0000000000640102

AUTHOR

Barbara Giordana

showing 2 related works from this author

Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism

2016

Bacillus thuringiensis is a widely used bacterial entomopathogen producing insecticidal toxins, some of which are expressed in insect-resistant transgenic crops. Surprisingly, the killing mechanism of B. thuringiensis remains controversial. In particular, the importance of the septicemia induced by the host midgut microbiota is still debated as a result of the lack of experimental evidence obtained without drastic manipulation of the midgut and its content. Here this key issue is addressed by RNAi-mediated silencing of an immune gene in a lepidopteran host Spodoptera littoralis, leaving the midgut microbiota unaltered. The resulting cellular immunosuppression was characterized by a reduced …

Crops Agricultural0301 basic medicineHemocytesSerratiaBacillus thuringiensisSpodopteraSerratiaMicrobiologyHemolysin Proteins03 medical and health sciencesBacterial ProteinsInsect-pathogen interactionImmunityBacillus thuringiensisAnimalsPest Control Biologicalbioinsecticide | insect-pathogen interactions | insect biocontrol | pore-forming toxins | immunitySpodoptera littoralisRNA Double-StrandedClostridiumImmunosuppression TherapyPore-forming toxinMultidisciplinaryBacillus thuringiensis ToxinsInsect biocontrolbiologyHost (biology)MicrobiotafungiImmunityMidgutBiological Sciencesbiology.organism_classificationImmunity InnateBioinsecticideEndotoxinsIntestines030104 developmental biologyGene Expression RegulationLarvaPore-forming toxinInsect ProteinsRNA InterferenceImmunocompetenceProceedings of the National Academy of Sciences
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Toxicity and mode of action of Bacillus thuringiensis Cry proteins in the Mediterranean corn borer, Sesamia nonagrioides (Lefebvre)

2006

ABSTRACT Sesamia nonagrioides is one of the most damaging pests of corn in Spain and other Mediterranean countries. Bt corn expressing the Bacillus thuringiensis Cry1Ab toxin is being grown on about 58,000 ha in Spain. Here we studied the mode of action of this Cry protein on S. nonagrioides (binding to specific receptors, stability of binding, and pore formation) and the modes of action of other Cry proteins that were found to be active in this work (Cry1Ac, Cry1Ca, and Cry1Fa). Binding assays were performed with 125 I- or biotin-labeled toxins and larval brush border membrane vesicles (BBMV). Competition experiments indicated that these toxins bind specifically and that Cry1Aa, Cry1Ab, an…

Cell Membrane PermeabilityMembrane permeabilityBacterial ToxinsBacillus thuringiensisSesamia nonagrioidesBacterial ToxinBacterial ProteinZea maysApplied Microbiology and BiotechnologyOstriniaHemolysin ProteinsZea mayBacterial ProteinsEndotoxinBacillus thuringiensisBotanyInvertebrate MicrobiologyAnimalsBacillus thuringiensiBinding siteMode of actionPest Control BiologicalGenetically modified maizeBacillus thuringiensis ToxinsEcologybiologyMicrovilliAnimalfungifood and beveragesHemolysin Proteinbiology.organism_classificationPlants Genetically ModifiedEndotoxinsLepidopteraCry1AcBiochemistryLarvaFood ScienceBiotechnology
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