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Lin S, Yang J, Wang W, Huang P, Asad M, Yang G. Hsp70 and Hsp90 Elaborately Regulate RNAi Efficiency in Plutella xylostella. Int J Mol Sci 2023; 24:16167. [PMID: 38003357 PMCID: PMC10671170 DOI: 10.3390/ijms242216167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 11/05/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Heat-shock proteins (HSPs) serve as molecular chaperones in the RNA interference (RNAi) pathway of eukaryotic organisms. In model organisms, Hsp70 and Hsp90 facilitate the folding and remodeling of the client protein Argonaute (Ago). However, the specific function of HSPs in the RNAi pathway of Plutella xylostella (L.) (Lepidoptera: Plutellidae) remains unknown. In this study, we identified and analyzed the coding sequences of PxHsc70-4 and PxHsp83 (also known as PxHsp90). Both PxHsc70-4 and PxHsp83 exhibited three conserved domains that covered a massive portion of their respective regions. The knockdown or inhibition of PxHsc70-4 and PxHsp83 in vitro resulted in a significant increase in the gene expression of the dsRNA-silenced reporter gene PxmRPS18, leading to a decrease in its RNAi efficiency. Interestingly, the overexpression of PxHsc70-4 and PxHsp83 in DBM, Sf9, and S2 cells resulted in an increase in the bioluminescent activity of dsRNA-silenced luciferase, indicating a decrease in its RNAi efficiency via the overexpression of Hsp70/Hsp90. Furthermore, the inhibition of PxHsc70-4 and PxHsp83 in vivo resulted in a significant increase in the gene expression of PxmRPS18. These findings demonstrated the essential involvement of a specific quantity of Hsc70-4 and Hsp83 in the siRNA pathway in P. xylostella. Our study offers novel insights into the roles played by HSPs in the siRNA pathway in lepidopteran insects.
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Affiliation(s)
- Sujie Lin
- State Key Laboratory of Ecological Pest Control for Fujian and 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
- Key Laboratory of Green Pest Control (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China
| | - Jie Yang
- State Key Laboratory of Ecological Pest Control for Fujian and 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
- Key Laboratory of Green Pest Control (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China
| | - Weiqing Wang
- State Key Laboratory of Ecological Pest Control for Fujian and 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
- Key Laboratory of Green Pest Control (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China
| | - Pengrong Huang
- State Key Laboratory of Ecological Pest Control for Fujian and 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
- Key Laboratory of Green Pest Control (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China
| | - Muhammad Asad
- State Key Laboratory of Ecological Pest Control for Fujian and 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
- Key Laboratory of Green Pest Control (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China
| | - Guang Yang
- State Key Laboratory of Ecological Pest Control for Fujian and 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
- Key Laboratory of Green Pest Control (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China
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Wu Y, Weng Z, Yan H, Yao Z, Li Z, Sun Y, Ma K, Hull JJ, Zhang D, Ma W, Hua H, Lin Y. The microRNA-7322-5p/p38/Hsp19 axis modulates Chilo suppressalis cell-defences against Cry1Ca: an effective target for a stacked transgenic rice approach. PLANT BIOTECHNOLOGY JOURNAL 2023; 21:1827-1838. [PMID: 37353991 PMCID: PMC10440986 DOI: 10.1111/pbi.14095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/08/2023] [Accepted: 05/16/2023] [Indexed: 06/25/2023]
Abstract
Bacillus thuringiensis (Bt)-secreted crystal (Cry) toxins form oligomeric pores in host cell membranes and are a common element in generating insect-resistant transgenic crops. Although Cry toxin function has been well documented, cellular defences against pore-formation have not been as well developed. Elucidation of the processes underlying this defence, however, could contribute to the development of enhanced Bt crops. Here, we demonstrate that Cry1Ca-mediated downregulation of microRNA-7322-5p (miR-7322-5p), which binds to the 3' untranslated region of p38, negatively regulates the susceptibility of Chilo suppressalis to Cry1Ca. Moreover, Cry1Ca exposure enhanced phosphorylation of Hsp19, and hsp19 downregulation increased susceptibility to Cry1Ca. Further, Hsp19 phosphorylation occurs downstream of p38, and pull-down assays confirmed the interactions between Hsp19 and Cry1Ca, suggesting that activation of Hsp19 by the miR-7322-5p/p38/Hsp19 pathway promotes Cry1Ca sequestration. To assess the efficacy of targeting this pathway in planta, double-stranded RNA (dsRNA) targeting C. suppressalis p38 (dsp38) was introduced into a previously generated cry1Ca-expressing rice line (1CH1-2) to yield a single-copy cry1Ca/dsp38 rice line (p38-rice). Feeding on this rice line triggered a significant reduction in C. suppressalis p38 expression and the line was more resistant to C. suppressalis than 1CH1-2 in both short term (7-day) and continuous feeding bioassays as well as field trials. These findings provide new insights into invertebrate epithelium cellular defences and demonstrate a potential new pyramiding strategy for Bt crops.
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Affiliation(s)
- Yan Wu
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhanHubeiChina
- College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Zijin Weng
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhanHubeiChina
- College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Haixia Yan
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhanHubeiChina
- College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Zhuotian Yao
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhanHubeiChina
- College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Zhenzhen Li
- College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Yajie Sun
- College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Kangsheng Ma
- College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - J. Joe Hull
- U.S. Arid Land Agricultural Research Center, Department of AgricultureU.S. Agricultural Research ServiceMaricopaArizonaUSA
| | - Delin Zhang
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhanHubeiChina
- College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Weihua Ma
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhanHubeiChina
- College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Hongxia Hua
- College of Plant Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
| | - Yongjun Lin
- National Key Laboratory of Crop Genetic Improvement and National Centre of Plant Gene Research, Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhanHubeiChina
- College of Life Science and TechnologyHuazhong Agricultural UniversityWuhanHubeiChina
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García-Gomez BI, Sánchez TA, Cano SN, do Nascimento NA, Bravo A, Soberón M. Insect chaperones Hsp70 and Hsp90 cooperatively enhance toxicity of Bacillus thuringiensis Cry1A toxins and counteract insect resistance. Front Immunol 2023; 14:1151943. [PMID: 37153577 PMCID: PMC10157212 DOI: 10.3389/fimmu.2023.1151943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 04/11/2023] [Indexed: 05/09/2023] Open
Abstract
Bacillus thuringiensis (Bt) produces different insecticidal proteins effective for pest control. Among them, Cry insecticidal proteins have been used in transgenic plants for the control of insect pests. However, evolution of resistance by insects endangers this technology. Previous work showed that the lepidopteran insect Plutella xylostella PxHsp90 chaperone enhanced the toxicity of Bt Cry1A protoxins by protecting them from degradation by the larval gut proteases and by enhancing binding of the protoxin to its receptors present in larval midgut cells. In this work, we show that PxHsp70 chaperone also protects Cry1Ab protoxin from gut proteases degradation, enhancing Cry1Ab toxicity. We also show that both PxHsp70 and PxHsp90 chaperones act cooperatively, increasing toxicity and the binding of Cry1Ab439D mutant, affected in binding to midgut receptors, to cadherin receptor. Also, insect chaperones recovered toxicity of Cry1Ac protein to a Cry1Ac-highly resistant P. xylostella population, NO-QAGE, that has a disruptive mutation in an ABCC2 transporter linked to Cry1Ac resistance. These data show that Bt hijacked an important cellular function for enhancing its infection capability, making use of insect cellular chaperones for enhancing Cry toxicity and for lowering the evolution of insect resistance to these toxins.
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Bacillus thuringiensis Cry1Ac Protoxin and Activated Toxin Exert Differential Toxicity Due to a Synergistic Interplay of Cadherin with ABCC Transporters in the Cotton Bollworm. Appl Environ Microbiol 2022; 88:e0250521. [PMID: 35262369 DOI: 10.1128/aem.02505-21] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Bacillus thuringiensis Cry proteins are used worldwide for insect control. It was proposed that Cry-protoxins must be converted into activated toxin by proteases to bind midgut cell proteins to kill insects. However, Cry-protoxins also bind to midgut proteins and kill insects that have evolved resistance to activated toxins suggesting an independent toxicity pathway. Cadherin (CAD) and ABCC transporters are recognized as important receptors for Cry proteins. Here we constructed different Helicoverpa armigera mutations in these receptors by CRISPR/Cas9. HaCAD-KO mutant showed much higher resistance to Cry1Ac activated toxin than to Cry1Ac protoxin. In contrast, the HaABCC2-M and HaABCC3-M mutants showed higher resistance to Cry1Ac-protoxin than to activated toxin. However, in the double HaABCC2/3-KO mutant, very high levels of resistance were observed to both Cry1Ac protoxin and activated toxin, supporting that both ABC transporters have redundant functions for these two proteins. In addition, Hi5 cells transfected with HaCAD were susceptible only to the activated toxin but not to protoxin. In contrast, both forms of Cry1Ac were similarly toxic to Hi5 cells expressing HaABCC2 or HaABCC3. Co-expression of HaCAD with HaABCC2 or HaABCC3 revealed a more important synergistic effect for activated toxin compared to protoxin. Overall, our results show that toxicity of Cry1Ac activated toxin involves synergistic interplay of HaCAD with ABCC transporters, while the Cry1Ac protoxin toxicity is mainly mediated by ABCC transporters with little participation of HaCAD. These data help to understand the mode of action of Cry proteins that will be relevant to enhance efficacy and durability of Bt-crops. IMPORTANCE Better understanding of the mode of action of Bacillus thuringiensis toxins is beneficial for the sustainable application of Bt crops. It is generally accepted that Cry-protoxins need to be activated by proteases to bind with midgut cell proteins and exert toxicity against insects. Here, we provide new insights into the toxic pathway of Cry proteins in the cotton bollworm. First, our results demonstrate that Cry1Ac protoxin is able to exert cytotoxicity against the insect cells expressing ABCC transporters. Second, we reveal that CAD plays a critical role in the different toxicity of protoxin and toxin by facilitating a synergistic interplay with ABCC transporters. Our results provide in vivo and in vitro experimental evidence supporting that Cry1Ac protoxin exerts toxicity against H. armigera via different steps from that of toxin. These new findings on the mode of action of Cry proteins could be beneficial for efficacy enhancement and durability of Bt-crops.
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A Novel Reference for Bt-Resistance Mechanism in Plutella xylostella Based on Analysis of the Midgut Transcriptomes. INSECTS 2021; 12:insects12121091. [PMID: 34940179 PMCID: PMC8708430 DOI: 10.3390/insects12121091] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 11/27/2021] [Accepted: 12/01/2021] [Indexed: 11/18/2022]
Abstract
Simple Summary Plutella xylostella is a very serious pest to cruciferous vegetables. At present, the control methods used are mainly traditional insecticides and the cultivation of Bt crops. However, with the long-term and large-scale use of insecticides, the diamondback moth has developed strong resistance to many kinds of insecticides and Bt crops. The Cry1S1000 strain of P. xylostella used here is a strain with more than 8000 times resistance to Bt Cry1Ac protoxin. In this paper, we used transcriptome sequencing to determine the midgut transcriptome of the G88-susceptible strain, Cry1S1000-resistant strain and its corresponding toxin-induced strains to find more genes related to Bt resistance. Our results will provide a reference for optimizing the control strategy of diamondback moth resistance and improving the control efficiency of biopesticides and Bt crops. Abstract The diamondback moth, Plutella xylostella, is a lepidopteran insect that mainly harms cruciferous vegetables, with strong resistance to a variety of agrochemicals, including Bacillus thuringiensis (Bt) toxins. This study intended to screen genes associated with Bt resistance in P. xylostella by comparing the midgut transcriptome of Cry1Ac-susceptible and -resistant strains together with two toxin-treated strains 24 h before sampling. A total of 12 samples were analyzed by BGISEQ-500, and each sample obtained an average of 6.35 Gb data. Additionally, 3284 differentially expressed genes (DEGs) were identified in susceptible and resistant strains. Among them, five DEGs for cadherin, 14 for aminopeptidase, zero for alkaline phosphatase, 14 for ATP binding cassette transport, and five heat shock proteins were potentially involved in resistance to Cry1Ac in P. xylostella. Furthermore, DEGs associated with “binding”, “catalytic activity”, “cellular process”, “metabolic process”, and “cellular anatomical entity” were more likely to be responsible for resistance to Bt toxin. Thus, together with other omics data, our results will offer prospective genes for the development of Bt resistance, thereby providing a brand new reference for revealing the resistance mechanism to Bt of P. xylostella.
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Xie Y, Xu C, Gao M, Zhang X, Lu L, Hu X, Chen W, Jurat-Fuentes JL, Zhu Q, Liu Y, Lin M, Zhong J, Liu X. Docking-based generation of antibodies mimicking Cry1A/1B protein binding sites as potential insecticidal agents against diamondback moth (Plutella xylostella). PEST MANAGEMENT SCIENCE 2021; 77:4593-4606. [PMID: 34092019 DOI: 10.1002/ps.6499] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 05/19/2021] [Accepted: 06/06/2021] [Indexed: 05/26/2023]
Abstract
BACKGROUND Broad use of insecticidal Cry proteins from Bacillus thuringiensis in biopesticides and transgenic crops has resulted in cases of practical field resistance, highlighting the need for novel approaches to insect control. Previously we described an anti-Cry1Ab idiotypic-antibody (B12-scFv) displaying toxicity against rice leafroller (Cnaphalocrocis medinalis) larvae, supporting the potential of antibodies for pest control. The goal of the present study was to generate insecticidal antibodies against diamondback moth (Plutella xylostella) larvae. RESULTS Four genetically engineered antibodies (GEAbs) were designed in silico from B12-scFv using three-dimensional (3D) structure and docking predictions to alkaline phosphatase (ALP) as a Cry1Ac receptor in P. xylostella. Among these GEAbs, the GEAb-dVL antibody consisting of two light chains had overlapping binding sites with Cry1A and Cry1B proteins and displayed high binding affinity to P. xylostella midgut brush border membrane (BBM) proteins. Proteins in BBM identified by pull-down assays as binding to GEAb-dVL included an ABC transporter and V-ATPase subunit A protein. Despite lacking the α-helical structures in Cry1A that are responsible for pore formation, ingestion of GEAb-dVL disrupted the P. xylostella larval midgut epithelium and resulted in toxicity. Apoptotic genes were activated in gut cells upon treatment with GEAb-dVL . CONCLUSION This study describes the first insecticidal GEAb targeting P. xylostella by mimicking Cry proteins. Data support that GEAb-dVL toxicity is associated to activation of intracellular cell death pathways, in contrast to pore-formation associated toxicity of Cry proteins. This work provides a foundation for the design of novel insecticidal antibodies for insect control. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Yajing Xie
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Chongxin Xu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Meijing Gao
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Xiao Zhang
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Lina Lu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Xiaodan Hu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Wei Chen
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Juan L Jurat-Fuentes
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN, USA
| | - Qing Zhu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Yuan Liu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Manman Lin
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Jianfeng Zhong
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
| | - Xianjin Liu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, P. R. China
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Wei J, Yang S, Zhou S, Liu S, Cao P, Liu X, Du M, An S. Suppressing calcineurin activity increases the toxicity of Cry2Ab to Helicoverpa armigera. PEST MANAGEMENT SCIENCE 2021; 77:2142-2150. [PMID: 33336541 DOI: 10.1002/ps.6243] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/12/2020] [Accepted: 12/17/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Extensive planting of transgenetic Bacillus thuringiensis crops has driven the evolution of pest resistance to Cry1Ac. Adjustment of cropping structures has promoted further outbreak of Helicoverpa armigera in China. To control this pest, a combination of pyramiding RNA interference (RNAi) and Cry2Ab is considered a promising strategy for countering cross-resistance and enhancing the toxicity of Cry2Ab to cotton bollworm. We explored the possibility of using calcineurin (CAN) as a target RNAi gene, because it is involved in cotton bollworm responses to the toxicity of Cry2Ab. RESULTS Cry2Ab treatment led to a significant increase in HaCAN mRNA level and HaCAN activity. Suppression of HaCAN activity due to RNAi-mediated knockdown of HaCAN increased the susceptibility of midgut cells to Cry2Ab. The increase in HaCAN activity shown by heterologous expression of HaCAN reduced the cytotoxicity of Cry2Ab to Sf9 cells. Moreover, ingestion of HaCAN-specific inhibitor FK506 increased the toxicity of Cry2Ab in larvae. Interestingly, HaCAN does not function as a Cry2Ab direct binding protein that participates in Cry2Ab toxicity. CONCLUSIONS The results in this study provide evidence that suppression of HaCAN not only affected the development of the cotton bollworm, but also enhanced the toxicity of Cry2Ab to the pest. HaCAN is therefore an important candidate gene in cotton bollworm that can be targeted for pest control when the pest infests RNAi+Cry2Ab crops. Meanwhile, the mechanism of action of HaCAN in Cry2Ab toxicity suggested that protein dephosphorylation was involved. © 2020 Society of Chemical Industry.
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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
| | - Shuo Yang
- State Key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Shuai Zhou
- State Key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Shaokai Liu
- State Key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Pei Cao
- Kaifeng Agricultural Technology Extension Station, Kaifeng, China
| | - Xiaoguang Liu
- State Key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Mengfang Du
- State Key Laboratory of Wheat and Maize Crop Science/College of Plant Protection, Henan Agricultural University, Zhengzhou, 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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Wei J, Yao X, Yang S, Liu S, Zhou S, Cen J, Liu X, Du M, Tang Q, An S. Suppression of Calcineurin Enhances the Toxicity of Cry1Ac to Helicoverpa armigera. Front Microbiol 2021; 12:634619. [PMID: 33643268 PMCID: PMC7904703 DOI: 10.3389/fmicb.2021.634619] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 01/25/2021] [Indexed: 12/14/2022] Open
Abstract
Insect resistance to Bacillus thuringiensis (Bt) insecticidal proteins has rapidly evolved with the expansion of the planting area of transgenic Bt crops. Pyramiding RNA interference (RNAi) and Bt in crops is urgently needed to counter the rapid increase in pest resistance. The ideal “pyramid” strategy simultaneously targets different action pathways that exert synergetic effects on each other. Here, we identified a dephosphatase, namely, Helicoverpa armigera calcineurin (HaCAN), which might enhance the insecticidal activity of Cry1Ac against Helicoverpa armigera by regulating immune gene expression via dephosphatase activity, but not by acting as a receptor. Notably, blocking enzyme activity or knocking down endogenous HaCAN significantly promoted the enhancement in Cry1Ac toxicity to insect larvae and cells. Correspondingly, the increase in HaCAN activity reduced the cytotoxicity of Cry1Ac as shown by the heterologous expression of HaCAN. Our results provide a probable that HaCAN is an important candidate gene for pyramiding RNAi and Cry1Ac crops to control cotton bollworm.
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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
| | - Xue Yao
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Shuo Yang
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Shaokai Liu
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Shuai Zhou
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Junjuan Cen
- Bureau of Agriculture and Rural Affairs of Qixian, Kaifeng, China
| | - Xiaoguang Liu
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Mengfang Du
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, China
| | - Qingbo Tang
- State Key Laboratory of Wheat and Maize Crop Science, College of Plant Protection, Henan Agricultural University, Zhengzhou, 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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Kryukov VY, Rotskaya U, Yaroslavtseva O, Polenogova O, Kryukova N, Akhanaev Y, Krivopalov A, Alikina T, Vorontsova YL, Slepneva I, Kabilov M, Glupov VV. Fungus Metarhizium robertsii and neurotoxic insecticide affect gut immunity and microbiota in Colorado potato beetles. Sci Rep 2021; 11:1299. [PMID: 33446848 PMCID: PMC7809261 DOI: 10.1038/s41598-020-80565-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 12/14/2020] [Indexed: 12/13/2022] Open
Abstract
Fungal infections and toxicoses caused by insecticides may alter microbial communities and immune responses in the insect gut. We investigated the effects of Metarhizium robertsii fungus and avermectins on the midgut physiology of Colorado potato beetle larvae. We analyzed changes in the bacterial community, immunity- and stress-related gene expression, reactive oxygen species (ROS) production, and detoxification enzyme activity in response to topical infection with the M. robertsii fungus, oral administration of avermectins, and a combination of the two treatments. Avermectin treatment led to a reduction in microbiota diversity and an enhancement in the abundance of enterobacteria, and these changes were followed by the downregulation of Stat and Hsp90, upregulation of transcription factors for the Toll and IMD pathways and activation of detoxification enzymes. Fungal infection also led to a decrease in microbiota diversity, although the changes in community structure were not significant, except for the enhancement of Serratia. Fungal infection decreased the production of ROS but did not affect the gene expression of the immune pathways. In the combined treatment, fungal infection inhibited the activation of detoxification enzymes and prevented the downregulation of the JAK-STAT pathway caused by avermectins. The results of this study suggest that fungal infection modulates physiological responses to avermectins and that fungal infection may increase avermectin toxicosis by blocking detoxification enzymes in the gut.
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Affiliation(s)
- Vadim Yu Kryukov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia. .,Tomsk State University, Tomsk, 634050, Russia.
| | - Ulyana Rotskaya
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Olga Yaroslavtseva
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Olga Polenogova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Natalia Kryukova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Yuriy Akhanaev
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Anton Krivopalov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Tatyana Alikina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Yana L Vorontsova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Irina Slepneva
- Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Marsel Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Viktor V Glupov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
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10
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Vílchez S. Making 3D-Cry Toxin Mutants: Much More Than a Tool of Understanding Toxins Mechanism of Action. Toxins (Basel) 2020; 12:toxins12090600. [PMID: 32948025 PMCID: PMC7551160 DOI: 10.3390/toxins12090600] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/15/2020] [Accepted: 08/20/2020] [Indexed: 12/21/2022] Open
Abstract
3D-Cry toxins, produced by the entomopathogenic bacterium Bacillus thuringiensis, have been extensively mutated in order to elucidate their elegant and complex mechanism of action necessary to kill susceptible insects. Together with the study of the resistant insects, 3D-Cry toxin mutants represent one of the pillars to understanding how these toxins exert their activity on their host. The principle is simple, if an amino acid is involved and essential in the mechanism of action, when substituted, the activity of the toxin will be diminished. However, some of the constructed 3D-Cry toxin mutants have shown an enhanced activity against their target insects compared to the parental toxins, suggesting that it is possible to produce novel versions of the natural toxins with an improved performance in the laboratory. In this report, all mutants with an enhanced activity obtained by accident in mutagenesis studies, together with all the variants obtained by rational design or by directed mutagenesis, were compiled. A description of the improved mutants was made considering their historical context and the parallel development of the protein engineering techniques that have been used to obtain them. This report demonstrates that artificial 3D-Cry toxins made in laboratories are a real alternative to natural toxins.
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Affiliation(s)
- Susana Vílchez
- Institute of Biotechnology, Department of Biochemistry and Molecular Biology I, Faculty of Science, University of Granada, 18071 Granada, Spain
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11
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Qi L, Qiu X, Yang S, Li R, Wu B, Cao X, He T, Ding X, Xia L, Sun Y. Cry1Ac Protoxin and Its Activated Toxin from Bacillus thuringiensis Act Differentially during the Pathogenic Process. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:5816-5824. [PMID: 32379448 DOI: 10.1021/acs.jafc.0c01172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Although the new dual model of the Bacillus thuringiensis insecticidal mechamism indicated that both Cry1A protoxin and activated toxin have the potency to kill insects, the difference in the toxic pathways elicited by the protoxin and activated toxin was less understood at the molecular level. Through utilizing the CF-203 cell line derived from the midgut of Choristoneura fumiferana, we found that there existed obvious differences in the binding sites and endocytosis pathways for the two forms of Cry1Ac. In addition, it was revealed that Cry1Ac protoxin existed predominantly in the midgut of Plutella xylostella at the early stage after ingesting Cry1Ac crystals, which brought about obvious damage to the midgut epithelium and exhibited different binding sites on the brush border membrane vesicle compared to the toxin. These findings supported the dual mode of action of B. thuringiensis Cry1A proteins and improved our understanding of the molecular features that contribute to the protoxin toxicity.
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Affiliation(s)
- Lingling Qi
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Xianfeng Qiu
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Sisi Yang
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Ran Li
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Binbin Wu
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Xiaomei Cao
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Ting He
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Xuezhi Ding
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Liqiu Xia
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
| | - Yunjun Sun
- College of Life Science, State Key Laboratory of Developmental Biology of Freshwater Fish, Hunan Normal University, Changsha 410081, People's Republic of China
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