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Ren Y, Fu S, Dong W, Chen J, Xue H, Bu W. The ncRNA-mediated regulatory networks of defensins and lysozymes in Riptortus pedestris: involvement in response to gut bacterial disturbances. Front Microbiol 2024; 15:1386345. [PMID: 38827147 PMCID: PMC11140134 DOI: 10.3389/fmicb.2024.1386345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 04/23/2024] [Indexed: 06/04/2024] Open
Abstract
Insects depend on humoral immunity against intruders through the secretion of antimicrobial peptides (AMPs) and immune effectors via NF-κB transcription factors, and their fitness is improved by gut bacterial microbiota. Although there are growing numbers of reports on noncoding RNAs (ncRNAs) involving in immune responses against pathogens, comprehensive studies of ncRNA-AMP regulatory networks in Riptortus pedestris, which is one of the widely distributed pests in East Asia, are still not well understood under feeding environmental changes. The objective of this study employed the whole-transcriptome sequencing (WTS) to systematically identify the lncRNAs (long noncoding RNA) and circRNAs (circular RNA) and to obtain their differential expression from the R. pedestris gut under different feeding conditions. Functional annotation indicated that they were mainly enriched in various biological processes with the GO and KEGG databases, especially in immune signaling pathways. Five defensin (four novel members) and eleven lysozyme (nine novel members) family genes were identified and characterized from WTS data, and meanwhile, phylogenetic analysis confirmed their classification. Subsequently, the miRNA-mRNA interaction network of above two AMPs and lncRNA-involved ceRNA (competing endogenous RNA) regulatory network of one lysozyme were predicted and built based on bioinformatic prediction and calculation, and the expression patterns of differentially expressed (DE) defensins, and DE lysozymes and related DE ncRNAs were estimated and selected among all the comparison groups. Finally, to integrate the analyses of WTS and previous 16S rRNA amplicon sequencing, we conducted the Pearson correlation analysis to reveal the significantly positive or negative correlation between above DE AMPs and ncRNAs, as well as most changes in the gut bacterial microbiota at the genus level of R. pedestris. Taken together, the present observations provide great insights into the ncRNA regulatory networks of AMPs in response to rearing environmental changes in insects and uncover new potential strategies for pest control in the future.
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Affiliation(s)
- Yipeng Ren
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China
| | - Siying Fu
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China
| | - Wenhao Dong
- Tianjin Key Laboratory of Food and Biotechnology, School of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China
| | - Juhong Chen
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China
| | - Huaijun Xue
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China
| | - Wenjun Bu
- Institute of Entomology, College of Life Sciences, Nankai University, Tianjin, China
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2
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Dos Santos Moreira LM, Marinho LS, Neves RCS, Harakava R, Bessa LA, Vitorino LC. Assessment of the Entomopathogenic Potential of Fungal and Bacterial Isolates from Fall Armyworm Cadavers Against Spodoptera frugiperda Caterpillars and the Adult Boll Weevil, Anthonomus grandis. NEOTROPICAL ENTOMOLOGY 2024:10.1007/s13744-024-01159-0. [PMID: 38714593 DOI: 10.1007/s13744-024-01159-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 04/13/2024] [Indexed: 05/10/2024]
Abstract
Increased attention is being focused on the biological control of agricultural pests using microorganisms, owing to their potential as a viable substitute for chemical control methods. Insect cadavers constitute a potential source of entomopathogenic microorganisms. We tested whether bacteria and fungi isolated from Spodoptera frugiperda (JE Smith) cadavers could affect its survival, development, egg-laying pattern, and hatchability, as well as induce mortality in Anthonomus grandis Boheman adults. We isolated the bacteria Enterobacter hormaechei and Serratia marcescens and the fungi Scopulariopsis sp. and Aspergillus nomiae from fall armyworm cadavers and the pest insects were subjected to an artificial diet enriched with bacteria cells or fungal spores to be tested, in the case of S. frugiperda, and only fungal spores in the case of A. grandis. Enterobacter hormaechei and A. nomiae were pathogenic to S. frugiperda, affecting the survival of adults and pupae. The fungus Scopulariopsis sp. does not affect the survival of S. frugiperda caterpillars and pupae; however, due to late action, moths and eggs may be affected. Aspergillus nomiae also increased mortality of A. grandis adults, as well as the development of S. frugiperda in the early stages of exposure to the diet, as indicated by the vertical spore transfer to offspring and low hatchability. Enterobacter hormaechei and A. nomiae are potential biocontrol agents for these pests, and warrant further investigation from a toxicological point of view and subsequently in field tests involving formulations that could improve agricultural sustainability practices.
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Affiliation(s)
- Lidiane Maria Dos Santos Moreira
- Instituto Goiano de Agricultura (IGA), Montividiu, GO, Brazil
- Lab of Agricultural Microbiology, Instituto Federal Goiano, Rio Verde Campus, Rio Verde, GO, Brazil
| | | | | | | | - Layara Alexandre Bessa
- Lab of Biodiversity Metabolism and Genetics, Instituto Federal Goiano, Rio Verde Campus, Rio Verde, GO, Brazil
- Simple Agro Corporation, Rio Verde, GO, Brazil
| | - Luciana Cristina Vitorino
- Simple Agro Corporation, Rio Verde, GO, Brazil.
- Lab of Agricultural Microbiology, Instituto Federal Goiano, Rio Verde Campus, Rio Verde, GO, Brazil.
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3
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Jang S, Ishigami K, Mergaert P, Kikuchi Y. Ingested soil bacteria breach gut epithelia and prime systemic immunity in an insect. Proc Natl Acad Sci U S A 2024; 121:e2315540121. [PMID: 38437561 PMCID: PMC10945853 DOI: 10.1073/pnas.2315540121] [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: 09/07/2023] [Accepted: 01/11/2024] [Indexed: 03/06/2024] Open
Abstract
Insects lack acquired immunity and were thought to have no immune memory, but recent studies reported a phenomenon called immune priming, wherein sublethal dose of pathogens or nonpathogenic microbes stimulates immunity and prevents subsequential pathogen infection. Although the evidence for insect immune priming is accumulating, the underlying mechanisms are still unclear. The bean bug Riptortus pedestris acquires its gut microbiota from ambient soil and spatially structures them into a multispecies and variable community in the anterior midgut and a specific, monospecies Caballeronia symbiont population in the posterior region. We demonstrate that a particular Burkholderia strain colonizing the anterior midgut stimulates systemic immunity by penetrating gut epithelia and migrating into the hemolymph. The activated immunity, consisting of a humoral and a cellular response, had no negative effect on the host fitness, but on the contrary protected the insect from subsequent infection by pathogenic bacteria. Interruption of contact between the Burkholderia strain and epithelia of the gut weakened the host immunity back to preinfection levels and made the insects more vulnerable to microbial infection, demonstrating that persistent acquisition of environmental bacteria is important to maintain an efficient immunity.
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Affiliation(s)
- Seonghan Jang
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Hokkaido Center, 062-8517Sapporo, Japan
| | - Kota Ishigami
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Hokkaido Center, 062-8517Sapporo, Japan
| | - Peter Mergaert
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell, 91198Gif-sur-Yvette, France
| | - Yoshitomo Kikuchi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Hokkaido Center, 062-8517Sapporo, Japan
- Unit of Applied Biological Chemistry, Graduate School of Agriculture, Hokkaido University, 060-8589Sapporo, Japan
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4
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Lin DJ, Zhou JX, Ali A, Fu HY, Gao SJ, Jin L, Fang Y, Wang JD. Biocontrol efficiency and characterization of insecticidal protein from sugarcane endophytic Serratia marcescens (SM) against oriental armyworm Mythimna separata (Walker). Int J Biol Macromol 2024; 262:129978. [PMID: 38340916 DOI: 10.1016/j.ijbiomac.2024.129978] [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: 11/10/2023] [Revised: 01/25/2024] [Accepted: 02/02/2024] [Indexed: 02/12/2024]
Abstract
The plant endophytic bacteria are a great source of nature insecticides. However, no such endophytic bacteria have been found in sugarcane, to address this gap, we isolated and identified a strain of Serratia marcescens with moderate insecticidal activity from sugarcane. Taken armyworm Mythimna separata as example, the mortality rates of oral infection and injection infection were 47.06 % and 91 %, respectively. The SM has significant negative affect on the growth, development, and reproduction of M. separata. After determining that these insecticidal substances, 33 potential virulence proteins were screened through the identification and prediction of bacterial proteins. Later we confirmed serralysin was a vital toxic protein from SM that caused M. separata death by prokaryotic expression. In addition, we also found that the intestinal tissue cells infected with SM or serralysin were severely diseased, which may be a major factor in M. separata demise. Finally, through gene expression level, protein molecular docking, we found the aminopeptidase-N would be one of the potential receptors of serralysin. Taken together, our findings indicate that sugarcane endophyte S. marcescens may be beneficial for pest control in sugarcane and explain its insecticidal mechanism. This study provides new ideas and materials for the biological control of pests.
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Affiliation(s)
- Dong-Jiang Lin
- National Engineering Research Center of Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Jiang-Xiong Zhou
- National Engineering Research Center of Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Ahmad Ali
- National Engineering Research Center of Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Hua-Ying Fu
- National Engineering Research Center of Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - San-Ji Gao
- National Engineering Research Center of Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China
| | - Lin Jin
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yong Fang
- Hunan Agricultural Biotechnology Research Institute, Hunan Academy of Agriculture science, Changsha, Hunan 410125, PR China
| | - Jin-da Wang
- National Engineering Research Center of Sugarcane, Fujian Agriculture and Forestry University, Fuzhou 350002, PR China.
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5
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Lee J, Kim JU, Lee BL, Kim JK. Alteration of lipopolysaccharide O antigen leads to avirulence of gut-colonizing Serratia marcescens. Front Microbiol 2023; 14:1278917. [PMID: 38029092 PMCID: PMC10665507 DOI: 10.3389/fmicb.2023.1278917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/26/2023] [Indexed: 12/01/2023] Open
Abstract
The reason why the potent entomopathogen Serratia marcescens fails to kill insects through oral infection is unknown. To compare effects of septic injection and oral administration of S. marcescens, we used a model bean bug, Riptortus pedestris. Most R. pedestris insects survived oral infections, but not septic infections. Although the number of S. marcescens cells in hemolymph after oral infection, which were originated from gut-colonizing S. marcescens, was higher than the fatal number of cells used in septic injection, they did not kill host insects, suggesting a loss of virulence in gut-colonizing S. marcescens cells. When gut-colonizing S. marcescens cells were septically injected into insects, they failed to kill R. pedestris and survive in hemolymph. To understand the avirulence mechanisms in gut-colonizing bacteria, lipopolysaccharides of S. marcescens were analyzed and revealed that the O antigen was lost during gut colonization. Gut-colonizing S. marcescens cells were resistant to humoral immune responses but susceptible to cellular immune responses, easily succumbing to phagocytosis of hemocytes. When cellular immunity was suppressed, the gut-colonizing S. marcescens cells recovered their virulence and killed insects through septic injection. These results suggest that a key mechanism of avirulence in orally infected S. marcescens is the loss of the O antigen, resulting in susceptibility to host's cellular immune responses.
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Affiliation(s)
- Junbeom Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan, Republic of Korea
| | - Jong Uk Kim
- Host Defense Protein Laboratory, College of Pharmacy, Pusan National University, Busan, Republic of Korea
| | - Bok Luel Lee
- Host Defense Protein Laboratory, College of Pharmacy, Pusan National University, Busan, Republic of Korea
| | - Jiyeun Kate Kim
- Department of Microbiology, Kosin University College of Medicine, Busan, Republic of Korea
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Fischer ML, Fabian B, Pauchet Y, Wielsch N, Sachse S, Vilcinskas A, Vogel H. An Assassin's Secret: Multifunctional Cytotoxic Compounds in the Predation Venom of the Assassin Bug Psytalla horrida (Reduviidae, Hemiptera). Toxins (Basel) 2023; 15:toxins15040302. [PMID: 37104240 PMCID: PMC10144120 DOI: 10.3390/toxins15040302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 04/28/2023] Open
Abstract
Predatory assassin bugs produce venomous saliva that enables them to overwhelm, kill, and pre-digest large prey animals. Venom from the posterior main gland (PMG) of the African assassin bug Psytalla horrida has strong cytotoxic effects, but the responsible compounds are yet unknown. Using cation-exchange chromatography, we fractionated PMG extracts from P. horrida and screened the fractions for toxicity. Two venom fractions strongly affected insect cell viability, bacterial growth, erythrocyte integrity, and intracellular calcium levels in Drosophila melanogaster olfactory sensory neurons. LC-MS/MS analysis revealed that both fractions contained gelsolin, redulysins, S1 family peptidases, and proteins from the uncharacterized venom protein family 2. Synthetic peptides representing the putative lytic domain of redulysins had strong antimicrobial activity against Escherichia coli and/or Bacillus subtilis but only weak toxicity towards insect or mammalian cells, indicating a primary role in preventing the intake of microbial pathogens. In contrast, a recombinant venom protein family 2 protein significantly reduced insect cell viability but exhibited no antibacterial or hemolytic activity, suggesting that it plays a role in prey overwhelming and killing. The results of our study show that P. horrida secretes multiple cytotoxic compounds targeting different organisms to facilitate predation and antimicrobial defense.
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Affiliation(s)
- Maike Laura Fischer
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Benjamin Fabian
- Research Group Olfactory Coding, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Yannick Pauchet
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Natalie Wielsch
- Research Group Mass Spectrometry/Proteomics, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Silke Sachse
- Research Group Olfactory Coding, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
| | - Andreas Vilcinskas
- Institute for Insect Biotechnology, Justus Liebig University, 35392 Giessen, Germany
- Branch Bioresources of the Fraunhofer Institute for Molecular Biology and Applied Ecology, 35392 Giessen, Germany
| | - Heiko Vogel
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, 07745 Jena, Germany
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7
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Lee J, Lee DW. Burkholderia gut symbiont induces insect host fecundity by modulating Kr-h1 gene expression. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2023; 112:e21987. [PMID: 36448663 DOI: 10.1002/arch.21987] [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: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Full-length cDNAs of the Broad-Complex (BR-C) from Riptortus pedestris were cloned. Moreover, Kr-h1 and BR-C expression levels in apo-symbiotic and symbiotic host insects were compared to verify whether they are modulated by Burkholderia gut symbionts. Interestingly, Kr-h1 expression level was significantly increased in symbiotic females. To determine how Kr-h1 affects fecundity in insects, the biosynthesis of two reproduction-associated proteins, hexamerin-α and vitellogenin, was investigated in R. pedestris females. Hexamerin-α and vitellogenin expression at the transcriptional and translational levels decreased in Kr-h1-suppressed symbiotic females, subsequently reduced egg production. These results suggest that Burkholderia gut symbiont modulates Kr-h1 expression to enhance ovarian development and egg production of R. pedestris by increasing the biosynthesis of the two proteins.
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Affiliation(s)
- Junbeom Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan, Republic of Korea
| | - Dae-Weon Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan, Republic of Korea
- Department of SmartBio, Kyungsung University, Busan, Republic of Korea
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8
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Medina V, Rosso BE, Soria M, Gutkind GO, Pagano EA, Zavala JA. Feeding on soybean crops changed gut bacteria diversity of the southern green stinkbug (Nezara viridula) and reduced negative effects of some associated bacteria. PEST MANAGEMENT SCIENCE 2022; 78:4608-4617. [PMID: 35837785 DOI: 10.1002/ps.7080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 07/07/2022] [Accepted: 07/15/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND The southern green stinkbug (Nezara viridula) is a mayor pest of soybean. However, the mechanism underlying stinkbug resistance to soybean defenses is yet ignored. Although gut bacteria could play an essential role in tolerating plant defenses, most studies testing questions related to insect-plant-bacteria interactions have been performed in laboratory condition. Here we performed experiments in laboratory and field conditions with N. viridula and its gut bacteria, studying gut lipid peroxidaxion levels and cysteine activity in infected and unifected nymphs, testing the hypothesis that feeding on field-grown soybean decreases bacterial abundance in stinkbugs. RESULTS Gut bacterial abundance and infection ratio were higher in N. viridula adults reared in laboratory than in those collected from soybean crops, suggesting that stinkbugs in field conditions may modulate gut bacterial colonization. Manipulating gut microbiota by infecting stinkbugs with Yokenella sp. showed that these bacteria abundance decreased in field conditions, and negatively affected stinkbugs performance and were more aggressive in laboratory rearing than in field conditions. Infected nymphs that fed on soybean pods had lower mortality, higher mass and shorter development period than those reared in the laboratory, and suggested that field conditions helped nymphs to recover from Yokenella sp. infection, despite of increased lipid peroxidation and decreased cysteine proteases activity in nymphs' guts. CONCLUSIONS Our results demonstrated that feeding on field-grown soybean reduced bacterial abundance and infection in guts of N. viridula and highlighted the importance to test functional activities or pathogenicity of microbes under realistic field conditions prior to establish conclusions on three trophic interactions. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Virginia Medina
- Facultad de Agronomía, Cátedra de Bioquímica - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Bruno E Rosso
- Facultad de Agronomía, Cátedra de Microbiologia - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Marcelo Soria
- Facultad de Agronomía, Cátedra de Microbiologia - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Gabriel O Gutkind
- Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina (CONICET), Buenos Aires, Argentina
| | - Eduardo A Pagano
- Facultad de Agronomía, Cátedra de Bioquímica - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jorge A Zavala
- Facultad de Agronomía, Cátedra de Bioquímica - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales (INBA-CONICET), Universidad de Buenos Aires, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina (CONICET), Buenos Aires, Argentina
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9
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Garcia L, Molina MC, Padgett-Pagliai KA, Torres PS, Bruna RE, García Véscovi E, González CF, Gadea J, Marano MR. A serralysin-like protein of Candidatus Liberibacter asiaticus modulates components of the bacterial extracellular matrix. Front Microbiol 2022; 13:1006962. [DOI: 10.3389/fmicb.2022.1006962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/26/2022] [Indexed: 11/13/2022] Open
Abstract
Huanglongbing (HLB), the current major threat for Citrus species, is caused by intracellular alphaproteobacteria of the genus Candidatus Liberibacter (CaL), with CaL asiaticus (CLas) being the most prevalent species. This bacterium inhabits phloem cells and is transmitted by the psyllid Diaphorina citri. A gene encoding a putative serralysin-like metalloprotease (CLIBASIA_01345) was identified in the CLas genome. The expression levels of this gene were found to be higher in citrus leaves than in psyllids, suggesting a function for this protease in adaptation to the plant environment. Here, we study the putative role of CLas-serralysin (Las1345) as virulence factor. We first assayed whether Las1345 could be secreted by two different surrogate bacteria, Rhizobium leguminosarum bv. viciae A34 (A34) and Serratia marcescens. The protein was detected only in the cellular fraction of A34 and S. marcescens expressing Las1345, and increased protease activity of those bacteria by 2.55 and 4.25-fold, respectively. In contrast, Las1345 expressed in Nicotiana benthamiana leaves did not show protease activity nor alterations in the cell membrane, suggesting that Las1345 do not function as a protease in the plant cell. Las1345 expression negatively regulated cell motility, exopolysaccharide production, and biofilm formation in Xanthomonas campestris pv. campestris (Xcc). This bacterial phenotype was correlated with reduced growth and survival on leaf surfaces as well as reduced disease symptoms in N. benthamiana and Arabidopsis. These results support a model where Las1345 could modify extracellular components to adapt bacterial shape and appendages to the phloem environment, thus contributing to virulence.
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10
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Lee J, Lee DW. Insecticidal Serralysin of Serratia marcescens Is Detoxified in M3 Midgut Region of Riptortus pedestris. Front Microbiol 2022; 13:913113. [PMID: 35711769 PMCID: PMC9197470 DOI: 10.3389/fmicb.2022.913113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 05/06/2022] [Indexed: 11/18/2022] Open
Abstract
Riptortus pedestris insect indiscriminately acquires not only the symbiotic bacterium Burkholderia insecticola, but also entomopathogens that are abundant in the soil via feeding. However, it is unclear how the host insect survives oral infections of entomopathogens. A previous study suggested that serralysin, a potent virulence factor produced by Serratia marcescens, suppresses cellular immunity by degrading adhesion molecules, thereby contributing to bacterial pathogenesis. Here, we observed that S. marcescens orally administered to R. pedestris stably colonized the insect midgut, while not exhibiting insecticidal activity. Additionally, oral infection with S. marcescens did not affect the host growth or fitness. When co-incubated with the midgut lysates of R. pedestris, serralysin was remarkably degraded. The detoxification activity against serralysin was enhanced in the midgut extract of gut symbiont-colonizing insects. The mRNA expression levels of serralysin genes were negligible in M3-colonizing S. marcescens. M3-colonizing S. marcescens did not produce serralysin toxin. Immunoblot analyses revealed that serralysin was not detected in the M3 midgut region. The findings of our study suggest that orally infected S. marcescens lose entomopathogenicity through host-derived degrading factors and suppression of serralysin.
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Affiliation(s)
- Junbeom Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan, South Korea
| | - Dae-Weon Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan, South Korea.,Department of SmartBio, Kyungsung University, Busan, South Korea
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11
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Lee J, Cha WH, Lee DW. Multiple Precursor Proteins of Thanatin Isoforms, an Antimicrobial Peptide Associated With the Gut Symbiont of Riptortus pedestris. Front Microbiol 2022; 12:796548. [PMID: 35069496 PMCID: PMC8767025 DOI: 10.3389/fmicb.2021.796548] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 12/10/2021] [Indexed: 01/08/2023] Open
Abstract
Thanatin is an antimicrobial peptide (AMP) generated by insects for defense against bacterial infections. In the present study, we performed cDNA cloning of thanatin and found the presence of multiple precursor proteins from the bean bug, Riptortus pedestris. The cDNA sequences encoded 38 precursor proteins, generating 13 thanatin isoforms. In the phylogenetic analysis, thanatin isoforms were categorized into two groups based on the presence of the membrane attack complex/perforin (MACPF) domain. In insect-bacterial symbiosis, specific substances are produced by the immune system of the host insect and are known to modulate the symbiont’s population. Therefore, to determine the biological function of thanatin isoforms in symbiosis, the expression levels of three AMP genes were compared between aposymbiotic insects and symbiotic R. pedestris. The expression levels of the thanatin genes were significantly increased in the M4 crypt, a symbiotic organ, of symbiotic insects upon systemic bacterial injection. Further, synthetic thanatin isoforms exhibited antibacterial activity against gut-colonized Burkholderia symbionts rather than in vitro-cultured Burkholderia cells. Interestingly, the suppression of thanatin genes significantly increased the population of Burkholderia gut symbionts in the M4 crypt under systemic Escherichia coli K12 injection. Overgrown Burkholderia gut symbionts were observed in the hemolymph of host insects and exhibited insecticidal activity. Taken together, these results suggest that thanatin of R. pedestris is a host-derived symbiotic factor and an AMP that controls the population of gut-colonized Burkholderia symbionts.
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Affiliation(s)
- Junbeom Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan, South Korea
| | - Wook Hyun Cha
- Department of Bio-Safety, Kyungsung University, Busan, South Korea
| | - Dae-Weon Lee
- Metabolomics Research Center for Functional Materials, Kyungsung University, Busan, South Korea.,Department of Bio-Safety, Kyungsung University, Busan, South Korea
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12
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Wang Z, Feng K, Tang F, Xu M. Activation of the Host Immune Response in Hyphantria cunea (Drury) (Lepidoptera: Noctuidae) Induced by Serratia marcescens Bizio. INSECTS 2021; 12:insects12110983. [PMID: 34821784 PMCID: PMC8617612 DOI: 10.3390/insects12110983] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 10/04/2021] [Accepted: 10/27/2021] [Indexed: 01/07/2023]
Abstract
Simple Summary Hyphantria cunea (Drury) is a quarantine pest, due to its extensive host, leading to serious economic losses in the agricultural and forestry industries. To control this pest, it is increasingly important to use microbial pesticides because they are biologically active and ecologically safe. Serratia marcescens Bizio (SM1) is a potential biocontrol bacterium. Although SM1 has a pathogenic role in H. cunea, H. cunea self-defense reduces the pathogenic effect of SM1. In this study, immune-related differentially expressed genes (DEGs) in H. cunea were first identified after SM1 infection, and the immune regulation mode of H. cunea in response to SM1, including antimicrobial peptide synthesis pathways, melanization and cellular immunity, was revealed. According to the analysis, the immune system of H. cunea was induced by SM1. In summary, our study demonstrates how the immune systems of the H. cunea work to resist the infection of SM1, which provides the theoretical basis for researching more efficient microbial pesticides for H. cunea. Abstract Host–pathogen interactions are essential to our understanding of biological pesticides. Hyphantria cunea (Drury) is an important forest pest worldwide. The immune mechanism of the interaction between H. cunea and Serratia marcescens Bizio (SM1) is unclear. First, transcriptome sequencing and quantitative real-time PCR (qRT-PCR) analysis described the H. cunea immune response to SM1. A total of 234 immune-related differentially expressed genes (DEGs) were found. Many immune regulatory genes in three classical pathways were found. Antimicrobial peptides, including attacin B, cecropin A, gloverin, lebocin and diapausin, are involved in defending against SM1 challenge, and are mainly produced by Toll and immune deficiency (IMD) pathways. Some melanization genes were changed in H. cunea, which suggested that H. cunea melanization was activated by SM1. Furthermore, phagocytosis, autophagolysosome and apoptosis pathways in cellular immunity were activated in H. cunea against SM1. Finally, the expression patterns of 10 immune genes were analyzed systematically by qRT-PCR, and most of the genes were upregulated compared to the control. Our studies provide useful information about the immune response of H. cunea under the stress of SM1, which is important to understand how SM1 affects the immune system of H. cunea and provides new ideas to control H. cunea by using SM1.
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Affiliation(s)
- Zhiqiang Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China; (Z.W.); (K.F.); (M.X.)
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China
| | - Kai Feng
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China; (Z.W.); (K.F.); (M.X.)
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China
| | - Fang Tang
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China; (Z.W.); (K.F.); (M.X.)
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China
- Correspondence: ; Tel.: +86-13813966269
| | - Meng Xu
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China; (Z.W.); (K.F.); (M.X.)
- College of Forestry, Nanjing Forestry University, Nanjing 210037, China
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Zhang C, Wickham JD, Zhao L, Sun J. A new bacteria-free strategy induced by MaGal2 facilitates pinewood nematode escape immune response from its vector beetle. INSECT SCIENCE 2021; 28:1087-1102. [PMID: 32443173 DOI: 10.1111/1744-7917.12823] [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: 03/19/2020] [Revised: 04/24/2020] [Accepted: 05/04/2020] [Indexed: 05/17/2023]
Abstract
Symbiotic microbes play a crucial role in regulating parasite-host interactions; however, the role of bacterial associates in parasite-host interactions requires elucidation. In this study, we showed that, instead of introducing numerous symbiotic bacteria, dispersal of 4th-stage juvenile (JIV ) pinewood nematodes (PWNs), Bursaphelenchus xylophilus, only introduced few bacteria to its vector beetle, Monochamus alternatus (Ma). JIV showed weak binding ability to five dominant bacteria species isolated from the beetles' pupal chamber. This was especially the case for binding to the opportunistic pathogenic species Serratia marcescens; the nematodes' bacteria binding ability at this critical stage when it infiltrates Ma for dispersal was much weaker compared with Caenorhabditis elegans, Diplogasteroides asiaticus, and propagative-stage PWN. The associated bacterium S. marcescens, which was isolated from the beetles' pupal chambers, was unfavorable to Ma, because it caused a higher mortality rate upon injection into tracheae. In addition, S. marcescens in the tracheae caused more immune effector disorders compared with PWN alone. Ma_Galectin2 (MaGal2), a pattern-recognition receptor, was up-regulated following PWN loading. Recombinant MaGal2 protein formed aggregates with five dominant associated bacteria in vitro. Moreover, MaGal2 knockdown beetles had up-regulated prophenoloxidase gene expression, increased phenoloxidase activity, and decreased PWN loading. Our study revealed a previously unknown strategy for immune evasion of this plant pathogen inside its vector, and provides novel insights into the role of bacteria in parasite-host interactions.
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Affiliation(s)
- Chi Zhang
- 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
| | - Jacob D Wickham
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Lilin Zhao
- 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
| | - Jianghua Sun
- 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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14
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Huang HJ, Ye YX, Ye ZX, Yan XT, Wang X, Wei ZY, Chen JP, Li JM, Sun ZT, Zhang CX. Chromosome-level genome assembly of the bean bug Riptortus pedestris. Mol Ecol Resour 2021; 21:2423-2436. [PMID: 34038033 DOI: 10.1111/1755-0998.13434] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 05/16/2021] [Accepted: 05/20/2021] [Indexed: 12/21/2022]
Abstract
The bean bug (Riptortus pedestris) causes great economic losses of soybeans by piercing and sucking pods and seeds. Although R. pedestris has become the focus of numerous studies associated with insect-microbe interactions, plant-insect interactions, and pesticide resistance, a lack of genomic resources has limited deeper insights. Here, we report the first R. pedestris genome at the chromosomal level using PacBio, Illumina, and Hi-C technologies. The assembled genome was 1.080 Gb in size with a contig N50 of 2.882 Mb. More than 96.3% of the total genome bases were successfully anchored to six unique chromosomes. Genome resequencing of male and female individuals and chromosomic staining demonstrated that the sex chromosome system of R. pedestris is XO, and the shortest chromosome is the X chromosome. In total, 19,026 protein-coding genes were predicted, 18,745 of which were validated as being expressed. Temporospatial expression of R. pedestris genes in six tissues and 37 development stages revealed 4,657 and 7,793 genes mainly expressed in gonads and egg periods, respectively. Evolutionary analysis demonstrated that R. pedestris and Oncopeltus fasciatus formed a sister group and split ∼80 million years ago (Mya). Additionally, a 5.04 Mb complete genome of symbiotic Serratia marcescens Rip1 was assembled, and the virulence factors that account for successful colonization in the host midgut were identified. The high-quality R. pedestris genome provides a valuable resource for further research, as well as for the pest management of bug pests.
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Affiliation(s)
- Hai-Jian Huang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Yu-Xuan Ye
- Institute of Insect Science, Zhejiang University, Hangzhou, China
| | - Zhuang-Xin Ye
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Xiao-Tian Yan
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Xin Wang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Zhong-Yan Wei
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Jian-Ping Chen
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Jun-Min Li
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Zong-Tao Sun
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
| | - Chuan-Xi Zhang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of MOA of China and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
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15
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Lee J, Kim CH, Jang HA, Kim JK, Kotaki T, Shinoda T, Shinada T, Yoo JW, Lee BL. Burkholderia gut symbiont modulates titer of specific juvenile hormone in the bean bug Riptortus pedestris. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2019; 99:103399. [PMID: 31195052 DOI: 10.1016/j.dci.2019.103399] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 05/17/2019] [Accepted: 05/17/2019] [Indexed: 06/09/2023]
Abstract
Recent studies have provided molecular evidence that gut symbiotic bacteria modulate host insect development, fitness and reproduction. However, the molecular mechanisms through which gut symbionts regulate these aspects of host physiology remain elusive. To address these questions, we prepared two different Riptortus-Burkholderia insect models, Burkholderia gut symbiont-colonized (Sym) Riptortus pedestris insects and gut symbiont-noncolonized (Apo) insects. Upon LC-MS analyses, juvenile hormone III skipped bisepoxide (JHSB3) was newly identified from Riptortus Apo- and Sym-female and male adults' insect hemolymph and JHSB3 titer in the Apo- and Sym-female insects were measured because JH is important for regulating reproduction in adult insects. The JHSB3 titer in the Sym-females were consistently higher compared to those of Apo-females. Since previous studies reported that Riptortus hexamerin-α and vitellogenin proteins were upregulated by the topical abdominal application of a JH-analog, chemically synthesized JHSB3 was administered to Apo-females. As expected, the hexamerin-α and vitellogenin proteins were dramatically increased in the hemolymph of JHSB3-treated Apo-females, resulting in increased egg production compared to that in Sym-females. Taken together, these results demonstrate that colonization of Burkholderia gut symbiont in the host insect stimulates biosynthesis of the heteroptera-specific JHSB3, leading to larger number of eggs produced and enhanced fitness in Riptortus host insects.
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Affiliation(s)
- Junbeom Lee
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan, 46241, South Korea
| | - Chan-Hee Kim
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan, 46241, South Korea
| | - Ho Am Jang
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan, 46241, South Korea
| | - Jiyeun Kate Kim
- Department of Microbiology, College of Medicine, Kosin University, Busan, 49267, South Korea
| | - Toyomi Kotaki
- National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, 305-8634, Japan
| | - Tetsuro Shinoda
- Faculty of Food and Agricultural Sciences Fukushima University, 1 Kanayagawa, Fukushima, 960-1248, Japan
| | - Tetsuro Shinada
- (e)Graduate School of Science, Osaka City University, Osaka, 558-8585, Japan
| | - Jin-Wook Yoo
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan, 46241, South Korea
| | - Bok Luel Lee
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan, 46241, South Korea.
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Mankoci S, Ewing J, Dalai P, Sahai N, Barton HA, Joy A. Bacterial Membrane Selective Antimicrobial Peptide-Mimetic Polyurethanes: Structure–Property Correlations and Mechanisms of Action. Biomacromolecules 2019; 20:4096-4106. [DOI: 10.1021/acs.biomac.9b00939] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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17
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Scopel W, Cônsoli FL. Culturable symbionts associated with the reproductive and digestive tissues of the Neotropical brown stinkbug Euschistus heros. Antonie van Leeuwenhoek 2018; 111:2413-2424. [PMID: 30019154 DOI: 10.1007/s10482-018-1130-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 07/10/2018] [Indexed: 11/26/2022]
Abstract
Symbionts are widely distributed in eukaryotes, and potentially affect the physiology, ecology and evolution of their host. Most insects harbour free-living bacteria in their haemocoel and gut lumen, intracellular-living bacteria in a range of tissues or bacteria in host-derived specialized cells. Stinkbugs, as do many arthropods, harbour extracellular bacteria in the gut that may affect the fitness of their host. This study identified the culturable symbionts associated with the ovaries, spermatheca, seminal vesicle and posterior midgut region (V4) of males and females of Euschistus heros (F.) (Hemiptera: Pentatomidae). Several culture media were used to isolate the bacteria associated with these structures. The selected colonies (morphotypes) were cultured in liquid medium, subjected to genomic DNA extraction, 16S rRNA gene amplification, and restriction fragment length polymorphism (RFLP) analyses. Morphotypes with distinct RFLP patterns were purified and sequenced, and the sequences obtained were used for putative identification and phylogenetic analysis. Comparison of the sequences with those available in the EzTaxon-e database and the use of a matrix of paired distances grouped the isolates in phylotypes belonging to the Phylum Proteobacteria. Proteobacteria was represented by γ-Proteobacteria phylotypes belonging to Enterobacteriaceae, while Firmicutes had Bacilli phylotypes distributed in Enterococcaceae and Staphylococcaceae. Some of the phylotypes identified were associated exclusively with single structures, such as ovaries, spermatheca and the V4 midgut region of males and females. All culturable bacteria associated with the seminal vesicle were also associated with other tissues.
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Affiliation(s)
- Wanessa Scopel
- Insect Interactions Laboratory, Department of Entomology and Acarology, College of Agriculture Luiz de Queiroz (ESALQ), University of São Paulo (USP), Av. Pádua Dias 11, Piracicaba, SP, 13418-900, Brazil
| | - Fernando Luis Cônsoli
- Insect Interactions Laboratory, Department of Entomology and Acarology, College of Agriculture Luiz de Queiroz (ESALQ), University of São Paulo (USP), Av. Pádua Dias 11, Piracicaba, SP, 13418-900, Brazil.
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18
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Lee SA, Jang SH, Kim BH, Shibata T, Yoo J, Jung Y, Kawabata SI, Lee BL. Insecticidal activity of the metalloprotease AprA occurs through suppression of host cellular and humoral immunity. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 81:116-126. [PMID: 29174605 DOI: 10.1016/j.dci.2017.11.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 11/22/2017] [Accepted: 11/22/2017] [Indexed: 06/07/2023]
Abstract
The biochemical characterization of virulence factors from entomopathogenic bacteria is important to understand entomopathogen-insect molecular interactions. Pseudomonas entomophila is a typical entomopathogenic bacterium that harbors virulence factors against several insects. However, the molecular actions of these factors against host innate immune responses are not clearly elucidated. In this study, we observed that bean bugs (Riptortus pedestris) that were injected with P. entomophila were highly susceptible to this bacterium. To determine how P. entomophila counteracts the host innate immunity to survive within the insect, we purified a highly enriched protein with potential host insect-killing activity from the culture supernatant of P. entomophila. Then, a 45-kDa protein was purified to homogeneity and identified as AprA which is an alkaline zinc metalloprotease of the genus Pseudomonas by liquid chromatography mass spectrometry (LC-MS). Purified AprA showed a pronounced killing effect against host insects and suppressed both host cellular and humoral innate immunity. Furthermore, to show that AprA is an important insecticidal protein of P. entomophila, we used an aprA-deficient P. entomophila mutant strain (ΔaprA). When ΔaprA mutant cells were injected to host insects, this mutant exhibited extremely attenuated virulence. In addition, the cytotoxicity against host hemocytes and the antimicrobial peptide-degrading ability of the ΔaprA mutant were greatly decreased. These findings suggest that AprA functions as an important insecticidal protein of P. entomophila via suppression of host cellular and humoral innate immune responses.
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Affiliation(s)
- Seung Ah Lee
- Global Research Laboratory of Insect Symbiosis, Pusan National University, Busan 46241, South Korea
| | - Seong Han Jang
- Global Research Laboratory of Insect Symbiosis, Pusan National University, Busan 46241, South Korea
| | - Byung Hyun Kim
- Global Research Laboratory of Insect Symbiosis, Pusan National University, Busan 46241, South Korea
| | - Toshio Shibata
- Institute for Advanced Study, Kyushu University, Fukuoka 819-0395, Japan; Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Jinwook Yoo
- College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Yunjin Jung
- College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Shun-Ichiro Kawabata
- Institute for Advanced Study, Kyushu University, Fukuoka 819-0395, Japan; Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Bok Luel Lee
- Global Research Laboratory of Insect Symbiosis, Pusan National University, Busan 46241, South Korea.
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CpxR-Dependent Thermoregulation of Serratia marcescens PrtA Metalloprotease Expression and Its Contribution to Bacterial Biofilm Formation. J Bacteriol 2018; 200:JB.00006-18. [PMID: 29378892 DOI: 10.1128/jb.00006-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 01/20/2018] [Indexed: 12/19/2022] Open
Abstract
PrtA is the major secreted metalloprotease of Serratia marcescens Previous reports implicate PrtA in the pathogenic capacity of this bacterium. PrtA is also clinically used as a potent analgesic and anti-inflammatory drug, and its catalytic properties attract industrial interest. Comparatively, there is scarce knowledge about the mechanisms that physiologically govern PrtA expression in Serratia In this work, we demonstrate that PrtA production is derepressed when the bacterial growth temperature decreases from 37°C to 30°C. We show that this thermoregulation occurs at the transcriptional level. We determined that upstream of prtA, there is a conserved motif that is directly recognized by the CpxR transcriptional regulator. This feature is found along Serratia strains irrespective of their isolation source, suggesting an evolutionary conservation of CpxR-dependent regulation of PrtA expression. We found that in S. marcescens, the CpxAR system is more active at 37°C than at 30°C. In good agreement with these results, in a cpxR mutant background, prtA is derepressed at 37°C, while overexpression of the NlpE lipoprotein, a well-known CpxAR-inducing condition, inhibits PrtA expression, suggesting that the levels of the activated form of CpxR are increased at 37°C over those at 30°C. In addition, we establish that PrtA is involved in the ability of S. marcescens to develop biofilm. In accordance, CpxR influences the biofilm phenotype only when bacteria are grown at 37°C. In sum, our findings shed light on regulatory mechanisms that fine-tune PrtA expression and reveal a novel role for PrtA in the lifestyle of S. marcescensIMPORTANCE We demonstrate that S. marcescens metalloprotease PrtA expression is transcriptionally thermoregulated. While strongly activated below 30°C, its expression is downregulated at 37°C. We found that in S. marcescens, the CpxAR signal transduction system, which responds to envelope stress and bacterial surface adhesion, is activated at 37°C and able to downregulate PrtA expression by direct interaction of CpxR with a binding motif located upstream of the prtA gene. Moreover, we reveal that PrtA expression favors the ability of S. marcescens to develop biofilm, irrespective of the bacterial growth temperature. In this context, thermoregulation along with a highly conserved CpxR-dependent modulation mechanism gives clues about the relevance of PrtA as a factor implicated in the persistence of S. marcescens on abiotic surfaces and in bacterial host colonization capacity.
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Park KE, Jang SH, Lee J, Lee SA, Kikuchi Y, Seo YS, Lee BL. The roles of antimicrobial peptide, rip-thanatin, in the midgut of Riptortus pedestris. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2018; 78:83-90. [PMID: 28919360 DOI: 10.1016/j.dci.2017.09.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 09/11/2017] [Accepted: 09/11/2017] [Indexed: 06/07/2023]
Abstract
Recently, we have reported the structural determination of antimicrobial peptides (AMPs), such as riptocin, rip-defensin, and rip-thanatin, from Riptortus pedestris. However, the biological roles of AMPs in the host midgut remain elusive. Here, we compared the expression levels of AMP genes in apo-symbiotic insects with those of symbiotic insects. Interestingly, the expression level of rip-thanatin was only significantly increased in the posterior midgut region of symbiotic insects. To further determine the role of rip-thanatin, we checked antimicrobial activity in vitro. Rip-thanatin showed high antimicrobial activity and had the same structural characteristics as other reported thanatins. To find the novel function of rip-thanatin, rip-thanatin was silenced by RNA interference, and the population of gut symbionts was measured. When rip-thanatin was silenced, the symbionts' titer was increased upon bacterial infection. These results suggest that rip-thanatin functions not only as an antimicrobial peptide but also in controlling the symbionts' titer in the host midgut.
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Affiliation(s)
- Kyoung-Eun Park
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Seong Han Jang
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Junbeom Lee
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Seung Ah Lee
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Yoshitomo Kikuchi
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Hokkaido Center, Sapporo, Japan; Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
| | - Young-Su Seo
- Department of Microbiology, Pusan National University, Busan 46241, South Korea
| | - Bok Luel Lee
- Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea.
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Kim JK, Jang HA, Kim MS, Cho JH, Lee J, Di Lorenzo F, Sturiale L, Silipo A, Molinaro A, Lee BL. The lipopolysaccharide core oligosaccharide of Burkholderia plays a critical role in maintaining a proper gut symbiosis with the bean bug Riptortus pedestris. J Biol Chem 2017; 292:19226-19237. [PMID: 28972189 DOI: 10.1074/jbc.m117.813832] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 09/14/2017] [Indexed: 12/26/2022] Open
Abstract
Lipopolysaccharide, the outer cell-wall component of Gram-negative bacteria, has been shown to be important for symbiotic associations. We recently reported that the lipopolysaccharide O-antigen of Burkholderia enhances the initial colonization of the midgut of the bean bug, Riptortus pedestris However, the midgut-colonizing Burkholderia symbionts lack the O-antigen but display the core oligosaccharide on the cell surface. In this study, we investigated the role of the core oligosaccharide, which directly interacts with the host midgut, in the Riptortus-Burkholderia symbiosis. To this end, we generated the core oligosaccharide mutant strains, ΔwabS, ΔwabO, ΔwaaF, and ΔwaaC, and determined the chemical structures of their oligosaccharides, which exhibited different compositions. The symbiotic properties of these mutant strains were compared with those of the wild-type and O-antigen-deficient ΔwbiG strains. Upon introduction into Riptortus via the oral route, the core oligosaccharide mutant strains exhibited different rates of colonization of the insect midgut. The symbiont titers in fifth-instar insects revealed significantly reduced population sizes of the inner core oligosaccharide mutant strains ΔwaaF and ΔwaaC These two strains also negatively affected host growth rate and fitness. Furthermore, R. pedestris individuals colonized with the ΔwaaF and ΔwaaC strains were vulnerable to septic bacterial challenge, similar to insects without a Burkholderia symbiont. Taken together, these results suggest that the core oligosaccharide from Burkholderia symbionts plays a critical role in maintaining a proper symbiont population and in supporting the beneficial effects of the symbiont on its host in the Riptortus-Burkholderia symbiosis.
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Affiliation(s)
- Jiyeun Kate Kim
- From the Department of Microbiology, Kosin University College of Medicine, Busan 49267, South Korea
| | - Ho Am Jang
- the Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Min Seon Kim
- the Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Jae Hyun Cho
- the Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Junbeom Lee
- the Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea
| | - Flaviana Di Lorenzo
- the Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, Napoli 80126, Italy, and
| | - Luisa Sturiale
- the CNR-Istituto per i Polimeri, Compositi e Biomateriali IPCB, Via P. Gaifami 18, Catania 95126, Italy
| | - Alba Silipo
- the Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, Napoli 80126, Italy, and
| | - Antonio Molinaro
- the Dipartimento di Scienze Chimiche, Università di Napoli Federico II, Complesso Universitario Monte S. Angelo, Via Cintia 4, Napoli 80126, Italy, and
| | - Bok Luel Lee
- the Global Research Laboratory, College of Pharmacy, Pusan National University, Busan 46241, South Korea,
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