Attachment ofMetarhizium anisopliaeto the Southern Green Stink BugNezara viridulaCuticle and Fungistatic Effect of Cuticular Lipids and Aldehydes

Sosa-Gómez, Daniel Ricardo; Boucias, Drion G.; Nation, James L.

doi:10.1006/jipa.1996.4619

Cited by 143 publications

(89 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The underlying biochemical mechanism(s) behind such resistance and counterattempts by the fungus to overcome such defenses has remained obscure. For some insects, resistance has been attributed to the production of antimicrobial cuticular compounds (53)(54)(55). More recently there is growing evidence that some of these compounds are not produced by the insects themselves but by endogenous microbial flora, adding an interesting twist to coevolutionary scenarios (56,57).…”

Section: Discussionmentioning

confidence: 99%

Tenebrionid secretions and a fungal benzoquinone oxidoreductase form competing components of an arms race between a host and pathogen

Pedrini

Ortiz‐Urquiza

Huarte‐Bonnet

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

127

118

View full text Add to dashboard Cite

Entomopathogenic fungi and their insect hosts represent a model system for examining invertebrate-pathogen coevolutionary selection processes. Here we report the characterization of competing components of an arms race consisting of insect protective antimicrobial compounds and evolving fungal mechanisms of detoxification. The insect pathogenic fungus Beauveria bassiana has a remarkably wide host range; however, some insects are resistant to fungal infection. Among resistant insects is the tenebrionid beetle Tribolium castaneum that produces benzoquinone-containing defensive secretions. Reduced fungal germination and growth was seen in media containing T. castaneum dichloromethane extracts or synthetic benzoquinone. In response to benzoquinone exposure, the fungus expresses a 1,4-benzoquinone oxidoreductase, BbbqrA, induced >40-fold. Gene knockout mutants (ΔBbbqrA) showed increased growth inhibition, whereas B. bassiana overexpressing BbbqrA (Bb::BbbqrAO) displayed increased resistance to benzoquinone compared with wild type. Increased benzoquinone reductase activity was detected in wild-type cells exposed to benzoquinone and in the overexpression strain. Heterologous expression and purification of BbBqrA in Escherichia coli confirmed NAD(P)H-dependent benzoquinone reductase activity. The ΔBbbqrA strain showed decreased virulence toward T. castaneum, whereas overexpression of BbbqrA increased mortality versus T. castaneum. No change in virulence was seen for the ΔBbbqrA or Bb::BbbqrAO strains when tested against the greater wax moth Galleria mellonella or the beetle Sitophilus oryzae, neither of which produce significant amounts of cuticular quinones. The observation that artificial overexpression of BbbqrA results in increased virulence only toward quinone-secreting insects implies the lack of strong selection or current failure of B. bassiana to counteradapt to this particular host defense throughout evolution.

show abstract

Section: Discussionmentioning

confidence: 99%

Tenebrionid secretions and a fungal benzoquinone oxidoreductase form competing components of an arms race between a host and pathogen

Pedrini

Ortiz‐Urquiza

Huarte‐Bonnet

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

127

118

View full text Add to dashboard Cite

show abstract

“…hydrophobic and electrostatic forces [21,22], and the second step involves secretion of enzymes and mucilage. Hydrolytic enzymes degrade the cuticle, release nutrients and facilitate penetration [23–25], while mucilage is often secreted to enhance binding to the host cuticle [26]. The adhesin, Mad1 assists in attachment of fungi to the insect cuticle, thus contributing to pathogenesis.…”

Section: Introductionmentioning

confidence: 99%

Highly specific host-pathogen interactions influence Metarhizium brunneum blastospore virulence against Culex quinquefasciatus larvae

et al. 2018

View full text Add to dashboard Cite

Entomopathogenic fungi are potential biological control agents of mosquitoes. Our group observed that not all mosquitoes were equally susceptible to fungal infection and observed significant differences in virulence of different spore types. Conidiospores and blastospores were tested against Culex quinquefasciatus larvae. Blastospores are normally considered more virulent than conidia as they form germ tubes and penetrate the host integument more rapidly than conidia. However, when tested against Cx. quinquefasciatus, blastospores were less virulent than conidia. This host-fungus interaction was studied by optical, electron and atomic force microscopy (AFM). Furthermore, host immune responses and specific gene expression were investigated. Metarhizium brunneum (formerly M. anisopliae) ARSEF 4556 blastospores did not readily adhere to Culex larval integument and the main route of infection was through the gut. Adhesion forces between blastospores and Culex cuticle were significantly lower than for other insects. Larvae challenged with blastospores showed enhanced immune responses, with increased levels of phenoloxidase, glutathione-S-transferase, esterase, superoxide dismutase and lipid peroxidase activity. Interestingly, M. brunneum pathogenicity/stress-related genes were all down-regulated in blastospores exposed to Culex. Conversely, when conidia were exposed to Culex, the pathogenicity genes involved in adhesion or cuticle degradation were up-regulated. Delayed host mortality following blastospore infection of Culex was probably due to lower adhesion rates of blastospores to the cuticle and enhanced host immune responses deployed to counter infection. The results here show that subtle differences in host-pathogen interactions can be responsible for significant changes in virulence when comparing mosquito species, having important consequences for biological control strategies and the understanding of pathogenicity processes.

show abstract

“…To better understand this premise, the interactions among insect pests, their natural enemies and their host plants must be intensely studied. For example, susceptibility may be affected by components of the insect cuticle, seeing that conidia may suffer from toxicity, fungistatic effects and eventual stimulating effects (Sosa-Gómez et al 1997;Gillespie et al 2000;Santiago-Alvarez et al 2006) by compounds in the cuticle of the insects, those sequestrated from alimentary sources (Tallamy et al 1998), or even through volatiles produced by metathoracic glands (Lopes et al 2015). This effect has been demonstrated for fungi (Nishida et al 1992;Tallamy et al 1998;Poprawski et al 2000a;Poprawski et al 2000b;Klingen et al 2002).…”

Section: Discussionmentioning

confidence: 99%

“…(Ascomycota: Clavicipitaceae). The incidence of these infections is generally low (Moscardi et al 1988) and the occurrence of natural epizootics with high prevalence are restricted to greenhouse conditions (Sosa-Gómez et al 1997). Studies have been undertaken with the aim of determining the effects of fungal infection on laboratory stink bug populations.…”

Section: Introductionmentioning

confidence: 99%

“…Studies have been undertaken with the aim of determining the effects of fungal infection on laboratory stink bug populations. The results of these studies demonstrated that high concentrations of conidia are required to reach a satisfactory mortality index (Moscardi et al 1985;Sosa-Gómez et al 1997;Sosa-Gómez et al 1998). The different species belonging to the soybeanstink bug complex exhibit various levels of susceptibility to entomopathogenic fungi, and some are inherently tolerant to infection by such fungi (Sosa-Gómez et al 1997).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Biological Parameters of Euschistus heros (F.) (Heteroptera: Pentatomidae) and its Susceptibility to Entomopathogenic Fungi When Fed on Different Diets

Oliveira¹,

Dudczak

Alves

et al. 2016

Braz. arch. biol. technol.

View full text Add to dashboard Cite

show abstract

Attachment ofMetarhizium anisopliaeto the Southern Green Stink BugNezara viridulaCuticle and Fungistatic Effect of Cuticular Lipids and Aldehydes

Cited by 143 publications

References 0 publications

Tenebrionid secretions and a fungal benzoquinone oxidoreductase form competing components of an arms race between a host and pathogen

Tenebrionid secretions and a fungal benzoquinone oxidoreductase form competing components of an arms race between a host and pathogen

Highly specific host-pathogen interactions influence Metarhizium brunneum blastospore virulence against Culex quinquefasciatus larvae

Biological Parameters of Euschistus heros (F.) (Heteroptera: Pentatomidae) and its Susceptibility to Entomopathogenic Fungi When Fed on Different Diets

Contact Info

Product

Resources

About