed individually, a costly and time-consuming process. In this study, we tested a group selection-based approach that could be used to screen an uncharacterized pool of Cry toxin mutants. This involved selecting for infectivity between subpopulations of Bt clones within metapopulations of infected insects in three rounds of passage. We also tested whether additional mutagenesis from exposure to ethyl methanesulfonate could increase infectivity or supply additional Cry toxin diversity during passage. Sequencing of pools of mutants at the end of selection showed that we could effectively screen out Cry toxin variants that had reduced toxicity with our group selection approach. The addition of extra mutagenesis during passage decreased the efficiency of selection for infectivity and did not produce any additional novel toxin diversity. Toxins with loss-of-function mutations tend to dominate mutagenized libraries, and so a process for screening out these mutants without time-consuming sequencing and characterization steps could be beneficial when applied to larger libraries. IMPORTANCE Insecticidal toxins from the bacterium Bacillus thuringiensis are widely exploited in genetically modified plants. This application creates a demand for novel insecticidal toxins that can be used to better manage resistant pests or control new or recalcitrant target species. An important means of producing novel toxins is via high-throughput mutagenesis and screening of existing toxins, a lengthy and resource-intensive process. This study describes the development and testing of an efficient means of screening a test library of mutagenized insecticidal toxins. Here, we showed that it is possible to screen out loss-of-function mutations with low infectivity within a pool without the need to characterize and sequence each mutant individually. This has the potential to improve the efficiency of processes used to identify novel proteins.
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Affiliation(s)
| | | | - Neil Crickmore
- Department of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Ben Raymond
- University of Exeter, Penryn, United Kingdom
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13
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Wen Z, Conville J, Matthews P, Hootman T, Himes J, Wong S, Huang F, Ni X, Chen JS, Bramlett M. More than 10 years after commercialization, Vip3A-expressing MIR162 remains highly efficacious in controlling major Lepidopteran maize pests: laboratory resistance selection versus field reality. Pestic Biochem Physiol 2023; 192:105385. [PMID: 37105627 DOI: 10.1016/j.pestbp.2023.105385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/24/2023] [Accepted: 03/06/2023] [Indexed: 06/19/2023]
Abstract
MIR162, a maize event that expresses Vip3Aa20 (Vip3A) approved for commercial cultivation around 2010, has been excellent for control of major Lepidopteran pests. However, development of fall armyworm (FAW) resistance to Vip3A is a serious concern. Resistant colonies selected in the laboratory can serve as valuable tools not only for better understanding of Vip3A's mode of action (MOA) and mechanism of resistance (MOR) but also for screening novel leads of new MOA that will help control FAW in case resistance to Vip3A in the field becomes a reality. We selected a Vip3A-resistant FAW strain, FAWVip3AR, by subjecting a FAW founder population containing field genetics to Vip3A exposure. FAWVip3AR had >9800-fold resistance to Vip3A by diet surface overlay bioassays and resistance was stable. Feeding bioassays using detached leaf tissues or whole plants indicated that FAWVip3AR larvae readily fed and completed the full life cycle on Vip3A-expressing MIR162 maize plants and leaf tissues that killed 100% of susceptible larvae. Yet, FAWVip3AR faced at least two challenges. First, FAWVip3AR suffered an apparent disadvantage (incomplete resistance) when feeding on MIR162 in comparison to FAWVip3AR feeding on Vip3A-free isoline AX5707 maize; and second, FAWVip3AR showed a fitness costs in comparison to a Vip3A-susceptible strain when both fed on AX5707. We also demonstrated that, >10 years after commercialization, MIR162 and Vip3A remain highly efficacious against field populations of three major Lepidopteran pests from different geographic locations and FAW strains resistant to other Bacillus thuringiensis (Bt) toxins that are currently on the market.
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Affiliation(s)
- Zhimou Wen
- Syngenta Crop Protection, LLC, 9 Davis Drive, Research Triangle Park, NC 27709, USA.
| | - Jared Conville
- Syngenta Crop Protection, LLC, 9 Davis Drive, Research Triangle Park, NC 27709, USA
| | - Phillip Matthews
- Syngenta Crop Protection, LLC, 9 Davis Drive, Research Triangle Park, NC 27709, USA
| | - Travis Hootman
- Syngenta Crop Protection, LLC, 9 Davis Drive, Research Triangle Park, NC 27709, USA
| | - Jo Himes
- Syngenta Crop Protection, LLC, 9 Davis Drive, Research Triangle Park, NC 27709, USA
| | - Sarah Wong
- Syngenta Crop Protection, LLC, 9 Davis Drive, Research Triangle Park, NC 27709, USA
| | - Fangneng Huang
- Department of Entomology, Louisianan State University AgCenter, Baton Rouge, LA 70803, USA
| | - Xinzhi Ni
- Crop Genetics and Breeding Research Unit, USDA-ARS, Tifton, GA 31793, USA
| | - Jeng Shong Chen
- Syngenta Crop Protection, LLC, 9 Davis Drive, Research Triangle Park, NC 27709, USA
| | - Matthew Bramlett
- Syngenta Crop Protection, LLC, 9 Davis Drive, Research Triangle Park, NC 27709, USA
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14
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Santiago-González JC, Kerns DL, Head GP, Yang F. A Modified F2 Screen for Estimating Cry1Ac and Cry2Ab Resistance Allele Frequencies in Helicoverpa zea (Lepidoptera: Noctuidae). J Econ Entomol 2023; 116:289-296. [PMID: 36610074 DOI: 10.1093/jee/toac181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Indexed: 05/30/2023]
Abstract
Evaluating the frequency of resistance alleles is important for resistance management and sustainable use of transgenic crops that produce insecticidal proteins from Bacillus thuringiensis. Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) is a major crop pest in the United States that has evolved practical resistance to the crystalline (Cry) proteins in Bt corn and cotton. The standard F2 screen for estimating resistance allele frequency does not work well for H. zea because successful single-pair matings are rare. In this study, we developed and implemented a modified F2 screen for H. zea that generates F1 progeny by crossing three laboratory susceptible female moths with one feral male moth instead of single-pair crosses. During 2019-2020, we used this modified method to establish 192 F2 families from 623 matings between susceptible females and feral males from Arkansas, Louisiana, Mississippi, and Tennessee. From each F2 family, we screened 128 neonates against discriminating concentrations of Cry1Ac and Cry2Ab in diet overlay bioassays. Based on these discriminating concentration bioassays, families were considered positive for resistance if at least five larvae survived to second instar, including at least one to third instar. The percentage of positive families was 92.7% for Cry1Ac and 38.5% for Cry2Ab, which yields an estimated resistance allele frequency (with 95% confidence interval) of 0.722 (0.688-0.764) for Cry1Ac and 0.217 (0.179-0.261) for Cry2Ab. The modified F2 screen developed and implemented here may be useful for future resistance monitoring studies of H. zea and other pests.
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Affiliation(s)
| | - David L Kerns
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | | | - Fei Yang
- Department of Entomology, Texas A&M University, College Station, TX, USA
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15
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García M, García-Benítez C, Ortego F, Farinós GP. Monitoring Insect Resistance to Bt Maize in the European Union: Update, Challenges, and Future Prospects. J Econ Entomol 2023; 116:275-288. [PMID: 36610405 PMCID: PMC10125040 DOI: 10.1093/jee/toac154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Indexed: 05/30/2023]
Abstract
Transgenic maize producing the Cry1Ab toxin of Bacillus thuringiensis (Bt maize) was approved for cultivation in the European Union (EU) in 1998 to control the corn borers Sesamia nonagrioides (Lefèbvre) and Ostrinia nubilalis (Hübner). In the EU since then, Cry1Ab is the only Bt toxin produced by Bt maize and Spain is the only country where Bt maize has been planted every year. In 2021, about 100,000 hectares of Bt maize producing Cry1Ab were cultivated in the EU, with Spain accounting for 96% and Portugal 4% of this area. In both countries, Bt maize represented less than 25% of all maize planted in 2021, with a maximum regional adoption of 64% Bt maize in northeastern Spain. Insect resistance management based on the high-dose/refuge strategy has been implemented in the EU since 1998. This has been accompanied by monitoring to enable early detection of resistance. The monitoring data from laboratory bioassays show no decrease in susceptibility to Cry1Ab had occurred in either pest as of 2021. Also, control failures have not been reported, confirming that Bt maize producing Cry1Ab remains effective against both pests. Conditions in the EU preventing approval of new genetically modified crops, including maize producing two or more Bt toxins targeting corn borers, may limit the future effectiveness of resistance management strategies.
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Affiliation(s)
| | | | - Félix Ortego
- Laboratory of Applied Entomology for Human and Plant Health, Centro de Investigaciones Biológicas Margarita Salas, CSIC, 28040 Madrid, Spain
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16
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Ge L, Song L, Wang L, Li Y, Sun Y, Wang C, Chen J, Wu G, Pan A, Wu Y, Quan Z, Li P. Evaluating response mechanisms of soil microbiomes and metabolomes to Bt toxin additions. J Hazard Mater 2023; 448:130904. [PMID: 36860032 DOI: 10.1016/j.jhazmat.2023.130904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 01/21/2023] [Accepted: 01/27/2023] [Indexed: 06/18/2023]
Abstract
The accumulation and persistence of Bt toxins in soils from Bt plants and Bt biopesticides may result in environmental hazards such as adverse impacts on soil microorganisms. However, the dynamic relationships among exogenous Bt toxins, soil characteristics, and soil microorganisms are not well understood. Cry1Ab is one of the most commonly used Bt toxins and was added to soils in this study to evaluate subsequent changes in soil physiochemical properties, microbial taxa, microbial functional genes, and metabolites profiles via 16S rRNA gene pyrosequencing, high-throughput qPCR, metagenomic shotgun sequencing, and untargeted metabolomics. Higher additions of Bt toxins led to higher concentrations of soil organic matter (SOM), ammonium (NH+4-N), and nitrite (NO2--N) compared against controls without addition after 100 days of soil incubation. High-throughput qPCR analysis and shotgun metagenomic sequencing analysis revealed that the 500 ng/g Bt toxin addition significantly affected profiles of soil microbial functional genes involved in soil carbon (C), nitrogen (N), and phosphorus (P) cycling after 100 days of incubation. Furthermore, combined metagenomic and metabolomic analyses indicated that the 500 ng/g Bt toxin addition significantly altered low molecular weight metabolite profiles of soils. Importantly, some of these altered metabolites are involved in soil nutrient cycling, and robust associations were identified among differentially abundant metabolites and microorganisms due to Bt toxin addition treatments. Taken together, these results suggest that higher levels of Bt toxin addition can alter soil nutrients, probably by affecting the activities of Bt toxin-degrading microorganisms. These dynamics would then activate other microorganisms involved in nutrient cycling, finally leading to broad changes in metabolite profiles. Notably, the addition of Bt toxins did not cause the accumulation of potential microbial pathogens in soils, nor did it adversely affect the diversity and stability of microbial communities. This study provides new insights into the putative mechanistic associations among Bt toxins, soil characteristics, and microorganisms, providing new understanding into the ecological impacts of Bt toxins on soil ecosystems.
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Affiliation(s)
- Lei Ge
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Lili Song
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Luyao Wang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Yujie Li
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Yu Sun
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Cui Wang
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Jun Chen
- East China University of Technology, Nanchang 330013, China
| | - Guogan Wu
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Aihu Pan
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Yunfei Wu
- The College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Zhexue Quan
- School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Peng Li
- Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China.
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17
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Zhao W, Poncet-Legrand C, Staunton S, Quiquampoix H. pH-Dependent Changes in Structural Stabilities of Bt Cry1Ac Toxin and Contrasting Model Proteins following Adsorption on Montmorillonite. Environ Sci Technol 2023; 57:5693-5702. [PMID: 36989144 DOI: 10.1021/acs.est.2c09310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The environmental fate of insecticidal Cry proteins, including time-dependent conservation of biological properties, results from their structural stability in soils. The complex cascade of reactions involved in biological action requires Cry proteins to be in solution. However, the pH-dependent changes in conformational stability and the adsorption-desorption mechanisms of Cry protein on soil minerals remain unclear. We used Derjaguin-Landau-Verwey-Overbeek (DLVO) calculation and differential scanning calorimetry to interpret the driving forces and structural stabilities of Cry1Ac and two contrasting model proteins adsorbed by montmorillonite. The structural stability of Cry1Ac is closer to that of the "hard" protein, α-chymotrypsin, than that of the "soft" bovine serum albumin (BSA). The pH-dependent adsorption of Cry1Ac and α-chymotrypsin could be explained by DLVO theory, whereas the BSA adsorption deviated from it. Patch-controlled electrostatic attraction, hydrophobic effects, and entropy changes following protein unfolding on a mineral surface could contribute to Cry1Ac adsorption. Cry1Ac, like chymotrypsin, was partly denatured on montmorillonite, and its structural stability decreased with an increase in pH. Moreover, small changes in the conformational heterogeneity of both Cry1Ac and chymotrypsin were observed following adsorption. Conversely, adsorbed BSA was completely denatured regardless of the solution pH. The moderate conformational rearrangement of adsorbed Cry1Ac may partially explain why the insecticidal activity of Bt toxin appears to be conserved in soils, albeit for a relatively short time period.
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Affiliation(s)
- Wenqiang Zhao
- Eco&Sols, INRAE, IRD, Cirad, Institut Agro, Univ Montpellier, 34090 Montpellier, France
- CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China
| | | | - Siobhan Staunton
- Eco&Sols, INRAE, IRD, Cirad, Institut Agro, Univ Montpellier, 34090 Montpellier, France
| | - Hervé Quiquampoix
- Eco&Sols, INRAE, IRD, Cirad, Institut Agro, Univ Montpellier, 34090 Montpellier, France
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18
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Yang J, Chen S, Xu X, Lin S, Wu J, Lin G, Bai J, Song Q, You M, Xie M. Novel miR-108 and miR-234 target juvenile hormone esterase to regulate the response of Plutella xylostella to Cry1Ac protoxin. Ecotoxicol Environ Saf 2023; 254:114761. [PMID: 36907089 DOI: 10.1016/j.ecoenv.2023.114761] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 03/05/2023] [Accepted: 03/08/2023] [Indexed: 06/18/2023]
Abstract
Insect hormones, such as juvenile hormone (JH), precisely regulate insect life-history traits. The regulation of JH is tightly associated with the tolerance or resistance to Bacillus thuringiensis (Bt). JH esterase (JHE) is a primary JH-specific metabolic enzyme which plays a key role in regulating JH titer. Here, we characterized a JHE gene from Plutella xylostella (PxJHE), and found it was differentially expressed in the Bt Cry1Ac resistant and susceptible strains. Suppression of PxJHE expression with RNAi increased the tolerance of P. xylostella to Cry1Ac protoxin. To investigate the regulatory mechanism of PxJHE, two target site prediction algorithms were applied to predict the putative miRNAs targeting PxJHE, and the resulting putative miRNAs were subsequently verified for their function targeting PxJHE using luciferase reporter assay and RNA immunoprecipitation. MiR-108 or miR-234 agomir delivery dramatically reduced PxJHE expression in vivo, whilst only miR-108 overexpression consequently increased the tolerance of P. xylostella larvae to Cry1Ac protoxin. By contrast, reduction of miR-108 or miR-234 dramatically increased PxJHE expression, accompanied by the decreased tolerance to Cry1Ac protoxin. Furthermore, injection of miR-108 or miR-234 led to developmental defects in P. xylostella, whilst injection of antagomir did not cause any obvious abnormal phenotypes. Our results indicated that miR-108 or miR-234 can be applied as potential molecular targets to combat P. xylostella and perhaps other lepidopteran pests, providing novel insights into miRNA-based integrated pest management.
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Affiliation(s)
- Jie Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Shiyao Chen
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xuejiao Xu
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Sujie Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jiaqi Wu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Guifang Lin
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Jianlin Bai
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Qisheng Song
- Division of Plant Science and Technology, University of Missouri, Columbia, MO 65211, USA
| | - Minsheng You
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Miao Xie
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou 350002, China; College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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19
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Lin S, Head G, Price P, Niu Y, Huang F. Relative fitness of susceptible and Cry1A.105/Cry2Ab2-single-/dual-protein-resistant Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) on non-Bt diet and a diet containing a low concentration of two proteins. Insect Sci 2023; 30:398-410. [PMID: 35670378 DOI: 10.1111/1744-7917.13087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/22/2022] [Accepted: 05/26/2022] [Indexed: 06/15/2023]
Abstract
Helicoverpa zea (Boddie) is a destructive agricultural pest species that is targeted by both Bacillus thuringiensis (Bt) maize and cotton in the United States. Cry1A.105 and Cry2Ab2 are two Bt proteins expressed in a widely planted maize event MON 89034. In this study, two tests (Test-I and Test-II) were conducted to evaluate the relative fitness of Bt-susceptible and -resistant H. zea on non-Bt diet (Test-I and Test-II) and a diet containing a mix of Cry1A.105 and Cry2Ab2 at a low concentration (Test-II only). Insect populations evaluated in Test-I were two Bt-susceptible strains and three Bt-resistant strains (a single-protein Cry1A.105-, a single-protein Cry2Ab2-, and a dual-protein Cry1A.105/Cry2Ab2-resistant strains). Test-II analyzed the same two susceptible strains, three backcrossed-and-reselected Cry1A.105/Cry2Ab2-single-/dual-protein-resistant strains, and three F1 heterozygous strains. Measurements of life table parameters showed that neither the single- nor dual-protein Cry1A.105/Cry2Ab2 resistance in H. zea was associated with fitness costs under the test conditions. The single Cry protein resistances at a concentration of a mix of Cry1A.105 and Cry2Ab2 that resulted in a zero net reproductive rate for the two susceptible strains were functionally incomplete recessive or codominant, and the dual-protein resistance was completely dominant. The lack of fitness costs could be a factor contributing to the rapid revolution of resistance to the Cry proteins in this species. Data generated from this study should aid our understanding of Cry protein resistance evolution and help in refining IRM programs for H. zea.
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Affiliation(s)
- Shucong Lin
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, USA
| | - Graham Head
- Bayer Crop Science, Chesterfield, Missouri, USA
| | - Paula Price
- Bayer Crop Science, Chesterfield, Missouri, USA
| | - Ying Niu
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, USA
| | - Fangneng Huang
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, USA
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20
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Wang Y, Zhao W, Han S, Wang L, Chang X, Liu K, Quan Y, Wang Z, He K. Seven Years of Monitoring Susceptibility to Cry1Ab and Cry1F in Asian Corn Borer. Toxins (Basel) 2023; 15:toxins15020137. [PMID: 36828451 PMCID: PMC9967349 DOI: 10.3390/toxins15020137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/02/2023] [Accepted: 02/04/2023] [Indexed: 02/11/2023] Open
Abstract
Resistance monitoring in the Asian corn borer, Ostrinia furnacalis, is necessary to accommodate the commercial introduction and stewardship of Bt maize in China. The susceptibility of 56 O. furnacalis field populations, collected between 2015 and 2021 from the corn belt regions of China, to Cry1Ab and Cry1F toxins was determined. Neonate larvae (within 12 h after hatching) were placed on the surface of semi-artificial agar-free diet incorporating a series of concentrations of purified toxins, and mortality was evaluated after 7d. The median lethal concentration (LC50) values of Cry1Ab and Cry1F were 0.05 to 0.37 µg/g (protein/diet) and 0.10 to 1.22 µg/g, respectively. Although interpopulation variation in susceptibility to the toxins was observed, the magnitude of the differences was 5.8-fold and 8.3-fold for Cry1Ab and Cry1F, respectively. These results suggested that the observed susceptibility differences reflect natural geographical variation in response and not variation caused by prior exposure to selection pressures. Therefore, the O. furnacalis populations were apparently still susceptible to Cry1Ab and Cry1F across their range within China. The monitoring data established here will serve as a comparative reference for early warning signs of field-evolved resistance after the cultivation of Bt maize in China.
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Affiliation(s)
- Yueqin Wang
- State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (Y.W.); (K.H.); Tel.: +86-10-6281-5614 (Y.W.)
| | - Wenlu Zhao
- Dezhou Academy of Agricultural Sciences, Dezhou 253000, China
| | - Shuang Han
- Dezhou Academy of Agricultural Sciences, Dezhou 253000, China
| | - Lianxia Wang
- Qiqihar Sub-Academy of Heilongjiang Academy of Agricultural Sciences, Qiqihar 161006, China
| | - Xue Chang
- Institute of Plant Protection, Jilin Academy of Agricultural Sciences, Gongzhuling 136100, China
| | - Kaiqiang Liu
- State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yudong Quan
- State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zhenying Wang
- State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Kanglai He
- State Key Laboratory for the Biology of the Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (Y.W.); (K.H.); Tel.: +86-10-6281-5614 (Y.W.)
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Liao C, Zhang D, Cheng Y, Yang Y, Liu K, Wu K, Xiao Y. Down-regulation of HaABCC3, potentially mediated by a cis-regulatory mechanism, is involved in resistance to Cry1Ac in the cotton bollworm, Helicoverpa armigera. Insect Sci 2023; 30:135-145. [PMID: 35603737 DOI: 10.1111/1744-7917.13080] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/28/2022] [Accepted: 05/06/2022] [Indexed: 05/29/2023]
Abstract
Evolution of resistance to Cry proteins in multiple pest insects has been threatening the sustainable use of Bacillus thuringiensis (Bt)-transgenic crops. Better understanding about the mechanism of resistance to Cry proteins in insects is needed. Our preliminary study reported that the transcription of HaABCC3 was significantly decreased in a near-isogenic line (LFC2) of a Cry1Ac-resistant strain (LF60) of the global pest Helicoverpa armigera. However, the causality between HaABCC3 downregulation and resistance to Cry1Ac remains to be verified, and the regulatory mechanism underlying the HaABCC3 downregulation is still unclear. In this study, our data showed that both HaABCC3 and HaABCC3 downregulation were genetically linked to resistance to Cry1Ac in LF60. However, no InDels were observed in the coding sequence of HaABCC3 from LF60. Furthermore, F1 offspring from the cross of LF60 and a HaABCC2/3-knockout mutant exhibited moderate resistance to Cry1Ac toxin; this indicated that the high resistance to Cry1Ac toxin in LF60 may have resulted from multiple genetic factors, including HaABCC2 mis-splicing and HaABCC3 downregulation. Results from luciferase reporter assays showed that promoter activity of HaABCC3 in LF60 was significantly lower than that in the susceptible strain, which indicated that HaABCC3 downregulation was likely mediated by promoter variation. Consistently, multiple variations of the GATA- or FoxA-binding sites in the promoter region of HaABCC3 were identified. Collectively, all results in this study suggested that the downregulation of HaABCC3 observed in the H. armigera LF60 strain, which is resistant to Cry1Ac, may be mediated by a cis-regulatory mechanism.
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Affiliation(s)
- Chongyu Liao
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Dandan Zhang
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Ying Cheng
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
| | - Yongbo Yang
- College of Life Sciences, Central China Normal University, Wuhan, China
| | - Kaiyu Liu
- College of Life Sciences, Central China Normal University, Wuhan, China
| | - Kongming Wu
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yutao Xiao
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
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Yang X, Zhao S, Liu B, Gao Y, Hu C, Li W, Yang Y, Li G, Wang L, Yang X, Yuan H, Liu J, Liu D, Shen X, Wyckhuys KAG, Lu Y, Wu K. Bt maize can provide non-chemical pest control and enhance food safety in China. Plant Biotechnol J 2023; 21:391-404. [PMID: 36345605 PMCID: PMC9884019 DOI: 10.1111/pbi.13960] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/25/2022] [Accepted: 10/28/2022] [Indexed: 05/26/2023]
Abstract
China is the world's second-largest maize producer and consumer. In recent years, the invasive fall armyworm Spodoptera frugiperda (J.E. Smith) has adversely affected maize productivity and compromised food security. To mitigate pest-inflicted food shortages, China's Government issued biosafety certificates for two genetically modified (GM) Bt maize hybrids, Bt-Cry1Ab DBN9936 and Bt-Cry1Ab/Cry2Aj Ruifeng 125, in 2019. Here, we quantitatively assess the impact of both Bt maize hybrids on pest feeding damage, crop yield and food safety throughout China's maize belt. Without a need to resort to synthetic insecticides, Bt maize could mitigate lepidopteran pest pressure by 61.9-97.3%, avoid yield loss by 16.4-21.3% (range -11.9-99.2%) and lower mycotoxin contamination by 85.5-95.5% as compared to the prevailing non-Bt hybrids. Yield loss avoidance varied considerably between experimental sites and years, as mediated by on-site infestation pressure and pest identity. For either seed mixtures or block refuge arrangements, pest pressure was kept below established thresholds at 90% Bt maize coverage in Yunnan (where S. frugiperda was the dominant species) and 70% Bt maize coverage in other sites dominated by Helicoverpa armigera (Hübner) and Ostrinia furnacalis (Guenée). Drawing on experiences from other crop/pest systems, Bt maize in se can provide area-wide pest management and thus, contribute to a progressive phase-down of chemical pesticide use. Hence, when consciously paired with agroecological and biodiversity-based measures, GM insecticidal crops can ensure food and nutrition security, contribute to the sustainable intensification of China's agriculture and reduce food systems' environmental footprint.
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Affiliation(s)
- Xianming Yang
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
| | - Shengyuan Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
| | - Bing Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
| | - Yu Gao
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
| | - Chaoxing Hu
- Guizhou Provincial Key Laboratory for Agricultural Pest Management of the Mountainous RegionInstitute of Entomology, Guizhou UniversityGuiyangChina
| | - Wenjing Li
- Institute of Plant Protection and Soil FertilityHubei Academy of Agricultural SciencesWuhanChina
| | - Yizhong Yang
- College of Horticulture and Plant ProtectionYangzhou UniversityYangzhouJiangsu ProvinceChina
| | - Guoping Li
- Institute of Plant ProtectionHenan Academy of Agricultural SciencesZhengzhouChina
| | - Lili Wang
- Yantai Academy of Agricultural SciencesYantaiChina
| | - Xueqing Yang
- College of Plant ProtectionShenyang Agricultural UniversityShenyangChina
| | - Haibin Yuan
- College of Plant ProtectionJilin Agricultural UniversityChangchunChina
| | - Jian Liu
- College of AgricultureNortheast Agricultural UniversityHarbinChina
| | - Dazhong Liu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
- Agricultural Information InstituteChinese Academy of Agricultural SciencesBeijingChina
| | - Xiujing Shen
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
| | - Kris A. G. Wyckhuys
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
- Fujian Agriculture and Forestry UniversityFuzhouChina
- University of QueenslandBrisbaneQueenslandAustralia
- Chrysalis ConsultingHanoiVietnam
| | - Yanhui Lu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
| | - Kongming Wu
- State Key Laboratory for Biology of Plant Diseases and Insect PestsInstitute of Plant Protection, Chinese Academy of Agricultural SciencesBeijingChina
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Mahesh HM, Muralimohan K. Segregation of Cry Genes in the Seeds Produced by F 1 Bollgard ® II Cotton Differs between Hybrids: Could This Be Linked to the Observed Field Resistance in the Pink Bollworm? Genes (Basel) 2022; 14:genes14010065. [PMID: 36672806 PMCID: PMC9859209 DOI: 10.3390/genes14010065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/21/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Indian populations of the Pink Bollworm (PBW) are resistant to Bt (Bacillus thuringiensis) cotton hybrids containing Cry1Ac and Cry2Ab genes. Segregation of these Cry genes in F1 hybrids could subject PBW to sublethal concentrations. Moreover, planting hybrids with varying zygosities of Cry genes could produce diverse segregation patterns and expose PBW populations to highly variable toxin concentrations. This could potentially promote the rate of resistance development. Therefore, we studied the segregation patterns of Cry genes in different commercial Bt hybrids cultivated in India. Results showed that two hybrids segregated according to the Mendelian mono-hybrid ratio, three segregated according to the Mendelian di-hybrid ratio, and one showed a mixed segregation pattern. The assortment of seeds containing Cry genes varied between bolls of the same hybrid. In India, different Bt cotton hybrids are cultivated in small patches next to each other, exposing PBW populations to sublethal doses and wide variations in the occurrence of Cry genes. It is necessary to avoid segregation of Cry genes in the seeds produced by F1 hybrids. This study recommends using Bt parents homozygous for Cry genes in commercial Bt cotton hybrid development. This breeding strategy could be effective for similar transgenic crop hybrids as well.
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Babendreier D, Toepfer S, Bateman M, Kenis M. Potential Management Options for the Invasive Moth Spodoptera frugiperda in Europe. J Econ Entomol 2022; 115:1772-1782. [PMID: 36515106 PMCID: PMC9748578 DOI: 10.1093/jee/toac089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Indexed: 06/17/2023]
Abstract
We here review and discuss management options that growers in Europe could take in response to the expected invasion of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae). The focus is put on maize but the information provided is also relevant for other crops potentially affected. A sound forecasting system for fall armyworm both on a regional as well as at local scale should be established to alert growers as early as possible. Whilst a number of cultural control methods are adopted by maize growers in different regions globally to fight fall armyworm, many of them may either not be highly effective, too laborious, or otherwise unfeasible within the mechanized crop production systems used in Europe. Potential is seen in the stimulation of natural enemies through conservation biocontrol approaches, e.g., the planting of flower strips or intermediate cover crops, reducing tillage intensity, and avoiding broad-spectrum insecticides. To manage fall armyworm infestations, several effective biologically-based products are available globally, and some in Europe, e.g., based on specific baculoviruses, certain Bacillus thuringiensis strains, few entomopathogenic nematodes, and a number of botanicals. These should be given priority to avoid a major influx of insecticides into the maize agro-ecosystem once the fall armyworm arrives and in case growers are not prepared. Plant protection companies, particularly biocontrol companies should act proactively in starting registration of ingredients and products against fall armyworm in Europe. European maize growers should be made aware, in time, of key features of this new invasive pest and appropriate control options.
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Affiliation(s)
| | - Stefan Toepfer
- CABI Switzerland, Rue des Grillons 1, 2800 Delémont, Switzerland
| | - Melanie Bateman
- CABI Switzerland, Rue des Grillons 1, 2800 Delémont, Switzerland
| | - Marc Kenis
- CABI Switzerland, Rue des Grillons 1, 2800 Delémont, Switzerland
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Cai L, Liu X, Tian Z, Michaud JP, Shen Z, Li Z, Zhang S, Liu X. Safety of Bacillus thuringiensis Cry1Ah and Vip3Aa toxins for the predatory stink bug Arma custos (Hemiptera: Pentatomidae). Sci Total Environ 2022; 851:158120. [PMID: 35987246 DOI: 10.1016/j.scitotenv.2022.158120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/05/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
The widespread adoption of Bt crops expressing insecticidal proteins derived from Bacillus thuringiensis has created a need to assess the potential effects of these toxins on non-target organisms, especially species such as Arma custos, a generalist predator that provides important biological control services in many field crops in Asia. Direct dietary exposure of A. custos to Cry1Ah and Vip3Aa proteins produced no adverse effects on life history traits, despite continuous exposure throughout development and early adult life to concentrations significantly higher than the Bt protein concentration likely encountered by A.custos in the field, even when feeding directly on Bt plants. Enzyme-linked immunosorbent assay confirmed the presence of Bt proteins in A. custos midguts, but quantitative real-time PCR analysis of 12 genes associated with detoxification, antioxidative responses, immune responses, and metabolism revealed no significant changes in expression in adult bugs. Indirect exposure to these toxins via consumption of intoxicated prey, larvae of Helicoverpa armigera (Hübner), likewise produced no negative impacts on survival, development, adult weight, or female fecundity in either the F0 (exposed) or F1 (unexposed) generation, but female fresh weight was reduced in the F0 generation by the Cry1Ah (50 μg/g) treatment. Finally, a competitive binding assay with labelled protein and a ligand blotting assay both demonstrated that the Cry1Ah protein could not bind to receptors on the midgut brush border membrane vesicles (BBMVs) of A. custos adults. Therefore, we conclude that Cry1Ah and Vip3Aa proteins are unlikely to have significant negative effects on A. custos populations if employed as plant-incorporated protectants in field crops.
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Affiliation(s)
- Limei Cai
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Xiaoming Liu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Zhiqiang Tian
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - J P Michaud
- Department of Entomology, Kansas State University, Agricultural Research Station-Hays, Hays, KS 67601, USA
| | - Zhongjian Shen
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Zhen Li
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Songdou Zhang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Xiaoxia Liu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China.
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26
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de Oliveira WS, Sakuno CIR, Miraldo LL, Tavares MAGC, Komada KMA, Teresani D, Santos JLX, Huang F. Varied frequencies of resistance alleles to Cry1Ab and Cry1Ac among Brazilian populations of the sugarcane borer, Diatraea saccharalis (F.). Pest Manag Sci 2022; 78:5150-5163. [PMID: 36070208 DOI: 10.1002/ps.7133] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/11/2022] [Accepted: 08/18/2022] [Indexed: 05/29/2023]
Abstract
BACKGROUND Brazil is the largest grower of the world's 26 million ha of sugarcane, Saccharum officinarum. Pest damage mainly by the sugarcane borer, Diatraea saccharalis (F.), is a great challenge to the sugarcane industry. To control D. saccharalis, Brazil launched the world's first commercial use of Bt sugarcane in 2017. As part of the resistance management programs for Bt sugarcane planting, 535 F2 isoline families of D. saccharalis collected from three major sugarcane planting states (Goiás, Minas Gerais and São Paulo) in Brazil during 2019-2020 were screened for resistance to two Bt sugarcane varieties: CTC20BT expressing Cry1Ab and CTC9001BT expressing Cry1Ac. Here we report the results of the first study related to Bt resistance in a sugarcane cropping system. RESULTS Larval survivorships of these families in an F2 screen on CTC20BT were highly correlated with their survival on CTC9001BT, whereas the Cry1Ac tissues exhibited greater insecticidal activities than Cry1Ab. Resistance allele frequencies (RAFs) for populations from Goiás and Minas Gerais were relatively low at 0.0034 for Cry1Ab and 0.0045 to Cry1Ac. By contrast, RAFs for São Paulo populations were considerably greater (0.0393 to Cry1Ab, 0.0245 to Cry1Ac). CONCLUSIONS RAFs to Cry1Ab and Cry1Ac varied among Brazilian D. saccharalis populations. Prior selection resulting from an intensive use of single-gene Bt maize under low compliance of refuge planting could be a main factor contributing to the high RAF in São Paulo. The results suggest that mitigation measures including sufficient non-Bt maize refuge planting, effective resistance monitoring, and use of pyramided Bt sugarcane traits should be implemented promptly to prevent further increase in the RAF to ensure the sustainable use of Bt sugarcane in Brazil. MINI ABSTRACT To control Diatraea saccharalis, Brazil launched the world's first commercial use of Bt sugarcane in 2017. As part of the resistance management programs for Bt sugarcane planting in Brazil, 535 F2 isoline families of D. saccharalis collected from three major sugarcane planting states (Goiás, Minas Gerais and São Paulo) in Brazil during 2019-2020 were screened for resistance to Cry1Ab and Cry1Ac sugarcane plants Resistance allele frequencies (RAFs) for the populations from Goiás and Minas Gerais were relatively low at 0.0034 for Cry1Ab and 0.0045 to Cry1Ac. By contrast, RAFs for the São Paulo populations were considerably greater (0.0393 to Cry1Ab, 0.0245 to Cry1Ac). Prior selection resulting from an intensive use of single-gene Bt maize under low compliance of non-Bt maize refuge planting could be a main factor contributing to the high RAF in São Paulo. The results suggest that effective mitigation measures including sufficient non-Bt maize refuge planting, effective resistance monitoring and use of pyramided Bt sugarcane traits should be implemented promptly to prevent further increase in the RAF to ensure the sustainable use of Bt sugarcane in Brazil. © 2022 Society of Chemical Industry.
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Affiliation(s)
| | | | | | | | | | | | | | - Fangneng Huang
- Department of Entomology, Louisiana State University Agricultural Center, Baton Rouge, LA, USA
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de Carvalho KS, Leite NA, Mendes SM, de Paula Lana UG, Valicente FH. Toxicity of Bacillus thuringiensis Strains to Six Lepidopteran Pests of Brazilian Agricultural Landscape. Neotrop Entomol 2022; 51:869-876. [PMID: 36214967 DOI: 10.1007/s13744-022-00996-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/22/2022] [Indexed: 06/16/2023]
Abstract
The first step for biological insecticide production is the evaluating of the pathogenicity and strains virulence of entomopathogens against the target pests. Bacillus thuringiensis (Bt) is widespread in nature, lethal pathogen of a range of orders and the most widely used entomopathogenic biological control agent. Therefore, our objective was to study the susceptibility of six important lepidopteran pests in Brazilian agricultural production systems, Anticarsia gemmatalis (Hübner), Chrysodeixis includens (Walker) Helicoverpa armigera (Hübner), Spodoptera cosmioides (Walker), S. eridania (Cramer), and S. frugiperda (Smith), to Bt strains. In vitro bioassays were conducted with neonate larvae exposed to two Bt strains, 1680A and 775E, in seven concentrations of spores and protein crystals. After 7 days, the mortality was evaluated and indicated that lethal concentration (LC50) for 775E strain ranged from 7.72 × 104 to 2.45 × 106 spores mL-1 and for 1608A strain from 5.63 × 103 to 1.21 × 106 spores mL-1. The strain 1608A was more toxic for A. gemmatalis and H. armigera than 775E strain, and then was further evaluated in greenhouse bioassays with maize and soybean plants infested separately with target insects. The strain 1608A showed an efficient control for most insect species studied in the greenhouse bioassays, promoting considerable reduction in leaf injury and demonstrating a high potential in biological control of important lepidopteran species in crop production systems in Brazil.
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Affiliation(s)
- Karine Silva de Carvalho
- Biotechnology Department, Federal University of Lavras, Lavras, Brazil
- Embrapa Maize and Sorghum, Sete Lagoas, MG, Brazil
| | - Natália Alves Leite
- Crop Protection Department, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
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Yang F, Kerns DL, Little N, Brown SA, Stewart SD, Catchot AL, Cook DR, Gore J, Crow WD, Lorenz GM, Towles T, Tabashnik BE. Practical resistance to Cry toxins and efficacy of Vip3Aa in Bt cotton against Helicoverpa zea. Pest Manag Sci 2022; 78:5234-5242. [PMID: 36053801 DOI: 10.1002/ps.7142] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/14/2022] [Accepted: 08/23/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Crops genetically engineered to make insect-killing proteins from Bacillus thuringiensis (Bt) have revolutionized management of some pests. However, the benefits of such transgenic crops are reduced when pests evolve resistance to Bt toxins. We evaluated resistance to Bt toxins and Bt cotton plants using laboratory bioassays and complementary field trials focusing on Helicoverpa zea, one of the most economically important pests of cotton and other crops in the United States. RESULTS The data from 235 laboratory bioassays demonstrate resistance to Cry1Ac, Cry1Fa, and Cry2Ab occurred in most of the 95 strains of H. zea derived from Arkansas, Louisiana, Mississippi, Tennessee, and Texas during 2016 to 2021. Complementary field data show efficacy decreased for Bt cotton producing Cry1Ac + Cry1Fa or Cry1Ac + Cry2Ab, but not Cry1Ac + Cry1Fa + Vip3Aa. Moreover, analysis of data paired by field site and year shows higher survival in bioassays was generally associated with lower efficacy of Bt cotton. CONCLUSIONS The results confirm and extend previous evidence showing widespread practical resistance of H. zea in the United States to the Cry toxins produced by Bt cotton and corn, but not to Vip3Aa. Despite deployment in combination with Cry toxins in Bt crops, Vip3Aa effectively acts as a single toxin against H. zea larvae that are highly resistant to Cry toxins. Furthermore, Vip3Aa adoption is increasing and previous work provided an early warning of field-evolved resistance. Thus, rigorous resistance management measures are needed to preserve the efficacy of Vip3Aa against this highly adaptable pest. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Fei Yang
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - David L Kerns
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Nathan Little
- Southern Insect Management Research Unit, USDA-ARS, Stoneville, MS, USA
| | - Sebe A Brown
- Department of Entomology and Plant Pathology, University of Tennessee, Jackson, TN, USA
| | - Scott D Stewart
- Department of Entomology and Plant Pathology, University of Tennessee, Jackson, TN, USA
| | - Angus L Catchot
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
| | - Donald R Cook
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
| | - Jeffrey Gore
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
| | - Whitney D Crow
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Mississippi State, MS, USA
| | - Gustav M Lorenz
- Department of Entomology and Plant Pathology, University of Arkansas, Lonoke, AR, USA
| | - Tyler Towles
- Department of Entomology, Louisiana State University, Winnsboro, LA, USA
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Unzue A, Caballero CJ, Villanueva M, Fernández AB, Caballero P. Multifunctional Properties of a Bacillus thuringiensis Strain (BST-122): Beyond the Parasporal Crystal. Toxins (Basel) 2022; 14:toxins14110768. [PMID: 36356018 PMCID: PMC9695252 DOI: 10.3390/toxins14110768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
Chemical products still represent the most common form of controlling crop pests and diseases. However, their extensive use has led to the selection of resistances. This makes the finding of new solutions paramount to countering the economic losses that pests and diseases represent in modern agriculture. Bacillus thuringiensis (Bt) is one of the most reliable alternatives to chemical-based solutions. In this study, we aimed to further expand the global applicability of Bt strains beyond their spores and crystals. To this end, we selected a new Bt strain (BST-122) with relevant toxicity factors and tested its activity against species belonging to different phyla. The spore and crystal mixture showed toxicity to coleopterans. Additionally, a novel Cry5-like protein proved active against the two-spotted spider mite. In vivo and plant assays revealed significant control of the parasitic nematode, Meloidogyne incognita. Surprisingly, our data indicated that the nematocidal determinants may be secreted. When evaluated against phytopathogenic fungi, the strain seemed to decelerate their growth. Overall, our research has highlighted the potential of Bt strains, expanding their use beyond the confinements of spores and crystals. However, further studies are required to pinpoint the factors responsible for the wide host range properties of the BST-122 strain.
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Affiliation(s)
- Argine Unzue
- Institute of Multidisciplinary Research in Applied Biology-IMAB, Universidad Pública de Navarra, 31192 Mutilva, Spain
- Departamento de Investigación y Desarrollo, Bioinsectis SL, Plaza Cein 5, Nave A14, 31110 Noáin, Spain
| | - Carlos J. Caballero
- Departamento de Investigación y Desarrollo, Bioinsectis SL, Plaza Cein 5, Nave A14, 31110 Noáin, Spain
| | - Maite Villanueva
- Departamento de Investigación y Desarrollo, Bioinsectis SL, Plaza Cein 5, Nave A14, 31110 Noáin, Spain
| | - Ana Beatriz Fernández
- Departamento de Investigación y Desarrollo, Bioinsectis SL, Plaza Cein 5, Nave A14, 31110 Noáin, Spain
| | - Primitivo Caballero
- Institute of Multidisciplinary Research in Applied Biology-IMAB, Universidad Pública de Navarra, 31192 Mutilva, Spain
- Correspondence:
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Fabrick JA, Heu CC, LeRoy DM, DeGain BA, Yelich AJ, Unnithan GC, Wu Y, Li X, Carrière Y, Tabashnik BE. Knockout of ABC transporter gene ABCA2 confers resistance to Bt toxin Cry2Ab in Helicoverpa zea. Sci Rep 2022; 12:16706. [PMID: 36202979 PMCID: PMC9537329 DOI: 10.1038/s41598-022-21061-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/22/2022] [Indexed: 11/08/2022] Open
Abstract
Evolution of pest resistance reduces the benefits of widely cultivated genetically engineered crops that produce insecticidal proteins derived from Bacillus thuringiensis (Bt). Better understanding of the genetic basis of pest resistance to Bt crops is needed to monitor, manage, and counter resistance. Previous work shows that in several lepidopterans, resistance to Bt toxin Cry2Ab is associated with mutations in the gene encoding the ATP-binding cassette protein ABCA2. The results here show that mutations introduced by CRISPR/Cas9 gene editing in the Helicoverpa zea (corn earworm or bollworm) gene encoding ABCA2 (HzABCA2) can cause resistance to Cry2Ab. Disruptive mutations in HzABCA2 facilitated the creation of two Cry2Ab-resistant strains. A multiple concentration bioassay with one of these strains revealed it had > 200-fold resistance to Cry2Ab relative to its parental susceptible strain. All Cry2Ab-resistant individuals tested had disruptive mutations in HzABCA2. We identified five disruptive mutations in HzABCA2 gDNA. The most common mutation was a 4-bp deletion in the expected Cas9 guide RNA target site. The results here indicate that HzABCA2 is a leading candidate for monitoring Cry2Ab resistance in field populations of H. zea.
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Affiliation(s)
- Jeffrey A Fabrick
- USDA ARS, U.S. Arid Land Agricultural Research Center, 21881 N. Cardon Lane, Maricopa, AZ, 85138, USA.
| | - Chan C Heu
- USDA ARS, U.S. Arid Land Agricultural Research Center, 21881 N. Cardon Lane, Maricopa, AZ, 85138, USA
| | - Dannialle M LeRoy
- USDA ARS, U.S. Arid Land Agricultural Research Center, 21881 N. Cardon Lane, Maricopa, AZ, 85138, USA
| | - Ben A DeGain
- Department of Entomology, University of Arizona, Tucson, AZ, 85721, USA
| | - Alex J Yelich
- Department of Entomology, University of Arizona, Tucson, AZ, 85721, USA
| | | | - Yidong Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Xianchun Li
- Department of Entomology, University of Arizona, Tucson, AZ, 85721, USA
| | - Yves Carrière
- Department of Entomology, University of Arizona, Tucson, AZ, 85721, USA
| | - Bruce E Tabashnik
- Department of Entomology, University of Arizona, Tucson, AZ, 85721, USA
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31
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Luong TTA, Downes SJ, Perkins LE, Zalucki MP. Drop-off behaviour of Bt-resistant and Bt-susceptible Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) larvae on Bt-cotton and non-Bt cotton plants. Bull Entomol Res 2022; 112:604-612. [PMID: 35199633 DOI: 10.1017/s0007485321001206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The highest natural mortality rate of larval Lepidoptera in field populations occurs in the first instar, but it is highly variable. The pattern and degree of survival is not easily predicted but depends on their ability to establish on host plants. Lepidopteran larval dispersal behaviour, known as 'drop-off', happens when the host is unsuitable for larvae to settle and begin feeding. Understanding drop-off behaviour of Helicoverpa armigera (Hübner) with and without physiological resistance to Bt toxins on Bt and non-Bt cotton plants is an important component for resistance management strategies for this insect. We examined the drop-off behaviour of H. armigera to determine: (1) whether they move the same way or differently in response to Bt and non-Bt, and (2) could H. armigera larvae detect Bt toxin levels in cotton plants or did they move independently of toxin levels? In this study, we assessed the drop-off behaviour of Bt-resistant and Bt-susceptible H. armigera neonates on artificial diets and cotton plants with and without Bt toxin during the first 12 h after hatching. Bt-resistant and Bt-susceptible H. armigera neonates behaved differently on Bt and non-Bt substrates. The percentages of Bt-resistant larvae that dropped off Bt and non-Bt cotton plants were not significantly different. In contrast, significantly more Bt-susceptible larvae dropped off Bt cotton than non-Bt cotton plants over time. Although Bt-susceptible larvae could not detect Bt toxin, they showed preference on non-Bt toxin substrates and were more likely to drop off substrates with Bt toxin.
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Affiliation(s)
- T T A Luong
- Phu Yen University, Phu Yen 620000, Vietnam
- School of Biological Sciences, The University of Queensland, Brisbane 4072, Australia
| | - S J Downes
- CSIRO Agriculture and Food, Australian Cotton Research Institute, Narrabri 2390, Australia
| | - L E Perkins
- School of Biological Sciences, The University of Queensland, Brisbane 4072, Australia
| | - M P Zalucki
- School of Biological Sciences, The University of Queensland, Brisbane 4072, Australia
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Tabashnik BE, Unnithan GC, Yelich AJ, Fabrick JA, Dennehy TJ, Carrière Y. Responses to Bt toxin Vip3Aa by pink bollworm larvae resistant or susceptible to Cry toxins. Pest Manag Sci 2022; 78:3973-3979. [PMID: 35633103 DOI: 10.1002/ps.7016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/17/2022] [Accepted: 05/28/2022] [Indexed: 05/29/2023]
Abstract
BACKGROUND Transgenic crops that make insecticidal proteins from Bacillus thuringiensis (Bt) have revolutionized management of some pests. However, evolution of resistance to Bt toxins by pests diminishes the efficacy of Bt crops. Resistance to crystalline (Cry) Bt toxins has spurred adoption of crops genetically engineered to produce the Bt vegetative insecticidal protein Vip3Aa. Here we used laboratory diet bioassays to evaluate responses to Vip3Aa by pink bollworm (Pectinophora gossypiella), one of the world's most damaging pests of cotton. RESULTS Against pink bollworm larvae susceptible to Cry toxins, Vip3Aa was less potent than Cry1Ac or Cry2Ab. Conversely, Vip3Aa was more potent than Cry1Ac or Cry2Ab against laboratory strains highly resistant to those Cry toxins. Five Cry-susceptible field populations were less susceptible to Vip3Aa than a Cry-susceptible laboratory strain (APHIS-S). Relative to APHIS-S, significant resistance to Vip3Aa did not occur in strains selected in the laboratory for > 700-fold resistance to Cry1Ac or both Cry1Ac and Cry2Ab. CONCLUSIONS Resistance to Cry1Ac and Cry2Ab did not cause strong cross-resistance to Vip3Aa in pink bollworm, which is consistent with predictions based on the lack of shared midgut receptors between these toxins and previous results from other lepidopterans. Comparison of the Bt toxin concentration in plants relative to the median lethal concentration (LC50 ) from bioassays may be useful for estimating efficacy. The moderate potency of Vip3Aa against Cry1Ac- and Cry2Ab-resistant and susceptible pink bollworm larvae suggests that Bt cotton producing this toxin together with novel Cry toxins might be useful as one component of integrated pest management. © 2022 Society of Chemical Industry.
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Affiliation(s)
| | | | | | - Jeffrey A Fabrick
- USDA ARS, US Arid Land Agricultural Research Center, Maricopa, AZ, USA
| | | | - Yves Carrière
- Department of Entomology, University of Arizona, Tucson, AZ, USA
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Tariq M, Tabassum B, Bakhsh A, Farooq AM, Qamar Z, Akram F, Naz F, Rao AQ, Malik K, Nasir IA. Heterologous expression of cry1Ia12 insecticidal gene in cotton encodes resistance against pink bollworm, Pectinophora gossypiella (Lepidoptera: Gelechiidae); an alternate insecticidal gene for insect pest management. Mol Biol Rep 2022; 49:10557-10564. [PMID: 36169899 DOI: 10.1007/s11033-022-07824-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 07/26/2022] [Indexed: 10/14/2022]
Abstract
BACKGROUND Cotton is continuously exposed to sucking and chewing insect pest pressure since emergence to harvesting. Pink bollworm (Pectinophora gossypiella) has become major chewing insect pest to reduce the cotton yield and results in bad lint quality even in transgenic crops. The efficiency of insecticidal genes has been compromised due to extensive utilization of transgenic crops. METHODS AND RESULTS The present study was conducted to evaluate the efficacy of an alternate cry1Ia12 insecticidal gene against pink bollworm (PBW) in cotton. Agrobacterium tumefaciens strain LBA4404 harboring pCAMBIA2300 expression vector containing cry1Ia12 gene under the control of 35S CaMV was used to transform a local cotton cultivar GS-01. The various molecular analyses revealed the transgene integration and expression in primary transformants. Among five selected transgenic plants, tcL-08 showed maximum (16.06-fold) mRNA expression of cry1Ia12 gene whereas tcL-03 showed minimum (2.33-fold) expression. Feeding bioassays of 2nd and 3rd instar pink bollworm (PBW) larvae on immature cotton bolls, flowers and cotton squares revealed up to 33.33% mortality on tcL-08 while lowest mortality (13.33%) was observed in tcL-03 and tcL-15. Furthermore, the average weight and size of survived larvae fed on transgenic plants was significantly lesser than the average weight of larvae survived on non-transgenic plants. CONCLUSIONS The present study suggests the cry1Ia12 gene as an alternate insecticidal gene for the resistance management of cotton bollworms, especially PBW.
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Affiliation(s)
- Muhammad Tariq
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan.
| | - Bushra Tabassum
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan
- School of Biological Sciences, University of the Punjab, Lahore, Pakistan
| | - Allah Bakhsh
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan
| | - Abdul Munim Farooq
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan
| | - Zahida Qamar
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan
| | - Faheem Akram
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan
| | - Farah Naz
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan
| | - Abdul Qayyum Rao
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan
| | - Kausar Malik
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan
| | - Idrees Ahmad Nasir
- National Centre of Excellence in Molecular Biology (CEMB), University of the Punjab, 53700, Lahore, Pakistan.
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Dechkla M, Charoenjotivadhanakul S, Imtong C, Visitsattapongse S, Li HC, Angsuthanasombat C. Cry4Aa and Cry4Ba Mosquito-Active Toxins Utilize Different Domains in Binding to a Particular Culex ALP Isoform: A Functional Toxin Receptor Implicating Differential Actions on Target Larvae. Toxins (Basel) 2022; 14:toxins14100652. [PMID: 36287921 PMCID: PMC9607545 DOI: 10.3390/toxins14100652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/10/2022] [Accepted: 09/16/2022] [Indexed: 11/16/2022] Open
Abstract
The three-domain Cry4Aa toxin produced from Bacillus thuringiensis subsp. israelensis was previously shown to be much more toxic to Culex mosquito larvae than its closely related toxin—Cry4Ba. The interaction of these two individual toxins with target receptors on susceptible larval midgut cells is likely to be the critical determinant in their differential toxicity. Here, two full-length membrane-bound alkaline phosphatase (mALP) isoforms from Culex quinquefasciatus larvae, Cq-mALP1263and Cq-mALP1264, predicted to be GPI-linked was cloned and functionally expressed in Spodoptera frugiperda (Sf9) cells as 57- and 61-kDa membrane-bound proteins, respectively. Bioinformatics analysis disclosed that both Cq-mALP isoforms share significant sequence similarity to Aedes aegypti-mALP—a Cry4Ba toxin receptor. In cytotoxicity assays, Sf9 cells expressing Cq-mALP1264, but not Cq-mALP1263, showed remarkably greater susceptibility to Cry4Aa than Cry4Ba, while immunolocalization studies revealed that both toxins were capable of binding to each Cq-mALP expressed on the cell membrane surface. Molecular docking of the Cq-mALP1264-modeled structure with individual Cry4 toxins revealed that Cry4Aa could bind to Cq-mALP1264 primarily through particular residues on three surface-exposed loops in the receptor-binding domain—DII, including Thr512, Tyr513 and Lys514 in the β10-β11loop. Dissimilarly, Cry4Ba appeared to utilize only certain residues in its C-terminal domain—DIII to interact with such a Culex counterpart receptor. Ala-substitutions of selected β10-β11loop residues (T512A, Y513A and K514A) revealed that only the K514A mutant displayed a drastic decrease in biotoxicity against C. quinquefasciatus larvae. Further substitution of Lys514 with Asp (K514D) revealed a further decrease in larval toxicity. Furthermore, in silico calculation of the binding affinity change (ΔΔGbind) in Cry4Aa-Cq-mALP1264 interactions upon these single-substitutions revealed that the K514D mutation displayed the largest ΔΔGbind value as compared to three other mutations, signifying an adverse impact of a negative charge at this critical receptor-binding position. Altogether, our present study has disclosed that these two related-Cry4 mosquito-active toxins conceivably exploited different domains in functional binding to the same Culex membrane-bound ALP isoform—Cq-mALP1264 for mediating differential toxicity against Culex target larvae.
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Affiliation(s)
- Manussawee Dechkla
- Department of Environmental Biology, Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok 10300, Thailand
- Correspondence: (M.D.); (C.A.)
| | - Sathapat Charoenjotivadhanakul
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand
| | - Chompounoot Imtong
- Laboratory of Structural Biochemistry and Cell Chemical Biology, Biophysics Institute for Research and Development (BIRD), Fang, Chiang Mai 50110, Thailand
| | - Sarinporn Visitsattapongse
- Department of Biomedical Engineering, School of Engineering, King Mongkut’s Institute of Technology Ladkrabang, Ladkrabang, Bangkok 10520, Thailand
| | - Hui-Chun Li
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
| | - Chanan Angsuthanasombat
- Bacterial Toxin Research Innovation Cluster (BRIC), Institute of Molecular Biosciences, Salaya Campus, Mahidol University, Nakorn Pathom 73170, Thailand
- Laboratory of Structural Biochemistry and Cell Chemical Biology, Biophysics Institute for Research and Development (BIRD), Fang, Chiang Mai 50110, Thailand
- Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien 97004, Taiwan
- Correspondence: (M.D.); (C.A.)
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35
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Hu X, Zhang X, Liu Y, Gao M, Lin M, Xie Y, Zhu Q, Xu C, Liu X, Vosloo D, Pooe OJ. Generation of Human Domain Antibody Fragments as Potential Insecticidal Agents against Helicoverpa armigera by Cadherin-Based Screening. J Agric Food Chem 2022; 70:11510-11519. [PMID: 35944165 DOI: 10.1021/acs.jafc.2c02000] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
New insecticidal genes and approaches for pest control are a hot research area. In the present study, we explored a novel strategy for the generation of insecticidal proteins. The midgut cadherin of Helicoverpa armigera (H. armigera) was used as a target to screen materials that have insecticidal activity. After three rounds of panning, the phage-displayed human domain antibody B1F6, which not only binds to the H. armigera cadherin CR9-CR11 but also significantly inhibits Cry1Ac toxins from binding to CR9-CR11, was obtained from a phage-displayed human domain antibody (DAb) library. To better analyze the relevant activity of B1F6, soluble B1F6 protein was expressed by Escherichia coli BL21 (DE3). The cytotoxicity assays demonstrated that soluble B1F6 induced Sf9 cell death when expressing H. armigera cadherin on the cell membrane. The insect bioassay results showed that soluble B1F6 protein (90 μg/cm2) caused 49.5 ± 3.3% H. armigera larvae mortality. The midgut histological results showed that soluble B1F6 caused damage to the midgut epithelium of H. armigera larvae. The present study explored a new strategy and provided a basic material for the generation of new insecticidal materials.
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Affiliation(s)
- Xiaodan Hu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Xiao Zhang
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yuan Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Meijing Gao
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Manman Lin
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Yajing Xie
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Qing Zhu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Chongxin Xu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Xianjin Liu
- Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality (Ministry of Agriculture), Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Dalene Vosloo
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
| | - Ofentse Jacob Pooe
- School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
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Kang S, Zhu X, Wu Q, Wang S, Crickmore N, Zhang Y, Guo Z. Critical Analysis of Multi-Omic Data from a Strain of Plutella xylostella Resistant to Bacillus thuringiensis Cry1Ac Toxin. J Agric Food Chem 2022; 70:11419-11428. [PMID: 36040024 DOI: 10.1021/acs.jafc.2c03618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Rapid evolution of resistance in crop pests to Bacillus thuringiensis (Bt) products threatens their widespread use, especially as pests appear to develop resistance through a range of different physiological adaptations. With such a diverse range of mechanisms reported, researchers have resorted to multi-omic approaches to understand the molecular basis of resistance. Such approaches generate a lot of data making it difficult to establish where causal links between physiological changes and resistance exist. In this study, a combination of RNA-Seq and iTRAQ was used with a strain of diamondback moth, Plutella xylostella (L.), whose resistance mechanism is well understood. While some of the causal molecular changes in the resistant strain were detected, other previously verified changes were not detected. We suggest that while multi-omic studies have use in validating a proposed resistance mechanism, they are of limited value in identifying such a mechanism in the first place.
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Affiliation(s)
- Shi Kang
- School of Life Sciences, Institute of Life Sciences and Green Development, Hebei University, Baoding 071002, China
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xun Zhu
- State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Qingjun Wu
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Shaoli Wang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Neil Crickmore
- School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
| | - Youjun Zhang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhaojiang Guo
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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37
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Yin Y, Xu Y, Cao K, Zhao X, Cao C, Dong X, Liang J, Shi W. Effect of genetically modified maize expressing the Cry1Ab and EPSPS proteins on growth, development, and gut bacterial diversity of the non-target arthropod Locusta migratoria. Environ Sci Pollut Res Int 2022; 29:63837-63845. [PMID: 35467188 DOI: 10.1007/s11356-022-20147-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/04/2022] [Indexed: 06/14/2023]
Abstract
The widespread cultivation of genetically modified (GM) crops has raised concerns for their safety. Here, we evaluated the effects of a GM maize variety expressing the Cry1Ab (14.76 ± 0.87 μg/g FW) and EPSPS proteins (191.55 ± 15.69 μg/g FW) on the life-history traits and gut bacterial community of a non-target arthropod, Locusta migratoria, in the laboratory. We found that GM maize had no significant effect on the survival or body weight of different development stages of L. migratoria. The midgut and hindgut bacterial diversities and compositions were determined using high-throughput sequencing targeting the V3-V4 regions of the 16S rRNA. No significant changes were found in the species diversity or abundance between insects in the GM-fed treatment and the non-GM control. Furthermore, the concentration of Cry1Ab and EPSPS in the gut was determined after digestion of GM maize. Results showed that the contents of Cry1Ab/EPSPS rapidly decreased and were hard to detect after 72 h. Based on the parameters assessed, we can conclude that the GM maize variety examined has no significant adverse effect on L. migratoria.
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Affiliation(s)
- Yue Yin
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100094, China
| | - Yudi Xu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100094, China
| | - Kaili Cao
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100094, China
| | - Xinxin Zhao
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100094, China
| | - Chuan Cao
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100094, China
| | - Xuehui Dong
- Department of Agriculture Science, China Agricultural University, Beijing, 100094, China
| | - Jingang Liang
- Development Center of Science and Technology, Ministry of Agriculture and Rural Affairs, Beijing, 100176, China
| | - Wangpeng Shi
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, China Agricultural University, Beijing, 100094, China.
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38
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Zheng S, Chen R, Wang L, Pan S, Liu W, Zhu X, Gao X, Luo J, Cui J. Effect of Metabolic Changes in Aphis gossypii-Damaged Cotton Plants on Oviposition Preference and Larval Development of Subsequent Helicoverpa armigera. J Agric Food Chem 2022; 70:9584-9595. [PMID: 35861328 DOI: 10.1021/acs.jafc.2c02876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Aphis gossypii and Helicoverpa armigera are two important agricultural pests in cotton plants. However, whether early colonization of A. gossypii affects subsequent H. armigera is unknown. We implemented ecological experiments to reveal that A. gossypii-damaged cotton plants [Bacillus thuringiensis (Bt) and non-Bt] had a significant avoidance effect on the oviposition preference of H. armigera adults. However, A. gossypii-damaged cotton plants (non-Bt) increased the weight and pupation rate and reduced the mortality of H. armigera larvae. Transcriptomic and metabolomic analyses showed that 13 and 9 genes were significantly upregulated to be involved in salicylic acid (SA) and indole acetic acid (IAA) biosynthesis, and SA and IAA contents were significantly increased, respectively. However, 15 genes involved in jasmonic acid (JA) biosynthesis were significantly downregulated as a result of the antagonism of SA and JA. Moreover, there was significant upregulation in multiple genes involved in the biosynthesis of l-histidine, fructose, maltotetraose, melezitose, lecithin, stearidonic acid, and mannitol, in which metabolites were confirmed to promote the growth and development of H. armigera. Our study is a reference for investigating the evolutionary relationships and provides insights into implementing effective insect biocontrol between H. armigera and A. gossypii.
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Affiliation(s)
- Shuaichao Zheng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, People's Republic of China
| | - Ruifang Chen
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou, Henan 450001, People's Republic of China
| | - Lisha Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
| | - Shaodong Pan
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
| | - Weijiao Liu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
| | - Xiangzhen Zhu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
| | - Xueke Gao
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
| | - Junyu Luo
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
| | - Jinjie Cui
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan 455000, People's Republic of China
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Edrington T, Wang R, McKinnon L, Kessenich C, Hodge-Bell K, Li W, Tan J, Brown G, Wang C, Li B, Giddings K. Food and feed safety of the Bacillus thuringiensis derived protein Vpb4Da2, a novel protein for control of western corn rootworm. PLoS One 2022; 17:e0272311. [PMID: 35921368 PMCID: PMC9348738 DOI: 10.1371/journal.pone.0272311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 07/18/2022] [Indexed: 11/30/2022] Open
Abstract
Western corn rootworm (WCR), Diabrotica virgifera virgifera, LeConte, is an insect pest that poses a significant threat to the productivity of modern agriculture, causing significant economic and crop losses. The development of genetically modified (GM) crops expressing one or more proteins that confer tolerance to specific insect pests, such as WCR, was a historic breakthrough in agricultural biotechnology and continues to serve as an invaluable tool in pest management. Despite this, evolving resistance to existing insect control proteins expressed in current generation GM crops requires continued identification of new proteins with distinct modes of action while retaining targeted insecticidal efficacy. GM crops expressing insecticidal proteins must undergo extensive safety assessments prior to commercialization to ensure that they pose no increased risk to the health of humans or other animals relative to their non-GM conventional counterparts. As part of these safety evaluations, a weight of evidence approach is utilized to assess the safety of the expressed insecticidal proteins to evaluate any potential risk in the context of dietary exposure. This study describes the food and feed safety assessment of Vpb4Da2, a new Bacillus thuringiensis insecticidal protein that confers in planta tolerance to WCR. Vpb4Da2 exhibits structural and functional similarities to other insect control proteins expressed in commercialized GM crops. In addition, the lack of homology to known toxins or allergens, a lack of acute toxicity in mice, inactivation by conditions commonly experienced in the human gut or during cooking/food processing, and the extremely low expected dietary exposure to Vpb4Da2 provide a substantial weight of evidence to demonstrate that the Vpb4Da2 protein poses no indication of a risk to the health of humans or other animals.
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Affiliation(s)
| | - Rong Wang
- Bayer Crop Science, Chesterfield, MO, United States of America
- * E-mail:
| | - Lucas McKinnon
- Bayer Crop Science, Chesterfield, MO, United States of America
| | | | | | - Wenze Li
- Bayer Crop Science, Chesterfield, MO, United States of America
| | - Jianguo Tan
- Bayer Crop Science, Chesterfield, MO, United States of America
| | - Gregory Brown
- Bayer Crop Science, Chesterfield, MO, United States of America
| | - Cunxi Wang
- Bayer Crop Science, Chesterfield, MO, United States of America
| | - Bin Li
- Bayer Crop Science, Chesterfield, MO, United States of America
| | - Kara Giddings
- Bayer Crop Science, Chesterfield, MO, United States of America
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40
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Horikoshi RJ, Ferrari G, Dourado PM, Climaco JI, Vertuan HV, Evans A, Pleau M, Morrell K, José MOMA, Anderson H, Martinelli S, Ovejero RFL, Berger GU, Head G. MON 95379 Bt maize as a new tool to manage sugarcane borer (Diatraea saccharalis) in South America. Pest Manag Sci 2022; 78:3456-3466. [PMID: 35567382 PMCID: PMC9545257 DOI: 10.1002/ps.6986] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/26/2022] [Accepted: 05/14/2022] [Indexed: 05/10/2023]
Abstract
BACKGROUND The sugarcane borer (SCB), Diatraea saccharalis (Lepidoptera: Crambidae), is a key pest of maize in Argentina, and genetically modified maize, producing Bacillus thuringiensis (Bt) proteins, has revolutionized the management of this insect in South America. However, field-evolved resistance to some Bt technologies has been observed in SCB in Argentina. Here we assessed a new Bt technology, MON 95379, in the laboratory, greenhouse and field for efficacy against SCB. RESULTS In a laboratory leaf disc bioassay, both MON 95379 (producing Cry1B.868 and Cry1Da_7) and Cry1B.868_single maize (producing only Cry1B.868) resulted in 100% mortality of SCB. The level of Cry1B.868 in the Cry1B.868_single maize is comparable to that in MON 95379 maize. However, the Cry1Da_7 protein does not have high efficacy against SCB, as evidenced by < 20% mortality on Cry1Da_7_single leaf tissue. Total (100%) mortality of SCB in a Cry1B.868_single tissue dilution bioassay indicated that Cry1B.868_single maize meets the criteria to be classified as a high dose. Similar median lethal concentration (LC50 ) values were observed for MON 89034-R and susceptible SCB strains exposed to Cry1B.868 protein. MON 95379 also controlled SCB strains resistant to MON 89034 (Cry1A.105/Cry2Ab2) and Cry1Ab. Under field conditions in Brazil and Argentina, MON 95379 maize plants were consistently protected from SCB damage. CONCLUSION MON 95379 maize will bring value to maize growers in South America by effectively managing SCB even in locations where resistance to other Bt-containing maize technologies has been reported. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
| | | | | | | | | | - Adam Evans
- Plant BiotechnologyBayer Crop Science USChesterfieldMOUSA
| | - Michael Pleau
- Plant BiotechnologyBayer Crop Science USChesterfieldMOUSA
| | | | | | | | | | | | | | - Graham Head
- Regulatory ScienceBayer Crop Science USChesterfieldMOUSA
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Shen ZJ, Zhu F, Liu YJ, Li Z, Moural TW, Liu XM, Liu X. MicroRNAs miR-14 and miR-2766 regulate tyrosine hydroxylase to control larval-pupal metamorphosis in Helicoverpa armigera. Pest Manag Sci 2022; 78:3540-3550. [PMID: 35587569 DOI: 10.1002/ps.6997] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/06/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The cotton bollworm, Helicoverpa armigera, is a worldwide polyphagous pest, causing huge economic losses in vegetable, cotton and corn crops, among others. Owing to long-term exposure to Bacillus thuringiensis (Bt) toxins, evolution of resistance has been detected in this pest. As a conservative and effective neurotransmitter, dopamine (DA) has an important role in insect growth and development. In this study, we investigated the regulatory functions of DA and its associated non-coding RNA in metamorphosis in H. armigera. RESULTS Expression profiles indicated that DA and DA pathway genes were highly expressed during larval-pupal metamorphosis in H. armigera. RNA interference and pharmacological experiments confirmed that tyrosine hydroxylase (TH), dopa decarboxylase, vesicular amine transporter and DA receptor 2 are critical genes related to the development of H. armigera from larvae to pupae. We also found that miR-14 and miR-2766 targeted the 3' untranslated region to post-transcriptionally regulate HaTH function. Application of miR-2766 and miR-14 antagomirs significantly increased levels of HaTH transcripts and proteins, while injection of miR-2766 and miR-14 agomirs not only suppressed messenger RNA and protein levels of HaTH, but also resulted in defective pupation in H. armigera. CONCLUSION These results suggest that DA deficiency inhibits larval-pupal metamorphosis in H. armigera. Potentially, DA pathway genes and their microRNAs could be used as a novel target for H. armigera management. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Zhong-Jian Shen
- Department of Entomology, MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Haidian, Beijing, China
| | - Fang Zhu
- Department of Entomology, Pennsylvania State University, University Park, State College, PA, USA
| | - Yan-Jun Liu
- Department of Entomology, MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Haidian, Beijing, China
| | - Zhen Li
- Department of Entomology, MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Haidian, Beijing, China
| | - Timothy W Moural
- Department of Entomology, Pennsylvania State University, University Park, State College, PA, USA
| | - Xiao-Ming Liu
- Department of Entomology, MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Haidian, Beijing, China
| | - Xiaoxia Liu
- Department of Entomology, MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Haidian, Beijing, China
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Wang W, Zhang D, Zhao S, Wu K. Susceptibilities of the Invasive Fall Armyworm ( Spodopterafrugiperda) to the Insecticidal Proteins of Bt maize in China. Toxins (Basel) 2022; 14:toxins14080507. [PMID: 35893749 PMCID: PMC9331229 DOI: 10.3390/toxins14080507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/13/2022] [Accepted: 07/22/2022] [Indexed: 11/16/2022] Open
Abstract
To control the fall armyworm (FAW), Spodoptera frugiperda (Smith), a serious threat to maize production in China, the Chinese government has issued biosafety certificates for transgenic insect-resistant maize expressing Bt (Bacillus thuringiensis) toxins including Bt-Cry1Ab maize (crop event DBN9936), Bt-Vip3Aa maize (event DBN9501), Bt-(Cry1Ab+Vip3Aa) maize with superimposed traits (event DBN9936 × DBN9501) and Bt-(Cry1Ab+Vip3Aa) maize with superimposed traits (event Bt11 × MIR162), but the susceptibility baselines of geographically distinct FAW populations to these events, which form the basis for managing resistance development in the pest to these events, are not clear. We used the diet-incorporated bioassays method to detect the susceptibilities of the seven FAW populations collected from Yunnan, Henan and Hubei provinces in China in 2021 to the insecticidal proteins of the four Bt maize events. The result showed that the susceptibilities of different geographical populations to Bt insecticidal proteins were significantly different. In the seven populations, the range in median lethal concentrations (LC50) of Cry1Ab expressed in DBN9936 was 0.87-2.63 μg/g, 0.14-0.30 μg/g for Vip3Aa expressed in DBN9501, 0.78-1.86 μg/g for Cry1Ab+Vip3Aa expressed in DBN9936 × DBN9501, and 0.36-1.42 μg/g for CryAb+Vip3Aa expressed in Bt11 × MIR162. The growth inhibition responses also showed that the susceptibilities varied with the different median growth inhibitory concentration (GIC50) ranges (0.38-1.22, 0.08-0.28, 0.28-0.87, and 0.24-0.78 μg/g, respectively). The variations in the ranges of the susceptibility baselines of the geographical populations of fall armyworm in China to the insecticidal proteins expressed in the four events provide a scientific basis for monitoring FAW population resistance to Bt maize and managing the populations using different Bt maize events.
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Affiliation(s)
- Wenhui Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (W.W.); (D.Z.); (S.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510640, China
| | - Dandan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (W.W.); (D.Z.); (S.Z.)
- School of Grassland Science, Beijing Forestry University, Beijing 100083, China
| | - Shengyuan Zhao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (W.W.); (D.Z.); (S.Z.)
- Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510640, China
| | - Kongming Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (W.W.); (D.Z.); (S.Z.)
- Correspondence:
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Peng Y, Lv B, Lei ZY, Peng YD, Chen LJ, Wang Z. Toxic effects of the combined cadmium and Cry1Ab protein exposure on the protective and transcriptomic responses of Pirata subpiraticus. Ecotoxicol Environ Saf 2022; 239:113631. [PMID: 35598445 DOI: 10.1016/j.ecoenv.2022.113631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/05/2022] [Accepted: 05/08/2022] [Indexed: 06/15/2023]
Abstract
Cadmium (Cd) pollution poses a serious threat to agricultural production and paddy field fauna. Crystalline proteins (e.g., Cry1Ab and Cry1Ac) are secreted by Bacillus thuringiensis, which can manage pests via a complicated toxic mechanism and have been widely used for pest control due to the commercialization of transgenic crops (e.g., cotton and rice) that expresses Bt insecticidal proteins. Nonetheless, studies on the effects of combined stress of Cd and Cry1Ab protein on field indicator species are limited. In the present study, we showed that spiders, Pirata subpiraticus, fed with Cd-containing flies+Cry1Ab had dramatically higher Cd accumulation than that in the spiders fed with Cd-containing flies (p < 0.05). In addition, the enrichment of Cd led to the activation of the protective mechanism by elevating the concentrations of glutathione peroxidase, glutathione S-transferase, and metallothionein in the spiders (p < 0.05). An in-depth transcriptome analysis revealed that the activities of ion metal binding proteins, transporters, and channels might play essential roles in the Cd accumulation process. More importantly, the higher Cd concentration in the combined Cd+Cry1Ab exposure prolonged developmental duration of P. subpiraticus, due to the down-regulated cuticle proteins (CPs) encoding genes involved in the molting process, which was regulated by a series of putative transcriptional factors such as ZBTB and zf-C2H2. Collectively, this integrated analysis illustrates that the combined Cd+Cry1Ab exposure increases the adverse effects of Cd stress on the growth, antioxidase, and CPs encoding genes of P. subpiraticus, thus providing a research basis and prospect for the rationality of transgenic Cry1Ab crops in the cultivation of heavy metal contaminated soil.
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Affiliation(s)
- Yong Peng
- College of Life Science, Hunan Normal University, Changsha 410006, Hunan, China
| | - Bo Lv
- College of Life Science, Hunan Normal University, Changsha 410006, Hunan, China
| | - Zi-Yan Lei
- College of Resources and Environment, Hunan Agricultural University, Changsha 410128, China
| | - Yuan-de Peng
- Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, Hunan, China
| | - Li-Jun Chen
- College of Life Science, Hunan Normal University, Changsha 410006, Hunan, China; Shaoyang University, Shaoyang 422000, Hunan, China.
| | - Zhi Wang
- College of Life Science, Hunan Normal University, Changsha 410006, Hunan, China.
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Endo H. Molecular and Kinetic Models for Pore Formation of Bacillus thuringiensis Cry Toxin. Toxins (Basel) 2022; 14:toxins14070433. [PMID: 35878171 PMCID: PMC9321905 DOI: 10.3390/toxins14070433] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 06/03/2022] [Accepted: 06/22/2022] [Indexed: 02/05/2023] Open
Abstract
Cry proteins from Bacillus thuringiensis (Bt) and other bacteria are pesticidal pore-forming toxins. Since 2010, when the ABC transporter C2 (ABCC2) was identified as a Cry1Ac protein resistant gene, our understanding of the mode of action of Cry protein has progressed substantially. ABCC2 mediates high Cry1A toxicity because of its high activity for helping pore formation. With the discovery of ABCC2, the classical killing model based on pore formation and osmotic lysis became nearly conclusive. Nevertheless, we are still far from a complete understanding of how Cry proteins form pores in the cell membrane through interactions with their host gut membrane proteins, known as receptors. Why does ABCC2 mediate pore formation with high efficiency unlike other Cry1A-binding proteins? Is the “prepore” formation indispensable for pore formation? What is the mechanism underlying the synergism between ABCC2 and the 12-cadherin domain protein? We examine potential mechanisms of pore formation via receptor interactions in this paper by merging findings from prior studies on the Cry mode of action before and after the discovery of ABC transporters as Cry protein receptors. We also attempt to explain Cry toxicity using Cry–receptor binding affinities, which successfully predicts actual Cry toxicity toward cultured cells coexpressing ABC transporters and cadherin.
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Affiliation(s)
- Haruka Endo
- Department of Integrated Bioscience, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8562, Japan
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Yang L, Sun Y, Chang M, Zhang Y, Qiao H, Huang S, Kan Y, Yao L, Li D, Ayra-Pardo C. RNA Interference-Mediated Knockdown of Bombyx mori Haemocyte-Specific Cathepsin L ( Cat L)-Like Cysteine Protease Gene Increases Bacillus thuringiensis kurstaki Toxicity and Reproduction in Insect Cadavers. Toxins (Basel) 2022; 14:toxins14060394. [PMID: 35737055 PMCID: PMC9230843 DOI: 10.3390/toxins14060394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/31/2022] [Accepted: 06/03/2022] [Indexed: 12/10/2022] Open
Abstract
The silkworm’s Cat L-like gene, which encodes a lysosomal cathepsin L-like cysteine protease, is thought to be part of the insect’s innate immunity via an as-yet-undetermined mechanism. Assuming that the primary function of Cat L-like is microbial degradation in mature phagosomes, we hypothesise that the suppression of the Cat L-like gene expression would increase Bacillus thuringiensis (Bt) bacteraemia and toxicity in knockdown insects. Here, we performed a functional analysis of Cat L-like in larvae that were fed mulberry leaves contaminated with a commercial biopesticide formulation based on Bt kurstaki (Btk) (i.e., Dipel) to investigate its role in insect defence against a known entomopathogen. Exposure to sublethal doses of Dipel resulted in overexpression of the Cat L-like gene in insect haemolymph 24 and 48 h after exposure. RNA interference (RNAi)-mediated suppression of Cat L-like expression significantly increased the toxicity of Dipel to exposed larvae. Moreover, Btk replication was higher in RNAi insects, suggesting that Cat L-like cathepsin may be involved in a bacterial killing mechanism of haemocytes. Finally, our results confirm that Cat L-like protease is part of the antimicrobial defence of insects and suggest that it could be used as a target to increase the insecticidal efficacy of Bt-based biopesticides.
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Affiliation(s)
- Linlin Yang
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
| | - Yanyan Sun
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
| | - Meiling Chang
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
| | - Yun Zhang
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
| | - Huili Qiao
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
| | - Siliang Huang
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
| | - Yunchao Kan
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
- School of Life Science, Henan University, Jin Ming Avenue, Kaifeng 475004, China
| | - Lunguang Yao
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
| | - Dandan Li
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
- Correspondence: (D.L.); (C.A.-P.)
| | - Camilo Ayra-Pardo
- China-UK-NYNU-RRES Joint Laboratory of Insect Biology, Henan Key Laboratory of Insect Biology in Funiu Mountain, School of Life Sciences and Agricultural Engineering, Nanyang Normal University (NYNU), Nanyang 473061, China; (L.Y.); (Y.S.); (M.C.); (Y.Z.); (H.Q.); (S.H.); (Y.K.); (L.Y.)
- Correspondence: (D.L.); (C.A.-P.)
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Wang H, Zhang C, Chen G, Li Y, Yang X, Han L, Peng Y. Downregulation of the CsABCC2 gene is associated with Cry1C resistance in the striped stem borer Chilo suppressalis. Pestic Biochem Physiol 2022; 184:105119. [PMID: 35715058 DOI: 10.1016/j.pestbp.2022.105119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 06/15/2023]
Abstract
Chilo suppressalis is a major target pest of transgenic rice expressing the Bacillus thuringiensis (Bt) Cry1C toxin in China. The evolution of resistance of this pest is a major threat to Bt rice. Since Bt functions by binding to receptors in the midgut (MG) of target insects, identification of Bt functional receptors in C. suppressalis is crucial for evaluating potential resistance mechanisms and developing effective management strategies. ATP-binding cassette (ABC) transporters have been vastly reported to interact with Cry1A toxins, as receptors and their mutations cause insect Bt resistance. However, the role of ABC transporters in Cry1C resistance to C. suppressalis remains unknown. Here, we measured CsABCC2 expression in C. suppressalis Cry1C-resistant (Cry1C-R) and Cry1C-susceptible strains (selected in the laboratory) via quantitative real-time PCR (qRT-PCR); the transcript level of CsABCC2 in the Cry1C-R strain was significantly lower than that in the Cry1C-susceptible strain. Furthermore, silencing CsABCC2 in C. suppressalis via RNA interference (RNAi) significantly decreased Cry1C susceptibility. Overall, CsABCC2 participates in Cry1C mode of action, and reduced expression of CsABCC2 is functionally associated with Cry1C resistance in C. suppressalis.
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Affiliation(s)
- Huilin Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Chuan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Geng Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Yunhe Li
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Xiaowei Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
| | - Lanzhi Han
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China.
| | - Yufa Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
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Wang X, Yi XL, Hou CX, Wang XY, Sun X, Zhang ZJ, Qin S, Li MW. Map-based cloning and functional analysis revealed ABCC2 is responsible for Cry1Ac toxin resistance in Bombyx mori. Arch Insect Biochem Physiol 2022; 110:e21886. [PMID: 35307854 DOI: 10.1002/arch.21886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/22/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Bt toxins are parasporal crystals produced by Bacillus thuringiensis (Bt). They have specific killing activity against various insects and have been widely used to control agricultural pests. However, their widespread use has developed the resistance of many target insects. To maintain the sustainable use of Bt products, the resistance mechanism of insects to Bt toxins must be fully clarified. In this study, Bt-resistant and Bt-susceptible silkworm strains were used to construct genetic populations, and the genetic pattern of silkworm resistance to Cry1Ac toxin was determined. Sequence-tagged site molecular marker technology was used to finely map the resistance gene and to draw a molecular genetic linkage map, and the two closest markers were T1590 and T1581, indicating the resistance gene located in the 155 kb genetic region. After analyzing the sequence of the predicted gene in the genetic region, an ATP binding cassette transporter (ABCC2) was identified as the candidate gene. Molecular modeling and protein-protein docking result showed that a tyrosine insertion in the mutant ABCC2 might be responsible for the interaction between Cry1Ac and ABCC2. Moreover, CRISPR/Cas9-mediated genome editing technology was used to knockout ABCC2 gene. The homozygous mutant ABCC2 silkworm was resistant to Cry1Ac toxin, which indicated ABCC2 is the key gene that controls silkworm resistance to Cry1Ac toxin. The results have laid the foundation for elucidating the molecular resistance mechanism of silkworms to Cry1Ac toxin and could provide a theoretical basis for the biological control of lepidopteran pests.
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Affiliation(s)
- Xin Wang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
| | - Xiao-Li Yi
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
| | - Cheng-Xiang Hou
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, China
| | - Xue-Yang Wang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, China
| | - Xia Sun
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, China
| | - Zhong-Jie Zhang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
| | - Sheng Qin
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, China
| | - Mu-Wang Li
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, China
- Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, China
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Liu L, Xu P, Liu K, Wei W, Chang Z, Cheng D. [Advances in receptor-mediated resistance mechanisms of Lepidopteran insects to Bacillus thuringiensis toxin]. Sheng Wu Gong Cheng Xue Bao 2022; 38:1809-1823. [PMID: 35611730 DOI: 10.13345/j.cjb.210834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Bacillus thuringiensis is widely used as an insecticide which is safe and environmentally friendly to humans and animals. One of the important insecticidal mechanisms is the binding of Bt toxins to specific toxin receptors in insect midgut and forming a toxin perforation which eventually leads to insect death. The resistance of target pests to Bt toxins is an important factor hampering the long-term effective cultivation of Bt crops and the continuous use of Bt toxins. This review summarizes the mechanism of insect resistance to Bt toxins from the perspective of important Bt toxin receptors in midgut cells of Lepidopteran insects, which may facilitate the in-depth study of Bt resistance mechanism and pest control.
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Affiliation(s)
- Leilei Liu
- Center of Applied Biotechnology, School of Life Sciences and Technology, Wuhan University of Bioengineering, Wuhan 430415, Hubei, China
| | - Peiwen Xu
- Center of Applied Biotechnology, School of Life Sciences and Technology, Wuhan University of Bioengineering, Wuhan 430415, Hubei, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Kaiyu Liu
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan 430079, Hubei, China
| | - Wei Wei
- Center of Applied Biotechnology, School of Life Sciences and Technology, Wuhan University of Bioengineering, Wuhan 430415, Hubei, China
| | - Zhongshen Chang
- Center of Applied Biotechnology, School of Life Sciences and Technology, Wuhan University of Bioengineering, Wuhan 430415, Hubei, China
| | - Dahui Cheng
- Center of Applied Biotechnology, School of Life Sciences and Technology, Wuhan University of Bioengineering, Wuhan 430415, Hubei, China
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49
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Alam I, Batool K, Idris AL, Tan W, Guan X, Zhang L. Role of Lectin in the Response of Aedes aegypti Against Bt Toxin. Front Immunol 2022; 13:898198. [PMID: 35634312 PMCID: PMC9136036 DOI: 10.3389/fimmu.2022.898198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 04/19/2022] [Indexed: 12/05/2022] Open
Abstract
Aedes aegypti is one of the world’s most dangerous mosquitoes, and a vector of diseases such as dengue fever, chikungunya virus, yellow fever, and Zika virus disease. Currently, a major global challenge is the scarcity of antiviral medicine and vaccine for arboviruses. Bacillus thuringiensis var israelensis (Bti) toxins are used as biological mosquito control agents. Endotoxins, including Cry4Aa, Cry4Ba, Cry10Aa, Cry11Aa, and Cyt1Aa, are toxic to mosquitoes. Insect eradication by Cry toxin relies primarily on the interaction of cry toxins with key toxin receptors, such as aminopeptidase (APN), alkaline phosphatase (ALP), cadherin (CAD), and ATP-binding cassette transporters. The carbohydrate recognition domains (CRDs) of lectins and domains II and III of Cry toxins share similar structural folds, suggesting that midgut proteins, such as C-type lectins (CTLs), may interfere with interactions among Cry toxins and receptors by binding to both and alter Cry toxicity. In the present review, we summarize the functional role of C-type lectins in Ae. aegypti mosquitoes and the mechanism underlying the alteration of Cry toxin activity by CTLs. Furthermore, we outline future research directions on elucidating the Bti resistance mechanism. This study provides a basis for understanding Bti resistance, which can be used to develop novel insecticides.
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Affiliation(s)
- Intikhab Alam
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
- College of Life Sciences, South China Agricultural University, Guangzhou, China
| | - Khadija Batool
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Aisha Lawan Idris
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Weilong Tan
- Nanjing Bioengineering (Gene) Technology Center for Medicines, Nanjing, China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Lingling Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Key Lab of Biopesticides and Chemical Biology, MOE, Fujian Agriculture and Forestry University, Fuzhou, China
- *Correspondence: Lingling Zhang,
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Lv N, Liu Y, Guo T, Liang P, Li R, Liang P, Gao X. The influence of Bt cotton cultivation on the structure and functions of the soil bacterial community by soil metagenomics. Ecotoxicol Environ Saf 2022; 236:113452. [PMID: 35366565 DOI: 10.1016/j.ecoenv.2022.113452] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 03/19/2022] [Accepted: 03/22/2022] [Indexed: 06/14/2023]
Abstract
Bt cotton successfully controlled major devastating pests in cotton,such as Helicoverpa armigera and Spodoptera exigua, and led to a drastic decrease in insecticide use in cotton fields, and it has been grown commercially worldwide. However, Bt cotton cultivation left Bt toxin residues in the soil, resulting in a response by its microbiome that caused potential environmental risks. In this research, the metagenomics analysis was performed to investigate the structure and functions of the soil bacterial community in the Bt cotton field from the Binzhou, Shandong province of China, where the Bt cotton has been cultivated for over fifteen years. Analysis of the function genes proved that the receptors of Bt toxins were absent in the soil bacteria and Bt toxins failed to target the soil bacteria. The microbiome structure and function were highly influenced by Bt cotton cultivation, however, no significant change in the total abundance of the bacteria was observed. Proteobacteria was the largest taxonomic group in the soil bacterial (42-52%) and its abundance was significantly increased after Bt cotton cultivation. The increase of Proteobacteria abundance resulted in an increase in ABC transporters gene abundance, indicating the improved ability of detoxification metabolism over Bt cotton cultivation. Xanthomonadales could be a biomarker of the Bt cotton group, whose abundance was significantly increased to contribute to the increase of the genes abundance in ABC transporters. The abundance of apoptosis genes was significantly decreased, and it might be related to the increase of Proteobacteria abundance by Bt cotton cultivation. In addition, Myxococcales was responsible for carotenoid biosynthesis, whoes genes abundance was significantly decreased due to the decrease of Myxococcales abundance by Bt cotton cultivation. These changes in soil bacterial community structure and functions indicate the influence by Bt cotton cultivation, leading to an understanding of the bacteria colonization patterns due to successive years of Bt cotton cultivation. These research results should be significant for the rational risk assessment of Bt cotton cultivation.
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Affiliation(s)
- Nannan Lv
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Ying Liu
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Tianfeng Guo
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Pingzhuo Liang
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Ren Li
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Pei Liang
- Department of Entomology, China Agricultural University, Beijing 100193, China
| | - Xiwu Gao
- Department of Entomology, China Agricultural University, Beijing 100193, China.
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