1
|
Jiang K, Gao X. Current advances on Vip3 highlight the promising potential of bacterial insecticidal proteins. Trends Microbiol 2024:S0966-842X(24)00145-8. [PMID: 38902178 DOI: 10.1016/j.tim.2024.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/22/2024]
Abstract
Biological control, based on microbial insecticidal proteins, has become an important strategy for sustainable pest management. This forum discusses recent advancements and research strategies of the bacterial insecticidal protein vegetative insecticidal protein 3 (Vip3), aiming to provide valuable insights for future investigations on Vip3 and other insecticidal proteins.
Collapse
Affiliation(s)
- Kun Jiang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.
| | - Xiang Gao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, China.
| |
Collapse
|
2
|
Wang C, Li M, Chen X, Fan S, Lan J. Binding Analysis of Sf-SR-C MAM Domain and Sf-FGFR Ectodomain to Vip3Aa. INSECTS 2024; 15:428. [PMID: 38921143 PMCID: PMC11203654 DOI: 10.3390/insects15060428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 05/16/2024] [Accepted: 06/04/2024] [Indexed: 06/27/2024]
Abstract
Bacillus thuringiensis Vip3Aa has been widely used in transgenic crops to resist the erosion of insects. The Scavenger Receptor-C (SR-C) and Fibroblast Growth Factor Receptor (FGFR) of Spodoptera frugiperda (Sf-SR-C and Sf-FGFR) have formerly been identified as the cell receptors of Vip3Aa. However, the interaction mechanism of Vip3Aa binding to Sf-SR-C or Sf-FGFR is still unknown. Here, we purified the MAM domain of Sf-SR-C (Sf-MAM) and the Sf-FGFR ectodomain expressed extracellularly by Sf9 cells. We then solved the crystal structure of the Sf-MAM domain. Structure docking analysis of the Sf-MAM and Vip3Aa C-terminal domain (CTD) excluded the possibility of the two proteins binding. A further surface plasmon resonance (SPR) assay also revealed that the Sf-MAM and Sf-FGFR ectodomain could not bind to the Vip3Aa protein. Our results have raised the urgency of determining the authentic cell receptor for Vip3Aa.
Collapse
Affiliation(s)
- Chenghai Wang
- School of Biomedical Sciences, Hunan University, Changsha 410082, China;
| | - Min Li
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; (M.L.); (X.C.); (S.F.)
| | - Xiling Chen
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; (M.L.); (X.C.); (S.F.)
| | - Shilong Fan
- Beijing Advanced Innovation Center for Structural Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; (M.L.); (X.C.); (S.F.)
| | - Jun Lan
- School of Biomedical Sciences, Hunan University, Changsha 410082, China;
| |
Collapse
|
3
|
Soonsanga S, Rungrod A, Promdonkoy B. Protein Engineering of Vip3A in a Selected Bacillus thuringiensis Host for Consistent High Protein Production. Curr Microbiol 2024; 81:211. [PMID: 38839629 DOI: 10.1007/s00284-024-03721-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 04/26/2024] [Indexed: 06/07/2024]
Abstract
This study aimed to obtain reliable high Vip3A production from Bacillus thuringiensis (Bt) by modifying Vip3A to acquire higher thermostability in a suitable host. Bt117 is a great host for Vip3A production due to protein production consistency, low protease activity in culture media, and large amounts of mostly full-length protein, but it produces Vip3A with lower thermostability (Vip3Aa35). The C-terminal region of Bt117 Vip3A was replaced with that of a Vip3A with higher thermostability (Vip3Aa64 from Bt294) to generate the recombinant Bt117-Vip3Aa64-C. Like the parental strain Bt117, this strain expressed mostly full-length protein and exhibited low protease activity and similar protein expression profiles in culture media but retained greater larvicidal activity upon 37 °C storage like Bt294 Vip3Aa64. Importantly, every culture batch of Bt117-Vip3Aa64-C yielded over 200 mg/l Vip3A, which is a notable improvement over the original Vip3Aa64-producing strain Bt294 where 45% of culture batches failed to produce Vip3A at the same level. Successfully, we combined the superior qualities of two Bt strains, Bt294, which produces thermostable Vip3A but at low and inconsistent levels, and Bt117, which produces Vip3A with low thermostability but at consistently high levels. Protein engineering of Vip3A in Bt117 ultimately yielded an improved strain producing a thermostable Vip3A with reliably high protein production.
Collapse
Affiliation(s)
- Sumarin Soonsanga
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand.
| | - Amporn Rungrod
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand
| | - Boonhiang Promdonkoy
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani, 12120, Thailand
| |
Collapse
|
4
|
Ma T, Huang J, Xu P, Shu C, Wang Z, Geng L, Zhang J. In Vivo and In Vitro Interactions between Exopolysaccharides from Bacillus thuringensis HD270 and Vip3Aa11 Protein. Toxins (Basel) 2024; 16:215. [PMID: 38787067 PMCID: PMC11125869 DOI: 10.3390/toxins16050215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 04/29/2024] [Accepted: 05/01/2024] [Indexed: 05/25/2024] Open
Abstract
Bacillus thuringiensis (Bt) secretes the nutritional insecticidal protein Vip3Aa11, which exhibits high toxicity against the fall armyworm (Spodoptera frugiperda). The Bt HD270 extracellular polysaccharide (EPS) enhances the toxicity of Vip3Aa11 protoxin against S. frugiperda by enhancing the attachment of brush border membrane vesicles (BBMVs). However, how EPS-HD270 interacts with Vip3Aa11 protoxin in vivo and the effect of EPS-HD270 on the toxicity of activated Vip3Aa11 toxin are not yet clear. Our results indicated that there is an interaction between mannose, a monosaccharide that composes EPS-HD270, and Vip3Aa11 protoxin, with a dissociation constant of Kd = 16.75 ± 0.95 mmol/L. When EPS-HD270 and Vip3Aa11 protoxin were simultaneously fed to third-instar larvae, laser confocal microscopy observations revealed the co-localization of the two compounds near the midgut wall, which aggravated the damage to BBMVs. EPS-HD270 did not have a synergistic insecticidal effect on the activated Vip3Aa11 protein against S. frugiperda. The activated Vip3Aa11 toxin demonstrated a significantly reduced binding capacity (548.73 ± 82.87 nmol/L) towards EPS-HD270 in comparison to the protoxin (34.96 ± 9.00 nmol/L). Furthermore, this activation diminished the affinity of EPS-HD270 for BBMVs. This study provides important evidence for further elucidating the synergistic insecticidal mechanism between extracellular polysaccharides and Vip3Aa11 protein both in vivo and in vitro.
Collapse
Affiliation(s)
- Tianjiao Ma
- College of Life Sciences, Northeast Agricultural University, Harbin 150030, China; (T.M.); (J.H.)
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jinqiu Huang
- College of Life Sciences, Northeast Agricultural University, Harbin 150030, China; (T.M.); (J.H.)
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Pengdan Xu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- College of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Changlong Shu
- 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
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jie Zhang
- College of Life Sciences, Northeast Agricultural University, Harbin 150030, China; (T.M.); (J.H.)
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| |
Collapse
|
5
|
Shao E, Huang H, Yuan J, Yan Y, Ou L, Chen X, Pan X, Guan X, Sha L. N-Terminal α-Helices in Domain I of Bacillus thuringiensis Vip3Aa Play Crucial Roles in Disruption of Liposomal Membrane. Toxins (Basel) 2024; 16:88. [PMID: 38393166 PMCID: PMC10892741 DOI: 10.3390/toxins16020088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 01/29/2024] [Accepted: 02/04/2024] [Indexed: 02/25/2024] Open
Abstract
Bacillus thuringiensis Vip3 toxins form a tetrameric structure crucial for their insecticidal activity. Each Vip3Aa monomer comprises five domains. Interaction of the first four α-helices in domain I with the target cellular membrane was proposed to be a key step before pore formation. In this study, four N-terminal α-helix-deleted truncations of Vip3Aa were produced and, it was found that they lost both liposome permeability and insecticidal activity against Spodoptera litura. To further probe the role of domain I in membrane permeation, the full-length domain I and the fragments of N-terminal α-helix-truncated domain I were fused to green fluorescent protein (GFP), respectively. Only the fusion carrying the full-length domain I exhibited permeability against artificial liposomes. In addition, seven Vip3Aa-Cry1Ac fusions were also constructed by combination of α-helices from Vip3Aa domains I and II with the domains II and III of Cry1Ac. Five of the seven combinations were determined to show membrane permeability in artificial liposomes. However, none of the Vip3Aa-Cry1Ac combinations exhibited insecticidal activity due to the significant reduction in proteolytic stability. These results indicated that the N-terminal helix α1 in the Vip3Aa domain I is essential for both insecticidal activity and liposome permeability and that domain I of Vip3Aa preserved a high liposome permeability independently from domains II-V.
Collapse
Affiliation(s)
- Ensi Shao
- China National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (E.S.); (J.Y.); (Y.Y.); (L.O.); (X.C.)
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (H.H.); (X.P.); (X.G.)
| | - Hanye Huang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (H.H.); (X.P.); (X.G.)
| | - Jin Yuan
- China National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (E.S.); (J.Y.); (Y.Y.); (L.O.); (X.C.)
| | - Yaqi Yan
- China National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (E.S.); (J.Y.); (Y.Y.); (L.O.); (X.C.)
| | - Luru Ou
- China National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (E.S.); (J.Y.); (Y.Y.); (L.O.); (X.C.)
| | - Xiankun Chen
- China National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (E.S.); (J.Y.); (Y.Y.); (L.O.); (X.C.)
| | - Xiaohong Pan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (H.H.); (X.P.); (X.G.)
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (H.H.); (X.P.); (X.G.)
| | - Li Sha
- China National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (E.S.); (J.Y.); (Y.Y.); (L.O.); (X.C.)
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou 350002, China; (H.H.); (X.P.); (X.G.)
| |
Collapse
|
6
|
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. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 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] [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.
Collapse
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
| |
Collapse
|
7
|
Hou X, Li M, Mao C, Jiang L, Zhang W, Li M, Geng X, Li X, Liu S, Yang G, Zhou J, Fang Y, Cai J. Domain III β4- β5 Loop and β14- β15 Loop of Bacillus thuringiensis Vip3Aa Are Involved in Receptor Binding and Toxicity. Toxins (Basel) 2024; 16:23. [PMID: 38251240 PMCID: PMC10820090 DOI: 10.3390/toxins16010023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/23/2023] [Accepted: 12/30/2023] [Indexed: 01/23/2024] Open
Abstract
Vip3Aa, secreted by Bacillus thuringiensis, is effective at controlling major agricultural pests such as Spodoptera frugiperda. However, to control Vip3Aa resistance evolved in the field by different lepidoptera species, an in-depth study of sequence--structure--activity relationships is necessary to design new Vip3Aa variants. In this study, the four specific loops (β4-β5 loop, β9-β10 loop, β12-β13 loop, and β14-β15 loop) in domain III were selected and four loop mutants were constructed by replacing all residues in each specific loop with alanine. We obtained soluble proteins for three of the loop mutants, excluding the β9-β10 loop. These loop mutants have been characterized by toxicity bioassays against S. frugiperda, proteolytic processing, and receptor binding. These results indicate that the β4-β5 loop and β14-β15 loop are involved in receptor binding and Vip3Aa toxicity. Based on this, we constructed numerous mutants and obtained three single mutants (Vip3Aa-S366T, Vip3Aa-S366L, and Vip3Aa-R501A) that exhibited significantly increased toxicity of 2.61-fold, 3.39-fold, and 2.51-fold, respectively. Compared to Vip3Aa, the receptor affinity of Vip3Aa-S366T and Vip3Aa-S366L was significantly enhanced. Furthermore, we also analyzed and aligned the three-dimensional structures of the mutants and Vip3Aa. In summary, these results indicate that the loops in domain III have the potential to be targeted to enhance the insecticidal toxicity of the Vip3Aa protein.
Collapse
Affiliation(s)
- Xiaoyue Hou
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China; (X.H.); (S.L.); (G.Y.)
- Co–Innovation Center of Jiangsu Marine Bio–Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Marine Resources Development Research Institute, Jiangsu Ocean University, Lianyungang 222005, China
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
- College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Mengjiao Li
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Chengjuan Mao
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Lei Jiang
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Wen Zhang
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Mengying Li
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Xiaomeng Geng
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Xin Li
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Shu Liu
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China; (X.H.); (S.L.); (G.Y.)
- Co–Innovation Center of Jiangsu Marine Bio–Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Marine Resources Development Research Institute, Jiangsu Ocean University, Lianyungang 222005, China
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Guang Yang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China; (X.H.); (S.L.); (G.Y.)
- Co–Innovation Center of Jiangsu Marine Bio–Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Marine Resources Development Research Institute, Jiangsu Ocean University, Lianyungang 222005, China
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Jing Zhou
- Lianyungang City Quality Technology Comprehensive Inspection and Quality Inspection Center, Lianyungang 222346, China;
| | - Yaowei Fang
- Jiangsu Key Laboratory of Marine Bioresources and Environment, Jiangsu Ocean University, Lianyungang 222005, China; (X.H.); (S.L.); (G.Y.)
- Co–Innovation Center of Jiangsu Marine Bio–Industry Technology, Jiangsu Ocean University, Lianyungang 222005, China
- Jiangsu Marine Resources Development Research Institute, Jiangsu Ocean University, Lianyungang 222005, China
- College of Marine Food and Bioengineering, Jiangsu Ocean University, Lianyungang 222005, China; (M.L.); (C.M.); (L.J.); (W.Z.); (M.L.); (X.G.); (X.L.)
| | - Jun Cai
- College of Life Sciences, Nankai University, Tianjin 300071, China
| |
Collapse
|
8
|
Kerns DD, Yang F, Kerns DL, Stewart SD, Jurat-Fuentes JL. Reduced toxin binding associated with resistance to Vip3Aa in the corn earworm ( Helicoverpa zea). Appl Environ Microbiol 2023; 89:e0164423. [PMID: 38014960 PMCID: PMC10734485 DOI: 10.1128/aem.01644-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 10/17/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE Helicoverpa zea is a major crop pest in the United States that is managed with transgenic corn and cotton that produce insecticidal proteins from the bacterium, Bacillus thuringiensis (Bt). However, H. zea has evolved widespread resistance to the Cry proteins produced in Bt corn and cotton, leaving Vip3Aa as the only plant-incorporated protectant in Bt crops that consistently provides excellent control of H. zea. The benefits provided by Bt crops will be substantially reduced if widespread Vip3Aa resistance develops in H. zea field populations. Therefore, it is important to identify resistance alleles and mechanisms that contribute to Vip3Aa resistance to ensure that informed resistance management strategies are implemented. This study is the first report of reduced binding of Vip3Aa to midgut receptors associated with resistance.
Collapse
Affiliation(s)
- Dawson D. Kerns
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA
| | - Fei Yang
- Department of Entomology, University of Minnesota, St. Paul, Minnesota, USA
| | - David L. Kerns
- Department of Entomology, Texas A&M University, College Station, Texas, USA
| | - Scott D. Stewart
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA
| | - Juan Luis Jurat-Fuentes
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, Tennessee, USA
| |
Collapse
|
9
|
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] [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.
Collapse
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;
| |
Collapse
|
10
|
Chen Z, Shi Y, Wang D, Liu X, Jiao X, Gao X, Jiang K. Structural insight into Bacillus thuringiensis Sip1Ab reveals its similarity to ETX_MTX2 family beta-pore-forming toxin. PEST MANAGEMENT SCIENCE 2023; 79:4264-4273. [PMID: 37341620 DOI: 10.1002/ps.7622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 06/15/2023] [Accepted: 06/21/2023] [Indexed: 06/22/2023]
Abstract
BACKGROUND Microbially derived, protein-based biopesticides are an important approach for sustainable pest management. The secreted insecticidal proteins (Sips) produced by the bacterium Bacillus thuringiensis exhibit potent insecticidal activity against coleopteran pests and are, therefore, attractive as candidate biopesticides. However, the modes-of-action of Sips are unclear as comprehensive structural information for these proteins is lacking. RESULTS Using X-ray crystallography, we elucidated the structure of monomeric Sip1Ab at 2.28 Å resolution. Structural analyses revealed that Sip1Ab has the three domains and conserved fold characteristic of other aerolysin-like beta-pore-forming toxins (β-PFTs). Based on the sequence and structural similarities between Sip1Ab and other ETX_MTX2 subfamily toxins, we suggested the mechanism of these proteins and proposed that it is common to them all. CONCLUSION The atomic-level structural data for Sip1Ab generated by the present study could facilitate future structural and mechanistic research on Sips as well as their application in sustainable insect pest management. © 2023 Society of Chemical Industry.
Collapse
Affiliation(s)
- Zhe Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yiting Shi
- Taishan College, Shandong University, Jinan, China
| | - Dongdong Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiaoyu Liu
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China
| | - Xuyao Jiao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Xiang Gao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Kun Jiang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| |
Collapse
|
11
|
Wang Z, Yang W, Yin C, Ma W, Liao M, Li F, Zhang J. Cry9A and Vip3A protein-induced transcriptional changes correspond to their synergistic damage to the midgut of Chilo suppressalis. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 196:105596. [PMID: 37945246 DOI: 10.1016/j.pestbp.2023.105596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/13/2023] [Accepted: 08/28/2023] [Indexed: 11/12/2023]
Abstract
Cry and Vip3 proteins are both pore-forming toxins produced by Bacillus thuringiensis that show synergistic insecticidal activity against different insect pests. However, the synergistic effect of Cry and Vip3 proteins on the midgut in target insects is still unclear. In this study, faster and more serious damage was observed after treatment with both Cry9A and Vip3A proteins in the Chilo suppressalis midgut compared to single-protein treatment. Through RNA sequencing, midgut transcriptomic comparison was performed between dual- and single-protein treatments according to midgut injury. After 6 h, 609 differentially expressed genes were found with the combined Cry9A and Vip3A treatments, which was much more than that in the single treatment, corresponding to faster and more serious damage. These genes were mainly enriched in similar pathways, such as lipid metabolic, oxidation-reduction and carbohydrate metabolic process, peptide secretion and cell-cell adhesion; however, the number and expression level of differentially expressed genes are increased. For specific genes significantly regulated by induction of Cry9A and Vip3A, lipases, phospholipid scramblase, probable tape measure protein and arylsulfatase J were significantly downregulated after 6 h treatment. In addition, regular genes related to the activation and receptor binding of B. thuringiensis toxins were differentially regulated, such as ATP-binding cassette subfamily G member 1 and serine protease. Validation with RT-qPCR showed agreement with the sequencing results. Overall, our results support that stronger and faster midgut responses at the cellular and transcriptional levels are induced by the synergistic toxicity of Cry9A and Vip3A in C. suppressalis.
Collapse
Affiliation(s)
- 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
| | - Wenquan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; School of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Chuanlin Yin
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Weihua Ma
- National Key Laboratory of Crop Genetic Improvement, National Centre of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China
| | - Min Liao
- School of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Fei Li
- State Key Laboratory of Rice Biology & Ministry of Agricultural and Rural Affairs Key Laboratory of Molecular Biology of Crop Pathogens and Insect Pests, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; School of Plant Protection, Anhui Agricultural University, Hefei 230036, China.
| |
Collapse
|
12
|
Jin M, Shan Y, Peng Y, Wang W, Zhang H, Liu K, Heckel DG, Wu K, Tabashnik BE, Xiao Y. Downregulation of a transcription factor associated with resistance to Bt toxin Vip3Aa in the invasive fall armyworm. Proc Natl Acad Sci U S A 2023; 120:e2306932120. [PMID: 37874855 PMCID: PMC10622909 DOI: 10.1073/pnas.2306932120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 09/11/2023] [Indexed: 10/26/2023] Open
Abstract
Transgenic crops producing insecticidal proteins from Bacillus thuringiensis (Bt) have revolutionized control of some major pests. However, more than 25 cases of field-evolved practical resistance have reduced the efficacy of transgenic crops producing crystalline (Cry) Bt proteins, spurring adoption of alternatives including crops producing the Bt vegetative insecticidal protein Vip3Aa. Although practical resistance to Vip3Aa has not been reported yet, better understanding of the genetic basis of resistance to Vip3Aa is urgently needed to proactively monitor, delay, and counter pest resistance. This is especially important for fall armyworm (Spodoptera frugiperda), which has evolved practical resistance to Cry proteins and is one of the world's most damaging pests. Here, we report the identification of an association between downregulation of the transcription factor gene SfMyb and resistance to Vip3Aa in S. frugiperda. Results from a genome-wide association study, fine-scale mapping, and RNA-Seq identified this gene as a compelling candidate for contributing to the 206-fold resistance to Vip3Aa in a laboratory-selected strain. Experimental reduction of SfMyb expression in a susceptible strain using RNA interference (RNAi) or CRISPR/Cas9 gene editing decreased susceptibility to Vip3Aa, confirming that reduced expression of this gene can cause resistance to Vip3Aa. Relative to the wild-type promoter for SfMyb, the promoter in the resistant strain has deletions and lower activity. Data from yeast one-hybrid assays, genomics, RNA-Seq, RNAi, and proteomics identified genes that are strong candidates for mediating the effects of SfMyb on Vip3Aa resistance. The results reported here may facilitate progress in understanding and managing pest resistance to Vip3Aa.
Collapse
Affiliation(s)
- Minghui Jin
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen518116, China
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing100193, China
| | - Yinxue Shan
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen518116, China
| | - Yan Peng
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen518116, China
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan430070, China
| | - Wenhui Wang
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing100193, China
| | - Huihui Zhang
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan430079, China
| | - Kaiyu Liu
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan430079, China
| | - David G. Heckel
- Department of Entomology, Max Planck Institute for Chemical Ecology, JenaD-07745, Germany
| | - Kongming Wu
- The State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing100193, China
| | | | - Yutao Xiao
- Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen518116, China
| |
Collapse
|
13
|
Xue B, Wang M, Wang Z, Shu C, Geng L, Zhang J. Analysis of Synergism between Extracellular Polysaccharide from Bacillus thuringensis subsp. kurstaki HD270 and Insecticidal Proteins. Toxins (Basel) 2023; 15:590. [PMID: 37888621 PMCID: PMC10610938 DOI: 10.3390/toxins15100590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/28/2023] Open
Abstract
Bacillus thuringiensis (Bt) is the most widely used biopesticide worldwide and can produce several insecticidal crystal proteins and vegetative insecticidal proteins (Vips) at different growth stages. In our previous study, extracellular polysaccharides (EPSs) of Bt strain HD270 were found to enhance the insecticidal activity of Cry1Ac protoxin against Plutella xylostella (L.) and promote the binding of Cry1Ac to the intestinal brush border membrane vesicles (BBMVs). Whether the synergistic activity of Bt EPSs is common to other Cry1-type or Vip proteins is unclear, as is the potential synergistic mechanism. In this study, crude EPS-HD270 was found to increase the toxicity of Cry1-type toxins and Vip3Aa11 against different lepidopteran pests by approximately 2-fold. The purified EPS-HD270 also possessed synergistic activity against the toxicity of Cry1Ac and Vip3Aa11 against Spodoptera frugiperda (J.E. Smith) and Helicoverpa armigera (Hübner). Furthermore, we found that EPS-HD270 had a strong binding ability with Vip3Aa11 and promoted the binding of Vip3Aa11 to the BBMVs of H. armigera and S. frugiperda. Bt EPS-HD270 also protected Vip3Aa11 from proteolytic processing in larval midgut juice. Bt EPSs had universal synergistic effects on Cry1-type or Vip toxins against S. frugiperda and H. armigera. Bt EPS-HD270 exhibited synergistic activity with Vip3Aa through promotion of binding to BBMVs and protection from digestion by midgut protease. The results indicated that synergistic activity with Bt toxins was an important function of Bt EPSs, which was very different from other Bacillus spp.
Collapse
Affiliation(s)
- Bai Xue
- College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Meiling Wang
- 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
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Jie Zhang
- College of Life Sciences, Northeast Agricultural University, Harbin 150030, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| |
Collapse
|
14
|
Pacheco S, Gómez I, Peláez-Aguilar AE, Verduzco-Rosas LA, García-Suárez R, do Nascimento NA, Rivera-Nájera LY, Cantón PE, Soberón M, Bravo A. Structural changes upon membrane insertion of the insecticidal pore-forming toxins produced by Bacillus thuringiensis. FRONTIERS IN INSECT SCIENCE 2023; 3:1188891. [PMID: 38469496 PMCID: PMC10926538 DOI: 10.3389/finsc.2023.1188891] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 04/04/2023] [Indexed: 03/13/2024]
Abstract
Different Bacillus thuringiensis (Bt) strains produce a broad variety of pore-forming toxins (PFTs) that show toxicity against insects and other invertebrates. Some of these insecticidal PFT proteins have been used successfully worldwide to control diverse insect crop pests. There are several studies focused on describing the mechanism of action of these toxins that have helped to improve their performance and to cope with the resistance evolved by different insects against some of these proteins. However, crucial information that is still missing is the structure of pores formed by some of these PFTs, such as the three-domain crystal (Cry) proteins, which are the most commercially used Bt toxins in the biological control of insect pests. In recent years, progress has been made on the identification of the structural changes that certain Bt insecticidal PFT proteins undergo upon membrane insertion. In this review, we describe the models that have been proposed for the membrane insertion of Cry toxins. We also review the recently published structures of the vegetative insecticidal proteins (Vips; e.g. Vip3) and the insecticidal toxin complex (Tc) in the membrane-inserted state. Although different Bt PFTs show different primary sequences, there are some similarities in the three-dimensional structures of Vips and Cry proteins. In addition, all PFTs described here must undergo major structural rearrangements to pass from a soluble form to a membrane-inserted state. It is proposed that, despite their structural differences, all PFTs undergo major structural rearrangements producing an extended α-helix, which plays a fundamental role in perforating their target membrane, resulting in the formation of the membrane pore required for their insecticidal activity.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Alejandra Bravo
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico
| |
Collapse
|
15
|
Wang C, Deng Z, Yuan J, Xu K, Sha L, Guan X, Huang Z, Shao E. Removal of an Aminopeptidase N From Midgut Brush Border Does Not Affect Susceptibility of Spodoptera litura (Lepidoptera: Noctuidae) Larvae to Four Insecticidal Proteins of Bacillus thuringiensis (Bacillales: Bacillaceae). JOURNAL OF ECONOMIC ENTOMOLOGY 2023; 116:223-232. [PMID: 36421056 DOI: 10.1093/jee/toac184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Indexed: 06/16/2023]
Abstract
Spodoptera litura is one of the most destructive lepidopteran insects of cabbages and cauliflowers in the world. Cry1 and Vip3 toxins from Bacillus thuringiensis have been reported to show toxicity in multiple lepidopteran insects. Binding of toxic molecules to specific receptors on the midgut epithelial cells is known to be a key step in the action mode of Bt toxins. Aminopeptidase N (APN) -like proteins have been reported to be binding sites of multiple Cry toxins in the midgut of Cry susceptible insects. In the present study, we identified six midgut APNs by analysis of the genome and midgut transcriptome of S. litura. CRISPR/Cas9 mediated gene-knockout system was utilized to mutate the GPI-anchor signal peptide at the C terminus of SlAPN1. SlAPN1 was verified to be removed from the midgut brush border membrane vesicles of a homozygous knockout strain of S. litura (SlAPN1-KO). Bioassay results indicated that susceptibility of the SlAPN1-KO strain to Cry1Aa, Cry1Ac, Cry1Ca, and Vip3Aa toxins was close to that of the wild-type strain of S. litura. RT-qPCR results showed that the transcriptional level of SlAPN2-6 was not up-regulated after knockout of the SlAPN1. Results in this study indicated that the SlAPN1 did not play a critical role in the pathway of toxicity of Cry1Aa, Cry1Ac, Cry1Ca, and Vip3Aa toxins in S. litura.
Collapse
Affiliation(s)
- Can Wang
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Zhimin Deng
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Jin Yuan
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Kexin Xu
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Li Sha
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Xiong Guan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Zhipeng Huang
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops & Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education & Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| | - Ensi Shao
- National Engineering Research Center of JUNCAO Technology, College of Life Science, Fujian Agriculture and Forestry University, Fuzhou 350002, Fujian, China
| |
Collapse
|
16
|
Jiang K, Chen Z, Zang Y, Shi Y, Shang C, Jiao X, Cai J, Gao X. Functional characterization of Vip3Aa from Bacillus thuringiensis reveals the contributions of specific domains to its insecticidal activity. J Biol Chem 2023; 299:103000. [PMID: 36764522 PMCID: PMC10017365 DOI: 10.1016/j.jbc.2023.103000] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/31/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Microbially derived, protein-based biopesticides offer a more sustainable pest management alternative to synthetic pesticides. Vegetative insecticidal proteins (Vip3), multidomain proteins secreted by Bacillus thuringiensis, represent a second-generation insecticidal toxin that has been preliminarily used in transgenic crops. However, the molecular mechanism underlying Vip3's toxicity is poorly understood. Here, we determine the distinct functions and contributions of the domains of the Vip3Aa protein to its toxicity against Spodoptera frugiperda larvae. We demonstrate that Vip3Aa domains II and III (DII-DIII) bind the midgut epithelium, while DI is essential for Vip3Aa's stability and toxicity inside the protease-enriched host insect midgut. DI-DIII can be activated by midgut proteases and exhibits cytotoxicity similar to full-length Vip3Aa. In addition, we determine that DV can bind the peritrophic matrix via its glycan-binding activity, which contributes to Vip3Aa insecticidal activity. In summary, this study provides multiple insights into Vip3Aa's mode-of-action which should significantly facilitate the clarification of its insecticidal mechanism and its further rational development.
Collapse
Affiliation(s)
- Kun Jiang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Zhe Chen
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yuanrong Zang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Yiting Shi
- School of Life Sciences, Shandong University, Qingdao, China; Taishan College, Shandong University, Jinan, China
| | - Chengbin Shang
- School of Life Sciences, Shandong University, Qingdao, China
| | - Xuyao Jiao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jun Cai
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiang Gao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China.
| |
Collapse
|
17
|
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 MANAGEMENT SCIENCE 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] [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.
Collapse
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
| |
Collapse
|
18
|
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 MANAGEMENT SCIENCE 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] [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.
Collapse
Affiliation(s)
| | | | | | | | | | - Adam Evans
- Plant BiotechnologyBayer Crop Science USChesterfieldMOUSA
| | - Michael Pleau
- Plant BiotechnologyBayer Crop Science USChesterfieldMOUSA
| | | | | | | | | | | | | | - Graham Head
- Regulatory ScienceBayer Crop Science USChesterfieldMOUSA
| |
Collapse
|
19
|
Gao J, Ouyang C, Zhao J, Han Y, Guo Q, Liu X, Zhang T, Duan M, Wang X, Xu C. Coexpressing the Signal Peptide of Vip3A and the Trigger Factor of Bacillus thuringiensis Enhances the Production Yield and Solubility of eGFP in Escherichia coli. Front Microbiol 2022; 13:892428. [PMID: 35923407 PMCID: PMC9342664 DOI: 10.3389/fmicb.2022.892428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
Many fusion tags have been developed to improve the expression of recombinant proteins. Besides the translocation of cargo proteins, the signal peptides (SPs) of some secretory proteins, such as the ssTorA and Iasp, have been used as an inclusion body tag (IB-tag) or the recombinant expression enhancer in the cytosol of E. coli. In this study, the approach to utilize the SP of Vip3A (Vasp) from Bacillus thuringiensis (Bt) as a fusion tag was investigated. The results showed that either the Vasp or its predicted N- (VN), H- (VH), and C-regions (VC), as well as their combinations (VNH, VNC, and VHC), were able to significantly enhance the production yield of eGFP. However, the hydrophobic region of the Vasp (VH and/or VC) made more than half of the eGFP molecules aggregated (VeGFP, VHeGFP, VCeGFP, VNHeGFP, VNCeGFP, and VHCeGFP). Interestingly, the addition of the Bt trigger factor (BtTF) led to the neutralization of the negative impact and solubilization of the fusion proteins. Therefore, the coexpression of Vasp or its derivates with the chaperone BtTF could be a novel dual-enhancement system for the production yield and solubility of recombinant proteins. Notably, EcTF was unable to impact the solubility of Vasp or its derivates guided proteins, suggesting its different specificities on the recognition or interaction. Additionally, this study also suggested that the translocation of Vip3 in the host cell would be regulated by the BtTF-involved model.
Collapse
Affiliation(s)
- Jianhua Gao
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Life Sciences, Shanxi Agricultural University, Jinzhong, China
| | - Chunping Ouyang
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Life Sciences, Shanxi Agricultural University, Jinzhong, China
| | - Juanli Zhao
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Life Sciences, Shanxi Agricultural University, Jinzhong, China
| | - Yan Han
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Life Sciences, Shanxi Agricultural University, Jinzhong, China
| | - Qinghua Guo
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Life Sciences, Shanxi Agricultural University, Jinzhong, China
| | - Xuan Liu
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Life Sciences, Shanxi Agricultural University, Jinzhong, China
| | - Tianjiao Zhang
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Life Sciences, Shanxi Agricultural University, Jinzhong, China
| | - Ming Duan
- Experimental Teaching Center, Shanxi Agricultural University, Jinzhong, China
| | - Xingchun Wang
- Shanxi Key Laboratory of Minor Crops Germplasm Innovation and Molecular Breeding, College of Life Sciences, Shanxi Agricultural University, Jinzhong, China
- Xingchun Wang
| | - Chao Xu
- State Key Laboratory of Rice Biology, Institute of Insect Sciences, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- *Correspondence: Chao Xu
| |
Collapse
|
20
|
Fu BW, Xu L, Zheng MX, Chen QX, Shi Y, Zhu YJ. Stability is essential for insecticidal activity of Vip3Aa toxin against Spodoptera exigua. AMB Express 2022; 12:92. [PMID: 35834019 PMCID: PMC9283630 DOI: 10.1186/s13568-022-01430-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 07/02/2022] [Indexed: 11/10/2022] Open
Abstract
Vegetative insecticidal proteins 3A (Vip3A) were important insecticidal proteins for control of lepidopteran pests. Previous study demonstrated that Vip3Aa and Vip3Ad showed significant difference in insecticidal activities against Spodoptera exigua, while the molecular mechanism remained ambiguous. Here we demonstrated that the difference in insecticidal activities between Vip3Aa and Vip3Ad might be caused by the difference in stability of Vip3Aa and Vip3Ad in S. exigua midgut protease. Vip3Aa was quite stable while Vip3Ad could be further degraded. Molecular dynamics simulation revealed that Vip3Aa was more stable than Vip3Ad, with smaller RMSD and RMSF value. Amino acid sequence alignment indicated that three were three extra prolines (P591, P605 and P779) located on Vip3Aa. We further identified that residue P591 played a crucial role on stability and insecticidal activity of Vip3Aa. Taken together, our study demonstrated that the stability was essential for the insecticidal activity of Vip3A toxins, which might provide new insight into the action mode of Vip3A toxins and contribute to the design Vip3A variants with improved stability and insecticidal activity.
Collapse
Affiliation(s)
- Bai-Wen Fu
- School of Life Sciences, Xiamen University, Xiamen, 361005, China
| | - Lian Xu
- Agricultural Bio-Resources Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China
| | - Mei-Xia Zheng
- Agricultural Bio-Resources Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China
| | - Qing-Xi Chen
- School of Life Sciences, Xiamen University, Xiamen, 361005, China
| | - Yan Shi
- School of Life Sciences, Xiamen University, Xiamen, 361005, China.
| | - Yu-Jing Zhu
- Agricultural Bio-Resources Research Institute, Fujian Academy of Agricultural Sciences, Fuzhou, 350003, China.
| |
Collapse
|
21
|
Lázaro-Berenguer M, Paredes-Martínez F, Bel Y, Núñez-Ramírez R, Arias-Palomo E, Casino P, Ferré J. Structural and functional role of Domain I for the insecticidal activity of the Vip3Aa protein from Bacillus thuringiensis. Microb Biotechnol 2022; 15:2607-2618. [PMID: 35830334 PMCID: PMC9518980 DOI: 10.1111/1751-7915.14110] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/07/2022] [Accepted: 06/13/2022] [Indexed: 12/05/2022] Open
Abstract
Vip3 proteins are produced by Bacillus thuringiensis and are toxic against lepidopterans, reason why the vip3Aa gene has been introduced into cotton and corn to control agricultural pests. Recently, the structure of Vip3 proteins has been determined and consists of a tetramer where each monomer is composed of five structural domains. The transition from protoxin to the trypsin‐activated form involves a major conformational change of the N‐terminal Domain I, which is remodelled into a tetrameric coiled‐coil structure that is thought to insert into the apical membrane of the midgut cells. To better understand the relevance of this major change in Domain I for the insecticidal activity, we have generated several mutants aimed to alter the activity and remodelling capacity of this central region to understand its function. These mutants have been characterized by proteolytic processing, negative staining electron microscopy, and toxicity bioassays against Spodoptera exigua. The results show the crucial role of helix α1 for the insecticidal activity and in restraining the Domain I in the protoxin conformation, the importance of the remodelling of helices α2 and α3, the proteolytic processing that takes place between Domains I and II, and the role of the C‐t Domains IV and V to sustain the conformational change necessary for toxicity.
Collapse
Affiliation(s)
- Maria Lázaro-Berenguer
- Department of Genetics, Universitat de València, Burjassot, Spain.,Institut Universitari de Biotecnologia i Biomedicina BIOTECMED, Universitat de València, Burjassot, Spain
| | - Francisco Paredes-Martínez
- Institut Universitari de Biotecnologia i Biomedicina BIOTECMED, Universitat de València, Burjassot, Spain.,Department of Biochemistry and Molecular Biology, Universitat de València, Burjassot, Spain
| | - Yolanda Bel
- Department of Genetics, Universitat de València, Burjassot, Spain.,Institut Universitari de Biotecnologia i Biomedicina BIOTECMED, Universitat de València, Burjassot, Spain
| | | | | | - Patricia Casino
- Institut Universitari de Biotecnologia i Biomedicina BIOTECMED, Universitat de València, Burjassot, Spain.,Department of Biochemistry and Molecular Biology, Universitat de València, Burjassot, Spain.,CIBER de Enfermedades Raras (CIBERER-ISCIII), Madrid, Spain
| | - Juan Ferré
- Department of Genetics, Universitat de València, Burjassot, Spain.,Institut Universitari de Biotecnologia i Biomedicina BIOTECMED, Universitat de València, Burjassot, Spain
| |
Collapse
|
22
|
Zhang Y, Li X, Tian H, An B, Yan B, Cai J. Vegetative Insecticidal Protein Vip3Aa Is Transported via Membrane Vesicles in Bacillus thuringiensis BMB171. Toxins (Basel) 2022; 14:toxins14070480. [PMID: 35878218 PMCID: PMC9319297 DOI: 10.3390/toxins14070480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 11/16/2022] Open
Abstract
Vegetative insecticidal protein Vip3Aa, secreted by many Bacillus thuringiensis (Bt) strains during the vegetative growth stage, represents the second-generation insecticidal toxin. In recent years, significant progress has been made on its structure and action mechanism. However, how it is translocated across the cytoplasmic membrane into the environment remains a mystery. This work demonstrates that Vip3Aa is not secreted by the General Secretion (Sec) System. To reveal the secretory pathway of Vip3A, we purified the membrane vesicles (MVs) of B. thuringiensis BMB171 and observed by TEM. The size of MVs was determined by the dynamic light scattering method, and their diameter was approximately 40–200 nm, which is consistent with the vesicles in Gram-negative bacteria. Moreover, Vip3A could be detected in the purified MVs by Western blot, and immunoelectron microscopy reveals Vip3A antibody-coated gold particles located in the MVs. After deleting its signal peptide, chitinase B (ChiB) failed to be secreted. However, the recombinant ChiB, whose signal peptide was substituted with the N-terminal 39 amino acids from Vip3A, was secreted successfully through MVs. Thus, this sequence is proposed as the signal region responsible for vesicle transport. Together, our results revealed for the first time that Vip3Aa is transported to the medium via MVs.
Collapse
Affiliation(s)
- Yizhuo Zhang
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.Z.); (X.L.); (H.T.); (B.A.); (B.Y.)
| | - Xuelian Li
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.Z.); (X.L.); (H.T.); (B.A.); (B.Y.)
| | - Hongwei Tian
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.Z.); (X.L.); (H.T.); (B.A.); (B.Y.)
| | - Baoju An
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.Z.); (X.L.); (H.T.); (B.A.); (B.Y.)
| | - Bing Yan
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.Z.); (X.L.); (H.T.); (B.A.); (B.Y.)
| | - Jun Cai
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin 300071, China; (Y.Z.); (X.L.); (H.T.); (B.A.); (B.Y.)
- Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin 300071, China
- Tianjin Key Laboratory of Microbial Functional Genomics, Tianjin 300071, China
- Correspondence:
| |
Collapse
|
23
|
Singh P, G. K. S, Thakur S, Rathore M, Verma OP, Singh NP, Das A. Evaluation of transgenic chickpea harboring codon-modified Vip3Aa against gram pod borer (Helicoverpa armigera H.). PLoS One 2022; 17:e0270011. [PMID: 35749522 PMCID: PMC9231776 DOI: 10.1371/journal.pone.0270011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 06/01/2022] [Indexed: 11/29/2022] Open
Abstract
The gram pod borer is a major pest of chickpea, accounting for average annual yield losses to the tune of 40-50%. VIP3Aa, a class of insecticidal protein with different receptor binding site in the insect's midgut compared to Bt-crystal protein, offers an alternative protection strategy against Lepidopteran insects. Here, we report evaluation of genetically engineered chickpea lines harboring codon modified Vip3Aa (cmVip3Aa) against the Lepidopteran insect pest, gram pod borer. The synthetic codon modified, cmVip3Aa gene of 2,370 bp was sub-cloned in modified plant expression vector and used for direct transformation of embryonic axis explants of chickpea (cv. DCP 92-3), with transformation efficiency of 4.30%. Presence and transmission of transgene across two generations were confirmed by PCR and Southern blot analyses in the five selected transgenic chickpea lines. Real Time PCR analyses indicated variable levels of cmVip3Aa expression in the transgenic chickpea lines (average Cq values 15.01±0.86 to 19.32±0.10), which were absent in the non-transgenic counterpart. Detached leaf insect bioassay indicate larval mortality (up to 39.75%), reduced larval feeding (up to 82.91%) and reduced larval weight gain (up to 68.23%), compared to control lines. Evaluation of gene offers a platform to identify efficacious insecticidal gene that can be used for insect resistance management in chickpea.
Collapse
Affiliation(s)
- Prateek Singh
- Division of Plant Biotechnology, ICAR-Indian Institute of Pulses Research, Kanpur, Uttar Pradesh, India
- Department of Molecular and Cellular Engineering, Jacob Institute of Biotechnology and Bioengineering, SHUATS, Prayagraj, Uttar Pradesh, India
| | - Sujayanand G. K.
- Division of Crop Protection, ICAR-Indian Institute of Pulses Research, Kanpur, Uttar Pradesh, India
| | - Shallu Thakur
- Division of Plant Biotechnology, ICAR-Indian Institute of Pulses Research, Kanpur, Uttar Pradesh, India
| | - Meenal Rathore
- Division of Plant Biotechnology, ICAR-Indian Institute of Pulses Research, Kanpur, Uttar Pradesh, India
| | - Om Prakash Verma
- Department of Molecular and Cellular Engineering, Jacob Institute of Biotechnology and Bioengineering, SHUATS, Prayagraj, Uttar Pradesh, India
| | - Narendra Pratap Singh
- Division of Plant Biotechnology, ICAR-Indian Institute of Pulses Research, Kanpur, Uttar Pradesh, India
| | - Alok Das
- Division of Plant Biotechnology, ICAR-Indian Institute of Pulses Research, Kanpur, Uttar Pradesh, India
| |
Collapse
|
24
|
Sf-FGFR and Sf-SR-C Are Not the Receptors for Vip3Aa to Exert Insecticidal Toxicity in Spodoptera frugiperda. INSECTS 2022; 13:insects13060547. [PMID: 35735884 PMCID: PMC9224979 DOI: 10.3390/insects13060547] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/08/2022] [Accepted: 06/11/2022] [Indexed: 12/30/2022]
Abstract
Simple Summary The CRISPR/Cas9 gene editing and biochemical analysis show that knocking out the Sf-FGFR or Sf-SR-C gene will not change the sensitivity of Spodoptera frugiperda to Vip3Aa. Abstract Vip3Aa is a novel insecticidal protein secreted by Bacillus thuringiensis (Bt) during its vegetative growth stages. It has high insecticidal activity against lepidopteran pests such as Spodoptera frugiperda, and has no cross-resistance with Cry insecticidal proteins. As a new type of insecticide, it plays an important role in controlling agricultural pests. However, the insecticidal mechanism of the Vip3Aa toxin, especially its definite receptors, have not been fully revealed. In this study, the previously reported Vip3Aa receptor genes Sf-FGFR and Sf-SR-C were knocked out separately using the CRISPR/Cas9 system. Bioassay results showed that the sensitivity of these two knockout strains to Vip3Aa were not significantly changed compared to that of the normal strain. The current results are not consistent with the previously reports that Sf-SR-C and Sf-FGFR were the receptors of Vip3Aa in vitro. This suggests that the Sf-SR-C and Sf-FGFR genes we tested may not be critical in the mode of action of Vip3Aa in vivo in Spodoptera frugiperda.
Collapse
|
25
|
Yang X, Wang Z, Geng L, Chi B, Liu R, Li H, Gao J, Zhang J. Vip3Aa domain IV and V mutants confer higher insecticidal activity against Spodoptera frugiperda and Helicoverpa armigera. PEST MANAGEMENT SCIENCE 2022; 78:2324-2331. [PMID: 35243758 DOI: 10.1002/ps.6858] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 02/23/2022] [Accepted: 03/03/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND The fall armyworm Spodoptera frugiperda and cotton bollworm Helicoverpa armigera are major insect pests of corn and cotton worldwide. Genetically engineered crops producing Vip3Aa, a potent endotoxin, from the bacterium Bacillus thuringiensis (Bt) are effective in controlling these two harmful pests. However, Vip3Aa efficacy is relatively weak compared to that of other Bt proteins such as Cry1A and Cry1F. This study sought to modify Vip3Aa for increased insecticidal activity and determine the cause of elevated activity. RESULTS The two triple Vip3Aa mutants in domains IV and V (Vip3Aa-S543N/I544L/E627A and Vip3Aa-S543N/I544L/S686R) exhibited 7.3-fold and 2.8-fold increased toxicity against S. frugiperda, respectively, compared with the wild type while the toxicity of Vip3Aa-S543N/I544L/S686R was 3.2 times that of wild-type protein in H. armigera. The mutants had enhanced stability in midgut juice and 2.6-5.1 times higher binding affinity against S. frugiperda and H. armigera compared with wild type protein. CONCLUSIONS The enhanced toxicity of Vip3Aa mutants was due to increased stability and binding affinity during infection. The amino acids S543 and I544 combined with E627 or S686 in domains IV and V of Vip3Aa are important for maintaining structural stability and receptor binding. The results match insecticidal activity (LC50 ) with binding activity (Kd ), which provides novel clues for the rational design of Bt insecticidal proteins. © 2022 Society of Chemical Industry.
Collapse
Affiliation(s)
- Xiaoxue Yang
- Northeast Agricultural University, Harbin, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zeyu Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lili Geng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Baoyan Chi
- Northeast Agricultural University, Harbin, China
| | - Rongmei Liu
- Northeast Agricultural University, Harbin, China
| | - Haitao Li
- Northeast Agricultural University, Harbin, China
| | - Jiguo Gao
- Northeast Agricultural University, Harbin, China
| | - Jie Zhang
- Northeast Agricultural University, Harbin, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| |
Collapse
|
26
|
Viral Proteins Involved in the Adsorption Process of Deep-Purple, a Siphovirus Infecting Members of the Bacillus cereus Group. Appl Environ Microbiol 2022; 88:e0247821. [PMID: 35499330 PMCID: PMC9128512 DOI: 10.1128/aem.02478-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The infection of a bacterium by a tailed phage starts from the adsorption process, which consists of a specific and strong interaction between viral proteins called receptor binding proteins (RBPs) and receptors located on the bacterial surface. In addition to RBPs, other tail proteins, such as evolved distal tail (evoDit) proteins and tail lysins, harboring carbohydrate binding modules (CBMs) have been shown to facilitate the phage adsorption by interacting with host polysaccharides. In this work, the proteins involved in the adsorption of Deep-Purple, a siphovirus targeting bacteria of the Bacillus cereus group, were studied. Bioinformatic analysis of Deep-Purple tail protein region revealed that it contains two proteins presenting CBM domains: Gp28, an evoDit protein, and Gp29, the potential RBP. The implication of both proteins in the adsorption of Deep-Purple particles was confirmed through cell wall decoration assays. Interestingly, whereas RBP-Gp29 exhibited the same host spectrum as Deep-Purple, evoDit-Gp28 was able to bind to many B. cereus group strains, including some that are not sensitive to the phage infection. Using immunogold microscopy, both proteins were shown to be located in the phage baseplate. Additionally, an in silico analysis of the tail regions encoded by several Siphoviridae infecting the B. cereus group was performed. It revealed that although the tail organization displayed by Deep-Purple is the most prevalent, different tail arrangements are observed, suggesting that distinct baseplate organization and adsorption mechanisms are encountered in siphoviruses targeting the B. cereus group. IMPORTANCE The B. cereus group is a complex cluster of closely related species, among which certain strains can be pathogenic (i.e., Bacillus anthracis, Bacillus cereussensu stricto, and Bacillus cytotoxicus). Nowadays, phages are receiving increasing attention for applications in controlling and detecting such pathogens. Thus, understanding the molecular mechanisms governing the phage adsorption to its bacterial host is paramount as this step is a key determinant of the phage host spectrum. Until now, the knowledge regarding the adsorption process of tailed phage targeting the B. cereus groups was mainly restricted to the phage gamma infecting B. anthracis. With this work, we provide novel insights into the adsorption of Deep-Purple, a siphovirus infecting the B. cereus group. We showed that this phage recognizes polysaccharides and relies on two different viral proteins for its successful adsorption.
Collapse
|
27
|
Lázaro-Berenguer M, Quan Y, Hernández-Martínez P, Ferré J. In vivo competition assays between Vip3 proteins confirm the occurrence of shared binding sites in Spodoptera littoralis. Sci Rep 2022; 12:4578. [PMID: 35301405 PMCID: PMC8931066 DOI: 10.1038/s41598-022-08633-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/07/2022] [Indexed: 11/09/2022] Open
Abstract
Due to their different specificity, the use of Vip3 proteins from Bacillus thuringiensis in combination with the conventionally used Cry proteins in crop protection is being essential to counteract the appearance of insect resistance. Therefore, understanding the mode of action of Vip3 proteins is crucial for their better application, with special interest on the binding to membrane receptors as the main step for specificity. Derived from in vitro heterologous competition binding assays using 125I-Vip3A and other Vip3 proteins as competitors, it has been shown that Vip3 proteins share receptors in Spodoptera frugiperda and Spodoptera exigua brush border membrane vesicles (BBMV). In this study, using 125I-Vip3Aa, we have first extended the in vitro competition binding site model of Vip3 proteins to Spodoptera littoralis. With the aim to understand the relevance (in terms of toxicity) of the binding to the midgut sites observed in vitro on the insecticidal activity of these proteins, we have performed in vivo competition assays with S. littoralis larvae, using disabled mutant (non-toxic) Vip3 proteins as competitors for blocking the toxicity of Vip3Aa and Vip3Af. The results of the in vivo competition assays confirm the occurrence of shared binding sites among Vip3 proteins and help understand the functional role of the shared binding sites as revealed in vitro.
Collapse
Affiliation(s)
- María Lázaro-Berenguer
- Institute of Biotechnology and Biomedicine (BIOTECMED), Department of Genetics, Universitat de València, 46100, Burjassot, Spain
| | - Yudong Quan
- Institute of Biotechnology and Biomedicine (BIOTECMED), Department of Genetics, Universitat de València, 46100, Burjassot, Spain
| | - Patricia Hernández-Martínez
- Institute of Biotechnology and Biomedicine (BIOTECMED), Department of Genetics, Universitat de València, 46100, Burjassot, Spain
| | - Juan Ferré
- Institute of Biotechnology and Biomedicine (BIOTECMED), Department of Genetics, Universitat de València, 46100, Burjassot, Spain.
| |
Collapse
|
28
|
Challenges and approaches to studying pore-forming proteins. Biochem Soc Trans 2021; 49:2749-2765. [PMID: 34747994 PMCID: PMC8892993 DOI: 10.1042/bst20210706] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/19/2021] [Accepted: 10/06/2021] [Indexed: 02/07/2023]
Abstract
Pore-forming proteins (PFPs) are a broad class of molecules that comprise various families, structural folds, and assembly pathways. In nature, PFPs are most often deployed by their host organisms to defend against other organisms. In humans, this is apparent in the immune system, where several immune effectors possess pore-forming activity. Furthermore, applications of PFPs are found in next-generation low-cost DNA sequencing, agricultural crop protection, pest control, and biosensing. The advent of cryoEM has propelled the field forward. Nevertheless, significant challenges and knowledge-gaps remain. Overcoming these challenges is particularly important for the development of custom, purpose-engineered PFPs with novel or desired properties. Emerging single-molecule techniques and methods are helping to address these unanswered questions. Here we review the current challenges, problems, and approaches to studying PFPs.
Collapse
|
29
|
Critical domains in the specific binding of radiolabelled Vip3Af insecticidal protein to brush border membrane vesicles from Spodoptera spp. and cultured insect cells. Appl Environ Microbiol 2021; 87:e0178721. [PMID: 34586902 DOI: 10.1128/aem.01787-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Vegetative insecticidal proteins (Vip3) from Bacillus thuringiensis have been used, in combination with Cry proteins, to better control insect pests and as a strategy to delay the evolution of resistance to Cry proteins in Bt crops (crops protected from insect attack by the expression of proteins from B. thuringiensis). In this study, we have set up the conditions to analyze the specific binding of 125I-Vip3Af to Spodoptera frugiperda and Spodoptera exigua brush border membrane vesicles (BBMV). Heterologous competition binding experiments revealed that Vip3Aa shares the same binding sites with Vip3Af, but that Vip3Ca does not recognize all of them. As expected, Cry1Ac and Cry1F did not compete for Vip3Af binding sites. By trypsin treatment of selected alanine-mutants, we were able to generate truncated versions of Vip3Af. Their use as competitors with 125I-Vip3Af indicated that only those molecules containing domains I to III (DI-III and DI-IV) were able to compete with the trypsin-activated Vip3Af protein for binding, and that molecules only containing either domain IV or domains IV and V (DIV and DIV-V) were unable to compete with Vip3Af. These results were further confirmed with competition binding experiments using 125I-DI-III. In addition, the truncated protein 125I-DI-III also bound specifically to Sf21 cells. Cell viability assays showed that the truncated proteins DI-III and DI-IV were as toxic to Sf21 cells as the activated Vip3Af, suggesting that domains IV and V are not necessary for the toxicity to Sf21 cells, in contrast to their requirement in vivo. IMPORTANCE This study shows that Vip3Af binding sites are fully shared with Vip3Aa, only partially shared with Vip3Ca, and not shared with Cry1Ac and Cry1F in two Spodoptera spp. Truncated versions of Vip3Af revealed that only domains I to III were necessary for the specific binding, most likely because they can form the functional tetrameric oligomer and because domain III is supposed to contain the binding epitopes. In contrast to results obtained in vivo (bioassays against larvae), domains IV and V are not necessary for the ex vivo toxicity to Sf21 cells.
Collapse
|
30
|
Proteomic Analysis and Promoter Modification of Bacillus thuringiensis to Improve Insecticidal Vip3A Protein Production. Mol Biotechnol 2021; 64:100-107. [PMID: 34553315 DOI: 10.1007/s12033-021-00401-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 09/14/2021] [Indexed: 10/20/2022]
Abstract
Insecticidal protein Vip3A secreted from B. thuringiensis is a potential biocontrol agent for control of lepidopteran pests. Under laboratory conditions, high albeit variable Vip3A production from the local isolate Bt294 was only obtained from a much enriched TB culture medium. Proteomic analysis and strain improvement were therefore performed to improve Vip3A production. Studies indicated that the buffer capacity, carbon source, and nitrogen source are critical to efficiently produce Vip3A. Medium with lower amounts of peptone and yeast extract (compared to TB), with an additional carbon source and phosphate buffer (LB*G medium) was found to give reasonable yields of Vip3A. Proteomic analysis revealed higher expression of proteins involved in glutamate and histidine biosynthesis in cells cultured in TB compared to LB about 58 and 33 times, respectively. Experiments confirmed that glutamate supplementation could increase Vip3A production. In addition, promoter substitution with that of cry3A increased Vip3A yields by about 20-30%. Overall, very high yields of Vip3A could be obtained by culturing Bt294 (Pcry3A-vip3Aa64) in LB*G medium with glutamate supplementation.
Collapse
|
31
|
How Does Bacillus thuringiensis Crystallize Such a Large Diversity of Toxins? Toxins (Basel) 2021; 13:toxins13070443. [PMID: 34206796 PMCID: PMC8309854 DOI: 10.3390/toxins13070443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/22/2021] [Accepted: 06/24/2021] [Indexed: 12/31/2022] Open
Abstract
Bacillus thuringiensis (Bt) is a natural crystal-making bacterium. Bt diversified into many subspecies that have evolved to produce crystals of hundreds of pesticidal proteins with radically different structures. Their crystalline form ensures stability and controlled release of these major virulence factors. They are responsible for the toxicity and host specificity of Bt, explaining its worldwide use as a biological insecticide. Most research has been devoted to understanding the mechanisms of toxicity of these toxins while the features driving their crystallization have long remained elusive, essentially due to technical limitations. The evolution of methods in structural biology, pushing back the limits in size of amenable protein crystals now allows access to be gained to structural information hidden within natural crystals of such toxins. In this review, we present the main parameters that have been identified as key drivers of toxin crystallization in Bt, notably in the light of recent discoveries driven by structural biology studies. Then, we develop how the future evolution of structural biology will hopefully unveil new mechanisms of Bt toxin crystallization, opening the door to their hijacking with the aim of developing a versatile in vivo crystallization platform of high academic and industrial interest.
Collapse
|
32
|
Gupta M, Kumar H, Kaur S. Vegetative Insecticidal Protein (Vip): A Potential Contender From Bacillus thuringiensis for Efficient Management of Various Detrimental Agricultural Pests. Front Microbiol 2021; 12:659736. [PMID: 34054756 PMCID: PMC8158940 DOI: 10.3389/fmicb.2021.659736] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 04/19/2021] [Indexed: 11/25/2022] Open
Abstract
Bacillus thuringiensis (Bt) bacterium is found in various ecological habitats, and has natural entomo-pesticidal properties, due to the production of crystalline and soluble proteins during different growth phases. In addition to Cry and Cyt proteins, this bacterium also produces Vegetative insecticidal protein (Vip) during its vegetative growth phase, which is considered an excellent toxic candidate because of the difference in sequence homology and receptor sites from Cry proteins. Vip proteins are referred as second-generation insecticidal proteins, which can be used either alone or in complementarity with Cry proteins for the management of various detrimental pests. Among these Vip proteins, Vip1 and Vip2 act as binary toxins and have toxicity toward pests belonging to Hemiptera and Coleoptera orders, whereas the most important Vip3 proteins have insecticidal activity against Lepidopteran pests. These Vip3 proteins are similar to Cry proteins in terms of toxicity potential against susceptible insects. They are reported to be toxic toward pests, which can’t be controlled with Cry proteins. The Vip3 proteins have been successfully pyramided along with Cry proteins in transgenic rice, corn, and cotton to combat resistant pest populations. This review provides detailed information about the history and importance of Vip proteins, their types, structure, newly identified specific receptors, and action mechanism of this specific class of proteins. Various studies conducted on Vip proteins all over the world and the current status have been discussed. This review will give insights into the significance of Vip proteins as alternative promising candidate toxic proteins from Bt for the management of pests in most sustainable manner.
Collapse
Affiliation(s)
- Mamta Gupta
- ICAR-National Institute for Plant Biotechnology, New Delhi, India.,ICAR-Indian Institute of Maize Research, Ludhiana, India
| | - Harish Kumar
- Punjab Agricultural University, Regional Research Station, Faridkot, India
| | - Sarvjeet Kaur
- ICAR-National Institute for Plant Biotechnology, New Delhi, India
| |
Collapse
|
33
|
Byrne MJ, Iadanza MG, Perez MA, Maskell DP, George RM, Hesketh EL, Beales PA, Zack MD, Berry C, Thompson RF. Cryo-EM structures of an insecticidal Bt toxin reveal its mechanism of action on the membrane. Nat Commun 2021; 12:2791. [PMID: 33990582 PMCID: PMC8121907 DOI: 10.1038/s41467-021-23146-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 03/25/2021] [Indexed: 12/11/2022] Open
Abstract
Insect pests are a major cause of crop losses worldwide, with an estimated economic cost of $470 billion annually. Biotechnological tools have been introduced to control such insects without the need for chemical pesticides; for instance, the development of transgenic plants harbouring genes encoding insecticidal proteins. The Vip3 (vegetative insecticidal protein 3) family proteins from Bacillus thuringiensis convey toxicity to species within the Lepidoptera, and have wide potential applications in commercial agriculture. Vip3 proteins are proposed to exert their insecticidal activity through pore formation, though to date there is no mechanistic description of how this occurs on the membrane. Here we present cryo-EM structures of a Vip3 family toxin in both inactive and activated forms in conjunction with structural and functional data on toxin-membrane interactions. Together these data demonstrate that activated Vip3Bc1 complex is able to insert into membranes in a highly efficient manner, indicating that receptor binding is the likely driver of Vip3 specificity.
Collapse
Affiliation(s)
- Matthew J Byrne
- Astbury Centre for Structural and Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Matthew G Iadanza
- Astbury Centre for Structural and Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
- Scientific Computing Department, Science and Technology Facilities Council, Research Complex at Harwell, Didcot, UK
| | - Marcos Arribas Perez
- Astbury Centre for Structural and Molecular Biology, School of Chemistry, Faculty of Engineering and Physical Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | - Daniel P Maskell
- Astbury Centre for Structural and Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Rachel M George
- Astbury Centre for Structural and Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Emma L Hesketh
- Astbury Centre for Structural and Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Paul A Beales
- Astbury Centre for Structural and Molecular Biology, School of Chemistry, Faculty of Engineering and Physical Sciences & Astbury Centre for Structural and Molecular Biology, University of Leeds, Leeds, UK
| | | | - Colin Berry
- Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
| | - Rebecca F Thompson
- Astbury Centre for Structural and Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
| |
Collapse
|
34
|
The Essential and Enigmatic Role of ABC Transporters in Bt Resistance of Noctuids and Other Insect Pests of Agriculture. INSECTS 2021; 12:insects12050389. [PMID: 33924857 PMCID: PMC8145640 DOI: 10.3390/insects12050389] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 11/18/2022]
Abstract
Simple Summary The insect family, Noctuidae, contains some of the most damaging pests of agriculture, including bollworms, budworms, and armyworms. Transgenic cotton and maize expressing Cry-type insecticidal proteins from Bacillus thuringiensis (Bt) are protected from such pests and greatly reduce the need for chemical insecticides. However, evolution of Bt resistance in the insects threatens the sustainability of this environmentally beneficial pest control strategy. Understanding the interaction between Bt toxins and their targets in the insect midgut is necessary to evaluate the risk of resistance evolution. ABC transporters, which in eukaryotes typically expel small molecules from cells, have recently been proposed as a target for the pore-forming Cry toxins. Here we review the literature surrounding this hypothesis in noctuids and other insects. Appreciation of the critical role of ABC transporters will be useful in discovering counterstrategies to resistance, which is already evolving in some field populations of noctuids and other insects. Abstract In the last ten years, ABC transporters have emerged as unexpected yet significant contributors to pest resistance to insecticidal pore-forming proteins from Bacillus thuringiensis (Bt). Evidence includes the presence of mutations in resistant insects, heterologous expression to probe interactions with the three-domain Cry toxins, and CRISPR/Cas9 knockouts. Yet the mechanisms by which ABC transporters facilitate pore formation remain obscure. The three major classes of Cry toxins used in agriculture have been found to target the three major classes of ABC transporters, which requires a mechanistic explanation. Many other families of bacterial pore-forming toxins exhibit conformational changes in their mode of action, which are not yet described for the Cry toxins. Three-dimensional structures of the relevant ABC transporters, the multimeric pore in the membrane, and other proteins that assist in the process are required to test the hypothesis that the ATP-switch mechanism provides a motive force that drives Cry toxins into the membrane. Knowledge of the mechanism of pore insertion will be required to combat the resistance that is now evolving in field populations of insects, including noctuids.
Collapse
|
35
|
Pinos D, Andrés-Garrido A, Ferré J, Hernández-Martínez P. Response Mechanisms of Invertebrates to Bacillus thuringiensis and Its Pesticidal Proteins. Microbiol Mol Biol Rev 2021; 85:e00007-20. [PMID: 33504654 PMCID: PMC8549848 DOI: 10.1128/mmbr.00007-20] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Extensive use of chemical insecticides adversely affects both environment and human health. One of the most popular biological pest control alternatives is bioinsecticides based on Bacillus thuringiensis This entomopathogenic bacterium produces different protein types which are toxic to several insect, mite, and nematode species. Currently, insecticidal proteins belonging to the Cry and Vip3 groups are widely used to control insect pests both in formulated sprays and in transgenic crops. However, the benefits of B. thuringiensis-based products are threatened by insect resistance evolution. Numerous studies have highlighted that mutations in genes coding for surrogate receptors are responsible for conferring resistance to B. thuringiensis Nevertheless, other mechanisms may also contribute to the reduction of the effectiveness of B. thuringiensis-based products for managing insect pests and even to the acquisition of resistance. Here, we review the relevant literature reporting how invertebrates (mainly insects and Caenorhabditis elegans) respond to exposure to B. thuringiensis as either whole bacteria, spores, and/or its pesticidal proteins.
Collapse
Affiliation(s)
- Daniel Pinos
- Instituto Universitario de Biotecnología y Biomedicina (BIOTECMED), Department of Genetics, Universitat de València, Burjassot, Spain
| | - Ascensión Andrés-Garrido
- Instituto Universitario de Biotecnología y Biomedicina (BIOTECMED), Department of Genetics, Universitat de València, Burjassot, Spain
| | - Juan Ferré
- Instituto Universitario de Biotecnología y Biomedicina (BIOTECMED), Department of Genetics, Universitat de València, Burjassot, Spain
| | - Patricia Hernández-Martínez
- Instituto Universitario de Biotecnología y Biomedicina (BIOTECMED), Department of Genetics, Universitat de València, Burjassot, Spain
| |
Collapse
|
36
|
Yin Y, Flasinski S, Moar W, Bowen D, Chay C, Milligan J, Kouadio JL, Pan A, Werner B, Buckman K, Zhang J, Mueller G, Preftakes C, Hibbard BE, Price P, Roberts J. A new Bacillus thuringiensis protein for Western corn rootworm control. PLoS One 2020; 15:e0242791. [PMID: 33253273 PMCID: PMC7703998 DOI: 10.1371/journal.pone.0242791] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/09/2020] [Indexed: 11/23/2022] Open
Abstract
The Western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte is one of the most economically important insect pests in North America. Since 2003, transgenic maize expressing WCR-active proteins from Bacillus thuringiensis (Bt) have been widely adopted as the main approach to controlling WCR in the U.S. However, the emergence of field resistance to the Bt proteins in current commercial products has been documented in recent years, highlighting the need to develop additional tools for controlling this devasting pest. Here we report the discovery of Vpb4Da2 (initially assigned as Vip4Da2), a new insecticidal protein highly selective against WCR, through high-throughput genome sequencing of a Bt strain sourced from grain dust samples collected in the eastern and central regions of the US. Vpb4Da2 contains a sequence and domain signature distinct from families of other WCR-active proteins. Under field conditions, transgenic maize expressing Vpb4Da2 demonstrates commercial-level (at or below NIS 0.25) root protection against WCR, and reduces WCR beetle emergence by ≥ 97%. Our studies also conclude that Vpb4Da2 controls WCR populations that are resistant to WCR-active transgenic maize expressing Cry3Bb1, Cry34Ab1/Cry35Ab1 (reassigned as Gpp34Ab1/Tpp35Ab1), or DvSnf7 RNA. Based on these findings, Vpb4Da2 represents a valuable new tool for protecting maize against WCR.
Collapse
Affiliation(s)
- Yong Yin
- Bayer Crop Science, Chesterfield, Missouri, United States of America
- * E-mail:
| | | | - William Moar
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - David Bowen
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Cathy Chay
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jason Milligan
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | | | - Aihong Pan
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Brent Werner
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Karrie Buckman
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Jun Zhang
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Geoffrey Mueller
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Collin Preftakes
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - Bruce E. Hibbard
- USDA-ARS, Plant Genetics Research Unit, University of Missouri, Columbia, Missouri, United States of America
| | - Paula Price
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| | - James Roberts
- Bayer Crop Science, Chesterfield, Missouri, United States of America
| |
Collapse
|
37
|
Wang Z, Gan C, Wang J, Bravo A, Soberón M, Yang Q, Zhang J. Nutrient conditions determine the localization of Bacillus thuringiensis Vip3Aa protein in the mother cell compartment. Microb Biotechnol 2020; 14:551-560. [PMID: 33252200 PMCID: PMC7936315 DOI: 10.1111/1751-7915.13719] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 12/31/2022] Open
Abstract
Vip3Aa was first identified as a protein secreted during the vegetative growth phase of Bacillus thuringiensis (Bt) bacteria and which shows high insecticidal toxicity against lepidopteran insect pests (Estruch et al., 1996). Bt strains formulated as bio‐insecticides only had low amounts of Vip3Aa secreted to the medium. Here, we report that Vip3Aa proteins produced by three different Bt strains, including an industrial strain, were indeed not secreted to the culture solution when grown in sporulation medium, but were retained in the mother cell compartment. In order to further investigate the Vip3Aa secretion and location, we grew the strains in rich medium. We found that in rich medium, a fraction of Vip3Aa was secreted, suggesting that Vip3Aa secretion is nutrient‐dependent. Regardless of the growth conditions, we found that Vip3Aa retained in cell pellets exhibited high toxicity against Spodoptera frugiperda larvae. Hence, we speculate that the accumulation of Vip3Aa protein in the mother cell compartment under sporulation conditions could still be used as an efficient strategy for industrial production in commercial Bt strains.
Collapse
Affiliation(s)
- 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
| | - Chunxia Gan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.,School of Plant Protection, Anhui Agricultural University, Hefei, 230036, China
| | - Jian Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62250, Mexico
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62250, Mexico
| | - Qing Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Jie Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| |
Collapse
|
38
|
Current Insights on Vegetative Insecticidal Proteins (Vip) as Next Generation Pest Killers. Toxins (Basel) 2020; 12:toxins12080522. [PMID: 32823872 PMCID: PMC7472478 DOI: 10.3390/toxins12080522] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/09/2020] [Accepted: 08/11/2020] [Indexed: 02/01/2023] Open
Abstract
Bacillus thuringiensis (Bt) is a Gram negative soil bacterium. This bacterium secretes various proteins during different growth phases with an insecticidal potential against many economically important crop pests. One of the important families of Bt proteins is vegetative insecticidal proteins (Vip), which are secreted into the growth medium during vegetative growth. There are three subfamilies of Vip proteins. Vip1 and Vip2 heterodimer toxins have an insecticidal activity against many Coleopteran and Hemipteran pests. Vip3, the most extensively studied family of Vip toxins, is effective against Lepidopteron. Vip proteins do not share homology in sequence and binding sites with Cry proteins, but share similarities at some points in their mechanism of action. Vip3 proteins are expressed as pyramids alongside Cry proteins in crops like maize and cotton, so as to control resistant pests and delay the evolution of resistance. Biotechnological- and in silico-based analyses are promising for the generation of mutant Vip proteins with an enhanced insecticidal activity and broader spectrum of target insects.
Collapse
|