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Shen S, Zhang L, Zhang L. Population Density-Dependent Developmental Regulation in Migratory Locust. INSECTS 2024; 15:443. [PMID: 38921158 PMCID: PMC11203946 DOI: 10.3390/insects15060443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 06/05/2024] [Accepted: 06/06/2024] [Indexed: 06/27/2024]
Abstract
Insect development is intricately governed by hormonal signaling pathways, yet the pivotal upstream regulator that potentiates hormone activation remains largely elusive. The migratory locust, Locusta migratoria, exhibits population density-dependent phenotypic plasticity, encompassing traits such as flight capability, body coloration, and behavior. In this study, we elucidated a negative correlation between population density and ontogenetic development during the nymphal stage of locusts. We found that the level of density influences the developmental trajectory by modulating transcript abundance within the ecdysone signaling pathway, with knockdown of the prothoracicotropic hormone (PTTH) resulting in developmental delay. Transcriptomic analysis of locust brains across solitary and gregarious phases revealed significant differential expression of genes involved in various pathways, including protein synthesis, energy metabolism, hormonal regulation, and immunity. Notably, knockdown experiments targeting two energy regulators, adipokinetic hormone (AKH) and insulin-like polypeptide 1 (ilp1), failed to elicit changes in the developmental process in solitary locusts. However, knockdown of immunoglobulin (IG) significantly shortened the developmental time in higher-density populations. Collectively, our findings underscore the regulatory role of population density in determining developmental duration and suggest that an immune-related gene contributes to the observed differences in developmental patterns.
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Affiliation(s)
- Sifan Shen
- College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China;
| | - Long Zhang
- Institute of Plant Protection, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Liwei Zhang
- College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China;
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2
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Abbas MN, Gul I, Khosravi Z, Amarchi JI, Ye X, Yu L, Siyuan W, Cui H. Molecular characterization, immune functions and DNA protective effects of peroxiredoxin-1 gene in Antheraea pernyi. Mol Immunol 2024; 170:76-87. [PMID: 38640818 DOI: 10.1016/j.molimm.2024.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 04/06/2024] [Accepted: 04/08/2024] [Indexed: 04/21/2024]
Abstract
Peroxiredoxins are antioxidant proteins that detoxify peroxynitrite, hydrogen peroxide, and organic hydroperoxides, impacting various physiological processes such as immune responses, apoptosis, cellular homeostasis, and so on. In the present study, we identified and characterized peroxiredoxin 1 from Antheraea pernyi (thereafter designated as ApPrx-1) that encodes a predicted 195 amino acid residue protein with a 21.8 kDa molecular weight. Quantitative real-time PCR analysis revealed that the mRNA level of ApPrx-1 was highest in the hemocyte, fat body, and midgut. Immune-challenged larval fat bodies and hemocytes showed increased ApPrx-1 transcript. Moreover, ApPrx-1 expression was induced in hemocytes and the whole body of A. pernyi following exogenous H2O2 administration. A DNA cleavage assay performed using recombinant ApPrx-1 protein showed that rApPrx-1 protein manifests the ability to protect supercoiled DNA damage from oxidative stress. To test the rApPrx-1 protein antioxidant activity, the ability of the rApPrx-1 protein to remove H2O2 was assessed in vitro using rApPrx-1 protein and DTT, while BSA + DDT served as a control group. The results revealed that ApPrx-1 can efficiently remove H2O2 in vitro. In the loss of function analysis, we found that ApPrx-1 significantly increased the levels of H2O2 in ApPrx-1-depleted larvae compared to the control group. We also found a significantly lower survival rate in the larvae in which ApPrx-1 was knocked down. Interestingly, the antibacterial activity was significantly higher in the ApPrx-1 depleted larvae, compared to the control. Collectively, evidence strongly suggests that ApPrx-1 may regulate physiological activities and provides a reference for further studies to validate the utility of the key genes involved in reliving oxidative stress conditions and regulating the immune responses of insects.
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Affiliation(s)
- Muhammad Nadeem Abbas
- State Key Laboratory of Resource insects, Southwest University, Chongqing 400716, China; Jinfeng Laboratory, Chongqing 401329, China
| | - Isma Gul
- State Key Laboratory of Resource insects, Southwest University, Chongqing 400716, China; Jinfeng Laboratory, Chongqing 401329, China
| | - Zahra Khosravi
- State Key Laboratory of Resource insects, Southwest University, Chongqing 400716, China; Jinfeng Laboratory, Chongqing 401329, China
| | - Jemirade Ifejola Amarchi
- State Key Laboratory of Resource insects, Southwest University, Chongqing 400716, China; Jinfeng Laboratory, Chongqing 401329, China
| | - Xiang Ye
- State Key Laboratory of Resource insects, Southwest University, Chongqing 400716, China; Jinfeng Laboratory, Chongqing 401329, China
| | - Lang Yu
- State Key Laboratory of Resource insects, Southwest University, Chongqing 400716, China; Jinfeng Laboratory, Chongqing 401329, China
| | - Wu Siyuan
- State Key Laboratory of Resource insects, Southwest University, Chongqing 400716, China; Jinfeng Laboratory, Chongqing 401329, China
| | - Hongjuan Cui
- State Key Laboratory of Resource insects, Southwest University, Chongqing 400716, China; Jinfeng Laboratory, Chongqing 401329, China; Chongqing engineering and Technology Research Center for Silk Biomaterials and Regenerative medicine, Chongqing 400716, China.
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3
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Zhu YN, He J, Wang J, Guo W, Liu H, Song Z, Kang L. Parental experiences orchestrate locust egg hatching synchrony by regulating nuclear export of precursor miRNA. Nat Commun 2024; 15:4328. [PMID: 38773155 PMCID: PMC11109280 DOI: 10.1038/s41467-024-48658-7] [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: 06/14/2023] [Accepted: 05/08/2024] [Indexed: 05/23/2024] Open
Abstract
Parental experiences can affect the phenotypic plasticity of offspring. In locusts, the population density that adults experience regulates the number and hatching synchrony of their eggs, contributing to locust outbreaks. However, the pathway of signal transmission from parents to offspring remains unclear. Here, we find that transcription factor Forkhead box protein N1 (FOXN1) responds to high population density and activates the polypyrimidine tract-binding protein 1 (Ptbp1) in locusts. FOXN1-PTBP1 serves as an upstream regulator of miR-276, a miRNA to control egg-hatching synchrony. PTBP1 boosts the nucleo-cytoplasmic transport of pre-miR-276 in a "CU motif"-dependent manner, by collaborating with the primary exportin protein exportin 5 (XPO5). Enhanced nuclear export of pre-miR-276 elevates miR-276 expression in terminal oocytes, where FOXN1 activates Ptbp1 and leads to egg-hatching synchrony in response to high population density. Additionally, PTBP1-prompted nuclear export of pre-miR-276 is conserved in insects, implying a ubiquitous mechanism to mediate transgenerational effects.
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Affiliation(s)
- Ya Nan Zhu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100101, China
| | - Jing He
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jiawen Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Wei Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Hongran Liu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Zhuoran Song
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100101, China.
- College of Life Science, Hebei University, Baoding, Hebei, 071002, China.
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4
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Bi J, Liu P, Gao R, Jiang Y, Zhang C, Zhao T, Gao L, Wang Y. Silencing gram-negative bacteria binding protein 1 decreases the immunity of Tribolium castaneum against bacteria. Int J Biol Macromol 2024; 264:130631. [PMID: 38453114 DOI: 10.1016/j.ijbiomac.2024.130631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/22/2024] [Accepted: 03/03/2024] [Indexed: 03/09/2024]
Abstract
Gram-negative bacteria binding proteins (GNBPs) have the ability to recognize molecular patterns associated with microbial pathogens (PAMPs), leading to the activation of immune responses downstream. In the genome of Tribolium castaneum, three GNBP genes have been identified; however, their immunological roles remain unexplored. In our study, a GNBP1, designated as TcGNBP1, were identified from the cDNA library of T. castaneum. The coding sequence of TcGNBP1 consisted of 1137 bps and resulted in the synthesis of a protein comprising 378 amino acids. This protein encompasses a signal peptide, a low-complexity region, and a glycoside hydrolase 16 domain. TcGNBP1 was strongly expressed in early adult stages, and mainly distributed in hemolymph and gut. Upon being challenged with Escherichia coli or Staphylococcus aureus, the transcript levels of TcGNBP1 were significantly changed at different time points. Through molecular docking and ELISA analysis, it was observed that TcGNBP1 has the ability to interact with lipopolysaccharides, peptidoglycan, and β-1, 3-glucan. Based on these findings, it was further discovered that recombinant TcGNBP1 can directly bind to five different bacteria in a Ca2+-dependent manner. After knockdown of TcGNBP1 with RNA interference, expression of antimicrobial peptide genes and prophenoloxidase (proPO) activity were suppressed, the susceptibility of T. castaneum to E. coli or S. aureus infection was enhanced, leading to low survival rate. These results suggest a regulatory mechanism of TcGNBP1 in innate immunity of T. castaneum and provide a potential molecular target for dsRNA-based insect pest management.
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Affiliation(s)
- Jingxiu Bi
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Pingxiang Liu
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Rui Gao
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Yuying Jiang
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Chao Zhang
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Tong Zhao
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Lei Gao
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China
| | - Yutao Wang
- Laboratory of Quality and Safety Risk Assessment for Agro-Products of the Ministry of Agriculture (Jinan), Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, China; Cooperative of Vegetable and Grain Cultivation, Liaocheng Yifeng Bloc, Liaocheng, Shandong, China.
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5
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Zhang W, Chen X, Eleftherianos I, Mohamed A, Bastin A, Keyhani NO. Cross-talk between immunity and behavior: insights from entomopathogenic fungi and their insect hosts. FEMS Microbiol Rev 2024; 48:fuae003. [PMID: 38341280 PMCID: PMC10883697 DOI: 10.1093/femsre/fuae003] [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: 06/23/2023] [Revised: 02/05/2024] [Accepted: 02/09/2024] [Indexed: 02/12/2024] Open
Abstract
Insects are one of the most successful animals in nature, and entomopathogenic fungi play a significant role in the natural epizootic control of insect populations in many ecosystems. The interaction between insects and entomopathogenic fungi has continuously coevolved over hundreds of millions of years. Many components of the insect innate immune responses against fungal infection are conserved across phyla. Additionally, behavioral responses, which include avoidance, grooming, and/or modulation of body temperature, have been recognized as important mechanisms for opposing fungal pathogens. In an effort to investigate possible cross-talk and mediating mechanisms between these fundamental biological processes, recent studies have integrated and/or explored immune and behavioral responses. Current information indicates that during discrete stages of fungal infection, several insect behavioral and immune responses are altered simultaneously, suggesting important connections between the two systems. This review synthesizes recent advances in our understanding of the physiological and molecular aspects influencing cross-talk between behavioral and innate immune antifungal reactions, including chemical perception and olfactory pathways.
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Affiliation(s)
- Wei Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering (Ministry of Education), Guizhou University, Guiyang, Huaxi District 550025, China
| | - Xuanyu Chen
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering (Ministry of Education), Guizhou University, Guiyang, Huaxi District 550025, China
| | - Ioannis Eleftherianos
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, United States
| | - Amr Mohamed
- Department of Entomology, Faculty of Science, Cairo University, Giza 12613, Egypt
- Research fellow, King Saud University Museum of Arthropods, Plant Protection Department, College of Food and Agricultural Sciences, King Saud University, Saudi Arabia
| | - Ashley Bastin
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, United States
| | - Nemat O Keyhani
- Department of Biological Sciences, University of Illinois, Chicago, IL 60607, United States
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Gul I, Abbas MN, Hussaini N, Kausar S, Wu S, Cui H. Peroxiredoxin-2 gene in Antheraea pernyi modulates immune functions and protect DNA damage. Int J Biol Macromol 2024; 256:128410. [PMID: 38029918 DOI: 10.1016/j.ijbiomac.2023.128410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 11/17/2023] [Accepted: 11/22/2023] [Indexed: 12/01/2023]
Abstract
Peroxiredoxins have been shown to protect insects from oxidative damage and to play a role in the immune system. In the present study, we cloned and characterized the Antheraea pernyi peroxiredoxin 2 (ApPrx-2) gene, then assessed its functional roles. The ApPrx-2 gene has a 687 bp open reading frame that encodes a protein with 288 amino acid residues. Quantitative real-time PCR analysis revealed that the mRNA levels of ApPrx-2 were highest in the hemocytes. Immune challenge assay revealed that ApPrx-2 transcription could be induced after microbial challenge. A DNA cleavage assay employing recombinant ApPrx-2 protein and a metal-catalyzed oxidation system showed that rApPrx-2 protein could protect supercoiled DNA against oxidative stress. The protein antioxidant activity of rApPrx-2 was examined, and it was found that rApPrx-2 exhibited a high level of antioxidant activity by removing H2O2. In addition, ApPrx-2 knockdown larvae had higher H2O2 levels and a lower survival rate when compared to controls. Interestingly, the antibacterial activity was significantly higher in ApPrx-2 depleted larvae compared with control. Overall, our findings indicate that ApPrx-2 may be involved in a range of physiological functions of A. pernyi, as it protects supercoiled DNA from oxidative stress and regulates antibacterial activity.
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Affiliation(s)
- Isma Gul
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing 400716, China
| | - Muhammad Nadeem Abbas
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing 400716, China; Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing 400715, China
| | - Najibullah Hussaini
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing 400716, China
| | - Saima Kausar
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing 400716, China
| | - Siyuan Wu
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing 400716, China
| | - Hongjuan Cui
- State Key Laboratory of Resource Insects, Southwest University, Chongqing 400716, China; Chongqing Engineering and Technology Research Center for Silk Biomaterials and Regenerative Medicine, Chongqing 400716, China; Engineering Research Center for Cancer Biomedical and Translational Medicine, Southwest University, Chongqing 400715, China; Jinfeng Laboratory, Chongqing, 401329, China..
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7
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Zhang N, Feng S, Duan S, Yin Y, Ullah H, Li H, Davaasambuu U, Wei S, Nong X, Zhang Z, Tu X, Wang G. LmFKBP24 interacts with LmEaster to inhibit the antifungal immunity of Locusta migratoria. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 195:105515. [PMID: 37666582 DOI: 10.1016/j.pestbp.2023.105515] [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: 05/05/2023] [Revised: 06/27/2023] [Accepted: 07/02/2023] [Indexed: 09/06/2023]
Abstract
Locusta migratoria is one of the most destructive pests that threaten crop growth and food production security in China. Metarhizium anisopliae has been widely used to control locusts around the world. Previous laboratory studies have revealed that LmFKBP24 is significantly upregulated after M. anisopliae infection, suggesting that it may play a role in immune regulation, yet the mechanism remains largely unknown. To gain further insight, we conducted an RNA interference (RNAi) study to investigate the function of LmFKBP24 in the regulation of antifungal immunity and analyzed the expression patterns of immune-induced genes. Our research revealed that LmFKBP24 is activated and upregulated when locusts are infected by M. anisopliae, and it inhibits the expression of antimicrobial peptide (AMP) defensin in the downstream of Toll pathway by combining with LmEaster rather than LmCyPA, thus exerting an immunosuppressive effect. To further investigate this, we conducted yeast two-hybrid (Y2H) and pull down assays to identify the proteins interacting with LmFKBP24. Our results provided compelling evidence for revealing the immune mechanism of L. migratoria and uncovered an innovative target for the development of new biological pesticides. Furthermore, our research indicates that LmFKBP24 interacts with LmEaster through its intact structure, providing a strong foundation for further exploration.
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Affiliation(s)
- Neng Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Scientific Observation and Experimental Station of Pests in Xilingol Rangeland, Ministry of Agriculture and Rural Affairs, Xilinhot 026000, China
| | - Shiqian Feng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Saiya Duan
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yiting Yin
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Hidayat Ullah
- Department of Agriculture, The University of Swabi, Anbar-Swabi 23561, Khyber Pakhtunkhwa, Pakistan
| | - Hongmei Li
- MARA-CABI Joint Laboratory for Bio-safety, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Undarmaa Davaasambuu
- School of Agroecology, Mongolian University of Life Sciences, Ulaanbaatar 17024, Mongolia
| | - Shuhua Wei
- Institute of Plant Protection, Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan 750002, China
| | - Xiangqun Nong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zehua Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiongbing Tu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Scientific Observation and Experimental Station of Pests in Xilingol Rangeland, Ministry of Agriculture and Rural Affairs, Xilinhot 026000, China
| | - Guangjun Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Scientific Observation and Experimental Station of Pests in Xilingol Rangeland, Ministry of Agriculture and Rural Affairs, Xilinhot 026000, China.
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8
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Duffield KR, Rosales AM, Muturi EJ, Behle RW, Ramirez JL. Increased Phenoloxidase Activity Constitutes the Main Defense Strategy of Trichoplusia ni Larvae against Fungal Entomopathogenic Infections. INSECTS 2023; 14:667. [PMID: 37623376 PMCID: PMC10455440 DOI: 10.3390/insects14080667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/18/2023] [Accepted: 07/20/2023] [Indexed: 08/26/2023]
Abstract
The cabbage looper Trichoplusia ni is an important agricultural pest worldwide and is frequently used as a model organism for assessing entomopathogenic fungi virulence, though few studies have measured the host response repertoire to fungal biocontrol agents. Here, we quantified the immune response of T. ni larvae following exposure to two entomopathogenic fungal species: Beauveria bassiana and Cordyceps javanica. Results from our study demonstrate that T. ni larvae exposed to fungal entomopathogens had higher total phenoloxidase activity compared to controls, indicating that the melanization cascade is one of the main immune components driving defense against fungal infection and contrasting observations from other insect-fungi interaction studies. We also observed differences in host response depending on the species of entomopathogenic fungi, with significantly higher induction observed during infections with B. bassiana than with C. javanica. Larvae exposed to B. bassiana had an increased expression of genes involved in prophenoloxidase response and the Imd, JNK, and Jak/STAT immune signaling pathways. Our results indicate a notable absence of Toll pathway-related responses, further contrasting results to other insect-fungi pathosystems. Important differences were also observed in the induction of antimicrobial effectors, with B. bassiana infections eliciting three antimicrobial effectors (lysozyme, gloverin, and cecropin), while C. javanica only induced cecropin expression. These results provide insight into the host response strategies employed by T. ni for protection against entomopathogenic fungi and increase our understanding of insect-fungal entomopathogen interactions, aiding in the design of more effective microbial control strategies for this important agricultural pest.
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Affiliation(s)
- Kristin R. Duffield
- USDA-ARS, National Center for Agricultural Utilization Research, Crop BioProtection Research Unit, 1815 N. University St., Peoria, IL 61604, USA; (E.J.M.)
| | | | - Ephantus J. Muturi
- USDA-ARS, National Center for Agricultural Utilization Research, Crop BioProtection Research Unit, 1815 N. University St., Peoria, IL 61604, USA; (E.J.M.)
| | - Robert W. Behle
- USDA-ARS, National Center for Agricultural Utilization Research, Crop BioProtection Research Unit, 1815 N. University St., Peoria, IL 61604, USA; (E.J.M.)
| | - José L. Ramirez
- USDA-ARS, National Center for Agricultural Utilization Research, Crop BioProtection Research Unit, 1815 N. University St., Peoria, IL 61604, USA; (E.J.M.)
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9
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Tan S, Wei H, Camara I, Jia H, Cao K, Shi W. Symbiotic Bacteria System of Locusta migratoria Showed Antifungal Capabilities against Beauveria bassiana. Int J Mol Sci 2023; 24:ijms24043138. [PMID: 36834550 PMCID: PMC9965112 DOI: 10.3390/ijms24043138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 01/26/2023] [Accepted: 02/03/2023] [Indexed: 02/09/2023] Open
Abstract
The stability of symbiotic flora is an important indicator of the health of an organism. Symbiotic bacteria have been proven to be closely involved in the immune process of organisms. The pathogenicity of Beauveria bassiana was studied in relation to symbiotic bacteria on the surface and inside of the migratory locust (Locusta migratoria). The results showed that the surface disinfection of test locusts contributed to the pathogenicity of B. bassiana to locusts. Most of the surface bacteria of L. migratoria caused some inhibition of B. bassiana growth, and LM5-4 (Raoultella ornithinolytica), LM5-2 (Enterobacter aerogenes), and LM5-13 (Citrobacter freundii) showed the highest inhibitory effect on the growth of B. bassiana. The inoculation of locusts with additional surface symbiotic bacteria reduced the virulence of B. bassiana to L. migratoria. Infection by different strains of B. bassiana caused similar changes in the symbiotic flora of migratory locusts. The inoculation of locusts with additional intestinal symbiotic bacteria (Enterobacter sp.) reduced the virulence of B. bassiana to L. migratoria. These findings illustrate the effect of bacterial communities on fungal infections in L. migratoria when seen from the perspective of ecology in a microenvironment. The active antifungal substances of such bacteria and their mechanisms of action need further study.
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Affiliation(s)
- Shuqian Tan
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
- Correspondence: (S.T.); (W.S.)
| | - Hongshuang Wei
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100193, China
| | - Ibrahima Camara
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
- Department of Agriculture, Higher Agricultural and Veterinary Institute of Faranah Guinea, Faranah BP131, Guinea
| | - Haoran Jia
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Kaili Cao
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Wangpeng Shi
- Department of Entomology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing 100193, China
- Correspondence: (S.T.); (W.S.)
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10
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Cytosolic and mitochondrial ribosomal proteins mediate the locust phase transition via divergence of translational profiles. Proc Natl Acad Sci U S A 2023; 120:e2216851120. [PMID: 36701367 PMCID: PMC9945961 DOI: 10.1073/pnas.2216851120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The phase transition from solitary to gregarious locusts is crucial in outbreaks of locust plague, which threaten agricultural yield and food security. Research on the regulatory mechanisms of phase transition in locusts has focused primarily on the transcriptional or posttranslational level. However, the translational regulation of phase transition is unexplored. Here, we show a phase-dependent pattern at the translation level, which exhibits different polysome profiles between gregarious and solitary locusts. The gregarious locusts exhibit significant increases in 60S and polyribosomes, while solitary locusts possess higher peaks of the monoribosome and a specific "halfmer." The polysome profiles, a molecular phenotype, respond to changes in population density. In gregarious locusts, ten genes involved in the cytosolic ribosome pathway exhibited increased translational efficiency (TE). In solitary locusts, five genes from the mitochondrial ribosome pathway displayed increased TE. The high expression of large ribosomal protein 7 at the translational level promotes accumulation of the free 60S ribosomal subunit in gregarious locusts, while solitary locusts employ mitochondrial small ribosomal protein 18c to induce the assembly of mitochondrial ribosomes, causing divergence of the translational profiles and behavioral transition. This study reveals the translational regulatory mechanism of locust phase transition, in which the locusts employ divergent ribosome pathways to cope with changes in population density.
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11
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Glutamate-GABA imbalance mediated by miR-8-5p and its STTM regulates phase-related behavior of locusts. Proc Natl Acad Sci U S A 2023; 120:e2215660120. [PMID: 36574679 PMCID: PMC9910461 DOI: 10.1073/pnas.2215660120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The aggregation of locusts from solitary to gregarious phases is crucial for the formation of devastating locust plagues. Locust management requires research on the prevention of aggregation or alternative and greener solutions to replace insecticide use, and insect-derived microRNAs (miRNAs) show the potential for application in pest control. Here, we performed a genome-wide screen of the differential expression of miRNAs between solitary and gregarious locusts and showed that miR-8-5p controls the γ-aminobutyric acid (GABA)/glutamate functional balance by directly targeting glutamate decarboxylase (Gad). Blocking glutamate-GABA neurotransmission by miR-8-5p overexpression or Gad RNAi in solitary locusts decreased GABA production, resulting in locust aggregation behavior. Conversely, activating this pathway by miR-8-5p knockdown in gregarious locusts induced GABA production to eliminate aggregation behavior. Further results demonstrated that ionotropic glutamate/GABA receptors tuned glutamate/GABA to trigger/hamper the aggregation behavior of locusts. Finally, we successfully established a transgenic rice line expressing the miR-8-5p inhibitor by short tandem target mimic (STTM). When locusts fed on transgenic rice plants, Gad transcript levels in the brain increased greatly, and aggregation behavior was lost. This study provided insights into different regulatory pathways in the phase change of locusts and a potential control approach through behavioral regulation in insect pests.
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12
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Li S, Hao Z, Xu H, Gao Y, Zhang M, Liang J, Dang X. Silencing β-1,3-glucan binding protein enhances the susceptibility of Plutella xylostella to entomopathogenic fungus Isaria cicadae. PEST MANAGEMENT SCIENCE 2022; 78:3117-3127. [PMID: 35442542 DOI: 10.1002/ps.6938] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 03/31/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND The diamondback moth, Plutella xylostella is a notorious pest of brassicaceae crops globally and has developed serious resistance to insecticide. Insects primarily rely on their innate immunity to defense against various pathogens. In this study, we investigated the immunological functions of a β-1,3-glucan binding protein from P. xylostella (PxβGBP) and evaluated its potential for biocontrolling P. xylostella. RESULTS The open reading frame of PxβGBP is 1422 bp encoding 473 amino acids residues. PxβGBP contained a CBM39 domain, a PAC domain and a GH16 domain and shared evolutionary conservation with other lepidoptera βGRPs. PxβGBP was strongly expressed in the third instar larvae and fat body. PxβGBP transcript levels increased significantly after the challenge with microbes, including Isaria cicadae, Escherichia coli and Staphylococcus aureus. PxβGBP was identified in P. xylostella larvae challenged by I cicadae, but not in the naïve insects. Recombinant PxβGBP can directly bind fungal and bacterial cells, and also agglutinate the cells of I cicadae, S. aureus and E coli in a zinc-dependent manner. Knockdown of PxβGBP via RNA interference significantly down-regulated the expression of antimicrobial peptide gene gloverin, and enhanced the susceptibility of P. xylostella to I. cicadae infection, leading to high mortality. CONCLUSION These results indicated that PxβGBP plays an important role in the immune response of P. xylostella against I. cicadae infection, and could serve as a potential novel target for pest control. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Shuangshuang Li
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Zhongping Hao
- Crop Research Institute, Anhui Academy of Agricultural Sciences, Hefei, China
| | - Huihui Xu
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Yan Gao
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Mingyu Zhang
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Jian Liang
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Xiangli Dang
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, School of Plant Protection, Anhui Agricultural University, Hefei, China
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13
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Host–Pathogen Interactions between Metarhizium spp. and Locusts. J Fungi (Basel) 2022; 8:jof8060602. [PMID: 35736085 PMCID: PMC9224550 DOI: 10.3390/jof8060602] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/26/2022] [Accepted: 05/31/2022] [Indexed: 01/27/2023] Open
Abstract
The progress in research on the interactions between Metarhizium spp. and locusts has improved our understanding of the interactions between fungal infection and host immunity. A general network of immune responses has been constructed, and the pathways regulating fungal pathogenicity have also been explored in depth. However, there have been no systematic surveys of interaction between Metarhizium spp. and locusts. The pathogenesis of Metarhizium comprises conidial attachment, germination, appressorial formation, and colonization in the body cavity of the host locusts. Meanwhile, the locust resists fungal infection through humoral and cellular immunity. Here, we summarize the crucial pathways that regulate the pathogenesis of Metarhizium and host immune defense. Conidial hydrophobicity is mainly affected by the contents of hydrophobins and chitin. Appressorial formation is regulated by the pathways of MAPKs, cAMP/PKA, and Ca2+/calmodulin. Lipid droplets degradation and secreted enzymes contributed to fungal penetration. The humoral response of locust is coordinated by the Toll pathway and the ecdysone. The regulatory mechanism of hemocyte differentiation and migration is elusive. In addition, behavioral fever and density-dependent population immunity have an impact on the resistance of hosts against fungal infection. This review depicts a prospect to help us understand host–pathogen interactions and provides a foundation for the engineering of entomopathogenic fungi and the discovery of insecticidal targets to control insect pests.
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14
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piRNA-guided intron removal from pre-mRNAs regulates density-dependent reproductive strategy. Cell Rep 2022; 39:110593. [PMID: 35476998 DOI: 10.1016/j.celrep.2022.110593] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/05/2021] [Accepted: 03/09/2022] [Indexed: 11/23/2022] Open
Abstract
Animal density-dependent experiences have profound effects on reproductive strategies with marked fecundity differences. Migratory locust adopts distinct population density-dependent reproductive strategies to cope with their respective life cycles, but the mechanisms remain poorly understood. Here, we report that Piwi-interacting RNAs (piRNAs) in the locust germline play key roles in this process. We find that the locust Piwi protein Liwi1 and piRNAs are highly expressed in early developing egg chambers in solitarious locusts, which have higher fecundity than gregarious locusts. Approximately 40% of solitarious locust-associated piRNAs map to protein-coding genes. We find that Liwi1/piRNAs facilitate pre-mRNA splicing of oocyte development-related genes, such as oo18 RNA-binding protein (Orb), in the germline by recruiting the splicing factor U2AF35 to piRNA-targeted introns, thereby increasing fecundity. Such piRNA-guided pre-mRNA splicing is also functional in Drosophila and mouse germ cells. We uncover a piRNA-guided splicing mechanism for processing reproduction-related mRNAs and determining animal reproductive strategies.
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15
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Ahmed S, Roy MC, Choi D, Kim Y. HMG-Like DSP1 Mediates Immune Responses of the Western Flower Thrips ( Frankliniella occidentalis) Against Beauveria bassiana, a Fungal Pathogen. Front Immunol 2022; 13:875239. [PMID: 35450074 PMCID: PMC9016178 DOI: 10.3389/fimmu.2022.875239] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Western flower thrips, Frankliella occidentalis, is a serious pest by directly infesting host crops. It can also give indirect damage to host crops by transmitting a plant virus called tomato spotted wilt virus. A fungal pathogen, Beauveria bassiana, can infect thrips. It has been used as a biopesticide. However, little is known on the defense of thrips against this fungal pathogen. This study assessed the defense of thrips against the fungal infection with respect to immunity by analyzing immune-associated genes of F. occidentalis in both larvae and adults. Immunity-associated genes of western flower thrips were selected from three immunity steps: nonself recognition, mediation, and immune responses. For the pathogen recognition step, dorsal switch protein 1 (DSP1) was chosen. For the immune mediation step, phospholipase A2 (PLA2) and prostaglandin E2 synthase were also selected. For the step of immune responses, two phenoloxidases (PO) genes and four proPO-activating peptidase genes involved in melanization against pathogens were chosen. Dual oxidase gene involved in the production of reactive oxygen species and four antimicrobial peptide genes for executing humoral immune responses were selected. All immunity-associated genes were inducible to the fungal infection. Their expression levels were induced higher in adults than in larvae by the fungal infections. However, inhibitor treatments specific to DSP1 or PLA2 significantly suppressed the inducible expression of these immune-associated genes, leading to significant enhancement of fungal pathogenicity. These results suggest that immunity is essential for thrips to defend against B. bassiana, in which DSP1 and eicosanoids play a crucial role in eliciting immune responses.
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Affiliation(s)
- Shabbir Ahmed
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, South Korea
| | - Miltan Chandra Roy
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, South Korea
| | - Duyeol Choi
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, South Korea
| | - Yonggyun Kim
- Department of Plant Medicals, College of Life Sciences, Andong National University, Andong, South Korea
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16
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Chen D, Hou L, Wei J, Guo S, Cui W, Yang P, Kang L, Wang X. Aggregation pheromone 4-vinylanisole promotes the synchrony of sexual maturation in female locusts. eLife 2022; 11:74581. [PMID: 35258453 PMCID: PMC8903828 DOI: 10.7554/elife.74581] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 02/15/2022] [Indexed: 11/13/2022] Open
Abstract
Reproductive synchrony generally occurs in various group-living animals. However, the underlying mechanisms remain largely unexplored. The migratory locust, Locusta migratoria, a worldwide agricultural pest species, displays synchronous maturation and oviposition when forms huge swarm. The reproductive synchrony among group members is critical for the maintenance of locust swarms and population density of next generation. Here, we showed that gregarious female locusts displayed more synchronous sexual maturation and oviposition than solitarious females and olfactory deficiency mutants. Only the presence of gregarious male adults can stimulate sexual maturation synchrony of female adults. Of the volatiles emitted abundantly by gregarious male adults, the aggregation pheromone, 4-vinylanisole, was identified to play key role in inducing female sexual maturation synchrony. This maturation-accelerating effect of 4-vinylanisole disappeared in the females of Or35-/- lines, the mutants of 4-vinylanisole receptor. Interestingly, 4-vinylanisole displayed a time window action by which mainly accelerates oocyte maturation of young females aged at middle developmental stages (3–4 days post adult eclosion). We further revealed that juvenile hormone/vitellogenin pathway mediated female sexual maturation triggered by 4-vinylanisole. Our results highlight a ‘catch-up’ strategy by which gregarious females synchronize their oocyte maturation and oviposition by time-dependent endocrinal response to 4-vinylanisole, and provide insight into reproductive synchrony induced by olfactory signal released by heterosexual conspecifics in a given group. Since 2019, a plague of flying insects known as migratory locusts has been causing extensive damage to crops in East Africa. Migratory locusts sometimes live a solitary lifestyle but, if environmental conditions allow, they form large groups containing millions of individuals known as swarms that are responsible for causing locust plagues.Locusts are able to maintain such large swarms because they can aggregate and synchronize. When they live in swarms, individual locusts produce odors that are sensed by other individuals in the group. For example, an aggregation pheromone, called 4-vinylanisole, is known to help keep large groups of locusts together. However, it is less clear how odors synchronize the reproductive cycles of the females in a swarm so that they are ready to mate with males and lay their eggs at the same time. To address this question, Chen et al. examined when female locusts reached sexual maturity after they were exposed to odors produced by other locusts living alone or in groups. The experiments found that only 4-vinylanisole, which was abundantly released by adult male locusts living in groups, stimulated female locusts to reach sexual maturity at the same time. This odor increased the levels of a hormone known as juvenile hormone in less-developed females to help them reach sexual maturity sooner. These findings demonstrate that when migratory locusts are living in swarms, male locusts promote the female locusts to reach sexual maturity at the same time by promoting less-developed females to ‘catch up’ with other females in the group. A next step will be to investigate the neural and molecular mechanisms underlying the ‘catch up’ effect induced by 4-vinylanisole.
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Affiliation(s)
- Dafeng Chen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Li Hou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Jianing Wei
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Siyuan Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Weichan Cui
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Pengcheng Yang
- Beijing Institutes of Life Sciences, Chinese Academy of Sciences, Beijing, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China.,Beijing Institutes of Life Sciences, Chinese Academy of Sciences, Beijing, China
| | - Xianhui Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
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17
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Variation of TNF modulates cellular immunity of gregarious and solitary locusts against fungal pathogen Metarhizium anisopliae. Proc Natl Acad Sci U S A 2022; 119:2120835119. [PMID: 35110413 PMCID: PMC8833202 DOI: 10.1073/pnas.2120835119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2021] [Indexed: 12/11/2022] Open
Abstract
Ecological immunology addresses the interactions between host immunity and the environment. Locusts display density-dependent phase transitions between solitary and gregarious locusts. In control practices and laboratory bioassays, gregarious locusts always exhibit stronger resistance to fungal pathogens than solitary locusts. However, few studies have investigated the mechanism of altered immune switch in locusts. Here, we combined mathematical simulation and experimental studies to show that gregarious locusts inhibit tumor necrosis factor (TNF) to alter immune defense by enhancing humoral defense and reducing cellular defense, and high levels of TNF reduce the survival of solitary locusts. Our study provides an important cue for understanding cellular immunity variations in response to different population densities and for improving the control efficacy of locust plagues. Changes in population density lead to phenotypic differentiation of solitary and gregarious locusts, which display different resistance to fungal pathogens; however, how to regulate their cellular immune strategies remains unknown. Here, our stochastic simulation of pathogen proliferation suggested that humoral defense always enhanced resistance to fungal pathogens, while phagocytosis sometimes reduced defense against pathogens. Further experimental data proved that gregarious locusts had significantly decreased phagocytosis of hemocytes compared to solitary locusts. Additionally, transcriptional analysis showed that gregarious locusts promoted immune effector expression (gnbp1 and dfp) and reduced phagocytic gene expression (eater) and the cytokine tumor necrosis factor (TNF). Interestingly, higher expression of the cytokine TNF in solitary locusts simultaneously promoted eater expression and inhibited gnbp1 and dfp expression. Moreover, inhibition of TNF increased the survival of solitary locusts, and injection of TNF decreased the survival of gregarious locusts after fungal infection. Therefore, our results indicate that the alerted expression of TNF regulated the immune strategy of locusts to adapt to environmental changes.
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18
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Mayekar HV, Kodandaramaiah U. Effect of density on pupal colour plasticity in the butterfly
Mycalesis mineus
(Lepidoptera, Nymphalidae). J Zool (1987) 2021. [DOI: 10.1111/jzo.12950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- H. V. Mayekar
- IISER‐TVM Centre for Research and Education in Ecology and Evolution (ICREEE) School of Biology Indian Institute of Science Education and Research Thiruvananthapuram Thiruvananthapuram Kerala India
| | - U. Kodandaramaiah
- IISER‐TVM Centre for Research and Education in Ecology and Evolution (ICREEE) School of Biology Indian Institute of Science Education and Research Thiruvananthapuram Thiruvananthapuram Kerala India
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19
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Li H, Dai C, Zhu Y, Hu Y. Larvae Crowding Increases Development Rate, Improves Disease Resistance, and Induces Expression of Antioxidant Enzymes and Heat Shock Proteins in Mythimna separata (Lepidoptera: Noetuidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2021; 114:1808-1816. [PMID: 34104958 DOI: 10.1093/jee/toab105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Indexed: 06/12/2023]
Abstract
High population density (crowding) becomes a stress factor in insects. The oriental armyworm, Mythimna separata (Walker), displays gregarious and solitary phases at high and low population densities, respectively. In this study, we compared life history, disease resistance, and induction of antioxidant enzymes and heat shock protein (HSPs) in two phases of M. separata larvae. Results showed that gregarious larvae had a faster growth rate and lower pupal weight compared to solitary larvae. Furthermore, gregarious individuals exhibited higher survival rates than solitary individuals after Beauveria bassiana infection. The gregarious larvae had higher malondialdehyde content compared to solitary ones, but no differences in total antioxidant capacity were observed between the two larval phases before or after infection. Superoxide dismutase and glutathione peroxidase activities were significantly lower in gregarious M. separata larvae than solitary individuals before infection, but no difference was detected in two phases after infection. However, peroxidase and catalase activities in the two phases showed no difference either before or after infection. Hsp19.8 and Hsp90 expression in gregarious larvae were up-regulated when compared to solitary individuals before or after infection. CuZnSOD expression was not different between the two phases before infection, but it was up-regulated in gregarious ones compared to solitary ones after infection. However, expression of other stress-related genes in gregarious larvae was either repressed or unchanged when compared to solitary individuals before or after infection. Thus, larval crowding changed life history, improved disease resistance of M. separata larvae, and induced variable response of antioxidant enzymes and HSPs to fungal infection.
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Affiliation(s)
- Hongbo Li
- Institute of Plant Protection, Guizhou Academy of Agricultural Sciences, Guiyang, Guizhou, China
| | - Changgeng Dai
- Institute of Plant Protection, Guizhou Academy of Agricultural Sciences, Guiyang, Guizhou, China
| | - Yi Zhu
- Guizhou Station of Plant Protection and Quarantine, Guiyang, Guizhou, China
| | - Yang Hu
- Institute of Plant Protection, Guizhou Academy of Agricultural Sciences, Guiyang, Guizhou, China
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20
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Wang Y, Xie X, Qin L, Yu D, Wang Z, Huang B. Integration of dsRNA against host immune response genes augments the virulence of transgenic Metarhizium robertsii strains in insect pest species. Microb Biotechnol 2021; 14:1433-1444. [PMID: 33459518 PMCID: PMC8313288 DOI: 10.1111/1751-7915.13748] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 12/20/2020] [Accepted: 12/29/2020] [Indexed: 11/28/2022] Open
Abstract
The slow lethality of fungal biopesticides to insects restrains their widespread application as a strategy of pest control. In this study, unary, binary and ternary transgenic Metarhizium robertsii were created by integrating genes that encode the scorpion neurotoxin BjαIT, the cuticle-degrading protease Pr1A, and a double-stranded RNA (dsRNA) that targets host gnbp3, individually or collectively under a constitutive promoter to enhance virulence. Compared with the parental wild type, all unary transgenic strains had increased virulence against four insect species, Tenebrio molitor, Locusta migratoria, Plutella xylostella and Galleria mellonella, whereas the binary transgenic strain expressing both pr1A and BjαIT had increased virulence to T. molitor and L. migratoria, with no change in virulence against P. xylostella and G. mellonella. Importantly, all ternary transgenic strains simultaneously expressing pr1A, BjαIT, and the dsRNA specific to host gnbp3 exhibited the highest increase in insect-specific virulence. This finding highlights a novel strategy for genetic engineering of dsRNAs that target genes associated with the host immune response alongside virulence genes to maximize fungal virulence and lethality against insect pests.
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Affiliation(s)
- Yulong Wang
- Anhui Provincial Key Laboratory of Microbial Pest ControlAnhui Agricultural UniversityHefei230036China
| | - Xiangyun Xie
- Anhui Provincial Key Laboratory of Microbial Pest ControlAnhui Agricultural UniversityHefei230036China
| | - Li Qin
- Anhui Provincial Key Laboratory of Microbial Pest ControlAnhui Agricultural UniversityHefei230036China
| | - Deshui Yu
- Anhui Provincial Key Laboratory of Microbial Pest ControlAnhui Agricultural UniversityHefei230036China
| | - Zhangxun Wang
- Anhui Provincial Key Laboratory of Microbial Pest ControlAnhui Agricultural UniversityHefei230036China
- School of Plant ProtectionAnhui Agricultural UniversityHefei230036China
| | - Bo Huang
- Anhui Provincial Key Laboratory of Microbial Pest ControlAnhui Agricultural UniversityHefei230036China
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21
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Guo S, Yang P, Liang B, Zhou F, Hou L, Kang L, Wang X. Aging features of the migratory locust at physiological and transcriptional levels. BMC Genomics 2021; 22:257. [PMID: 33838645 PMCID: PMC8037904 DOI: 10.1186/s12864-021-07585-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/05/2021] [Indexed: 12/13/2022] Open
Abstract
Background Non-Drosophila insects provide diverse aging types and important complementary systems for studies of aging biology. However, little attention has been paid to the special roles of non-Drosophila insects in aging research. Here, the aging-related features of the migratory locust, Locusta migratoria, were determined at the physiological, cellular, and transcriptional levels. Results In physiological assessments, the flight performance and sperm state of locusts displayed clear aging-related decline in male adults. Transcriptional analyses demonstrated locusts have similar aging-related genes with model species. However, different from those of Drosophila and mammals, the organ-specific aging transcriptional features of locusts were characterized by intensive expression changes in flight muscle and fat body and little transcriptional changes in brain. The predominant transcriptional characteristics of flight muscle and fat body aging were changes in expression of mitochondrion-related genes and detoxification and phagocytosis genes, respectively. Cellular assessments revealed the incidence of mitochondrial abnormalities significantly increased in aged flight muscle, and apoptotic signals and nuclear abnormalities were enhanced in aged fat body but not in brain. In addition, some well-known aging genes and locust aging-related genes (i.e., IAP1, PGRP-SA, and LIPT1), whose roles in aging regulation were rarely reported, were demonstrated to affect lifespan, metabolism, and flight ability of locusts after RNAi. Conclusion This study revealed multi-level aging signatures of locust, thus laying a foundation for further investigation of aging mechanisms in this famous insect in the future. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07585-3.
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Affiliation(s)
- Siyuan Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Pengcheng Yang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China
| | - Bo Liang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Feng Zhou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Li Hou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China. .,Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Xianhui Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, 100049, China.
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22
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Li S, Xu C, Du G, Wang G, Tu X, Zhang Z. Synergy in Efficacy of Artemisia sieversiana Crude Extract and Metarhizium anisopliae on Resistant Oedaleus asiaticus. Front Physiol 2021; 12:642893. [PMID: 33828488 PMCID: PMC8019718 DOI: 10.3389/fphys.2021.642893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/26/2021] [Indexed: 11/13/2022] Open
Abstract
In order to explore the synergistic control effect of crude extracts of Artemisia sieversiana and Metarhizium anisopliae on Oedaleus asiaticus, we used different doses of M. anisopliae and crude extracts of A. sieversiana singly and in combination, to determine their toxicities to fourth instar O. asiaticus. The results showed that the combination of 10% crude extract of A. sieversiana with 107 and 108 spores/g M. anisopliae concentrations and the combination of 20% crude extract of A. sieversiana with 107 and 108 spores/g M. anisopliae concentrations had significant effects on the mortality, body weight gain, body length gain, growth rate, and overall performance of O. asiaticus than those of the crude extract of A. sieversiana and M. anisopliae alone. Among them, the 20% A. sieversiana crude extract mixed with 108 spores/g M. anisopliae and 10% A. sieversiana crude extract combined with 107 spores/g M. anisopliae, had the best control efficacy. In order to clarify the biochemical mechanism underlying the immune responses of O. asiaticus to the pesticide treatments, we monitored the activities of four enzymes: superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT), and polyphenol oxidase (PPO). The results showed that the activities of three enzymes (SOD, CAT, and PPO) were significantly increased from the treatment with the combination of M. anisopliae mixed with crude extract of A. sieversiana. Interestingly, compared to the crude extract, the combination treatment did not significantly induce the expression of POD enzyme activity, which may be a biochemical factor for increasing the control effect of the combination treatment. Our results showed that the combination treatment had synergistic and antagonistic effects on host mortality, growth, development, and enzyme activities in O. asiaticus.
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Affiliation(s)
- Shuang Li
- State Key Laboratory of Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Scientific Observation and Experimental Station of Pests in Xilin Gol Rangeland, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Xilinhot, China
| | - Chaomin Xu
- State Key Laboratory of Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Scientific Observation and Experimental Station of Pests in Xilin Gol Rangeland, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Xilinhot, China
| | - Guilin Du
- National Animal Husbandry Service, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Guangjun Wang
- State Key Laboratory of Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Scientific Observation and Experimental Station of Pests in Xilin Gol Rangeland, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Xilinhot, China
| | - Xiongbing Tu
- State Key Laboratory of Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Scientific Observation and Experimental Station of Pests in Xilin Gol Rangeland, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Xilinhot, China
| | - Zehua Zhang
- State Key Laboratory of Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.,Scientific Observation and Experimental Station of Pests in Xilin Gol Rangeland, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Xilinhot, China
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Tong X, Wang Y, Li J, Hu S, Yang P, Kang L. Transformation of glycerate kinase (GLYK) into Metarhizium acridum increases virulence to locust. PEST MANAGEMENT SCIENCE 2021; 77:1465-1475. [PMID: 33128436 DOI: 10.1002/ps.6165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/01/2020] [Accepted: 10/31/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Improvements in the virulence of the fungal pathogen Metarhizium acridum can crucially promote its efficacy to control locusts and grasshoppers. The polysaccharide components of the cell wall remarkably contribute to fungal virulence. RESULTS Here we found that M. acridum lacked the gene families of glycerate-3-kinase (GLYK) as the synthesis enzymes of saccharides. We then generated mutants by introducing the GLYK gene from the host-generalist M. robertsii into the host-specialist M. acridum. Consequently, compared with the wild-type strain, the mutant strain (Ma::MrGLYK) increased the level of phospho-6-fructose in mycelia, the length and density of the mannan fibril layer on the cell wall. The mutant strains increased the mannan fibril in the cell wall and resistance to heat stress. Further transcriptome analysis showed that compared with the wild-type strain, topical infection of Ma::MrGLYK strain induced higher expression of genes such as pattern-recognition proteins, serine protease, and CYP450s in locusts, while reduced the expression of antimicrobial peptide and phenoloxidase activity. Moreover, topical infection and injection of Ma::MrGLYK significantly increased the mortality and shortened the lifespan of locusts compared with wild-type M. acridum. CONCLUSION Our study highlighted the application potential of the novel genetically modified fungal mutant of the host-specialist M. acridum as a biocontrol agent against locust plagues. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Xiwen Tong
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Yundan Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Juan Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Shuai Hu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Pengcheng Yang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
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Zhao L, Guo W, Jiang F, He J, Liu H, Song J, Yu D, Kang L. Phase-related differences in egg production of the migratory locust regulated by differential oosorption through microRNA-34 targeting activinβ. PLoS Genet 2021; 17:e1009174. [PMID: 33406121 PMCID: PMC7787450 DOI: 10.1371/journal.pgen.1009174] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/06/2020] [Indexed: 12/02/2022] Open
Abstract
Outbreaks of locust plagues result from the long-term accumulation of high-density egg production. The migratory locust, Locusta migratoria, displays dramatic differences in the egg-laid number with dependence on population density, while solitarious locusts lay more eggs compared to gregarious ones. However, the regulatory mechanism for the egg-laid number difference is unclear. Herein, we confirm that oosorption plays a crucial role in the regulation of egg number through the comparison of physiological and molecular biological profiles in gregarious and solitarious locusts. We find that gregarious oocytes display a 15% higher oosorption ratio than solitarious ones. Activinβ (Actβ) is the most highly upregulated gene in the gregarious terminal oocyte (GTO) compared to solitarious terminal oocyte (STO). Meanwhile, Actβ increases sharply from the normal oocyte (N) to resorption body 1 (RB1) stage during oosorption. The knockdown of Actβ significantly reduces the oosorption ratio by 13% in gregarious locusts, resulting in an increase in the egg-laid number. Based on bioinformatic prediction and experimental verification, microRNA-34 with three isoforms can target Actβ. The microRNAs display higher expression levels in STO than those in GTO and contrasting expression patterns of Actβ from the N to RB1 transition. Overexpression of each miR-34 isoform leads to decreased Actβ levels and significantly reduces the oosorption ratio in gregarious locusts. In contrast, inhibition of the miR-34 isoforms results in increased Actβ levels and eventually elevates the oosorption ratio of solitarious locusts. Our study reports an undescribed mechanism of oosorption through miRNA targeting of a TGFβ ligand and provides new insights into the mechanism of density-dependent reproductive adaption in insects. The continuous accumulation of high-density eggs laid by flying swarms of adults results in huge populations of flightless juveniles, which contributes to the outbreaks of locust plagues. An interesting phenomenon is that locusts have the phenotypic plasticity of reproduction. The gregarious locusts lay fewer big eggs than do solitarious phase locusts. In contrast, the solitarious phase locusts lay more small eggs compared to the gregarious locusts. We find the egg-laid number is not only regulated by the phase status of parents but also controlled by oosorption, a type of oocyte death. Further studies confirmed the phase-related ratio of oocyte death in the mother is regulated by a microRNA, which posttranscriptionally influences the expression level of a TGFβ ligand. This maternal effect on progeny size is especially critical for gregarious locusts to control the population size and maintain population fitness, and for solitarious locusts to enhance chance for gregarization and further enlargement of population size. This is the first study to reveal the molecular mechanism underlying the regulation of a microRNA-gene circuit for locust oocyte death to determine the offspring number. These findings can provide some important clues to develop potential drugs to prevent vast locust reproduction from a plague upsurge.
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Affiliation(s)
- Lianfeng Zhao
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Wei Guo
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Feng Jiang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Jing He
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Hongran Liu
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Juan Song
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Dan Yu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Le Kang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Kong H, Liu Z, Yang P, Yuan L, Jing W, Dong C, Zheng M, Tian Z, Hou Q, Zhu S. Effects of Larval Density on Plutella xylostella Resistance to Granulosis Virus. INSECTS 2020; 11:insects11120857. [PMID: 33276568 PMCID: PMC7761614 DOI: 10.3390/insects11120857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 11/29/2020] [Accepted: 11/30/2020] [Indexed: 11/16/2022]
Abstract
Simple Summary Generally, the transmission of pathogens is positively density-dependent; therefore, the risk of insects becoming infected by diseases increases with increasing population density. It has been reported that some phase-polyphenic insects from high-density conditions are more resistant (or susceptible or identical) to pathogens than those from low-density conditions. This phenomenon is termed “density-dependent prophylaxis” (DDP). The diamondback moth (DBM), Plutella xylostella, one of the most destructive insect pests affecting cruciferous crops, is non phase-polyphenic. Biological control, especially by pathogens, plays an important role in the integrated pest management program of DBM. However, whether the P. xylostella larval population exhibits DDP has not been elucidated. The resistance of DBM larvae to P. xylostella granulosis virus (Plxy GV) and their immune response to the virus under different density treatments were investigated under laboratory conditions. Our results demonstrated that P. xylostella larvae exhibited DDP within a certain limited density. This study may help to elucidate the biocontrol effect of different density populations of P. xylostella by granulosis virus and guide improvements in future management strategy. Abstract It has been reported that some phase-polyphenic insects from high-density conditions are more resistant to pathogens than those from low-density conditions. This phenomenon is termed “density-dependent prophylaxis” (DDP). However, whether non phase-polyphenic insects exhibit DDP has rarely been elucidated. The diamondback moth (DBM), Plutella xylostella, one of the most destructive insect pests affecting cruciferous crops, is non phase-polyphenic. In this study, the resistance of DBM larvae to P. xylostella granulosis virus (Plxy GV) and their immune response to the virus when reared at densities of 1, 2, 5, 10, 15, and 20 larvae per Petri dish were investigated under laboratory conditions. Compared with larvae reared at lower densities, larvae reared at moderate density showed a significantly higher survival rate, but the survival rate significantly decreased with further increases in rearing density. Furthermore, the phenoloxidase, lysozyme and antibacterial activity and total hemocyte count in the hemolymph of the larvae, regardless of whether they were challenged with the virus, from different larval densities corresponded to the observed differences in resistance to Plxy GV. These results demonstrated that P. xylostella larvae exhibited DDP within a certain limited density. This study may help to elucidate the biocontrol effect of different density populations of P. xylostella by granulosis virus and guide improvements in future management strategy.
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Affiliation(s)
- Hailong Kong
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
- Correspondence: ; Tel.: +86-514-8797-8110
| | - Zhonglin Liu
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
| | - Pingjun Yang
- Suzhou Plant Protection and Plant Quarantine Station, Stadium Road, NO. 4, Suzhou 215006, China;
| | - Lin Yuan
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
| | - Wanghui Jing
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
| | - Chuanlei Dong
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
| | - Minyuan Zheng
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
| | - Zhen Tian
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
| | - Qiuli Hou
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
| | - Shude Zhu
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou 225009, China; (Z.L.); (L.Y.); (W.J.); (C.D.); (M.Z.); (Z.T.); (Q.H.); (S.Z.)
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Kong H, Yuan L, Dong C, Zheng M, Jing W, Tian Z, Hou Q, Cheng Y, Zhang L, Jiang X, Luo L. Immunological regulation by a β-adrenergic-like octopamine receptor gene in crowded larvae of the oriental Armyworm, Mythmina separata. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 113:103802. [PMID: 32712170 DOI: 10.1016/j.dci.2020.103802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 07/14/2020] [Accepted: 07/14/2020] [Indexed: 06/11/2023]
Abstract
Recent reports demonstrate that octopamine plays an important immunological role in crowded larvae of the Oriental Armyworm, Mythmina separata. We identified an octopamine receptor, the β-adrenergic-like gene (designated MsOctβ2R), with a 1191 bp open reading frame that encodes 396 amino acids and contains seven conserved hydrophobic transmembrane domains. Multiple sequence alignments and a phylogenetic analysis indicated that MsOctβ2R was orthologous to Octβ2R that is present in other lepidopterans. MsOctβ2R was expressed throughout all developmental stages with higher relative expression during the fourth instar and adult stages. MsOctβ2R was highly expressed in the ventral nerve cord and the fat body relative to other examined tissues. Elevated MsOctβ2R expression was observed in larvae that were under higher-density conditions (7 and 10 larvae per jar). Silencing MsOctβ2R expression via dsRNA injections in larvae from higher-density conditions significantly decreased phenoloxidase (PO) and lysozyme activity, total haemocyte counts, and survival rates against Beauveria bassiana infections (54.06%, 9.91%, 36.22%, and 23.53%, respectively) when compared with control larvae. These results suggest that high-density conditions might alter prophylactic immunity in larvae by regulating the MsOctβ2R gene in M. separara and provide new insights into density-dependent prophylaxis in insects.
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Affiliation(s)
- Hailong Kong
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China.
| | - Lin Yuan
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Chuanlei Dong
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Minyuan Zheng
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Wanghui Jing
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Zhen Tian
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Qiuli Hou
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Yunxia Cheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, No. 2, Beijing, 100193, China
| | - Lei Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, No. 2, Beijing, 100193, China
| | - Xingfu Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, No. 2, Beijing, 100193, China.
| | - Lizhi Luo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, No. 2, Beijing, 100193, China
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Guo X, Yu Q, Chen D, Wei J, Yang P, Yu J, Wang X, Kang L. 4-Vinylanisole is an aggregation pheromone in locusts. Nature 2020; 584:584-588. [DOI: 10.1038/s41586-020-2610-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 06/26/2020] [Indexed: 11/09/2022]
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Zhang S, Shen S, Yang Z, Kong X, Liu F, Zhen Z. Coding and Non-coding RNAs: Molecular Basis of Forest-Insect Outbreaks. Front Cell Dev Biol 2020; 8:369. [PMID: 32596236 PMCID: PMC7300193 DOI: 10.3389/fcell.2020.00369] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/24/2020] [Indexed: 12/19/2022] Open
Abstract
Insect population dynamics are closely related to 'human' ecological and economic environments, and a central focus of research is outbreaks. However, the lack of molecular-based investigations restricts our understanding of the intrinsic mechanisms responsible for insect outbreaks. In this context, the moth Dendrolimus punctatus Walker can serve as an ideal model species for insect population dynamics research because it undergoes periodic outbreaks. Here, high-throughput whole-transcriptome sequencing was performed using D. punctatus, sampled during latent and outbreak periods, to systemically explore the molecular basis of insect outbreaks and to identify the involved non-coding RNA (ncRNA) regulators, namely microRNAs, long non-coding RNAs, and circular RNAs. Differentially expressed mRNAs of D. punctatus from different outbreak periods were involved in developmental, reproductive, immune, and chemosensory processes; results that were consistent with the physiological differences in D. punctatus during differing outbreak periods. Targets analysis of the non-coding RNAs indicated that long non-coding RNAs could be the primary ncRNA regulators of D. punctatus outbreaks, while circular RNAs mainly regulated synapses and cell junctions. The target genes of differentially expressed microRNAs mainly regulated the metabolic and reproductive pathways during the D. punctatus outbreaks. Developmental, multi-organismal, and reproductive processes, as well as biological adhesion, characterized the competing endogenous RNA network. Chemosensory and immune genes closely related to the outbreak of D. punctatus were further analyzed in detail: from their ncRNA regulators' analysis, we deduce that both lncRNA and miRNA may play significant roles. This is the first report to examine the molecular basis of coding and non-coding RNAs' roles in insect outbreaks. The results provide potential biomarkers for control targets in forest insect management, as well as fresh insights into underlying outbreak-related mechanisms, which could be used for improving insect control strategies in the future.
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Affiliation(s)
- Sufang Zhang
- Key Laboratory of Forest Protection of State Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China
| | - Sifan Shen
- Key Laboratory of Forest Protection of State Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China
| | - Zhongwu Yang
- Forestry Comprehensive Development Center of Guilin, Guilin, China
| | - Xiangbo Kong
- Key Laboratory of Forest Protection of State Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China
| | - Fu Liu
- Key Laboratory of Forest Protection of State Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China
| | - Zhang Zhen
- Key Laboratory of Forest Protection of State Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, China
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Zhang W, Keyhani NO, Zhang H, Cai K, Xia Y. Inhibitor of apoptosis-1 gene as a potential target for pest control and its involvement in immune regulation during fungal infection. PEST MANAGEMENT SCIENCE 2020; 76:1831-1840. [PMID: 31821720 DOI: 10.1002/ps.5712] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 12/04/2019] [Accepted: 12/07/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Environmentally friendly insect management technologies, including RNA interference (RNAi) and entomopathogenic fungi, have attracted increasing attention as options for pest control. Here, we sought to extend RNAi-directed targeting of the inhibitor of apoptosis protein 1 (IAP1) gene to the locust, and to examine its relationship to immune responses and susceptibility to Metarhizium acridum, a locust-specific fungal pathogen. RESULTS Expression of the locust LmIAP gene was induced in the hemolymph and fat body after M. acridum infection. RNAi-directed silencing of locust LmIAP1 resulted in increased caspase 3 activity, degeneration of the gut and dose-dependent mortality. Synergistic mortality was seen in RNAi-LmIAP/fungal co-infection experiments with median survival time (MST) values decreasing from ∼ 5 days for RNAi and M. acridum treatments alone, to 2.6 days for co-treatments. Reduced hemocyte numbers and antimicrobial peptide levels were seen in co-treated locusts, with changes in gut opportunistic pathogenic bacteria seen between treatments. Enhanced fungal sporulation on co-treated insect cadavers was also compared with fungal infection alone. CONCLUSIONS Silencing of the locust LmIAP1 gene results in direct mortality and increases insect susceptibility to insect fungal pathogens, in part by decreasing immunity and altering the gut microbiome. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Wei Zhang
- School of Life Sciences, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing University, Chongqing, China
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Nemat O Keyhani
- School of Life Sciences, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing University, Chongqing, China
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Hao Zhang
- School of Life Sciences, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing University, Chongqing, China
| | - Kaiyong Cai
- Bioengineering College of Chongqing University, Chongqing, China
| | - Yuxian Xia
- School of Life Sciences, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing University, Chongqing, China
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Zhang X, Xu Y, Chen B, Kang L. Long noncoding RNA PAHAL modulates locust behavioural plasticity through the feedback regulation of dopamine biosynthesis. PLoS Genet 2020; 16:e1008771. [PMID: 32348314 PMCID: PMC7241820 DOI: 10.1371/journal.pgen.1008771] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/21/2020] [Accepted: 04/09/2020] [Indexed: 11/24/2022] Open
Abstract
Some long noncoding RNAs (lncRNAs) are specifically expressed in brain cells, implying their neural and behavioural functions. However, how lncRNAs contribute to neural regulatory networks governing the precise behaviour of animals is less explored. Here, we report the regulatory mechanism of the nuclear-enriched lncRNA PAHAL for dopamine biosynthesis and behavioural adjustment in migratory locusts (Locusta migratoria), a species with extreme behavioral plasticity. PAHAL is transcribed from the sense (coding) strand of the gene encoding phenylalanine hydroxylase (PAH), which is responsible for the synthesis of dopamine from phenylalanine. PAHAL positively regulates PAH expression resulting in dopamine production in the brain. In addition, PAHAL modulates locust behavioral aggregation in a population density-dependent manner. Mechanistically, PAHAL mediates PAH transcriptional activation by recruiting serine/arginine-rich splicing factor 2 (SRSF2), a transcription/splicing factor, to the PAH proximal promoter. The co-activation effect of PAHAL requires the interaction of the PAHAL/SRSF2 complex with the promoter-associated nascent RNA of PAH. Thus, the data support a model of feedback modulation of animal behavioural plasticity by an lncRNA. In this model, the lncRNA mediates neurotransmitter metabolism through orchestrating a local transcriptional loop. The neurotransmitter dopamine is crucial for the neuronal and behavioral response in animals. Phenylalanine hydroxylase (PAH) is involved in dopamine biosynthesis and behavioral regulation in the migratory locust. However, the molecular mechanism for the fine tuning of PAH expression in behavioral response remains ambiguous. Here we discovered a nuclear-enriched lncRNA PAHAL that is transcribed from the coding strand of the PAH gene in the locust (i.e., sense lncRNA). PAHAL positively regulated PAH expression and dopamine production in the brain. In addition, PAHAL modulated behavioral aggregation of the locust. Mechanistically, PAHAL mediated the transcriptional activation of PAH by recruiting SRSF2, a transcription/splicing factor, to the promoter-associated nascent RNA of PAH. These data support a model of feedback modulation of dopamine biosynthesis and behavioral plasticity via a sense lncRNA in the catecholamine metabolic pathway.
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Affiliation(s)
- Xia Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Beijing Institute of Life Sciences, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
| | - Ya'nan Xu
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Bing Chen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, Hebei University, Baoding, China
- * E-mail: (BC); (KL)
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Beijing Institute of Life Sciences, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing, China
- College of Life Sciences, Hebei University, Baoding, China
- * E-mail: (BC); (KL)
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Tong X, Wang Y, Yang P, Wang C, Kang L. Tryptamine accumulation caused by deletion of MrMao-1 in Metarhizium genome significantly enhances insecticidal virulence. PLoS Genet 2020; 16:e1008675. [PMID: 32271756 PMCID: PMC7173932 DOI: 10.1371/journal.pgen.1008675] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 04/21/2020] [Accepted: 02/17/2020] [Indexed: 02/06/2023] Open
Abstract
Metarhizium is a group of insect-pathogenic fungi that can produce insecticidal metabolites, such as destruxins. Interestingly, the acridid-specific fungus Metarhizium acridum (MAC) can kill locusts faster than the generalist fungus Metarhizium robertsii (MAA) even without destruxin. However, the underlying mechanisms of different pathogenesis between host-generalist and host-specialist fungi remain unknown. This study compared transcriptomes and metabolite profiles to analyze the difference in responsiveness of locusts to MAA and MAC infections. Results confirmed that the detoxification and tryptamine catabolic pathways were significantly enriched in locusts after MAC infection compared with MAA infection and that high levels of tryptamine could kill locusts. Furthermore, tryptamine was found to be capable of activating the aryl hydrocarbon receptor of locusts (LmAhR) to produce damaging effects by inducing reactive oxygen species production and immune suppression. Therefore, reducing LmAhR expression by RNAi or inhibitor (SR1) attenuates the lethal effects of tryptamine on locusts. In addition, MAA, not MAC, possessed the monoamine oxidase (Mao) genes in tryptamine catabolism. Hence, deleting MrMao-1 could increase the virulence of generalist MAA on locusts and other insects. Therefore, our study provides a rather feasible way to design novel mycoinsecticides by deleting a gene instead of introducing any exogenous gene or domain. Mycoinsecticides are widely used in place of chemical pesticides to protect crops from pest damage. Metarhizium spp. fungi specifically live inside the body cavity of insects and can produce insecticidal metabolites, such as beauvericin, destruxins, and taxol. The variable virulence between host-generalist fungus Metarhizium robertsii (MAA) and host-specialist fungus Metarhizium acridum (MAC) to locusts was studied. We found that MAC is more virulent than MAA on locusts, and MAC-infected locusts display higher amounts of tryptamine than do MAA-infected locusts. Furthermore, MAC cannot produce destruxins, but can produce abundant tryptamine to kill locusts when accumulated owing to the absence of a gene for tryptamine catabolism in the MAC genome. Tryptamine activates the aryl hydrocarbon receptor of locusts (LmAhR) that produces damaging effects by regulating reactive oxygen species production and suppressing the immune system of locusts. Therefore, the deletion of MrMao-1 in the generalist fungus MAA significantly improves the virulence of the fungus to locusts and other insect species. The resulting new insights into the core metabolism of high virulence of host-specialist fungus can provide an improved basis for designing mycoinsecticide strains.
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Affiliation(s)
- Xiwen Tong
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yundan Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Pengcheng Yang
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Chengshu Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Zhang W, Zheng X, Chen J, Keyhani NO, Cai K, Xia Y. Spatial and temporal transcriptomic analyses reveal locust initiation of immune responses to Metarhizium acridum at the pre-penetration stage. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 104:103524. [PMID: 31634520 DOI: 10.1016/j.dci.2019.103524] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 10/14/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
Insect hemocyte and fat body tissues play critical functional roles in insect immunity. Little, however, is known concerning the dynamic responses of these tissues to fungal infection. Here, we report on a time course of locust hemocyte and fat body transcriptomic responses to infection by the acridid specific fungal pathogen, Metarhizium acridum. Fat body responses were more pronounced at all infection stages as compared to hemocytes. Immune and other related genes were induced far earlier than previously considered including at pre-penetration stages. Differential expression in hemocyte and fat body tissues persisted throughout the course of infection up until host death. Our data indicate selective pressure on the host to recognize the infection as early as possible in order to limit its spread. Overall, fat body and hemocyte tissues launch a robust multi-tiered response to combat the fungal pathogen, with our data providing potential host targets for exploitation in pest control.
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Affiliation(s)
- Wei Zhang
- School of Life Sciences, Chongqing University, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 400030, China; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Bldg. 981, Museum Rd, Gainesville, FL32611, USA.
| | - Xiaoli Zheng
- School of Life Sciences, Chongqing University, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 400030, China; College of Preclinical Medicine, Southwest Medical University, Luzhou, 646000, PR China.
| | - Jianhong Chen
- School of Life Sciences, Chongqing University, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 400030, China.
| | - Nemat O Keyhani
- School of Life Sciences, Chongqing University, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 400030, China; Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Bldg. 981, Museum Rd, Gainesville, FL32611, USA.
| | - Kaiyong Cai
- School of Life Sciences, Chongqing University, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 400030, China.
| | - Yuxian Xia
- School of Life Sciences, Chongqing University, Chongqing Engineering Research Center for Fungal Insecticides, Chongqing, 400030, China.
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Ren D, Guo W, Yang P, Song J, He J, Zhao L, Kang L. Structural and functional differentiation of a fat body-like tissue adhering to testis follicles facilitates spermatogenesis in locusts. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 113:103207. [PMID: 31421206 DOI: 10.1016/j.ibmb.2019.103207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/27/2019] [Accepted: 07/28/2019] [Indexed: 06/10/2023]
Abstract
The fat body is distributed throughout the body of insects, playing the essential role in intermediary metabolism and nutrient storage. However, the function of differentiation of fat bodies adhering to different tissues remains largely unknown. Here, we identified a fat body-like tissue (FLT) surrounding testis follicles and described its features at morphological, cellular and molecular levels. The FLT is morphologically distinguished with the abdominal fat body (FB) and dominated by diploid cells instead of polyploid cells. The transcriptomic analysis demonstrated that the FLT and FB have dramatically different gene expression profiles. Moreover, genes in the cell cycle pathway, which include both DNA replication- and cell division-related genes, were successively active during development of the FLT, suggesting that FLT cells possibly undergo a mitotic cycle rather than an endocycle. Deprivation of the FLT resulted in distortion of the testis follicles, disappearance of sperm bundles, reduction of total sperm number and increase of dead sperm, indicating a critical role of the FLT in the spermatogenesis in testis follicles. The special functional differentiation of the two similar tissues suggested that FLT-FB cells are able to establish a promising system to study mitotic-to-endocycle transition.
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Affiliation(s)
- Dani Ren
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Wei Guo
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Pengcheng Yang
- Beijing Institute of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Juan Song
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jing He
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Lianfeng Zhao
- Beijing Institute of Life Science, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China; Beijing Institute of Life Science, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
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Li HB, Dai CG, He YF, Hu Y. Characterization and Expression of Genes Encoding Superoxide Dismutase in the Oriental Armyworm, Mythimna separata (Lepidoptera: Noctuidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2019; 112:2381-2388. [PMID: 31219570 DOI: 10.1093/jee/toz163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Indexed: 06/09/2023]
Abstract
Superoxide dismutase (SOD) is an antioxidant metalloenzyme that catalyzes the dismutation of the superoxide anion O2- to O2 and H2O2. Many studies have focused on the role of SOD in response to abiotic stress, but its role during biotic stress, such as changes in organismal population density, has rarely been investigated. The oriental armyworm, Mythimna separata, is an economically important pest that exhibits phenotypic changes in response to population density. Solitary and gregarious phases occur at low and high population density, respectively. To examine the role of SODs in response to population density stress, we cloned two genes encoding SOD, MsCuZnSOD and MsMnSOD, and compared their expression in solitary and gregarious phases of M. separata. The MsCuZnSOD and MsMnSOD ORFs were 480 and 651 bp and encoded predicted protein products of 159 and 216 amino acids, respectively. The two SODs contained motifs that are typical of orthologous proteins. Real-time PCR indicated that the two SOD genes were expressed throughout developmental stages and were significantly upregulated in more mature stages of gregarious M. separata. Expression of the two SOD genes in various tissues of sixth-instar larvae was higher in gregarious versus solitary insects. Furthermore, expression of the SOD genes was significantly upregulated in response to crowding in solitary individuals, but suppressed in gregarious insects subjected to isolation. Collectively, these results suggest that population density may be key factor in the induction of SOD genes in M. separata.
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Affiliation(s)
- Hong-Bo Li
- Department of Entomology, Institute of Plant Protection, Guizhou Academy of Agricultural Science, Guiyang, Guizhou, China
| | - Chang-Geng Dai
- Department of Entomology, Institute of Plant Protection, Guizhou Academy of Agricultural Science, Guiyang, Guizhou, China
| | - Yong-Fu He
- Department of Entomology, Institute of Plant Protection, Guizhou Academy of Agricultural Science, Guiyang, Guizhou, China
| | - Yang Hu
- Department of Entomology, Institute of Plant Protection, Guizhou Academy of Agricultural Science, Guiyang, Guizhou, China
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Kong H, Dong C, Jing W, Zheng M, Tian Z, Hou Q, Wang C, Cheng Y, Zhang L, Jiang X, Luo L, Zhu S. Transcriptomic insight into antimicrobial peptide factors involved in the prophylactic immunity of crowded Mythimna separata larvae. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2019; 98:34-41. [PMID: 30794832 DOI: 10.1016/j.dci.2019.02.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/10/2019] [Accepted: 02/14/2019] [Indexed: 06/09/2023]
Abstract
Similar to pathogenic infection, a high population density alters insect prophylactic immunity. Antimicrobial peptides (AMPs) are known to play critical roles in an insect's humoral immune response to microbial infection. We applied RNA sequencing to investigate differential gene expression levels in fat body and hemocyte samples from larvae reared in high- (10 larvae per jar) and low-density (1 larva per jar) conditions; the samples exhibited density-dependent prophylaxis. A number of AMP molecule-related proteins were annotated for the first time from 145,439 assembled unigenes from M. separata larvae. The transcript levels of AMP molecules such as gloverin-, defensin-, cecropin-, lebocin- and attacin-related unigenes were increased with the prophylactic immunity of high-density larvae. The pattern recognition receptor peptidoglycan recognition protein (PGRP), a key protein in the synthesis of AMPs in IMD- and Toll pathway-related unigenes, was also upregulated in the larvae from the high-density group. The resultant transcriptomic database was validated by the transcript levels of four selected AMP genes quantified from the high- and low-density larval groups with quantitative real-time PCR. The antimicrobial activity against gram-positive Staphylococcus aureus and Bacillus subtilis and gram-negative Edwardsiella ictaluri and Vibrio anguillarum in the hemolymph of larvae from the high-density group was significantly higher than that of larvae from the low-density group. Our findings provide the first insight into the role of AMP genes in the mechanisms of density-dependent prophylaxis in M. separata and provide new insight into the control of M. separata with biopesticides.
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Affiliation(s)
- Hailong Kong
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China.
| | - Chuanlei Dong
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Wanghui Jing
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Minyuan Zheng
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Zhen Tian
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Qiuli Hou
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Cheng Wang
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
| | - Yunxia Cheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests; Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, No. 2, Beijing, 100193, China
| | - Lei Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests; Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, No. 2, Beijing, 100193, China
| | - Xingfu Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests; Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, No. 2, Beijing, 100193, China.
| | - Lizhi Luo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests; Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Yuanmingyuan West Road, No. 2, Beijing, 100193, China
| | - Shude Zhu
- College of Horticulture and Plant Protection, Yangzhou University, Wenhui East Road, NO. 48, Yangzhou, Jiangsu Province, 225009, China
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Zhang J, Jiang H, Du Y, Keyhani NO, Xia Y, Jin K. Members of chitin synthase family in Metarhizium acridum differentially affect fungal growth, stress tolerances, cell wall integrity and virulence. PLoS Pathog 2019; 15:e1007964. [PMID: 31461507 PMCID: PMC6713334 DOI: 10.1371/journal.ppat.1007964] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 07/06/2019] [Indexed: 11/17/2022] Open
Abstract
Chitin is an important component of the fungal cell wall with a family of chitin synthases mediating its synthesis. Here, we report on the genetic characterization of the full suite of seven chitin synthases (MaChsI-VII) identified in the insect pathogenic fungus, Metarhizium acridum. Aberrant distribution of chitin was most evident in targeted gene knockouts of MaChsV and MaChsVII. Mutants of MaChsI, MaChsIII, MaChsIV showed delayed conidial germination, whereas ΔMaChsII and ΔMaChsV mutants germinated more rapidly when compared to the wild-type parent. All MaChs genes impacted conidial yield, but differentially affected stress tolerances. Inactivation of MaChsIII, MaChsV, MaChsVII resulted in cell wall fragility, and ΔMaChsV and ΔMaChsVII mutants showed high sensitivity to Congo red and calcofluor white, suggesting that the three genes are required for cell wall integrity. In addition, ΔMaChsIII and ΔMaChsVII mutants showed the highest sensitivities to heat and UV-B stress. Three of seven chitin synthase genes, MaChsIII, MaChsV, MaChsVII, were found to contribute to fungal virulence. Compared with the wild-type strain, ΔMaChsIII and ΔMaChsV mutants were reduced in virulence by topical inoculation, while the ΔMaChsVII mutant showed more severe virulence defects. Inactivation of MaChsIII, MaChsV, or MaChsVII impaired appressorium formation, affected growth of in insecta produced hyphal bodies, and altered the surface properties of conidia and hyphal bodies, resulting in defects in the ability of the mutant strains to evade insect immune responses. These data provide important links between the physiology of the cell wall and the ability of the fungus to parasitize insects and reveal differential functional consequences of the chitin synthase family in M. acridum growth, stress tolerances, cell wall integrity and virulence. The fungal cell wall is a dynamic and flexible organelle that modulates the interaction of the pathogen with its host and acts as a critical recognition and evasion interface with host defenses. Chitin is a hallmark constituent of the fungal cell wall and all fungi contain multiple chitin synthase (Chs) genes. However, systematic characterization of chitin synthase genes has not yet been reported in entomopathogenic fungi. By using the insect pathogen Metarhizium acridum as a model, we performed a systematic genetic analysis of the seven member Chs family (ChsI-VII) in the insect pathogenic fungus. Construction of strains bearing targeted single gene mutations revealed differential contributions of specific Chs genes to growth, cell wall integrity, and stress responses. In addition, we revealed that three chitin synthase genes MaChsIII, MaChsV and MaChsVII were shown to be important for fungal appressorium formation and evasion of insect cellular and/or humoral defenses, promoting the fungal dimorphic transition to the production of hyphal bodies that occurs within hosts, and ultimately to virulence. These data provide new insights into the roles of Chs genes and chitin as critical components affecting fungal membrane structure and function.
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Affiliation(s)
- Junjie Zhang
- School of Life Sciences, Chongqing University, Chongqing, People's Republic of China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People's Republic of China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, PR China
| | - Hui Jiang
- School of Life Sciences, Chongqing University, Chongqing, People's Republic of China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People's Republic of China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, PR China
| | - Yanru Du
- School of Life Sciences, Chongqing University, Chongqing, People's Republic of China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People's Republic of China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, PR China
| | - Nemat O Keyhani
- School of Life Sciences, Chongqing University, Chongqing, People's Republic of China.,Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, United States of America
| | - Yuxian Xia
- School of Life Sciences, Chongqing University, Chongqing, People's Republic of China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People's Republic of China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, PR China
| | - Kai Jin
- School of Life Sciences, Chongqing University, Chongqing, People's Republic of China.,Chongqing Engineering Research Center for Fungal Insecticide, Chongqing, People's Republic of China.,Key Laboratory of Gene Function and Regulation Technologies under Chongqing Municipal Education Commission, Chongqing, PR China
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Core transcriptional signatures of phase change in the migratory locust. Protein Cell 2019; 10:883-901. [PMID: 31292921 PMCID: PMC6881432 DOI: 10.1007/s13238-019-0648-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 06/17/2019] [Indexed: 01/21/2023] Open
Abstract
Phenotypic plasticity plays fundamental roles in successful adaptation of animals in response to environmental variations. Here, to reveal the transcriptome reprogramming in locust phase change, a typical phenotypic plasticity, we conducted a comprehensive analysis of multiple phase-related transcriptomic datasets of the migratory locust. We defined PhaseCore genes according to their contribution to phase differentiation by the adjustment for confounding principal components analysis algorithm (AC-PCA). Compared with other genes, PhaseCore genes predicted phase status with over 87.5% accuracy and displayed more unique gene attributes including the faster evolution rate, higher CpG content and higher specific expression level. Then, we identified 20 transcription factors (TFs) named PhaseCoreTF genes that are associated with the regulation of PhaseCore genes. Finally, we experimentally verified the regulatory roles of three representative TFs (Hr4, Hr46, and grh) in phase change by RNAi. Our findings revealed that core transcriptional signatures are involved in the global regulation of locust phase changes, suggesting a potential common mechanism underlying phenotypic plasticity in insects. The expression and network data are accessible in an online resource called LocustMine (http://www.locustmine.org:8080/locustmine).
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Freitak D, Tammaru T, Sandre S, Meister H, Esperk T. Longer life span is associated with elevated immune activity in a seasonally polyphenic butterfly. J Evol Biol 2019; 32:653-665. [PMID: 30903723 PMCID: PMC6850579 DOI: 10.1111/jeb.13445] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 02/13/2019] [Accepted: 03/06/2019] [Indexed: 12/13/2022]
Abstract
Seasonal polyphenism constitutes a specific type of phenotypic plasticity in which short-lived organisms produce different phenotypes in different times of the year. Seasonal generations of such species frequently differ in their overall lifespan and in the values of traits closely related to fitness. Seasonal polyphenisms provide thus excellent, albeit underused model systems for studying trade-offs between life-history traits. Here, we compare immunological parameters between the two generations of the European map butterfly (Araschnia levana), a well-known example of a seasonally polyphenic species. To reveal possible costs of immune defence, we also examine the concurrent differences in several life-history traits. Both in laboratory experiments and in the field, last instar larvae heading towards the diapause (overwintering) had higher levels of both phenoloxidase (PO) activity and lytic activity than directly developing individuals. These results suggest that individuals from the diapausing generation with much longer juvenile (pupal) period invest more in their immune system than those from the short-living directly developing generation. The revealed negative correlation between pupal mass and PO activity may be one of the reasons why, in this species, the diapausing generation has a smaller body size than the directly developing generation. Immunological parameters may thus well mediate trade-offs between body size-related traits.
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Affiliation(s)
- Dalial Freitak
- Faculty of Biological and Environmental SciencesOrganismal and Evolutionary Biology Research ProgrammeHelsinkiFinland
- Division of ZoologyInstitute of BiologyUniversity of GrazGrazAustria
| | - Toomas Tammaru
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Siiri‐Lii Sandre
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Hendrik Meister
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
| | - Toomas Esperk
- Department of ZoologyInstitute of Ecology and Earth SciencesUniversity of TartuTartuEstonia
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Tan S, Li A, Wang Y, Shi W. Role of the neuropeptide F 1 in regulating the appetite for food in Locusta migratoria. PEST MANAGEMENT SCIENCE 2019; 75:1304-1309. [PMID: 30350452 DOI: 10.1002/ps.5244] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/20/2018] [Accepted: 10/15/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Neuropeptide F (NPF) is an intercellular signaling molecule that mediates many physiological and behavioral processes. However, the function of neuropeptide F in mediating the feeding behavior of Locusta migratoria has been unclear. RESULTS The neuropeptide F 1 precursor cDNA from L. migratoria was obtained and analyzed, and its amino acid sequence deduced. Mature LmiNPF1 was composed of 36 amino acids and was similar to that of Schistocerca gregaria. The spatial and temporal expression profiles of LmiNPF1 were investigated. LmiNPF1 was primarily expressed in the central nervous system, especially in the brain, and the expression levels were higher during the day than during the night. However, starvation activated LmiNPF1 expression increases, and downregulation of LmiNPF1 inhibited locust feeding behavior. CONCLUSION LmiNPF1 promotes the feeding behavior of the locust and is a potential molecular target to control locust feeding. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Shuqian Tan
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Aomei Li
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yang Wang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Wangpeng Shi
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
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Vogel E, Santos D, Mingels L, Verdonckt TW, Broeck JV. RNA Interference in Insects: Protecting Beneficials and Controlling Pests. Front Physiol 2019; 9:1912. [PMID: 30687124 PMCID: PMC6336832 DOI: 10.3389/fphys.2018.01912] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 12/18/2018] [Indexed: 01/01/2023] Open
Abstract
Insects constitute the largest and most diverse group of animals on Earth with an equally diverse virome. The main antiviral immune system of these animals is the post-transcriptional gene-silencing mechanism known as RNA(i) interference. Furthermore, this process can be artificially triggered via delivery of gene-specific double-stranded RNA molecules, leading to specific endogenous gene silencing. This is called RNAi technology and has important applications in several fields. In this paper, we review RNAi mechanisms in insects as well as the potential of RNAi technology to contribute to species-specific insecticidal strategies. Regarding this aspect, we cover the range of strategies considered and investigated so far, as well as their limitations and the most promising approaches to overcome them. Additionally, we discuss patterns of viral infection, specifically persistent and acute insect viral infections. In the latter case, we focus on infections affecting economically relevant species. Within this scope, we review the use of insect-specific viruses as bio-insecticides. Last, we discuss RNAi-based strategies to protect beneficial insects from harmful viral infections and their potential practical application. As a whole, this manuscript stresses the impact of insect viruses and RNAi technology in human life, highlighting clear lines of investigation within an exciting and promising field of research.
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Affiliation(s)
- Elise Vogel
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Leuven, Belgium
| | - Dulce Santos
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Leuven, Belgium
| | - Lina Mingels
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Leuven, Belgium
| | - Thomas-Wolf Verdonckt
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Leuven, Belgium
| | - Jozef Vanden Broeck
- Research Group of Molecular Developmental Physiology and Signal Transduction, KU Leuven, Leuven, Belgium
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Wei J, Shao W, Cao M, Ge J, Yang P, Chen L, Wang X, Kang L. Phenylacetonitrile in locusts facilitates an antipredator defense by acting as an olfactory aposematic signal and cyanide precursor. SCIENCE ADVANCES 2019; 5:eaav5495. [PMID: 30746481 PMCID: PMC6357733 DOI: 10.1126/sciadv.aav5495] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/11/2018] [Indexed: 05/22/2023]
Abstract
Many aggregating animals use aposematic signals to advertise their toxicity to predators. However, the coordination between aposematic signals and toxins is poorly understood. Here, we reveal that phenylacetonitrile (PAN) acts as an olfactory aposematic signal and precursor of hypertoxic hydrogen cyanide (HCN) to protect gregarious locusts from predation. We found that PAN biosynthesis from phenylalanine is catalyzed by CYP305M2, a novel gene encoding a cytochrome P450 enzyme in gregarious locusts. The RNA interference (RNAi) knockdown of CYP305M2 increases the vulnerability of gregarious locusts to bird predation. By contrast, the elevation of PAN levels through supplementation with synthetic PAN increases the resistance of solitary locusts to predation. When locusts are attacked by birds, PAN is converted to HCN, which causes food poisoning in birds. Our results indicate that locusts develop a defense mechanism wherein an aposematic compound is converted to hypertoxic cyanide in resistance to predation by natural enemies.
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Affiliation(s)
- Jianing Wei
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China
| | - Wenbo Shao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, P. R. China
| | - Minmin Cao
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jin Ge
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Pengcheng Yang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, P. R. China
| | - Li Chen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China
| | - Xianhui Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China
- Corresponding author. (L.K.); (X.W.)
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100080, P. R. China
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing 100101, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- Corresponding author. (L.K.); (X.W.)
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Yang YT, Lee MR, Lee SJ, Kim S, Nai YS, Kim JS. Tenebrio molitor Gram-negative-binding protein 3 (TmGNBP3) is essential for inducing downstream antifungal Tenecin 1 gene expression against infection with Beauveria bassiana JEF-007. INSECT SCIENCE 2018; 25:969-977. [PMID: 28544681 DOI: 10.1111/1744-7917.12482] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/01/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
The Toll signaling pathway is responsible for defense against both Gram-positive bacteria and fungi. Gram-negative binding protein 3 (GNBP3) has a strong affinity for the fungal cell wall component, β-1,3-glucan, which can activate the prophenoloxidase (proPO) cascade and induce the Toll signaling pathway. Myeloid differentiation factor 88 (MyD88) is an intracellular adaptor protein involved in the Toll signaling pathway. In this study, we monitored the response of 5 key genes (TmGNBP3, TmMyD88, and Tenecin 1, 2, and 3) in the Toll pathway of the mealworm Tenebrio molitor immune system against the fungus Beauveria bassiana JEF-007 using RT-PCR. TmGNBP3, Tenecin 1, and Tenecin 2 were significantly upregulated after fungal infection. To better understand the roles of the Toll signaling pathway in the mealworm immune system, TmGNBP3 and TmMyD88 were knocked down by RNAi silencing. Target gene expression levels decreased at 2 d postknockdown and were dramatically reduced at 6 d post-dsRNA injection. Therefore, mealworms were compromised by B. bassiana JEF-007 at 6 d post-dsRNA injection. Silencing of TmMyD88 and TmGNBP3 resulted in reduced resistance of the host to fungal infection. Particularly, reducing TmGNBP3 levels obviously downregulated Tenecin 1 and Tenecin 2 expression levels, whereas silencing TmMyD88 expression resulted in decreased Tenecin 2 expression. These results indicate that TmGNBP3 is essential to induce downstream antifungal peptide Tenecin 1 expression against B. bassiana JEF-007.
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Affiliation(s)
- Yi-Ting Yang
- Department of Agricultural Biology, Chonbuk National University, Korea
| | - Mi Rong Lee
- Department of Agricultural Biology, Chonbuk National University, Korea
| | - Se Jin Lee
- Department of Agricultural Biology, Chonbuk National University, Korea
| | - Sihyeon Kim
- Department of Agricultural Biology, Chonbuk National University, Korea
| | - Yu-Shin Nai
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan, China
| | - Jae Su Kim
- Department of Agricultural Biology, Chonbuk National University, Korea
- Plant Medical Research Center, College of Agricultural and Life Sciences, Chonbuk National University, Jenoju, Korea
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Chen D, Tang JX, Li B, Hou L, Wang X, Kang L. CRISPR/Cas9-mediated genome editing induces exon skipping by complete or stochastic altering splicing in the migratory locust. BMC Biotechnol 2018; 18:60. [PMID: 30253761 PMCID: PMC6156852 DOI: 10.1186/s12896-018-0465-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/31/2018] [Indexed: 01/31/2023] Open
Abstract
Background The CRISPR/Cas9 system has been widely used to generate gene knockout/knockin models by inducing frameshift mutants in cell lines and organisms. Several recent studies have reported that such mutants can lead to in-frame exon skipping in cell lines. However, there was little research about post-transcriptional effect of CRISPR-mediated gene editing in vivo. Results We showed that frameshift indels also induced complete or stochastic exon skipping by deleting different regions to influence pre-mRNA splicing in vivo. In the migratory locust, the missing 55 bp at the boundary of intron 3 and exon 4 of an olfactory receptor gene, LmigOr35, resulted in complete exon 4 skipping, whereas the lacking 22 bp in exon 4 of LmigOr35 only resulted in stochastic exon 4 skipping. A single sgRNA induced small insertions or deletions at the boundary of intron and exon to disrupt the 3′ splicing site causing completely exon skipping, or alternatively induce small insertions or deletions in the exon to stochastic alter splicing causing the stochastic exon skipping. Conclusions These results indicated that complete or stochastic exon skipping could result from the CRISPR-mediated genome editing by deleting different regions of the gene. Although exon skipping caused by CRISPR-mediated editing was an unexpected outcome, this finding could be developed as a technology to investigate pre-mRNA splicing or to cure several human diseases caused by splicing mutations. Electronic supplementary material The online version of this article (10.1186/s12896-018-0465-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Dafeng Chen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ji-Xin Tang
- Affiliated Hospital of Guangdong Medical University, Zhanjiang, 524001, China
| | - Beibei Li
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Li Hou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xianhui Wang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
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Tan S, Wang Y, Liu P, Ge Y, Li A, Xing Y, Hunter DM, Shi W. Increase of Albinistic Hosts Caused by Gut Parasites Promotes Self-Transmission. Front Microbiol 2018; 9:1525. [PMID: 30042753 PMCID: PMC6048391 DOI: 10.3389/fmicb.2018.01525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 06/19/2018] [Indexed: 11/24/2022] Open
Abstract
Paranosema locustae is a gut parasite that has been applied widely in the control of grasshoppers in many parts of the world. Usually, P. locustae is transmitted horizontally via passive modes under natural conditions but in the current study, a positive transmission strategy of P. locustae was demonstrated. First, infection by P. locustae resulted in the cuticula of infected Locusta migratoria nymphs to become lighter in color: normally only a small proportion of locusts are pale with most either being partly or mostly black; but locusts infected with P. locustae became pale. And it was found that the change to pale occurred even among uninfected black and partly black nymphs reared with infected locusts. The eumelanin of the thorax and abdomen of infected individuals decreased significantly, as did the level of dopamine. In addition, there was a decrease in phenol oxidase activity and the expression of henna and pale, which are involved in the synthesis of cuticle melanin, decreased. What is the ecological significance of this increase in light-colored hosts caused by P. locustae? We discovered that light-colored locusts were more susceptible to the microsporidian pathogen than dark-colored individuals were, because of their weaker melanization. Phenol oxidase activity in pale locusts was lower than that of black locusts, but the serpin expression level of pale locusts was higher than that of black individuals. When examined for infection, it was found that initially uninfected nymphs had picked up P. locustae infections indicating that infections are readily passed from one pale locust to another. The infection rate of healthy locusts reared with light-colored locusts infected with P. locustae was 100% which was more than with black-colored ones. The increase in albinistic locusts clearly promoted the prevalence of P. locustae in the total population. In conclusion, these results elucidated a new strategy of positive self-transmission in P. locustae. Importance: Mother Nature always grants wisdom to her creatures and feeds them carefully. This wisdom is particularly apparent in the relationships between two interacting species. In this study, our team focused on the interaction between L. migratoria and P. locustae. In a previous study, it was found that L. migratoria isolate infected individuals, reducing avoiding the spread of P. locustae, in a previous study. The solitary, pale individuals infected by P. locustae were left behind as locust groups marched ahead, leading to a kind of behavioral immunity in the insects. Here, we reported that P. locustae promotes pigmentation loss in L. migratoria, causing a larger proportion of light-colored individuals, and these lighter individuals which possessed weaker immunity against pathogens. This strategy is advantageous to P. locustae, as it promotes its propagation and spread. These extraordinary abilities of L. migratoria and P. locustae have accumulated over millennia of years of interaction.
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Affiliation(s)
- Shuqian Tan
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yang Wang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Pingping Liu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yang Ge
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Aomei Li
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Yongjie Xing
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | | | - Wangpeng Shi
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
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Chen B, Feder ME, Kang L. Evolution of heat-shock protein expression underlying adaptive responses to environmental stress. Mol Ecol 2018; 27:3040-3054. [PMID: 29920826 DOI: 10.1111/mec.14769] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 06/03/2018] [Accepted: 06/07/2018] [Indexed: 12/27/2022]
Abstract
Heat-shock proteins (Hsps) and their cognates are primary mitigators of cell stress. With increasingly severe impacts of climate change and other human modifications of the biosphere, the ability of the heat-shock system to affect evolutionary fitness in environments outside the laboratory and to evolve in response is topic of growing importance. Since the last major reviews, several advances have occurred. First, demonstrations of the heat-shock response outside the laboratory now include many additional taxa and environments. Many of these demonstrations are only correlative, however. More importantly, technical advances in "omic" quantification of nucleic acids and proteins, genomewide association analysis, and manipulation of genes and their expression have enabled the field to move beyond correlation. Several consequent advances are already evident: The pathway from heat-shock gene expression to stress tolerance in nature can be extremely complex, mediated through multiple biological processes and systems, and even multiple species. The underlying genes are more numerous, diverse and variable than previously appreciated, especially with respect to their regulatory variation and epigenetic changes. The impacts and limitations (e.g., due to trade-offs) of natural selection on these genes have become more obvious and better established. At last, as evolutionary capacitors, Hsps may have distinctive impacts on the evolution of other genes and ecological consequences.
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Affiliation(s)
- Bing Chen
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Martin E Feder
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, Illinois
| | - Le Kang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Qu S, Wang S. Interaction of entomopathogenic fungi with the host immune system. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 83:96-103. [PMID: 29355579 DOI: 10.1016/j.dci.2018.01.010] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 01/14/2018] [Accepted: 01/15/2018] [Indexed: 06/07/2023]
Abstract
Entomopathogenic fungi can invade wide range of insect hosts in the natural world and have been used as environmentally friendly alternatives to chemical insecticides for pest control. Studies of host-pathogen interactions provide valuable insights into the coevolutionay arms race between fungal pathogens and their hosts. Entomopathogenic fungi have evolved a series of sophisticated strategies to counter insect immune defenses. In response to fungal infection, insect hosts rely on behavior avoidance, physical barrier and innate immune defenses in the fight against invading pathogens. The insect cuticle acts as the first physical barrier against pathogens. It is an inhospitable physiological environment that contains chemicals (e.g., antimicrobial peptides and reactive oxygen species), which inhibit fungal growth. In addition, innate immune responses, including cellular immunity and humoral immunity, play critical roles in preventing fungal infection. In this review, we outline the current state of our knowledge of insect defenses to fungal infection and discuss the strategies by which entomopathogenic fungi counter the host immune system. Increased knowledge regarding the molecular interactions between entomopathogenic fungi and the insect host could provide new strategies for pest management.
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Affiliation(s)
- Shuang Qu
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Sibao Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China.
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Payne P, Geyrhofer L, Barton NH, Bollback JP. CRISPR-based herd immunity can limit phage epidemics in bacterial populations. eLife 2018; 7:32035. [PMID: 29521625 PMCID: PMC5922976 DOI: 10.7554/elife.32035] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 03/08/2018] [Indexed: 01/27/2023] Open
Abstract
Herd immunity, a process in which resistant individuals limit the spread of a pathogen among susceptible hosts has been extensively studied in eukaryotes. Even though bacteria have evolved multiple immune systems against their phage pathogens, herd immunity in bacteria remains unexplored. Here we experimentally demonstrate that herd immunity arises during phage epidemics in structured and unstructured Escherichia coli populations consisting of differing frequencies of susceptible and resistant cells harboring CRISPR immunity. In addition, we develop a mathematical model that quantifies how herd immunity is affected by spatial population structure, bacterial growth rate, and phage replication rate. Using our model we infer a general epidemiological rule describing the relative speed of an epidemic in partially resistant spatially structured populations. Our experimental and theoretical findings indicate that herd immunity may be important in bacterial communities, allowing for stable coexistence of bacteria and their phages and the maintenance of polymorphism in bacterial immunity.
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Affiliation(s)
- Pavel Payne
- Institute of Integrative BiologyUniversity of LiverpoolLiverpoolUnited Kingdom,Institute of Science and Technology AustriaKlosterneuburgAustria
| | - Lukas Geyrhofer
- Department of Chemical EngineeringTechnion - Israel Institute of TechnologyHaifaIsrael
| | | | - Jonathan P Bollback
- Institute of Integrative BiologyUniversity of LiverpoolLiverpoolUnited Kingdom,Institute of Science and Technology AustriaKlosterneuburgAustria
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Central Nervous System Responses of the Oriental migratory, Locusta migratoria manilensis, to Fungal Infection. Sci Rep 2017; 7:10340. [PMID: 28871168 PMCID: PMC5583336 DOI: 10.1038/s41598-017-10622-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 08/11/2017] [Indexed: 02/07/2023] Open
Abstract
Responses of the central nervous system (CNS) to microbial challenge and the interplay between the CNS and the immune system are important for defending against pathogen attack. We have examined the CNS transcriptional response of Locusta migratoria manilensis to infection by the locust-specific fungal pathogen, Metarhizium acridum. CNS responses were examined during spore attachment, fungal germination and pre-penetration of the cuticle, and cuticle penetration/hemocoel ingress and proliferation. Effects were seen at the earliest time points (4 h post-infection) and the number of differentially expressed genes (DEGs) was highest during late mycosis (72 h post-infection). Significantly affected neurological pathways included genes involved in serotonergic, cholinergic, dopaminergic, GABAergic, and glutamergic synapse responses, as well as pathways responsible for synaptic vesicle cycle, long-term potentiation and depression, and neurotrophin and retrograde endocannabinoid signaling. In addition, a significant number of immune related DEGs were identified. These included components of the Toll, Imd and JAK/STAT pathways, consistent with interactions between the CNS and immune systems. The activation of immune response related CNS genes during early stage infection highlights the rapid detection of microbial pathogens and suggests an important role for the CNS in modulating immunity potentially via initiating behavioral adaptations along with innate immune responses.
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Duressa TF, Boonen K, Huybrechts R. A quantitative peptidomics approach to unravel immunological functions of angiotensin converting enzyme in Locusta migratoria. Gen Comp Endocrinol 2016; 235:120-129. [PMID: 27320038 DOI: 10.1016/j.ygcen.2016.06.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 06/06/2016] [Accepted: 06/15/2016] [Indexed: 01/15/2023]
Abstract
Locusta migratoria angiotensin converting enzyme (LmACE) is encoded by multiple exons displaying variable number of genomic duplications. Treatments of lipopolysaccharide (LPS) as well as peptidoglycan but not β-1-3 glucan resulted in enhanced expression of angiotensin converting enzyme in hemocytes of Locusta migratoria. No such effect was observed in fat body cells. Differential peptidomics using locust plasma samples post infection with LPS in combination with both an LmACE transcript knockdown by RNAi and a functional knockdown using captopril allowed the identification of 5 circulating LPS induced peptides which only appear in the hemolymph of locust having full LmACE functionality. As these peptides originate from larger precursor proteins such as locust hemocyanin-like protein, having known antimicrobial properties, the obtained results suggest a possible direct or indirect role of LmACE in the release of these peptides from their precursors. Additionally, this experimental setup confirmed the role of LmACE in the clearance of multiple peptides from the hemolymph.
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Affiliation(s)
- Tewodros Firdissa Duressa
- Insect Physiology and Molecular Ethology, Biology Department, KU Leuven, Naamsestraat 59, B-3000 Leuven, Belgium.
| | - Kurt Boonen
- Functional Genomics and Proteomics, Biology Department, KU Leuven, B-3000 Leuven, Belgium.
| | - Roger Huybrechts
- Insect Physiology and Molecular Ethology, Biology Department, KU Leuven, Naamsestraat 59, B-3000 Leuven, Belgium.
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Molecular Characterization of a Lysozyme Gene and Its Altered Expression Profile in Crowded Beet Webworm (Loxostege sticticalis). PLoS One 2016; 11:e0161384. [PMID: 27575006 PMCID: PMC5019359 DOI: 10.1371/journal.pone.0161384] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Accepted: 08/04/2016] [Indexed: 11/19/2022] Open
Abstract
There is growing evidence that insects living in high-density populations exhibit an increase in immune function to counter a higher risk of disease. This phenomenon, known as density-dependent prophylaxis, has been experimentally tested in a number of insect species. Although density-dependent prophylaxis is especially prevalent in insects exhibiting density-dependent phase polyphenism, the molecular mechanism remains unclear. Our previous study demonstrated that the antibacterial activity of lysozyme is important for this process in the beet webworm Loxostege sticticalis. In this study, a lysozyme cDNA from L. sticticalis was cloned and characterized. The full-length cDNA is 1078 bp long and contains an open reading frame of 426 bp that encodes 142 amino acids. The deduced protein possesses structural characteristics of a typical c-type lysozyme and clusters with c-type lysozymes from other Lepidoptera. LsLysozyme was found to be expressed throughout all developmental stages, showing the highest level in pupae. LsLysozyme was also highly expressed in the midgut and fat body. Elevated LsLysozyme expression was observed in L. sticticalis larvae infected by Beauveria bassiana and in larvae reared under crowding conditions. In addition, the expression level of LsLysozyme in infected larvae reared at a density of 10 larvae per jar was significantly higher compared to those reared at a density of l or 30 larvae per jar. These results suggest that larval crowding affects the gene expression profile of this lysozyme. This study provides additional insight into the expression of an immune-associated lysozyme gene and helps us to better understand the immune response of L. sticticalis under crowding conditions.
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