1
|
Yao X, Liu C, Duan Y, An S, Wei J, Liang G. ABCC2 is a functional receptor of Bacillus thuringiensis Cry1Ca in Spodoptera litura. Int J Biol Macromol 2022; 194:9-16. [PMID: 34861271 DOI: 10.1016/j.ijbiomac.2021.11.174] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 12/12/2022]
Abstract
Spodoptera litura is a serious polyphagous pest in the whole world, which has developed resistance to most conventional insecticides and even some Bacillus thuringiensis (Bt) toxins. Cry1Ca has excellent insecticide activity against S. litura with potential application to control S. litura and delay the development of insect resistance. However, the mode of action of Cry1Ca in S. litura is poorly understood. Here, Cry1Ca-binding proteins were identified from S. litura by using pull down assays and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results indicated that aminopeptidase-N (APN), ATP binding cassette subfamily C member 2 (ABCC2), polycalin, actin and V-type proton ATPase subunit A may bind with Cry1Ca. Further study confirmed that ABCC2 fragment expressed in vitro can bind to Cry1Ca as demonstrated by Ligand blot and homologous competition experiments. The over-expression of endogenous SlABCC2 in Sf9 cells increased Cry1Ca cytotoxicity. Correspondingly, the vivo loss of function analyses by SlABCC2 small interfering RNAs (siRNAs) in S. litura larvae decreased the toxicity of Cry1Ca to larvae. Altogether, these results show that ABCC2 of S. litura is a functional receptor that is involved in the action mode of Cry1Ca.
Collapse
Affiliation(s)
- Xue Yao
- State key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Chen Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, PR China
| | - Yunpeng Duan
- State key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Shiheng An
- State key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China
| | - Jizhen Wei
- State key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou 450002, China.
| | - Gemei Liang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing 100193, PR China.
| |
Collapse
|
2
|
Knockout of Two Cry-Binding Aminopeptidase N Isoforms Does Not Change Susceptibility of Aedes aegypti Larvae to Bacillus thuringiensis subsp. israelensis Cry4Ba and Cry11Aa Toxins. INSECTS 2021; 12:insects12030223. [PMID: 33807543 PMCID: PMC8002144 DOI: 10.3390/insects12030223] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 11/17/2022]
Abstract
Simple Summary The midgut aminopeptidase N (APN) isoforms have been identified as the binding receptor of insecticidal Cry toxins in numerous insects, including the major arbovirus vector Aedes aegypti (Ae. aegypti). However, whether the Cry-binding APN acts as an essential functional receptor to mediate Bacillus thuringiensis subsp. israelensis (Bti) toxicity in Ae. aegypti larvae remains to be determined. In this study, our results provide the direct molecular evidence demonstrating that two Cry-binding APN isoforms (AeAPN1 and AeAPN2) did not play a key role in mediating Bti Cry4Ba and Cry11Aa toxicity in Ae. aegypti larvae. Abstract The insecticidal Cry4Ba and Cry11Aa crystal proteins from Bacillus thuringiensis subsp. israelensis (Bti) are highly toxic to Ae. aegypti larvae. The glycosylphosphatidylinositol (GPI)-anchored APN was identified as an important membrane-bound receptor for multiple Cry toxins in numerous Lepidoptera, Coleoptera, and Diptera insects. However, there is no direct molecular evidence to link APN of Ae. aegypti to Bti toxicity in vivo. In this study, two Cry4Ba/Cry11Aa-binding Ae. aegypti GPI-APN isoforms (AeAPN1 and AeAPN2) were individually knocked-out using CRISPR/Cas9 mutagenesis, and the AeAPN1/AeAPN2 double-mutant homozygous strain was generated using the reverse genetics approach. ELISA assays showed that the high binding affinity of Cry4Ba and Cry11Aa protoxins to the midgut brush border membrane vesicles (BBMVs) from these APN knockouts was similar to the background from the wild-type (WT) strain. Likewise, the bioassay results showed that neither the single knockout of AeAPN1 or AeAPN2, nor the simultaneous disruption of AeAPN1 and AeAPN2 resulted in significant changes in susceptibility of Ae. aegypti larvae to Cry4Ba and Cry11Aa toxins. Accordingly, our results suggest that AeAPN1 and AeAPN2 may not mediate Bti Cry4Ba and Cry11Aa toxicity in Ae. aegypti larvae as their binding proteins.
Collapse
|
3
|
Li H, Zhang J, Ma T, Li C, Ma Z, Zhang X. Acting target of toosendanin locates in the midgut epithelium cells of Mythimna separate Walker larvae (lepidoptera: Noctuidae). ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 201:110828. [PMID: 32531576 DOI: 10.1016/j.ecoenv.2020.110828] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 05/15/2020] [Accepted: 05/27/2020] [Indexed: 06/11/2023]
Abstract
Toosendanin (TSN), which is extracted from the root bark of Melia toosendan Siebold and Zuccarini, has multiple modes of action against insects. Especially, this compound has a potent stomach poisoning activity against several lepidoptera pests. In this paper, the signs of toxicity, digestive enzymes activity, the histopathological changes and immuno-electron microscopic localization of TSN in the midgut epithelium of Mythimna separate Walker larvae were investigated for better understanding its action mechanism against insects. The bioassay results indicated that TSN has strong stomach poisoning against the fifth-instar larvae of M. separata (LC50 = 252.23 μg/mL). The typical poisoned symptom were regurgitation and paralysis. Activities of digestive enzymes had no obvious changes after treatment with LC80 dose of TSN. The midgut epithelial cells of insect were damaged by TSN, showing the degeneration of microvilli, hyperplasia of smooth endoplasmic reticulum and condensation of chromatin. Immunohistochemical analysis revealed that the gold particles existed on the microvilli of columnar cells and goblet cells, and gradually accumulated with the exacerbation of poisoning symptoms, showing that TSN targets on the microvilli of the midgutcells. Therefore, TSN acts on digestive system and locates in the microvilli of midgutcells of M. separata.
Collapse
Affiliation(s)
- Hai Li
- College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Jing Zhang
- Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Science, Haikou, 571010, China
| | - Ting Ma
- College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Chao Li
- College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zhiqing Ma
- College of Plant Protection, Northwest A&F University, Yangling, 712100, Shaanxi, China; Provincial Center for Bio-Pesticide Engineering, Yangling, Shaanxi Province, 712100, China.
| | - Xing Zhang
- Provincial Center for Bio-Pesticide Engineering, Yangling, Shaanxi Province, 712100, China
| |
Collapse
|
4
|
Wang J, Zuo Y, Li L, Wang H, Liu S, Yang Y, Wu Y. Knockout of three aminopeptidase N genes does not affect susceptibility of Helicoverpa armigera larvae to Bacillus thuringiensis Cry1A and Cry2A toxins. INSECT SCIENCE 2020; 27:440-448. [PMID: 30767423 PMCID: PMC7277041 DOI: 10.1111/1744-7917.12666] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/19/2019] [Accepted: 01/30/2019] [Indexed: 05/31/2023]
Abstract
Bacillus thuringiensis (Bt) insecticidal toxins have been globally utilized for control of agricultural insects through spraying or transgenic crops. Binding of Bt toxins to special receptors on midgut epithelial cells of target insects is a key step in the mode of action. Previous studies suggested aminopeptidase N1 (APN1) as a receptor or putative receptor in several lepidopteran insects including Helicoverpa armigera through evidence from RNA interefence-based gene silencing approaches. In the current study we tested the role of APNs in the mode of action of Bt toxins using clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9-mediated gene knockout. Three APN genes (HaAPN1, HaAPN2 and HaAPN5) were individually knocked out in a susceptible strain (SCD) of H. armigera to establish three homozygous knockout strains. Qualitative in vitro binding studies indicated binding of Cry1Ac or Cry2Ab to midgut brush border membrane vesicles was not obviously affected by APN knockout. Bioassay results showed that none of the three knockouts had significant changes in susceptibility to Cry1A or Cry2A toxins when compared with the SCD strain. This suggests that the three HaAPN genes we tested may not be critical in the mode of action of Cry1A or Cry2A toxins in H. armigera.
Collapse
Affiliation(s)
- Jing Wang
- College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Ya‐Yun Zuo
- College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Ling‐Li Li
- College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Hui Wang
- College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Shao‐Yan Liu
- College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Yi‐Hua Yang
- College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| | - Yi‐Dong Wu
- College of Plant ProtectionNanjing Agricultural UniversityNanjingChina
| |
Collapse
|
5
|
Liu L, Chen Z, Yang Y, Xiao Y, Liu C, Ma Y, Soberón M, Bravo A, Yang Y, Liu K. A single amino acid polymorphism in ABCC2 loop 1 is responsible for differential toxicity of Bacillus thuringiensis Cry1Ac toxin in different Spodoptera (Noctuidae) species. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 100:59-65. [PMID: 29964167 DOI: 10.1016/j.ibmb.2018.06.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 06/13/2018] [Accepted: 06/22/2018] [Indexed: 06/08/2023]
Abstract
Bacillus thuringiensis Cry toxins exert their toxicity by forming membrane pores after binding with larval midgut membrane proteins known as receptors. Spodoptera litura and Spodoptera frugiperda belong to the same genus, but S. litura is tolerant to Cry1Ac, while S. frugiperda is susceptible. The mechanism involved in the differential toxicity of Cry1Ac to these insect species is not understood. Amino acid sequences analysis of ABCC2, a well-recognized Cry1Ac receptor, from both species showed high sequence identity. Hi5 insect cells expressing SfABCC2 from S. frugiperda were 65-fold more susceptible than those expressing the SlABCC2 from S. litura. Substitution of fragments, point mutations and deletions between the ABCC2 of the two species revealed that ABCC2 amino acid Q125 from SfABCC2 or E125 from SlABCC2 was key factor for the differential Cry1Ac toxicity to Hi5 cells expressing these receptors. Consistently with this, cells expressing Helicoverpa armigera HaABCC2Q122-GFP, were more susceptible to Cry1Ac than cells expressing HaABCC2E122-GFP mutant. Q125 or E125 is located in a predicted exposed loop 1 region of ABCC2 indicating that this region could be important for Cry1Ac binding. These findings identified a single amino acid residue located in loop 1 of ABCC2 transporter as responsible for the different levels of susceptibility to Cry1Ac among various lepidopteran species.
Collapse
Affiliation(s)
- Leilei Liu
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Zuwen Chen
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Yanchao Yang
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Yutao Xiao
- Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Chenxi Liu
- State Key Laboratory for Biology of Plant Disease and Insect Pests, Chinese Academy of Agricultural Sciences, West Yuanmingyuan Road, Beijing, 100193, China
| | - Yuemin Ma
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, 62250, Morelos, Mexico
| | - Alejandra Bravo
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Apdo. Postal 510-3, Cuernavaca, 62250, Morelos, Mexico.
| | - Yongbo Yang
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
| | - Kaiyu Liu
- Institute of Entomology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.
| |
Collapse
|
6
|
Wang Y, Li D, Zhou H, Liu H, Niu L, Wang L, Ma W. Evaluation of Cry1Ac and Cry2Aa Toxin Binding to Two Important Beneficial Cotton Field Insects, Harmonia axyridis and Orius similis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:8698-8702. [PMID: 30059215 DOI: 10.1021/acs.jafc.8b02634] [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: 06/08/2023]
Abstract
Transgenic crops expressing Cry toxins are effective and considered environmentally friendly alternatives to synthetic pesticides, but assessment of environmental risks of their application on nontarget organisms is ongoing. The main risk is the transfer of Cry toxins to natural enemies through the food chain. There is reported evidence supporting that Cry toxins can be detected in the body and gut of some natural enemy insects. Considering that binding of Cry toxins to insect proteins is an essential step in the intoxication process, this work was conducted to evaluate interactions between Cry1Ac and Cry2Aa toxins with proteins from larvae/nymphs and adults of two important predatory natural enemies in cotton fields, Harmonia axyridis and Orius similis. Results support the absence of Cry1Ac or Cry2Aa binding proteins in immature stages of H. axyridis and O. similis, as well as in imaginal stage of H. axyridis. One same binding band about 70 kDa was found in imaginal total protein of O. similis when probed with the two Cry proteins, with the best match to Hsc70 of O. sauteri in the Uniprot database. However, nonspecific binding was verified by following competitive binding assays between the two Cry proteins and imaginal total protein of O. similis. From these results, we may infer that Cry1Ac and Cry2Aa have no likely detrimental effects on H. axyridis and O. similis.
Collapse
Affiliation(s)
- Yong Wang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory , Huazhong Agricultural University , Wuhan 430070 , China
- Hubei Key Laboratory of Quality Control of Characteristic Fruits and Vegetables , Hubei Engineering University , Xiaogan 432000 , China
| | - Dabo Li
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory , Huazhong Agricultural University , Wuhan 430070 , China
- Yichang Institute of Termite Control , Yichang 443000 , China
| | - Hao Zhou
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory , Huazhong Agricultural University , Wuhan 430070 , China
| | - Hui Liu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory , Huazhong Agricultural University , Wuhan 430070 , China
| | - Lin Niu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory , Huazhong Agricultural University , Wuhan 430070 , China
| | - Lihua Wang
- Hubei Key Laboratory of Quality Control of Characteristic Fruits and Vegetables , Hubei Engineering University , Xiaogan 432000 , China
| | - Weihua Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory , Huazhong Agricultural University , Wuhan 430070 , China
| |
Collapse
|