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Zhao D, Wu H, Li Y, Wang Q, Ji Y, Guo X, Guo W. Effects of the pyrE deletion mutant from Bacillus thuringiensis on gut microbiota and immune response of Spodoptera exigua. Front Microbiol 2023; 14:1182699. [PMID: 37333629 PMCID: PMC10272597 DOI: 10.3389/fmicb.2023.1182699] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 05/12/2023] [Indexed: 06/20/2023] Open
Abstract
The gut microbiota is essential for the growth and development of insects, and the intestinal immune system plays a critical role in regulating the homeostasis of intestinal microorganisms and their interactions with pathogenic bacteria. Infection with Bacillus thuringiensis (Bt) can disrupt the gut microbiota of insects, but the regulatory factors governing the interaction between Bt and gut bacteria are not well understood. Uracil secreted by exogenous pathogenic bacteria can activate DUOX-mediated reactive oxygen species (ROS) production, which helps maintain intestinal microbial homeostasis and immune balance. To elucidate the regulatory genes involved in the interaction between Bt and gut microbiota, we investigate the effects of uracil derived from Bt on gut microbiota, and host immunity using a uracil deficient Bt strain (Bt GS57△pyrE) obtained by homologous recombination. We analyze the biological characteristics of the uracil deficient strain and found that the deletion of uracil in Bt GS57 strain changed the diversity of gut bacteria in Spodoptera exigua, as investigated using Illumina HiSeq sequencing. Furthermore, qRT-PCR analysis showed that compared with Bt GS57 (control), the expression of the SeDuox gene and the level of ROS were significantly decreased after feeding with Bt GS57△pyrE. Adding uracil to Bt GS57△pyrE restored the expression level of DUOX and ROS to a higher level. Additionally, we observed that PGRP-SA, attacin, defensin and ceropin genes were significant different in the midgut of S. exigua infected by Bt GS57 and Bt GS57△pyrE, with a trend of increasing first and then decreasing. These results suggest that uracil regulates and activates the DUOX-ROS system, affects the expression of antimicrobial peptide genes, and disturb intestinal microbial homeostasis. We preliminarily speculate that uracil is a key factor in the interaction between Bt and gut microbiota, and these findings provide a theoretical basis for clarifying the interaction between Bt, host, and intestinal microorganisms, as well as for gaining new insights into the insecticidal mechanism of B. thuringiensis in insects.
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Affiliation(s)
- Dan Zhao
- College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Han Wu
- College of Plant Protection, Hebei Agricultural University, Baoding, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yazi Li
- College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Qian Wang
- College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Yujie Ji
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaochang Guo
- College of Plant Protection, Hebei Agricultural University, Baoding, China
| | - Wei Guo
- College of Plant Protection, Hebei Agricultural University, Baoding, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China
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2
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Zhang Z, Wang D, Shan Y, Chen J, Hu H, Song X, Ma X, Ren X, Ma Y. Knockdown of CYP9A9 increases the susceptibility to lufenuron, methoxyfenozide and a mixture of both in Spodoptera exigua. INSECT MOLECULAR BIOLOGY 2023; 32:263-276. [PMID: 36582185 DOI: 10.1111/imb.12829] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/27/2022] [Indexed: 05/15/2023]
Abstract
Lufenuron (LUF) and Methoxyfenozide (MET) as Insect Growth Regulators (IGRs) contribute to the current control of the catastrophic crop pest, Spodoptera exigua (Lepidoptera, Noctuidae). Yet S. exigua has evolved resistance to LUF and MET, which is possibly mediated by cytochrome P450 monooxygenases (P450s), particularly from the CYP3 clade family, as it plays a key role in the detoxification of insecticides. However, a mixture of LUF and MET (MML) (optimal ratio: 6:4) remains highly insecticidal. Here, we analysed the response of S. exigua to sublethal concentrations of LUF, MET, and MML via transcriptomics. Twelve differentially expressed genes (DEGs) encoding CYP3 clade members were observed in transcriptomes and CYP9A9 was significantly upregulated after treatment with LUF, MET, and MML. Further, CYP9A9 was most highly expressed in the midgut of L4 S. exigua larvae. RNAi-mediated knockdown of CYP9A9 reduced the activity of CYP450 and increased the susceptibility of S. exigua larvae to LUF, MET, and MML. Thus, CYP9A9 plays a key role in the detoxification of LUF, MET, and MML in S. exigua. These findings provide new insights into insecticidal actions of IGRs, which can be applied to the establishment of novel pest management strategies.
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Affiliation(s)
- Zhixian Zhang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Dan Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Yongpan Shan
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Jixiang Chen
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Hongyan Hu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Xianpeng Song
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
| | - Xiaoyan Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, China
| | - Xiangliang Ren
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, China
| | - Yan Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, China
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, China
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Li Y, Chang L, Xu K, Zhang S, Gao F, Fan Y. Research Progresses on the Function and Detection Methods of Insect Gut Microbes. Microorganisms 2023; 11:1208. [PMID: 37317182 DOI: 10.3390/microorganisms11051208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/20/2023] [Accepted: 04/27/2023] [Indexed: 06/16/2023] Open
Abstract
The insect gut is home to an extensive array of microbes that play a crucial role in the digestion and absorption of nutrients, as well as in the protection against pathogenic microorganisms. The variety of these gut microbes is impacted by factors such as age, diet, pesticides, antibiotics, sex, and caste. Increasing evidence indicates that disturbances in the gut microbiota can lead to compromised insect health, and that its diversity has a far-reaching impact on the host's health. In recent years, the use of molecular biology techniques to conduct rapid, qualitative, and quantitative research on the host intestinal microbial diversity has become a major focus, thanks to the advancement of metagenomics and bioinformatics technologies. This paper reviews the main functions, influencing factors, and detection methods of insect gut microbes, in order to provide a reference and theoretical basis for better research utilization of gut microbes and management of harmful insects.
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Affiliation(s)
- Yazi Li
- Tangshan Key Laboratory of Agricultural Pathogenic Fungi and Toxins, Department of Life Science, Tangshan Normal University, Tangshan 063000, China
| | - Liyun Chang
- Tangshan Key Laboratory of Agricultural Pathogenic Fungi and Toxins, Department of Life Science, Tangshan Normal University, Tangshan 063000, China
| | - Ke Xu
- Tangshan Key Laboratory of Agricultural Pathogenic Fungi and Toxins, Department of Life Science, Tangshan Normal University, Tangshan 063000, China
| | - Shuhong Zhang
- Tangshan Key Laboratory of Agricultural Pathogenic Fungi and Toxins, Department of Life Science, Tangshan Normal University, Tangshan 063000, China
| | - Fengju Gao
- Tangshan Key Laboratory of Agricultural Pathogenic Fungi and Toxins, Department of Life Science, Tangshan Normal University, Tangshan 063000, China
| | - Yongshan Fan
- Tangshan Key Laboratory of Agricultural Pathogenic Fungi and Toxins, Department of Life Science, Tangshan Normal University, Tangshan 063000, China
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He L, Shi Y, Ding W, Huang H, He H, Xue J, Gao Q, Zhang Z, Li Y, Qiu L. Cytochrome P450s genes CYP321A9 and CYP9A58 contribute to host plant adaptation in the fall armyworm Spodoptera frugiperda. PEST MANAGEMENT SCIENCE 2023; 79:1783-1790. [PMID: 36627818 DOI: 10.1002/ps.7355] [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: 06/24/2022] [Revised: 12/25/2022] [Accepted: 01/11/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND The fall armyworm, Spodoptera frugiperda is one of the most destructive agricultural pests, which can complete their entire life cycle on various plants. At present, some detoxification genes have been proved to be involved in the adaptability to plants in insects. However, the genetics behind insect pest responses to host switches, and their ability to adapt to new host plants, remain poorly understood. This study was conducted to evaluate the adaptation of S. frugiperda to host plant and determine the roles of CYP321A9 and CYP9A58 in the detoxification metabolism of the fall armyworm. RESULTS The results revealed that feeding on maize was more suitable for S. frugiperda to develop compared with rice. In addition, knocking down of SfCYP321A9 and SfCYP9A58 resulted in a prolonged developmental time of S. frugiperda larvae that fed on rice. Meanwhile, RNAi knockdown of SfCYP321A9 resulted in significantly higher mortality of S. frugiperda larvae when exposed to the rice allelochemicals, ferulic acid, gramine and tricin. Furthermore, overexpression of SfCYP321A9 significantly reduced mortality in Drosophila melanogaster when exposed to gramine and tricin. CONCLUSION Our results suggest that CYP321A9 and CYP9A58 genes play a key role in host plant adaptation in S. frugiperda, which contribute to a greater understanding of the molecular basis of host plant adaptation and provide the means to develop effective management tools for S. frugiperda resistance. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Li He
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Yang Shi
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Wenbing Ding
- National Research Center of Engineering & Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China
- Hunan Provincial Engineering & Technology Research Center for Biopesticide and Formulation Processing, Changsha, China
| | - Hong Huang
- Hunan Institute of Plant Protection, Changsha, China
| | - Hualiang He
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Jin Xue
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Qiao Gao
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Zhixiang Zhang
- College of Plant Protection, South China Agricultural University, Guangzhou, China
| | - Youzhi Li
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
- National Research Center of Engineering & Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China
| | - Lin Qiu
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
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Wen D, Li M, Dong X, Han K, Yu J, Cai Y, Hua H. Monitoring reduced accumulation and risk evaluation of Cry1Ca during food chain transfer from genetically engineered plant to endoparasitoid. PEST MANAGEMENT SCIENCE 2023. [PMID: 36947641 DOI: 10.1002/ps.7467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 03/02/2023] [Accepted: 03/22/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND The potential risk of insecticidal proteins produced by genetically engineered (GE) plants to nontarget organisms have long been an ecotoxicological concern. Apanteles chilonis, an important endoparasitoid of rice pest Chilo suppressalis, potentially is exposed to Bacillus thuringiensis (Bt) endotoxins through a food chain of transgenic Bt rice - C. suppressalis - A. chilonis, and thus, a rigorous risk assessment is urgently needed. Here, we combined a tri-trophic bioassay system with high-dose exposure approach using C. suppressalis hemolymph as the carrier of insecticidal protein to evaluate the biosafety of Cry1Ca to A. chilonis. RESULTS Cry1Ca protein could be transmitted and retained along the food chain and remains bioactive in the hemolymph of C. suppressalis during the pre-adult duration of A. chilonis. No significant differences in pre-adult period, male and female longevity, adult fecundity and weight, emergence rate nor sex ratio were observed when A. chilonis parasitized C. suppressalis feeding on cry1Ca rice compared with control treatment. However, the pupal period and weight were significantly prolonged and decreased. When A. chilonis parasitized C. suppressalis injected with a high dosage of Cry1Ca protein, no adverse effects on the life-history parameters, peroxidase (POD), superoxide dismutase (SOD) or glutathione reductase (GR) of A. chilonis were observed, demonstrating that the host quality mediates adverse effects during the food chain. CONCLUSIONS We confirmed that Cry1Ca posed no ecological risk to the nontarget endoparasitoid A. chilonis. This study may serve as an example for future risk assessment of transgenic crops to nontarget endoparasitoids. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Dong Wen
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Mengyu Li
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Xinxin Dong
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Kehong Han
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jiukun Yu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Yujuan Cai
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Hongxia Hua
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
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Sun Y, Li Y, Zhang W, Jiang B, Tao SM, Dai HY, Xu XT, Sun YX, Yang L, Zhang YJ. The main component of the aphid alarm pheromone ( E)-β-farnesene affects the growth and development of Spodoptera exigua by mediating juvenile hormone-related genes. FRONTIERS IN PLANT SCIENCE 2022; 13:863626. [PMID: 36082292 PMCID: PMC9445801 DOI: 10.3389/fpls.2022.863626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 07/28/2022] [Indexed: 06/15/2023]
Abstract
The (E)-β-farnesene (EβF) is one of the most important secondary metabolites in some plants and provides indirect defense against aphids. However, the direct effect of EβF against pests is still unclear. In this study, various concentrations of EβF (0.16, 0.8, and 4 g/kg) were provided in an artificial diet to determine the direct effects of EβF on Spodoptera exigua. The results showed that an artificial diet containing 4 g/kg of EβF reduced the final survival of the S. exigua larvae and per female fecundity of adults significantly when compared with CK and SC controls (p < 0.05), then ultimately it also significantly affected the intrinsic rate of increase (p < 0.05). Furthermore, the results of the EβF bioassay in an artificial diet also indicated that the proliferation of the S. exigua population was inhibited by the ingestion of EβF in a dose-dependent manner. Combined differential RNA-seq data and RT-qPCR analysis, it was found that four key genes involved in juvenile hormone degradation significantly upregulated in S. exigua larvae treated by EβF at a dose of 0.8 and 4 g/kg when compared with two controls (p < 0.05). This indicated that EβF could disturb the normal function of juvenile hormones and reduce the survival rate of S. exigua larvae. Additionally, two key genes that regulate per fecundity of S. exigua females, including SeVg and SeVgR, were significantly downregulated in adult females (p < 0.05) when they were treated with 0.8 and 4 g/kg of EβF at the larval stage, relative to the expression of these genes after treatment with controls. These findings suggested that EβF first disturbed the normal function of juvenile hormone by upregulating key degradation genes, and then inhibited the expression of SeVg/SeVgR genes and proteins, thus reducing the population size of S. exigua by increasing larval mortality and inhibiting per female fecundity.
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Affiliation(s)
- Yang Sun
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, China
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yan Li
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, China
- Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wen Zhang
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Bin Jiang
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Si-Min Tao
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Han-Yang Dai
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Xin-Tong Xu
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Yue-Xin Sun
- Key Laboratory for Conservation and Use of Important Biological Resources of Anhui Province, Anhui Provincial Key Laboratory of Molecular Enzymology and Mechanism of Major Diseases, College of Life Sciences, Anhui Normal University, Wuhu, China
| | - Lei Yang
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing, China
| | - Yong-Jun Zhang
- Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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Dutta TK, Veeresh A, Phani V, Kundu A, Santhoshkumar K, Mathur C, Sagar D, Sreevathsa R. Molecular characterization and functional analysis of Cry toxin receptor-like genes from the model insect Galleria mellonella. INSECT MOLECULAR BIOLOGY 2022; 31:434-446. [PMID: 35266587 DOI: 10.1111/imb.12770] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 02/25/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
Crystal (Cry) toxins produced from the soil bacterium, Bacillus thuringiensis (Bt), have gained worldwide attention for long due to their insecticidal potential. A number of receptor proteins located on the epithelial cells of the larval midgut were shown to be crucial for Cry intoxication in different insect pests belonging to order Lepidoptera, Diptera and Coleoptera. A beehive pest, Galleria mellonella, serves as an excellent insect model for biochemical research. However, information on the Cry receptor-like genes in G. mellonella is limited. In the present study, the full-length sequences of four putative Cry receptor genes (ABC transporter, alkaline phosphatase, aminopeptidase N and cadherin) were cloned from G. mellonella. All these receptor genes were substantially upregulated in the midgut tissue of fourth-instar G. mellonella larvae upon early exposure (6 h) to a sub-lethal dose of Cry1AcF toxin. Oral and independent delivery of bacterially-expressed dsRNAs corresponding to four receptor genes in G. mellonella suppressed the transcription of target receptors which in turn significantly reduced the larval sensitivity to Cry1AcF toxin. As the laboratory populations of G. mellonella develop Bt resistance in a relatively short time, molecular characterization of Cry receptor genes in G. mellonella performed in the present study may provide some useful information for future research related to the genetic basis of Bt resistance in the model insect.
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Affiliation(s)
- Tushar K Dutta
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Arudhimath Veeresh
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Victor Phani
- Department of Agricultural Entomology, College of Agriculture, Uttar Banga Krishi Viswavidyalaya, Dakshin Dinajpur, West Bengal, India
| | - Artha Kundu
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | | | - Chetna Mathur
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Doddachowdappa Sagar
- Division of Entomology, ICAR-Indian Agricultural Research Institute, New Delhi, India
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Cheng Q, Yu X, Xiong Z, Wan Z, Li Y, Ma W, Tan W, Liu M, Shea KJ. Abiotic Synthetic Antibodies to Target a Specific Protein Domain and Inhibit Its Function. ACS APPLIED MATERIALS & INTERFACES 2022; 14:19178-19191. [PMID: 35442625 DOI: 10.1021/acsami.2c02287] [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: 06/14/2023]
Abstract
The Bacillus thuringiensis (Bt) Cry proteins are widely used in insect pest control. Despite their economic benefits, remaining concerns over potential ecological and health risks warrant their ongoing surveillance. Affinity reagents, most often antibodies, protein scaffolds, and aptamers, are the traditional tools used for protein binding and detection. We report a synthetic antibody (SA) alternative to traditional biological affinity reagents for binding Bt Cry proteins. Analysis of hotspots of the Bt Cry protein-insect midgut cadherin-like receptor complexes was used for the design of the SA. The SA was selected from a small focused library of hydrogel copolymers containing functional monomers complementary to key exposed hotspots of Bt Cry proteins. A directed chemical evolution identified a SA, APhe-NP23, with affinity and selectivity for Bt Cry1Ab/Ac proteins. The putative intermolecular polymer-protein interfaces were identified by the SA's uptake of Bt Cry1Ac pepsin hydrolysates, binding epitope mutation studies, and protein-protein inhibition studies of the toxin binding to its native insect receptor binding domains. The SA inhibitor binds to the same protein domains as the insect's cadherin-like receptors, Bt-R1 and SeCad1b. The SA binds rapidly to Bt Cry1Ab/Ac with high capacity, is pH-responsive, and is synthesized reproducibly. We believe that a hotspot-directed approach is general for creation of abiotic protein affinity reagents that target functional protein domains. Affinity ligands are typically high-information content biologicals. Their structure and function are determined from their amino acid or oligo sequence. In contract, the SA described in this work is a statistical copolymer that lacks sequence specificity. These results are an important contribution to the concept that randomness and biospecificity are not mutually exclusive.
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Affiliation(s)
- Qiaolian Cheng
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Xiaoyang Yu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Zhouxuan Xiong
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Zihao Wan
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Yuxin Li
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Weihua Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Wenfeng Tan
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Mingming Liu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture and Rural Affairs, Hubei Key Laboratory of Soil Environment and Pollution Remediation, State Environmental Protection Key Laboratory of Soil Health and Green Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei Province 430070, China
| | - Kenneth J Shea
- Department of Chemistry, University of California-Irvine, Irvine, California 92697, United States
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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.
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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.
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10
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Chen Y, Liu Z, Régnière J, Vasseur L, Lin J, Huang S, Ke F, Chen S, Li J, Huang J, Gurr GM, You M, You S. Large-scale genome-wide study reveals climate adaptive variability in a cosmopolitan pest. Nat Commun 2021; 12:7206. [PMID: 34893609 PMCID: PMC8664911 DOI: 10.1038/s41467-021-27510-2] [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: 08/07/2020] [Accepted: 11/22/2021] [Indexed: 12/15/2022] Open
Abstract
Understanding the genetic basis of climatic adaptation is essential for predicting species' responses to climate change. However, intraspecific variation of these responses arising from local adaptation remains ambiguous for most species. Here, we analyze genomic data from diamondback moth (Plutella xylostella) collected from 75 sites spanning six continents to reveal that climate-associated adaptive variation exhibits a roughly latitudinal pattern. By developing an eco-genetic index that combines genetic variation and physiological responses, we predict that most P. xylostella populations have high tolerance to projected future climates. Using genome editing, a key gene, PxCad, emerged from our analysis as functionally temperature responsive. Our results demonstrate that P. xylostella is largely capable of tolerating future climates in most of the world and will remain a global pest beyond 2050. This work improves our understanding of adaptive variation along environmental gradients, and advances pest forecasting by highlighting the genetic basis for local climate adaptation.
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Affiliation(s)
- Yanting Chen
- grid.256111.00000 0004 1760 2876State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002 China ,grid.419897.a0000 0004 0369 313XJoint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002 China ,Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002 China ,grid.418033.d0000 0001 2229 4212Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350013 China
| | - Zhaoxia Liu
- grid.256111.00000 0004 1760 2876State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002 China ,grid.419897.a0000 0004 0369 313XJoint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002 China ,Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002 China ,grid.449406.b0000 0004 1757 7252College of Oceanology and Food Science, Quanzhou Normal University, Quanzhou, 362000 China
| | - Jacques Régnière
- grid.146611.50000 0001 0775 5922Natural Resources Canada, Canadian Forest Service, Quebec City, QC G1V 4C7 Canada
| | - Liette Vasseur
- grid.256111.00000 0004 1760 2876State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002 China ,grid.419897.a0000 0004 0369 313XJoint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002 China ,grid.411793.90000 0004 1936 9318Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1 Canada
| | - Jian Lin
- grid.256111.00000 0004 1760 2876College of Computer and Information Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Shiguo Huang
- grid.256111.00000 0004 1760 2876College of Computer and Information Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002 China
| | - Fushi Ke
- grid.256111.00000 0004 1760 2876State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002 China ,grid.419897.a0000 0004 0369 313XJoint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002 China ,Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002 China ,grid.458495.10000 0001 1014 7864Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650 China
| | - Shaoping Chen
- grid.256111.00000 0004 1760 2876State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002 China ,grid.419897.a0000 0004 0369 313XJoint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002 China ,Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002 China ,grid.418033.d0000 0001 2229 4212Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350013 China
| | - Jianyu Li
- grid.256111.00000 0004 1760 2876State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002 China ,grid.419897.a0000 0004 0369 313XJoint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002 China ,Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002 China ,grid.418033.d0000 0001 2229 4212Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou, 350013 China
| | - Jieling Huang
- grid.256111.00000 0004 1760 2876State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002 China ,grid.419897.a0000 0004 0369 313XJoint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002 China ,Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002 China
| | - Geoff M. Gurr
- grid.256111.00000 0004 1760 2876State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002 China ,grid.419897.a0000 0004 0369 313XJoint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002 China ,grid.1037.50000 0004 0368 0777Graham Centre, Charles Sturt University, Orange, NSW 2800 Australia
| | - Minsheng You
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. .,Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002, China. .,Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002, China.
| | - Shijun You
- State Key Laboratory of Ecological Pest Control for Fujian-Taiwan Crops, Institute of Applied Ecology, Fujian Agriculture and Forestry University, Fuzhou, 350002, China. .,Joint International Research Laboratory of Ecological Pest Control, Ministry of Education, Fuzhou, 350002, China. .,Key Laboratory of Integrated Pest Management for Fujian-Taiwan Crops, Ministry of Agriculture, Fuzhou, 350002, China.
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11
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Dutta TK, Veeresh A, Mathur C, Phani V, Mandal A, Sagar D, Nebapure SM. The induced knockdown of GmCAD receptor protein encoding gene in Galleria mellonella decreased the insect susceptibility to a Photorhabdus akhurstii oral toxin. Virulence 2021; 12:2957-2971. [PMID: 34882066 PMCID: PMC8667893 DOI: 10.1080/21505594.2021.2006996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 10/12/2021] [Accepted: 11/11/2021] [Indexed: 12/02/2022] Open
Abstract
Photorhabdus bacteria secrete a repertoire of protein toxins that can kill the host insect. Among them, toxin complex (Tc) proteins have gained significant attention due to their wider conservation across the different bacterial genera. In our laboratory, a C-terminal domain of TcaB protein was characterized from P. akhurstii bacterium that conferred the potent oral insecticidal effect on Galleria mellonella. However, the role of insect gut receptors in the TcaB intoxication process was yet to be investigated. In the current study, we examined the transcription of candidate midgut receptors in TcaB-infected larvae and subsequently cloned a cadherin-like gene, GmCAD, from G. mellonella. GmCAD was highly transcribed in the fourth-instar larval stage and specifically in the midgut tissues. Our ligand blot and binding ELISA assays indicated that TcaB binds to the truncated peptides from the GmCAD transmembrane-proximal region with greater affinity than that from the transmembrane-distal region. Oral administration of bacterially expressed GmCAD dsRNA in G. mellonella severely attenuated the expression of target mRNA, which in turn alleviated the negative effect of TcaB on insect survival (TcaB-induced mortality in CAD dsRNA pretreated larvae reduced by 72-83% compared to control), implying the association of GmCAD in the TcaB intoxication process. Present findings form a basis of future research related to the insect gut receptor interactions with Photorhabdus toxins.
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Affiliation(s)
- Tushar K. Dutta
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Arudhimath Veeresh
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Chetna Mathur
- Division of Nematology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Victor Phani
- Department of Agricultural Entomology, College of Agriculture, Uttar Banga Krishi Viswavidyalaya, Dakshin Dinajpur, India
| | - Abhishek Mandal
- Division of Agricultural Chemicals, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Doddachowdappa Sagar
- Division of Entomology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Suresh M. Nebapure
- Division of Entomology, ICAR-Indian Agricultural Research Institute, New Delhi, India
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12
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Zhang Z, Ma Y, Ma X, Hu H, Wang D, Song X, Ren X, Ma Y. Combined Transcriptomic Analysis and RNA Interference Reveal the Effects of Methoxyfenozide on Ecdysone Signaling Pathway of Spodoptera exigua. Int J Mol Sci 2021; 22:ijms22169080. [PMID: 34445782 PMCID: PMC8396458 DOI: 10.3390/ijms22169080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 12/05/2022] Open
Abstract
Spodoptera exigua is a worldwide pest afflicting edible vegetables and has developed varying levels of resistance to insecticides. Methoxyfenozide (MET), an ecdysteroid agonist, is effective against lepidopteran pests such as S. exigua. However, the mechanism of MET to S. exigua remains unclear. In this study, we analyzed the expression patterns of genes related to the ecdysone signaling pathway in transcriptome data treated with sublethal doses of MET and analyzed how expression levels of key genes affect the toxicity of MET on S. exigua. Our results demonstrated that 2639 genes were up-regulated and 2512 genes were down-regulated in S. exigua treated with LC30 of MET. Of these, 15 genes were involved in the ecdysone signaling pathway. qPCR results demonstrated that ecdysone receptor A (EcRA) expression levels significantly increased in S. exigua when treated with different doses of MET, and that the RNAi-mediated silencing of EcRA significantly increased mortality to 55.43% at 72 h when L3 S. exigua larvae were exposed to MET at the LC30 dose. Additionally, knocking down EcRA suppressed the most genes expressed in the ecdysone signaling pathway. The combination of MET and dsEcRA affected the expression of E74 and enhanced the expression of TREA. These results demonstrate that the adverse effects of sublethal MET disturb the ecdysone signaling pathway in S. exigua, and EcRA is closely related to MET toxic effect. This study increases our collective understanding of the mechanisms of MET in insect pests.
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Affiliation(s)
- Zhixian Zhang
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China; (Z.Z.); (X.M.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Yajie Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Xiaoyan Ma
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China; (Z.Z.); (X.M.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Hongyan Hu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Dan Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Xianpeng Song
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
| | - Xiangliang Ren
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China; (Z.Z.); (X.M.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
- Correspondence: (X.R.); or (Y.M.)
| | - Yan Ma
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou 450001, China; (Z.Z.); (X.M.)
- State Key Laboratory of Cotton Biology, Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang 455000, China; (Y.M.); (H.H.); (D.W.); (X.S.)
- Correspondence: (X.R.); or (Y.M.)
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13
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Chen G, Wang Y, Liu Y, Chen F, Han L. Differences in midgut transcriptomes between resistant and susceptible strains of Chilo suppressalis to Cry1C toxin. BMC Genomics 2020; 21:634. [PMID: 32928099 PMCID: PMC7490912 DOI: 10.1186/s12864-020-07051-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 09/03/2020] [Indexed: 12/02/2022] Open
Abstract
Background Chilo suppressalis is a widespread rice pest that poses a major threat to food security in China. This pest can develop resistance to Cry toxins from Bacillus thuringiensis (Bt), threatening the sustainable use of insect-resistant transgenic Bt rice. However, the molecular basis for the resistance mechanisms of C. suppressalis to Cry1C toxin remains unknown. This study aimed to identify genes associated with the mechanism of Cry1C resistance in C. suppressalis by comparing the midgut transcriptomic responses of resistant and susceptible C. suppressalis strains to Cry1C toxin and to provide information for insect resistance management. Results A C. suppressalis midgut transcriptome of 139,206 unigenes was de novo assembled from 373 million Illumina HiSeq and Roche 454 clean reads. Comparative analysis identified 5328 significantly differentially expressed unigenes (DEGs) between C. suppressalis Cry1C-resistant and -susceptible strains. DEGs encoding Bt Cry toxin receptors, aminopeptidase-P like protein, the ABC subfamily and alkaline phosphatase were downregulated, suggesting an association with C. suppressalis Cry1C resistance. Additionally, Cry1C resistance in C. suppressalis may be related to changes in the transcription levels of enzymes involved in hydrolysis, digestive, catalytic and detoxification processes. Conclusion Our study identified genes potentially involved in Cry1C resistance in C. suppressalis by comparative transcriptome analysis. The assembled and annotated transcriptome data provide valuable genomic resources for further study of the molecular mechanisms of C. suppressalis resistance to Cry toxins.
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Affiliation(s)
- Geng Chen
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanhui Wang
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yanmin Liu
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Fajun Chen
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Lanzhi Han
- The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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14
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Huang J, Xu Y, Zuo Y, Yang Y, Tabashnik BE, Wu Y. Evaluation of five candidate receptors for three Bt toxins in the beet armyworm using CRISPR-mediated gene knockouts. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 121:103361. [PMID: 32199887 DOI: 10.1016/j.ibmb.2020.103361] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 03/06/2020] [Accepted: 03/15/2020] [Indexed: 05/29/2023]
Abstract
Insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) can provide safe and effective control of some major pests, but evolution of resistance by pests diminishes these benefits. Better understanding of the genetics and mechanisms of resistance is urgently needed to improve methods for monitoring, managing, and countering pest resistance to Bt toxins. Here we used CRISPR-mediated knockouts to evaluate the role of five genes encoding candidate Bt toxin receptors in Spodoptera exigua (beet armyworm), a devastating pest of vegetable, field and flower crops. We compared susceptibility to Bt toxins Cry1Ac, Cry1Fa, and Cry1Ca between the parent susceptible strain and each of five strains homozygous for the knockout of one of the candidate genes (SeAPN1, SeCad1, SeABCC1, SeABCC2 or SeABCC3). The results from the 15 pairwise comparisons reveal that SeABCC2 has a major role and SeCad1 a minor role in mediating toxicity of Cry1Ac and Cry1Fa. SeABCC2 also has a minor role in toxicity of Cry1Ca. In addition, the results imply little or no role for the other three candidate receptors in toxicity of Cry1Ac or Cry1Fa; or for the four candidate receptors other than SeABCC2 in toxicity of Cry1Ca.
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Affiliation(s)
- Jianlei Huang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Yanjun Xu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Yayun Zuo
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Yihua Yang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Bruce E Tabashnik
- Department of Entomology, University of Arizona, Tucson, AZ, 85721, USA.
| | - Yidong Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
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15
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De Mandal S, Lin B, Shi M, Li Y, Xu X, Jin F. iTRAQ-Based Comparative Proteomic Analysis of Larval Midgut From the Beet Armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) Challenged With the Entomopathogenic Bacteria Serratia marcescens. Front Physiol 2020; 11:442. [PMID: 32457652 PMCID: PMC7227483 DOI: 10.3389/fphys.2020.00442] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Accepted: 04/08/2020] [Indexed: 12/21/2022] Open
Abstract
Entomopathogenic bacteria Serratia marcescens is widely used as an environmentally friendly biocontrol agent against various pests, including Spodoptera exigua. Understanding the immune defense mechanism of S. exigua through comparative proteomic analysis can identify the key proteins expressed in response to the microbial infection. Here, we employed the as isobaric tags for relative and absolute quantification (iTRAQ) technique to investigate the effects of S. marcescens on the proteomic expression of S. exigua. Based on the molecular functional analysis, the differentially expressed proteins (DEPs) were mainly involved in the binding process and catalytic activities. Further bioinformatics analysis revealed important DEPs that played a crucial role in innate immunity of S. exigua with recognition (C-type lectin), melanization (propanol oxidase 3, serine protease, Serine-type carboxypeptidase activity, clip domain serine protease 4), antimicrobial activity (lysozyme, lysozyme-like, gloverin, cecropin B), detoxification (acetyl-CoA C-acetyltransferase, 3-dehydroecdysone 3-alpha-reductase, glucuronosyltransferase, glutathione S-transferase) and others. The Quantitative real-time PCR (qRT-PCR) results further indicated the significant upregulation of the immune-related genes in Spodoptera exigua following S. marcescens infection. To the best of our knowledge, this is the first iTRAQ based study to characterize S. marcescens mediated proteomic changes in S. exigua and identified important immune-related DEPs. The results of this study will provide an essential resource for understanding the host-pathogen interactions and the development of novel microbial biopesticides against various pests.
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Affiliation(s)
| | | | | | | | - Xiaoxia Xu
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, College of Agriculture, South China Agricultural University, Guangzhou, China
| | - Fengliang Jin
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, College of Agriculture, South China Agricultural University, Guangzhou, China
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16
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Ren X, Wang Y, Ma Y, Jiang W, Ma X, Hu H, Wang D, Ma Y. Midgut de novo transcriptome analysis and gene expression profiling of Spodoptera exigua larvae exposed with sublethal concentrations of Cry1Ca protein. 3 Biotech 2020; 10:138. [PMID: 32158634 DOI: 10.1007/s13205-020-2129-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 02/11/2020] [Indexed: 12/01/2022] Open
Abstract
Spodoptera exigua (Hübner) is a polyphagous pest on agricultural crops, whose control is based mainly on the application of chemical insecticides. Bacillus thuringiensis (Bt) is one of the most important biological agents that have been successfully applied as a biological control, and Cry1Ca protein is considered to be active against S. exigua. Therefore, to understand the response of S. exigua to Cry1Ca protein, high-throughput sequencing was used to analyse the S. exigua larval midgut after treatment with sublethal concentrations of Cry1Ca protein. Transcriptome data showed that a total of 98,571 unigenes with an N50 value of 1135 bp and a mean length of 653 bp were obtained. Furthermore, 2962 differentially expressed genes (DEGs) were identified after Cry1Ca challenge, including 1508 up-regulated and 1454 down-regulated unigenes. Among these DEGs, detoxification (CYP, CarE, and GST) and Bt resistance (ALP, APN, and ABC transporter)-related genes were differentially expressed in the midgut of S. exigua after Cry1Ca treatment. However, most DEGs of protective enzymes were down-regulated, while most DEGs related with serine protease and REPAT were up-regulated. Furthermore, almost all DEGs related to the immune signaling pathway, antimicrobial protein, and lysozyme were up-regulated by Cry1Ca treatment. These results indicated that the detoxification enzyme, protective enzymes, Bt resistance-related genes, serine protease, REPAT, and the immune response might have been involved in the response of S. exigua to Cry1Ca protein. In summary, analysis of the transcriptomal expression of genes involved in Cry1Ca protein against S. exigua provided potential clues for elucidating the host response processes and defensive mechanisms underlying Cry1Ca toxicity.
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Affiliation(s)
- Xiangliang Ren
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, 455000 Henan China
| | - Yingying Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, 455000 Henan China
- Honghu Agricultural Technology Extension Center, Jingzhou, 433200 Hubei China
| | - Yajie Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, 455000 Henan China
| | - Weili Jiang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, 455000 Henan China
| | - Xiaoyan Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, 455000 Henan China
| | - Hongyan Hu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, 455000 Henan China
| | - Dan Wang
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, 455000 Henan China
| | - Yan Ma
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of CAAS, Anyang, 455000 Henan China
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17
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Gao M, Dong S, Hu X, Zhang X, Liu Y, Zhong J, Lu L, Wang Y, Chen L, Liu X. Roles of Midgut Cadherin from Two Moths in Different Bacillus thuringiensis Action Mechanisms: Correlation among Toxin Binding, Cellular Toxicity, and Synergism. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:13237-13246. [PMID: 31671945 DOI: 10.1021/acs.jafc.9b04563] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The midgut cadherin has been described as one of the main functional receptors for Bacillus thuringiensis (Bt) toxins. Plutella xylostella (P. xylostella) and Helicoverpa armigera (H. armigera) are two major target pests of Bt toxins in China, and the roles of their cadherins in the action of Bt toxins have been only partially studied. Here, we expressed the two cadherins in Sf9 cells and their partial extracellular domains in Escherichia coli and tested them for Bt toxin binding, cellular toxicity, and synergism with toxins. Our results suggested that PxCad might function as a Cry1Ac receptor, although it showed lower binding levels to Cry1Ac and reduced cytotoxicity compared with HaCad. PxCad and HaCad are not receptors for Cry2A, Cry1B, Cry1C, and Cry1F toxins, although some of them can bind to the cadherins. The PxCad-TBR exhibits higher enhancement of Cry1Ac and weak enhancement of Cry1F toxicity in P. xylostella larvae, although it is not the receptor of Cry1F.
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Affiliation(s)
- Meijing Gao
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Sa Dong
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
- School of Horticulture and Plant Protection , Yangzhou University , Yangzhou 225009 , China
| | - Xiaodan Hu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
- Discipline of Biology, School of Life Sciences , University of KwaZulu-Natal, Westville Campus , Private Bag X54001, Durban 4000 , South Africa
| | - Xiao Zhang
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Yuan Liu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Jianfeng Zhong
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Lina Lu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
| | - Yun Wang
- Horticulture Department , Jinling Institute of Technology , Nanjing 210038 , China
| | - Limen Chen
- Lishui Academy of Agricultural Sciences , Lishui 323000 , China
| | - Xianjin Liu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition , Jiangsu Academy of Agricultural Sciences , Nanjing 210014 , China
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Wei J, Zhang Y, An S. The progress in insect cross-resistance among Bacillus thuringiensis toxins. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2019; 102:e21547. [PMID: 30864250 DOI: 10.1002/arch.21547] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 06/09/2023]
Abstract
Bt crop pyramids produce two or more Bt proteins active to broaden the spectrum of action and to delay the development of resistance in exposed insect populations. The cross-resistance between Bt toxins is a vital restriction factor for Bt crop pyramids, which may reduce the effect of pyramid strategy. In this review, the status of the cross-resistance among more than 20 Bt toxins that are most commonly used against 13 insect pests was analyzed. The potential mechanisms of cross-resistance are discussed. The corresponding measures, including pyramid RNA interference and Bt toxin, "high dose/refuge," and so on are advised to be taken for adopting the pyramided strategy to delay the Bt evolution of resistance and control the target pest insect.
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Affiliation(s)
- Jizhen Wei
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Yaling Zhang
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
- Tibet Academy of Agriculture and Animal Husbandry Sciences, Lhasa, China
| | - Shiheng An
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
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19
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Tian P, Qiu L, Zhou A, Chen G, He H, Ding W, Li Y. Evaluation of Appropriate Reference Genes For Investigating Gene Expression in Chlorops oryzae (Diptera: Chloropidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2019; 112:2207-2214. [PMID: 31145453 DOI: 10.1093/jee/toz142] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Indexed: 06/09/2023]
Abstract
Reverse transcription quantitative polymerase chain reaction (PCR) has become an invaluable technique for analyzing gene expression in many insects. However, this approach requires the use of stable reference genes to normalize the data. Chlorops oryzae causes significant economic damage to rice crops throughout Asia. The lack of suitable reference genes has hindered research on the molecular mechanisms underlying many physiological processes of this species. In this study, we used quantitative real-time PCR to evaluate the expression of eight C. oryzae housekeeping genes glyceraldehyde-3-phosphate dehydrogenase (GAPDH), β-actin (βACT), beta-tubulin (βTUB), Delta Elongation factor-1 (EF1δ), ribosomal protein S11 (RPS11), RPS15, C-terminal-Binding Protein (CtBP), and ribosomal protein 49 (RP49) in different developmental stages and tissues in both larvae and adults. We analyzed the data with four different software packages: geNorm, NormFinder, BestKeeper, and RefFinder and compared the results obtained with each method. The results indicate that PRS15 and RP49 can be used as stable reference genes for quantifying gene expression in different developmental stages and larval tissues. GAPDH and βACT, which have been considered stable reference genes by previous studies, were the least stable of the candidate genes with respect to larval tissues. GAPDH was, however, the most stable reference gene for adult tissues. We verified the candidate reference genes identified and found that the expression levels of Cadherins (Cads) changed when different reference genes were used to normalize gene expression. This study provides a valuable foundation for future research on gene function, and investigating the molecular basis of physiological processes, in C. oryzae.
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Affiliation(s)
- Ping Tian
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Lin Qiu
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Ailin Zhou
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Guo Chen
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Hualiang He
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
| | - Wenbing Ding
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China
- Hunan Provincial Engineering and Technology Research Center for Biopesticide and Formulation Processing, Changsha, China
| | - Youzhi Li
- Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests, College of Plant Protection, Hunan Agricultural University, Changsha, China
- National Research Center of Engineering and Technology for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, China
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20
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Du L, Chen G, Han L, Peng Y. Cadherin CsCad plays differential functional roles in Cry1Ab and Cry1C intoxication in Chilo suppressalis. Sci Rep 2019; 9:8507. [PMID: 31186483 PMCID: PMC6559963 DOI: 10.1038/s41598-019-44451-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 04/25/2019] [Indexed: 12/11/2022] Open
Abstract
Transgenic rice lines expressing Bacillus thuringiensis (Bt) toxins have been successfully developed for the control of Chilo suppressalis. However, the evolution of insect resistance is a major threat to Bt rice durability. Bt toxins function by binding specific receptors in the midgut of target insects; specifically, cadherin proteins have been identified as Cry toxin receptors in diverse lepidopteran species. Here, we report the functional roles of cadherin CsCad in the midgut of C. suppressalis in Cry1Ab and Cry1C toxicity. We expressed a recombinant truncated CsCad peptide (CsCad-CR11-MPED) in Escherichia coli that included the eleventh cadherin repeat and MPED region. Based on ligand blotting and ELISA binding assays, the CsCad-CR11-MPED peptide specifically bound Cry1Ab with high affinity but weakly bound Cry1C. The CsCad-CR11-MPED peptide significantly enhanced the susceptibility of C. suppressalis larvae to Cry1Ab but not Cry1C. Furthermore, the knockdown of endogenous CsCad with Stealth siRNA reduced C. suppressalis larval susceptibility to Cry1Ab but not Cry1C, suggesting that CsCad plays differential functional roles in Cry1Ab and Cry1C intoxication in C. suppressalis. This information directly enhances our understanding of the potential resistance mechanisms of C. suppressalis against Bt toxins and may assist in the development of effective strategies for delaying insect resistance.
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Affiliation(s)
- Lixiao Du
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, Beijing, China
| | - Geng Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, Beijing, China
| | - Lanzhi Han
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, Beijing, China.
| | - Yufa Peng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193, Beijing, China
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21
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Gao X, Li W, Luo J, Zhang L, Ji J, Zhu X, Wang L, Zhang S, Cui J. Biodiversity of the microbiota in Spodoptera exigua (Lepidoptera: Noctuidae). J Appl Microbiol 2019; 126:1199-1208. [PMID: 30597740 DOI: 10.1111/jam.14190] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/23/2018] [Accepted: 12/27/2018] [Indexed: 02/05/2023]
Abstract
AIMS Spodoptera exigua is a serious pest of many agricultural crops. However, the bacterial communities of S. exigua are poorly studied, particularly over their entire life cycle. We aimed to study the biodiversity of the microbiota across the life cycle of S. exigua and to provide a better and obtain insight into new pest control strategies. METHODS AND RESULTS The bacterial diversity across the life cycle of S. exigua was studied using Illumina MiSeq sequencing of 16S rRNA genes. Spodoptera exigua is dominated by Proteobacteria and Firmicutes, with a total relative abundance of 90·03%. Enterococcus (24·6%), Pseudomonas (12·2%) and Asaia (45·9%) were abundant and active in eggs, while Methylobacterium (18·7%) and Halomonas (16·5%) dominated freshly eclosed larvae. The 3rd and 5th instar larvae were dominated by Enterococcus (76·3 and 62·0%). Pupal stages had the highest microbial diversity. There was no significant difference between newly emerged males and females. Symbionts of eggs were extremely similar and probably vertically transmitted by males during mating. CONCLUSIONS The result showed that the bacterial community was affected by the host developmental stages. Our results also suggest that symbionts of egg mass are probably vertically transmitted control by male spawning adults. SIGNIFICANCE AND IMPACT OF THE STUDY Our study documents the symbiont bacteria across the life cycle of S. exigua. Understanding the microbial symbionts may provide clues to develop potential biocontrol techniques against this pest.
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Affiliation(s)
- X Gao
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
| | - W Li
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
| | - J Luo
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
| | - L Zhang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
| | - J Ji
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
| | - X Zhu
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
| | - L Wang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
| | - S Zhang
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
| | - J Cui
- State Key Laboratory of Cotton Biology/Institute of Cotton Research, Chinese Academy of Agricultural Sciences, Anyang, Henan, PR China
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Spodoptera frugiperda (J. E. Smith) Aminopeptidase N1 Is a Functional Receptor of the Bacillus thuringiensis Cry1Ca Toxin. Appl Environ Microbiol 2018; 84:AEM.01089-18. [PMID: 29959247 DOI: 10.1128/aem.01089-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 06/25/2018] [Indexed: 11/20/2022] Open
Abstract
Bacillus thuringiensis Cry1Ca is toxic to different Spodoptera species. The aims of this work were to identify the Cry1Ca-binding proteins in S. frugiperda, to provide evidence on their participation in toxicity, and to identify the Cry1Ca amino acid residues involved in receptor binding. Pulldown assays using Spodoptera frugiperda brush border membrane vesicles (BBMV) identified aminopeptidase N (APN), APN1, and APN2 isoforms as Cry1Ca-binding proteins. Cry1Ca alanine substitutions in all residues of domain III β16 were characterized. Two β16 nontoxic mutants (V505A and S506A) showed a correlative defect on binding to the recombinant S. frugiperda APN1 (SfAPN1). Finally, silencing the expression of APN1 transcript, by double-stranded RNA (dsRNA) feeding, showed that silenced larvae are more tolerant of the Cry1Ca toxin, which induced less than 40% mortality in silenced larvae whereas nonsilenced larvae had 100% mortality. Overall, our results show that Cry1Ca relies on APN1 binding through domain III β16 to impart toxicity to S. frugiperdaIMPORTANCEBacillus thuringiensis Cry toxins rely on receptor binding to exert toxicity. Cry1Ca is toxic to different populations of S. frugiperda, a major corn pest in America. Nevertheless, the S. frugiperda midgut proteins that are involved in Cry1Ca toxicity have not been identified. Here we identified aminopeptidase N1 (APN1) as a functional receptor of Cry1Ca. Moreover, we showed that Cry1Ca domain III β16 is involved in APN1 binding. These results give insights on potential target sites for improving Cry1Ca toxicity to S. frugiperda.
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23
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Ren XL, Hu HY, Jiang WL, Ma XY, Ma YJ, Li GQ, Ma Y. Three GPI-anchored alkaline phosphatases are involved in the intoxication of Cry1Ca toxin to Spodoptera exigua larvae. J Invertebr Pathol 2018; 151:32-40. [DOI: 10.1016/j.jip.2017.10.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 10/22/2017] [Accepted: 10/26/2017] [Indexed: 02/08/2023]
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Martínez de Castro DL, García-Gómez BI, Gómez I, Bravo A, Soberón M. Identification of Bacillus thuringiensis Cry1AbMod binding-proteins from Spodoptera frugiperda. Peptides 2017; 98:99-105. [PMID: 28958733 DOI: 10.1016/j.peptides.2017.09.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 09/06/2017] [Accepted: 09/22/2017] [Indexed: 12/12/2022]
Abstract
Bacillus thuringiensis Cry toxins are currently used for pest control in transgenic crops but evolution of resistance by the insect pests threatens the use of this technology. The Cry1AbMod toxin was engineered to lack the alpha helix-1 of the parental Cry1Ab toxin and was shown to counter resistance to Cry1Ab and Cry1Ac toxins in different insect species including the fall armyworm Spodoptera frugiperda. In addition, Cry1AbMod showed enhanced toxicity to Cry1Ab-susceptible S. frugiperda populations. To gain insights into the mechanisms of this Cry1AbMod-enhanced toxicity, we isolated the Cry1AbMod toxin binding proteins from S. frugiperda brush border membrane vesicles (BBMV), which were identified by pull-down assay and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The LC-MS/MS results indicated that Cry1AbMod toxin could bind to four classes of aminopeptidase (N1, N3, N4 y N5) and actin, with the highest amino acid sequence coverage acquired for APN 1 and APN4. In addition to these proteins, we found other proteins not previously described as Cry toxin binding proteins. This is the first report that suggests the interaction between Cry1AbMod and APN in S. frugiperda.
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Affiliation(s)
- Diana L Martínez de Castro
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. Postal 510-3, Cuernavaca, 62250 Morelos, Mexico
| | - Blanca I García-Gómez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. Postal 510-3, Cuernavaca, 62250 Morelos, Mexico
| | - Isabel Gómez
- 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
| | - Mario Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México. Apdo. Postal 510-3, Cuernavaca, 62250 Morelos, Mexico.
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25
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Identification and Characterization of Hyphantria cunea Aminopeptidase N as a Binding Protein of Bacillus thuringiensis Cry1Ab35 Toxin. Int J Mol Sci 2017; 18:ijms18122575. [PMID: 29189732 PMCID: PMC5751178 DOI: 10.3390/ijms18122575] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 11/22/2022] Open
Abstract
The fall webworm, Hyphantria cunea (Drury) is a major invasive pest in China. Aminopeptidase N (APN) isoforms in lepidopteran larvae midguts are known for their involvement in the mode of action of insecticidal crystal (Cry) proteins from Bacillus thuringiensis. In the present work, we identified a putative Cry1Ab toxin-binding protein, an APN isoform designated HcAPN3, in the midgut of H. cunea by ligand blot and mass spectrometry. HcAPN3 was highly expressed throughout all larval developmental stages and was abundant in the midgut and hindgut tissues. HcAPN3 was down-regulated at 6 h, then was up-regulated significantly at 12 h and 24 h after Cry1Ab toxin treatment. We expressed HcAPN3 in insect cells and detected its interaction with Cry1Ab toxin by ligand blot assays. Furthermore, RNA interference (RNAi) against HcAPN3 using oral delivery and injection of double-stranded RNA (dsRNA) resulted in a 61–66% decrease in transcript level. Down-regulating of the expression of HcAPN3 was closely associated with reduced susceptibility of H. cunea to Cry1Ab. In addition, the HcAPN3E fragment peptide expressed in Escherichia coli enhanced Cry1Ab toxicity against H. cunea larvae. This work represents the first evidence to suggest that an APN in H. cunea is a putative binding protein involved in Cry1Ab susceptibility.
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Niu L, Mannakkara A, Qiu L, Wang X, Hua H, Lei C, Jurat-Fuentes JL, Ma W. Transgenic Bt rice lines producing Cry1Ac, Cry2Aa or Cry1Ca have no detrimental effects on Brown Planthopper and Pond Wolf Spider. Sci Rep 2017; 7:1940. [PMID: 28512299 PMCID: PMC5434062 DOI: 10.1038/s41598-017-02207-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 04/11/2017] [Indexed: 12/28/2022] Open
Abstract
Transgenic rice expressing cry genes from the bacterium Bacillus thuringiensis (Bt rice) is highly resistant to lepidopteran pests. The brown planthopper (BPH, Nilaparvata lugens) is the main non-target sap-sucking insect pest of Bt transgenic rice. The pond wolf spider (PWS, Pardosa pseudoannulata) is one of the most dominant predators of BPH in rice fields. Consequently, the safety evaluation of Bt rice on BPH and PWS should be conducted before commercialization. In the current study, two experiments were performed to assess the potential ecological effects of Bt rice on BPH and PWS: (1) a tritrophic experiment to evaluate the transmission of Cry1Ac, Cry2Aa and Cry1Ca protein in the food chain; and (2) binding assays of Cry1Ac, Cry2Aa and Cry1Ca to midgut brush border membrane proteins from BPH and PWS. Trace amounts of the three Cry proteins were detected in BPH feeding on Bt rice cultivars, but only Cry1Ac and Cry2Aa proteins could be transferred to PWS through feeding on BPH. In vitro binding of biotinylated Cry proteins and competition assays in midgut protein vesicles showed weak binding, and ligand blot analysis confirmed the binding specificity. Thus, we inferred that the tested Bt rice varieties have negligible effects on BPH and PWS.
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Affiliation(s)
- Lin Niu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Amani Mannakkara
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
- Department of Agricultural Biology, Faculty of Agriculture, University of Ruhuna, Kamburupitiya, 81100, Sri Lanka
| | - Lin Qiu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Xiaoping Wang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Hongxia Hua
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Chaoliang Lei
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China
| | - Juan Luis Jurat-Fuentes
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Weihua Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, Hubei, China.
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27
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Qiu L, Cui S, Liu L, Zhang B, Ma W, Wang X, Lei C, Chen L. Aminopeptidase N1 is involved in Bacillus thuringiensis Cry1Ac toxicity in the beet armyworm, Spodoptera exigua. Sci Rep 2017; 7:45007. [PMID: 28327568 PMCID: PMC5361178 DOI: 10.1038/srep45007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 02/17/2017] [Indexed: 12/23/2022] Open
Abstract
Understanding how insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) interact with their hosts is crucial to fully explain the molecular bases of Bt specificity and insecticidal activity. Previous studies support ATP binding cassette transporters (ABCC2/3) and one cadherin-like protein are Cry1Ac functional receptors in the beet armyworm (Spodoptera exigua). In this study, a combined one-dimensional gel electrophoresis and immunoblotting approach identified aminopeptidase N (APNs) as putative Cry1Ac binding proteins in the midgut brush border membrane of S. exigua larvae. Functional analyses by gene silencing of six different S. exigua APN genes (SeAPN1, SeAPN2, SeAPN3, SeAPN4, SeAPN5 and SeAPN6) showed that only suppression of SeAPN1 resulted in decreased larval susceptibility to Cry1Ac toxin. These results support that SeAPN1 plays important functional role in Cry1Ac toxicity in S. exigua.
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Affiliation(s)
- Lin Qiu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Songhe Cui
- College of Life Science, Jilin University, Changchun 130012, Jilin, China
| | - Lang Liu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Boyao Zhang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Weihua Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Xiaoping Wang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Chaoliang Lei
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
| | - Lizhen Chen
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
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28
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Qiu L, Zhang B, Liu L, Ma W, Wang X, Lei C, Chen L. Proteomic analysis of Cry2Aa-binding proteins and their receptor function in Spodoptera exigua. Sci Rep 2017; 7:40222. [PMID: 28067269 PMCID: PMC5220377 DOI: 10.1038/srep40222] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/01/2016] [Indexed: 01/09/2023] Open
Abstract
The bacterium Bacillus thuringiensis produces Crystal (Cry) proteins that are toxic to a diverse range of insects. Transgenic crops that produce Bt Cry proteins are grown worldwide because of their improved resistance to insect pests. Although Bt "pyramid" cotton that produces both Cry1A and Cry2A is predicted to be more resistant to several lepidopteran pests, including Spodoptera exigua, than plants that produce Cry1Ac alone, the mechanisms responsible for the toxicity of Cry2Aa in S. exigua are not well understood. We identified several proteins that bind Cry2Aa (polycalin, V-ATPase subunits A and B, actin, 4-hydroxybutyrate CoA-transferase [4-HB-CoAT]), and a receptor for activated protein kinase C (Rack), in S. exigua. Recombinant, expressed versions of these proteins were able to bind the Cry2Aa toxin in vitro assays. RNA interference gene knockdown of the Se-V-ATPase subunit B significantly decreased the susceptibility of S. exigua larvae to Cry2Aa, whereas knockdown of the other putative binding proteins did not. Moreover, an in vitro homologous competition assay demonstrated that the Se-V-ATPase subunit B binds specifically to the Cry2Aa toxin, suggesting that this protein acts as a functional receptor of Cry2Aa in S. exigua. This the first Cry2Aa toxin receptor identified in S. exigua brush-border membrane vesicles.
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Affiliation(s)
- Lin Qiu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People’s Republic of China
| | - Boyao Zhang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People’s Republic of China
| | - Lang Liu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People’s Republic of China
| | - Weihua Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People’s Republic of China
| | - Xiaoping Wang
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People’s Republic of China
| | - Chaoliang Lei
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People’s Republic of China
| | - Lizhen Chen
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan 430070, People’s Republic of China
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Ren XL, Jiang WL, Ma YJ, Hu HY, Ma XY, Ma Y, Li GQ. The Spodoptera exigua (Lepidoptera: Noctuidae) ABCC2 Mediates Cry1Ac Cytotoxicity and, in Conjunction with Cadherin, Contributes to Enhance Cry1Ca Toxicity in Sf9 Cells. JOURNAL OF ECONOMIC ENTOMOLOGY 2016; 109:2281-2289. [PMID: 27986933 DOI: 10.1093/jee/tow193] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/09/2016] [Indexed: 06/06/2023]
Abstract
In insects, the mode of Cry1A toxins action has been studied in detail and many receptors that participate in the process are known. Recent evidence has revealed that an ABC transporter (ABCC2) is involved in conferring resistance to Cry1A toxins and that ABCC2 could be a receptor of Cry1A. However, it is not known whether Cry1Ca interacts with the same receptor proteins as Cry1A. In this study, we report the cloning of an ABC transporter gene, SeABCC2b, from the midgut of Spodoptera exigua (Hübner) larvae, and its expression in Sf9 cells for a functional analysis. The addition of Cry1Ca and Cry1Ac to Sf9 cell culture caused swelling in 28.5% and 93.9% of the SeABCC2-expressing cells, respectively. In contrast, only 7.4% and 1.3% of the controls cells swelled in the presence of Cry1Ca and Cry1Ac. Thus, SeABCC2b-expressing Sf9 cells had increased susceptibility to Cry1Ca and Cry1Ac. Similarly, S. exigua cadherin (SeCad1b) expressed in Sf9 cells caused 47.1% and 1.8% of the SeCad1b-expressing cells to swell to Cry1Ca and Cry1Ac exposure. Therefore, Sf9 cells expressing SeCad1b were more sensitive to Cry1Ca than Cry1Ac. Together, our data suggest that SeABCC2b from S. exigua mediates Cry1Ac cytotoxicity and, in conjunction with SeCad1b, contributes to enhance Cry1Ca toxicity in Sf9 cells.
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Affiliation(s)
- Xiang-Liang Ren
- Institute of Cotton Research of CAAS/State Key Laboratory of Cotton Biology, Anyang, Henan 455000, China
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
| | - Wei-Li Jiang
- Institute of Cotton Research of CAAS/State Key Laboratory of Cotton Biology, Anyang, Henan 455000, China
| | - Ya-Jie Ma
- Institute of Cotton Research of CAAS/State Key Laboratory of Cotton Biology, Anyang, Henan 455000, China
| | - Hong-Yan Hu
- Institute of Cotton Research of CAAS/State Key Laboratory of Cotton Biology, Anyang, Henan 455000, China
| | - Xiao-Yan Ma
- Institute of Cotton Research of CAAS/State Key Laboratory of Cotton Biology, Anyang, Henan 455000, China
| | - Yan Ma
- Institute of Cotton Research of CAAS/State Key Laboratory of Cotton Biology, Anyang, Henan 455000, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
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Herrero S, Bel Y, Hernández-Martínez P, Ferré J. Susceptibility, mechanisms of response and resistance to Bacillus thuringiensis toxins in Spodoptera spp. CURRENT OPINION IN INSECT SCIENCE 2016; 15:89-96. [PMID: 27436737 DOI: 10.1016/j.cois.2016.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/29/2016] [Accepted: 04/13/2016] [Indexed: 06/06/2023]
Abstract
Bioinsecticides based on Bacillus thuringiensis have long been used as an alternative to synthetic insecticides to control insect pests. In this review, we focus on insects of the genus Spodoptera, including relevant polyphagous species that are primary and secondary pests of many crops, and how B. thuringiensis toxins can be used for Spodoptera spp. pest management. We summarize the main findings related to susceptibility, midgut binding specificity, mechanisms of response and resistance of this insect genus to B. thuringiensis toxins.
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Affiliation(s)
- Salvador Herrero
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) and Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain
| | - Yolanda Bel
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) and Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain
| | - Patricia Hernández-Martínez
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) and Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain
| | - Juan Ferré
- Estructura de Recerca Interdisciplinar en Biotecnologia i Biomedicina (ERI BIOTECMED) and Department of Genetics, Universitat de València, Dr Moliner 50, 46100 Burjassot, Spain.
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31
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Yi D, Yang W, Tang J, Wang L, Fang Z, Liu Y, Zhuang M, Zhang Y, Yang L. High resistance of transgenic cabbage plants with a synthetic cry1Ia8 gene from Bacillus thuringiensis against two lepidopteran species under field conditions. PEST MANAGEMENT SCIENCE 2016; 72:315-321. [PMID: 25721816 DOI: 10.1002/ps.3994] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 01/07/2015] [Accepted: 02/13/2015] [Indexed: 06/04/2023]
Abstract
BACKGROUND Plutella xylostella (Linnaeus) has become the most destructive pest in cabbage throughout the world. Cry1Ia8 cabbage has been developed to reduce pest attacks. To gain a better understanding of the efficacy of Cry1Ia8 cabbage, a homozygous Cry1Ia8 cabbage line A14-5 was produced, and its resistance to P. xylostella, Pieris rapae (Linnaeus) and other lepidopteran pests was evaluated in the field in 2011, 2012 and 2013. RESULTS Under natural infestation conditions, the homozygous transgenic line was highly resistant against P. xylostella and P. rapae as compared with the untransformed control and susceptible to Mamestra brassicae (Linnaeus) and Spodoptera exigua (Hübner). The homozygous transgenic plants showed slight symptoms of damaged leaves by lepidopteran species, while the untransformed plants exhibited serious damage symptoms throughout the cabbage growing season. CONCLUSION Compared with the control, the homozygous transgenic cabbage line showed great potential for protecting cabbage from attack by P. xylostella and P. rapae in the field.
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Affiliation(s)
- Dengxia Yi
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Weijie Yang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jun Tang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Li Wang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Zhiyuan Fang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yumei Liu
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mu Zhuang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yangyong Zhang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Limei Yang
- Key Laboratory of Biology and Genetic Improvement of Horticultural Crops, Ministry of Agriculture, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, China
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32
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Rebijith KB, Asokan R, Hande HR, Kumar NKK, Krishna V, Vinutha J, Bakthavatsalam N. RNA Interference of Odorant-Binding Protein 2 (OBP2) of the Cotton Aphid, Aphis gossypii (Glover), Resulted in Altered Electrophysiological Responses. Appl Biochem Biotechnol 2015; 178:251-66. [DOI: 10.1007/s12010-015-1869-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 09/23/2015] [Indexed: 01/18/2023]
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Guo WC, Fu KY, Yang S, Li XX, Li GQ. Instar-dependent systemic RNA interference response in Leptinotarsa decemlineata larvae. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2015; 123:64-73. [PMID: 26267054 DOI: 10.1016/j.pestbp.2015.03.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 02/28/2015] [Accepted: 03/15/2015] [Indexed: 06/04/2023]
Abstract
RNA interference (RNAi) is a promising approach to control Leptinotarsa decemlineata. In this study, RNAi efficiency by double-stranded RNA (dsRNA) targeting S-adenosyl-L-homocysteine hydrolase (LdSAHase) was compared among L. decemlineata first- to fourth-instar larvae. Ingesting dsLdSAHase successfully decreased the target gene expression, caused lethality, inhibited growth and impaired pupation in an instar- and concentration-dependent manner. To study the role of Dicer2 and Argonaute2 genes in RNAi efficiency, we identified LdDcr2a, LdDcr2b, LdAgo2a and LdAgo2b. Their expression levels were higher in young larvae than those in old ones. Exposure to dsegfp for 6 h significantly elevated LdDcr2a, LdDcr2b, LdAgo2a and LdAgo2b mRNA levels in the first-, second-, third- and fourth-instar larvae. When the exposure periods were extended, however, the expression levels were gradually reduced. Continuous exposure for 72 h significantly repressed the expression of LdAgo2a and LdAgo2b in the first, second and third larval instars, and the four genes in final instars. Moreover, we found that dsLdSAHase-caused LdSAHase suppressions and larval mortalities were influenced by previous dsegfp exposure: 12 h of previous exposure increased LdSAHase silencing and mortality of the final instar larvae, whereas 72 h of exposure reduced LdSAHase silencing and mortality. Thus, it seems the activities of core RNAi-machinery proteins affect RNAi efficiency in L. decemlineata.
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Affiliation(s)
- Wen-Chao Guo
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China
| | - Kai-Yun Fu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China
| | - Shuai Yang
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China
| | - Xiao-Xu Li
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
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Gong L, Wang H, Qi J, Han L, Hu M, Jurat-Fuentes JL. Homologs to Cry toxin receptor genes in a de novo transcriptome and their altered expression in resistant Spodoptera litura larvae. J Invertebr Pathol 2015; 129:1-6. [PMID: 25981133 DOI: 10.1016/j.jip.2015.05.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 05/04/2015] [Accepted: 05/08/2015] [Indexed: 10/23/2022]
Abstract
Insect resistance threatens sustainability of insecticides based on Cry proteins from the bacterium Bacillus thuringiensis (Bt). Since high levels of resistance to Cry proteins involve alterations in Cry-binding midgut receptors, their identification is needed to develop resistance management strategies. Through Illumina sequencing we generated a transcriptome containing 16,161 annotated unigenes for the Oriental leafworm (Spodoptera litura). Transcriptome mining identified 6 contigs with identity to reported lepidopteran Cry toxin receptors. Using PCR we confirmed their expression during the larval stage and compared their quantitative expression in larvae from susceptible and a field-derived Cry1Ca resistant strain of S. litura. Among reduced transcript levels detected for most tested contigs in the Cry1Ca-resistant S. litura larvae, the most dramatic reduction (up to 99%) was detected for alkaline phosphatase contigs. This study significantly expands S. litura transcriptomic resources and provides preliminary identification of putative receptor genes with altered expression in S. litura resistant to Cry1Ca toxin.
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Affiliation(s)
- Liang Gong
- Key Laboratory of Plant Resource Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, Guangdong Province, China; Key Laboratory of Pesticide and Chemical Biology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong Province, China
| | - Huidong Wang
- Key Laboratory of Pesticide and Chemical Biology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong Province, China
| | - Jiangwei Qi
- Key Laboratory of Pesticide and Chemical Biology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong Province, China
| | - Lanzhi Han
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Meiying Hu
- Key Laboratory of Pesticide and Chemical Biology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou 510642, Guangdong Province, China.
| | - Juan Luis Jurat-Fuentes
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, USA.
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35
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Qiu L, Hou L, Zhang B, Liu L, Li B, Deng P, Ma W, Wang X, Fabrick JA, Chen L, Lei C. Cadherin is involved in the action of Bacillus thuringiensis toxins Cry1Ac and Cry2Aa in the beet armyworm, Spodoptera exigua. J Invertebr Pathol 2015; 127:47-53. [DOI: 10.1016/j.jip.2015.02.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 02/20/2015] [Accepted: 02/27/2015] [Indexed: 12/23/2022]
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36
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Kim YH, Soumaila Issa M, Cooper AMW, Zhu KY. RNA interference: Applications and advances in insect toxicology and insect pest management. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2015; 120:109-17. [PMID: 25987228 DOI: 10.1016/j.pestbp.2015.01.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 01/05/2015] [Accepted: 01/05/2015] [Indexed: 05/27/2023]
Abstract
Since its discovery, RNA interference (RNAi) has revolutionized functional genomic studies due to its sequence-specific nature of post-transcriptional gene silencing. In this paper, we provide a comprehensive review of the recent literature and summarize the current knowledge and advances in the applications of RNAi technologies in the field of insect toxicology and insect pest management. Many recent studies have focused on identification and validation of the genes encoding insecticide target proteins, such as acetylcholinesterases, ion channels, Bacillus thuringiensis receptors, and other receptors in the nervous system. RNAi technologies have also been widely applied to reveal the role of genes encoding cytochrome P450 monooxygenases, carboxylesterases, and glutathione S-transferases in insecticide detoxification and resistance. More recently, studies have focused on understanding the mechanism of insecticide-mediated up-regulation of detoxification genes in insects. As RNAi has already shown great potentials for insect pest management, many recent studies have also focused on host-induced gene silencing, in which several RNAi-based transgenic plants have been developed and tested as proof of concept for insect pest management. These studies indicate that RNAi is a valuable tool to address various fundamental questions in insect toxicology and may soon become an effective strategy for insect pest management.
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Affiliation(s)
- Young Ho Kim
- Department of Entomology, Kansas State University, Manhattan, KS 66506-4004, USA
| | | | - Anastasia M W Cooper
- Department of Entomology, Kansas State University, Manhattan, KS 66506-4004, USA
| | - Kun Yan Zhu
- Department of Entomology, Kansas State University, Manhattan, KS 66506-4004, USA.
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Chen Z, He F, Xiao Y, Liu C, Li J, Yang Y, Ai H, Peng J, Hong H, Liu K. Endogenous expression of a Bt toxin receptor in the Cry1Ac-susceptible insect cell line and its synergistic effect with cadherin on cytotoxicity of activated Cry1Ac. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 59:1-17. [PMID: 25662100 DOI: 10.1016/j.ibmb.2015.01.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2014] [Revised: 01/18/2015] [Accepted: 01/23/2015] [Indexed: 06/04/2023]
Abstract
Although many insect cell lines derived from various tissues are available, it is unclear whether endogenous receptors of Bacillus thuringiensis (Bt) crystal toxins are expressed in these cell lines. In the present study, we demonstrated that the ovaries-derived Spodoptera litura Sl-HP cell line was susceptible to activated Cry1Ac although larvae of S. litura are not susceptible to the toxin. Assays of the transcriptome revealed that thirteen ATP-binding cassette transporter genes (ABC) were expressed at different levels in this cell line. Of these, the SlABCC3 shared 52-55% amino acid sequence identity with the known Bt toxin receptor ABCC2. RNAi-mediated knockdown targeting SlABCC3 significantly decreased the susceptibility of Sl-HP cells to activated Cry1Ac. Over-expression of the gene strongly increased the susceptibility of Trichoplusia ni Hi5 cells to the toxin. Not only was SlABCC3 comparable to the heterologously expressed Helicoverpa armigera Hacadherin on the receptor-mediated cytotoxicity of activated Cry1Ac to Hi5 cells, but also SlABCC3 and Hacadherin had a strong synergistic effect on cytotoxicity of activated Cry1Ac. These results suggested that Bt toxin receptors-expressing insect cell lines can be used as an alternative model for evaluating cytotoxicity of Bt toxins and studying their mechanisms of action.
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Affiliation(s)
- Zuwen Chen
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Fei He
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Yutao Xiao
- State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Chenxi Liu
- State Key Laboratory for Biology of Plant Disease and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, PR China
| | - Jianghuai Li
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Yongbo Yang
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Hui Ai
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Jianxin Peng
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Huazhu Hong
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Kaiyu Liu
- School of Life Sciences, Central China Normal University, Wuhan 430079, PR China.
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38
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Guo Z, Kang S, Zhu X, Wu Q, Wang S, Xie W, Zhang Y. The midgut cadherin-like gene is not associated with resistance to Bacillus thuringiensis toxin Cry1Ac in Plutella xylostella (L.). J Invertebr Pathol 2015; 126:21-30. [PMID: 25595643 DOI: 10.1016/j.jip.2015.01.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2014] [Revised: 12/24/2014] [Accepted: 01/07/2015] [Indexed: 11/16/2022]
Abstract
The Gram-positive bacterium Bacillus thuringiensis (Bt) produces Cry toxins that have been used to control important agricultural pests. Evolution of resistance in target pests threatens the effectiveness of these toxins when used either in sprayed biopesticides or in Bt transgenic crops. Although alterations of the midgut cadherin-like receptor can lead to Bt Cry toxin resistance in many insects, whether the cadherin gene is involved in Cry1Ac resistance of Plutella xylostella (L.) remains unclear. Here, we present experimental evidence that resistance to Cry1Ac or Bt var. kurstaki (Btk) in P. xylostella is not due to alterations of the cadherin gene. The bona fide P. xylostella cadherin cDNA sequence was cloned and analyzed, and comparisons of the cadherin cDNA sequence among susceptible and resistant P. xylostella strains confirmed that Cry1Ac resistance was independent of mutations in this gene. In addition, real-time quantitative PCR (qPCR) indicated that cadherin transcript levels did not significantly differ among susceptible and resistant P. xylostella strains. RNA interference (RNAi)-mediated suppression of cadherin gene expression did not affect larval susceptibility to Cry1Ac toxin. Furthermore, genetic linkage assays using four cadherin gDNA allelic biomarkers confirmed that the cadherin gene is not linked to resistance against Cry1Ac in P. xylostella. Taken together, our findings demonstrate that Cry1Ac resistance of P. xylostella is independent of the cadherin gene.
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Affiliation(s)
- Zhaojiang Guo
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Shi Kang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Xun Zhu
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Qingjun Wu
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Shaoli Wang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Wen Xie
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Youjun Zhang
- Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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39
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Asokan R, Rebijith KB, Roopa HK, Kumar NKK. Non-Invasive Delivery of dsGST Is Lethal to the Sweet Potato Whitefly, Bemisia tabaci (G.) (Hemiptera: Aleyrodidae). Appl Biochem Biotechnol 2014; 175:2288-99. [DOI: 10.1007/s12010-014-1437-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 11/28/2014] [Indexed: 11/24/2022]
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40
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Li H, Bouwer G. Evaluation of the synergistic activities of Bacillus thuringiensis Cry proteins against Helicoverpa armigera (Lepidoptera: Noctuidae). J Invertebr Pathol 2014; 121:7-13. [DOI: 10.1016/j.jip.2014.06.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 06/09/2014] [Accepted: 06/13/2014] [Indexed: 10/25/2022]
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41
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Ren XL, Ma Y, Cui JJ, Li GQ. RNA interference-mediated knockdown of three putative aminopeptidases N affects susceptibility of Spodoptera exigua larvae to Bacillus thuringiensis Cry1Ca. JOURNAL OF INSECT PHYSIOLOGY 2014; 67:28-36. [PMID: 24932922 DOI: 10.1016/j.jinsphys.2014.06.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2014] [Revised: 06/02/2014] [Accepted: 06/06/2014] [Indexed: 06/03/2023]
Abstract
Aminopeptidase N (APN) isoforms in insects have been documented to be involved in the mode of action of insecticidal crystal proteins (Cry) from Bacillus thuringiensis. Here we cloned two novel Seapns from the larval midgut of Spodoptera exigua, a major pest of many crops of economic importance in China. According to a phylogenetic analysis, these two novel SeAPNs, along with the four SeAPN isoforms already described, belong to six different clades. All the six SeAPNs share similar structural features. From N- to C-terminus a signal peptide, a gluzincin aminopeptidase motif, a zinc binding/gluzincin motif, and a glycosylphosphatidylinositol-anchor sequence are located. The six Seapn genes were highly expressed at the larval stage, especially in the larval gut. Ingestion during four consecutive days of double-stranded RNAs (dsRNAs) targeting Seapn1, Seapn2, Seapn3, Seapn4, Seapn5 and Seapn6 significantly reduced corresponding mRNA levels by 55.6%, 45.5%, 43.2%, 56.8%, 45.4%, and 46.0% respectively, compared with those recorded in control larvae fed on non-specific dsRNA (dsegfp). When the larvae that previously ingested phosphate buffered saline (PBS)-, dsegfp-, or six dsSeapns-overlaid diets were then exposed to a diet containing Cry1Ca, the larval mortalities were 71.2%, 69.3%, 52.0%, 77.2%, 43.3%, 62.0%, 65.4% and 53.8% respectively recorded after 6days. ANOVA analysis revealed that the larvae previously fed on dsSeapn1-, dsSeapn3-, and dsSeapn6-overlaid diets had significantly lower mortalities than those previously ingested PBS-, dsegfp-, dsSeapn2-, dsSeapn4- and dsSeapn5-overlaid diets. Thus, these results suggest that SeAPN1, SeAPN3 and SeAPN6 may be candidate receptors for Cry1Ca in S. exigua.
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Affiliation(s)
- Xiang-Liang Ren
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China
| | - Yan Ma
- Institute of Cotton Research of CAAS, State Key Laboratory of Cotton Biology, Anyang, Henan 455000, China
| | - Jin-Jie Cui
- Institute of Cotton Research of CAAS, State Key Laboratory of Cotton Biology, Anyang, Henan 455000, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, Jiangsu Province, China.
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Chen RR, Ren XL, Han ZJ, Mu LL, Li GQ, Ma Y, Cui JJ. A cadherin-like protein from the beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) is a putative Cry1Ac receptor. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2014; 86:58-71. [PMID: 24764290 DOI: 10.1002/arch.21163] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In S. exigua, ingestion of Cry1Ac reduces larval growth, shortens lifespan, and decreases copulation and oviposition of the adults. Cadherin-like protein SeCad1b in S. exigua has recently been published. Here, we tested whether SeCad1b mediates the negative effects of Cry1Ac. We identified three potential Cry toxin binding regions in SeCad1b, i.e., (879) EIAIQITDTNN(889) , (1357) SLLTVTI(1363) , and (1436) GVISLNFQ(1443) . We expressed and purified a truncated cadherin, rSeCad1bp, and its interspecific homologue, rHaBtRp, from H. armigera that contain the putative toxin binding regions. Using a toxin overlay assay, we found that rSeCad1bp specifically binds to biotinylated Cry1Ac in a dose-dependent manner. We also discovered that an addition of rSeCad1bp and rHaBtRp enhances the suppression of larval growth by Cry1Ac, although rSeCad1bp is less suppressive than rHaBtRp. Finally, RNA interference-mediated knockdown of SeCad1b reduced approximately 80% of the target gene and significantly alleviated the negative effect of CrylAc on larval growth. We infer that the S. exigua SeCad1b is a functional receptor of Cry1Ac.
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Affiliation(s)
- Rui-Rui Chen
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu Province, China
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RNA interference depletion of the Halloween gene disembodied implies its potential application for management of planthopper Sogatella furcifera and Laodelphax striatellus. PLoS One 2014; 9:e86675. [PMID: 24489765 PMCID: PMC3904942 DOI: 10.1371/journal.pone.0086675] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Accepted: 12/11/2013] [Indexed: 11/20/2022] Open
Abstract
Sogatella furcifera and Laodelphax striatellus are economically important rice pests in China by acting as vectors of several rice viruses, sucking the phloem sap and blocking the phloem vessels. Ecdysteroid hormone 20-hydroxyecdysone regulates insect development and reproduction. A cytochrome P450 monooxygenase CYP302A1 (22-hydroxylase), encoded by the Halloween gene disembodied (dib), plays a critical role in ecdysteroidogenesis. The objective of this study is to test whether dib genes are potential targets for RNA interference-based management of S. furcifera and L. striatellus. We cloned and characterized Sfdib and Lsdib. The open reading frame regions of dib genes were generated and used for designing and constructing dsRNA fragments. Experiments were conducted using oral delivery of dsdib to investigate the effectiveness of RNAi in S. furcifera and L. striatellus nymphs. Real-time quantitative reverse transcriptase-PCR analysis demonstrated that continuous ingestion of dsdib at the concentration of 0.01, 0.05 and 0.50 mg/ml diminished Sfdib expression levels by 35.9%, 45.1% and 66.2%, and ecdysone receptor (SfEcR) gene mRNA levels by 34.0%, 36.2% and 58.5% respectively in S. furcifera, and decreased Lsdib expression level by 18.8%, 35.8% and 56.7%, and LsEcR mRNA levels by 25.2%, 46.8% and 68.8% respectively in L. striatellus. The reduction in dib and EcR transcript abundance resulted in observable phenotypes. The development of nymphs was impaired and the survival was negatively affected. Our data will enable the development of new insect control strategies and functional analysis of vital genes in S. furcifera and L. striatellus nymphs.
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