scholarly journals Spodoptera frugiperdatranscriptional response to infestation bySteinernema carpocapsae

2019 ◽  
Author(s):  
Louise Huot ◽  
Simon George ◽  
Pierre-Alain Girard ◽  
Dany Severac ◽  
Nicolas Nègre ◽  
...  
Keyword(s):  
Biological Control ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Spodoptera Frugiperda ◽  
Fat Body ◽  
Steinernema Carpocapsae ◽  
Agricultural Pest ◽  
Xenorhabdus Nematophila ◽  
Transcriptional Responses ◽  
The World

AbstractSteinernema carpocapsaeis an entomopathogenic nematode (EPN) used in biological control of agricultural pest insects. It enters the hemocoel of its host via the intestinal tract and releases its symbiotic bacteriumXenorhabdus nematophila, which kills the insect in less than 48 hours. Although several aspects of its interactions with insects have been extensively studied, still little is known about the immune and physiological responses of its different hosts. In order to improve this knowledge, we examined the transcriptional responses to EPN infestation of the fat body, the hemocytes and the midgut in the lepidopteran pest modelSpodoptera frugiperda(Lepidoptera: Noctuidae).Our results indicate that the tissues poorly respond to the infestation at an early time post-infestation of 8 h, even though the proliferation of the bacterial symbiont within the hemocoel is detected. Only 5 genes are differentially expressed in the fat body of the caterpillars. However, strong transcriptional responses are observed at a later time point of 15 h post-infestation in all three tissues. While few genes are differentially expressed in the midgut, tissue-specific panels of induced metalloprotease inhibitors, immune receptors and antimicrobial peptides together with several uncharacterized genes are up-regulated in the fat body and the hemocytes. In addition, among the most up-regulated genes, we identified new potential immune effectors, unique to Lepidoptera, for which we present evidence of acquisition by Horizontal Gene Transfer from bacteria.Altogether, these results pave the way for further functional studies of the mobilized genes’ involvement in the interaction with the EPN.Author summaryThe Fall Armyworm,Spodoptera frugiperda, is a major agricultural pest. The caterpillars cause extensive damage to crops of importance such as corn, rice, sorghum and cotton. Originally from the Americas, it is currently becoming invasive in other parts of the world, first in Africa in 2016, then in India and now in south-east Asia. Programs of biological control against insect pests are increasingly encouraged around the world and include the use of pathogens. Entomopathogenic nematodes such asSteinernema carpocapsaeare already commercialized as organic pesticides. These nematodes live in the soil and enter the body of their insect preys. Once within the insects, they release their symbiotic bacteria (Xenorhabdus nematophilain this case), which infect and kill the host in a few hours. The nematodes can then feed on the dead insects, reproduce and resume their life cycle. It is a major challenge to understand how EPN achieve their pathogenicity as well as how the insects can resist them. Here we provide the foundation for such an interaction between EPN and a Lepidoptera. We analyzed the dynamic of transcriptional response in three insect tissues (midgut, fat body and hemocytes) upon infestation by EPN. Not many studies have been performed genome-wide on such an interaction, and none on a Lepidopteran model of economical importance. Our transcriptomic approach revealed some specificities of the Lepidopteran defense mechanisms. In particular, we discovered a set of genes, acquired in Lepidoptera from bacteria by Horizontal Gene Transfer, that probably encode proteins with antibiotic activity.

scholarly journals Spodoptera frugiperda transcriptional response to infestation by Steinernema carpocapsae

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Louise Huot ◽  
Simon George ◽  
Pierre-Alain Girard ◽  
Dany Severac ◽  
Nicolas Nègre ◽  
...  
Keyword(s):  
Spodoptera Frugiperda ◽  
Fat Body ◽  
Entomopathogenic Nematode ◽  
Transcriptional Response ◽  
Early Time ◽  
Symbiotic Bacterium ◽  
Steinernema Carpocapsae ◽  
Differentially Expressed ◽  
Xenorhabdus Nematophila ◽  
Transcriptional Responses

Abstract Steinernema carpocapsae is an entomopathogenic nematode (EPN) used in biological control of agricultural pest insects. It enters the hemocoel of its host via the intestinal tract and releases its symbiotic bacterium Xenorhabdus nematophila. In order to improve our knowledge about the physiological responses of its different hosts, we examined the transcriptional responses to EPN infestation of the fat body, the hemocytes and the midgut in the lepidopteran pest Spodoptera frugiperda. The tissues poorly respond to the infestation at an early time post-infestation of 8 h with only 5 genes differentially expressed in the fat body of the caterpillars. Strong transcriptional responses are observed at a later time point of 15 h post-infestation in all three tissues. Few genes are differentially expressed in the midgut but tissue-specific panels of induced metalloprotease inhibitors, immune receptors and antimicrobial peptides together with several uncharacterized genes are up-regulated in the fat body and the hemocytes. Among the most up-regulated genes, we identified new potential immune effectors, unique to Lepidoptera, which show homology with bacterial genes of unknown function. Altogether, these results pave the way for further functional studies of the responsive genes’ involvement in the interaction with the EPN.

scholarly journals Partner-specific induction of Spodoptera frugiperda immune genes in response to the entomopathogenic nematobacterial complex Steinernema carpocapsae-Xenorhabdus nematophila

2019 ◽  
Author(s):  
Louise Huot ◽  
Audrey Bigourdan ◽  
Sylvie Pagès ◽  
Jean-Claude Ogier ◽  
Pierre-Alain Girard ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Spodoptera Frugiperda ◽  
Fat Body ◽  
Functional Characterization ◽  
Steinernema Carpocapsae ◽  
Symbiotic Bacteria ◽  
Xenorhabdus Nematophila ◽  
Immune Genes ◽  
Specific Induction

AbstractThe Steinernema carpocapsae-Xenorhabdus nematophila association is a nematobacterial complex (NBC) used in biological control of insect crop pests. The ability of this dual pathogen to infest and kill an insect strongly depends on the dialogue between the host’s immune system and each partner of the complex. Even though this dialogue has been extensively studied from the two partners’ points of view in several insect models, still little is known about the structure and the molecular aspects of the insects’ immune response to the dual infection. Here, we used the lepidopteran pest Spodoptera frugiperda as a model to analyze the respective impact of each NBC partner in the spatiotemporal immune responses that are induced after infestation. To this aim, we first analyzed the expression variations of the insect’s immune genes in the fat bodies and hemocytes of infested larvae by using previously obtained RNAseq data. We then selected representative immune genes for RT-qPCR investigations of the temporal variations of their expressions after infestation and of their induction levels after independent injections of each partner. We found that the fat body and the hemocytes both produce potent and stable immune responses to the infestation by the NBC, which correspond to combinations of bacterium- and nematode-induced ones. Consistent with the nature of each pathogen, we showed that X. nematophila mainly induces genes classically involved in antibacterial responses, whereas S. carpocapsae is responsible for the induction of lectins and of genes expected to be involved in melanization and cellular encapsulation. In addition, we found that two clusters of unknown genes dramatically induced by the NBC also present partner-specific induction profiles, which paves the way for their functional characterization. Finally, we discuss putative relationships between the variations of the expression of some immune genes and the NBC’s immunosuppressive strategies.Author summaryEntomopathogenic nematodes (EPNs) are living in the soil and prey upon insect larvae. They enter the insect by the natural orifices, and reach the hemocoel through the intestinal epithelium. There, they release their symbiotic bacteria that will develop within the insect and eventually kill it. Nematodes can then feed and reproduce on the insect cadaver. By using transcriptomic approaches, we previously showed that Lepidoptera larvae (caterpillars of the fall armyworm Spodoptera frugiperda) produce a strong immune response in reaction to infestation by EPNs. However, we do not know if this immune reaction is triggered by the nematode itself -Steinernema carpacapsae - or its symbiotic bacteria - Xenorhabdus nematophila. To answer this question, we present in this work a careful annotation of immunity genes in S. frugiperda and surveyed their activation by quantitative PCR in reaction to an injection of the bacteria alone, the axenic nematode or the associated complex. We found that the immune genes are selectively activated by either the bacteria or the nematode and we discuss the implication of which pathway are involved in the defense against various pathogens. We also show that a cluster of newly discovered genes, present only in Lepidoptera, is activated by the nematode only and could represent nematicide genes.

scholarly journals Invasion history of Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) in Ecuador

2020 ◽  
Author(s):  
Diego F. Cisneros-Heredia ◽  
Emilia Peñaherrera-Romero
Keyword(s):  
Biological Control ◽  
Harmonia Axyridis ◽  
Economic Impacts ◽  
Invasion History ◽  
Museum Specimens ◽  
Agricultural Pest ◽  
Harlequin Ladybird ◽  
The World ◽  
History Of ◽  
Harmonia Axyridis Pallas

AbstractHarmonia axyridis is a ladybird extensively used around the world for biological control of agricultural pest. However, it has become invasive in several countries, producing negative ecological and socio-economic impacts. Herein, we review the invasion history of the Harlequin Ladybird Harmonia axyridis (Pallas, 1773) in Ecuador. Although first reported in Ecuador in 2012, museum specimens date back to 2004 and it is currently established across the country, especially along the Andean region. Due to its invasive nature, further studies are urgently needed to evaluate possible impacts of H. axyridis on the Ecuadorian biodiversity and agroindustry.

scholarly journals A survey investigating the diversity and distribution of entomopathogenic nematodes in the UK and the first confirmed UK record of Steinernema carpocapsae

Nematology ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 851-858 ◽  
Author(s):  
Cassandra Edmunds ◽  
Rory J. Post ◽  
Craig S. Wilding ◽  
Robbie Rae
Keyword(s):  
Biological Control ◽  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Soil Samples ◽  
Steinernema Carpocapsae ◽  
Biological Control Agents ◽  
Diverse Range ◽  
The World ◽  
The Uk ◽  
Insect Parasites

Summary Entomopathogenic nematodes (EPN) of the families Steinernematidae and Heterorhabditidae are lethal insect parasites that have been commercialised as biological control agents. EPN have been isolated from across the world but it has been more than 20 years since the last survey of the UK, and species like Steinernema carpocapsae have never been found here and positively identified through molecular biology. We collected 518 soil samples from a diverse range of habitats across the UK and baited them with Galleria mellonella to isolate EPN. Dead G. mellonella were placed in White traps and emergent EPN underwent DNA barcoding analyses. From the 518 samples, 3.5% were positive for EPN. No Heterorhabditis species were found, but seven isolates of S. glaseri, one isolate of S. feltiae, eight isolates of S. affine and two isolates of S. carpocapsae were found. This was the first confirmed record of S. carpocapsae in the UK.

scholarly journals Evidence of recent interspecies horizontal gene transfer regarding nucleopolyhedrovirus infection of Spodoptera frugiperda

BMC Genomics ◽  
2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Gloria Patricia Barrera ◽  
Mariano Nicolás Belaich ◽  
Manuel Alfonso Patarroyo ◽  
Laura Fernanda Villamizar ◽  
Pablo Daniel Ghiringhelli
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Spodoptera Frugiperda

scholarly journals Efficacy of some native entomopathogenic nematodes against the alfalfa weevil, Hypera postica (Gyllenhal) (Coleoptera: Curculionidae), and the lucerne beetle, Gonioctena fornicata (Brüggemann) (Coleoptera: Chrysomelidae), adults under laboratory conditions

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Ayşegül Çağlayan ◽  
Turgut Atay ◽  
İlker Kepenekci
Keyword(s):  
Biological Control ◽  
Black Sea ◽  
Entomopathogenic Nematodes ◽  
Insect Pests ◽  
Heterorhabditis Bacteriophora ◽  
Steinernema Carpocapsae ◽  
Alfalfa Weevil ◽  
Hypera Postica ◽  
Laboratory Conditions ◽  
The World

Abstract Background Entomopathogenic nematodes (EPNs) have more important role in biological control of economic insect pests. The effect of native EPNs on adults of the lucerne beetle, Gonioctena fornicata (Brüggemann, 1873) (Coleoptera: Chrysomelidae), and the alfalfa weevil, Hypera postica (Gyllenhal, 1813) (Coleoptera: Curculionidae), which are important alfalfa pests in Turkey and around the world, was investigated. Results Dose-mortality assays were carried out with 5 isolates [Steinernema carpocapsae (Weiser, 1955) (Nematoda: Steinernematidae) (Black sea isolate), S. feltiae Filipjev, 1934 (isolate 09-31), Heterorhabditis bacteriophora Poinar, 1976 (Nematoda: Heterorhabditidae) (isolate 09-43), H. bacteriophora Tokat-Songut, and S. carpocapsae Tokat-Ulas] using doses of 500, 1000, and 2000 IJs ml−1 under the laboratory conditions. Studies showed that all isolates had an effect 90% and more at 2000 IJs ml−1 and at the end of 112 h [except, H. bacteriophora (isolate 09-43) and H. bacteriophora Tokat-Songut isolates against H. postica]. In addition, LT30, LT50, and LT90 values at 1000 IJs ml−1 were determined. Conclusions According to the results, G. fornicata adults were susceptible to all isolates tested in the study and H. postica adults were susceptible to the isolates S. carpocapsae (Black sea isolate), S. feltiae (isolate 09-31), and S. carpocapsae Tokat-Ulas. This is the first study conducted in Turkey for the virulence of EPNs against G. fornicata and H. postica.

scholarly journals Diversity and Dynamics of the Canadian CoastalVibrioCommunity: an Emerging Trend Detected in the Temperate Regions

2018 ◽  
Vol 200 (15) ◽  
Author(s):  
Swapan K. Banerjee ◽  
Rebecca Rutley ◽  
Jeff Bussey
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Coastal Waters ◽  
Vibrio Parahaemolyticus ◽  
Nutrient Status ◽  
Surveillance Study ◽  
Human Consumption ◽  
Content Type ◽  
The World ◽  
Increasing Trend

ABSTRACTVibriospecies are indigenous to the marine and estuarine environments around the world and are the leading cause of water- and seafood-borne illnesses due to conditions favoring the transmission and growth of the species. Horizontal gene transfer, recombination, and mutation enableVibriospp. to adapt rapidly to environmental challenges from biotic and abiotic parameters, including temperature, salinity, and nutrient status of the coastal waters. This surveillance study provides evidence ofVibrio choleraeemerging in the temperate estuaries of Canada, thereby redefining the diversity and dynamics of its coastalVibriopopulation. The presence of the pathogenic context inVibrio parahaemolyticuswas also detected with an increasing trend during the study period.IMPORTANCEProliferation and abundance of the harmful biotypes ofVibriospp. in the estuaries of Canada indicate the possibility of producing contaminated seafood for human consumption. The findings of this surveillance study may lead to awareness which may help efforts to reduce the occurrence of illnesses or outbreaks caused byVibriospp. in seafood.

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