Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism
| Autor: | Silvia Gigliotti, Paola Varricchio, Gianluca Tettamanti, Francesco Pennacchio, Ilaria Di Lelio, Morena Casartelli, Barbara Giordana, Silvia Caccia, Núria Banyuls, Danilo Ercolini, Adriana Marinelli, Antonietta La Storia, Juan Ferré, Eleonora Franzetti |
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| Přispěvatelé: | Caccia, Silvia, DI LELIO, Ilaria, LA STORIA, Antonietta, Marinelli, Adriana, Varricchio, Paola, Franzetti, Eleonora, Banyuls, Núria, Tettamanti, Gianluca, Casartelli, Morena, Giordana, Barbara, Ferré, Juan, Gigliotti, Silvia, Ercolini, Danilo, Pennacchio, Francesco |
| Rok vydání: | 2016 |
| Předmět: |
Crops
Agricultural 0301 basic medicine Hemocytes Serratia Bacillus thuringiensis Spodoptera Microbiology Hemolysin Proteins 03 medical and health sciences Bacterial Proteins Insect-pathogen interaction Immunity Animals Pest Control Biological bioinsecticide | insect-pathogen interactions | insect biocontrol | pore-forming toxins | immunity Spodoptera littoralis RNA Double-Stranded Clostridium Immunosuppression Therapy Pore-forming toxin Multidisciplinary Bacillus thuringiensis Toxins Insect biocontrol biology Host (biology) Microbiota fungi Midgut Biological Sciences biology.organism_classification Immunity Innate Bioinsecticide Endotoxins Intestines 030104 developmental biology Gene Expression Regulation Larva Insect Proteins RNA Interference Immunocompetence |
| Zdroj: | Proceedings of the National Academy of Sciences of the United States of America 113 (2016). doi:10.1073/pnas.1521741113 info:cnr-pdr/source/autori:Silvia Caccia Ilaria Di Lelio, Antonietta La Storia, Adriana Marinelli, Paola Varricchio, Eleonora Franzetti, Núria Banyuls, Gianluca Tettamanti, Morena Casartelli, Barbara Giordana, Juan Ferré, Silvia Gigliotti, Danilo Ercolini, and Francesco Pennacchio/titolo:Midgut microbiota and host immunocompetence underlie Bacillus thuringiensis killing mechanism/doi:10.1073%2Fpnas.1521741113/rivista:Proceedings of the National Academy of Sciences of the United States of America/anno:2016/pagina_da:/pagina_a:/intervallo_pagine:/volume:113 |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.1521741113 |
| Popis: | 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 nodulation response, which was associated with a significant enhancement of host larvae mortality triggered by B. thuringiensis and a Cry toxin. This was determined by an uncontrolled proliferation of midgut bacteria, after entering the body cavity through toxin-induced epithelial lesions. Consequently, the hemolymphatic microbiota dramatically changed upon treatment with Cry1Ca toxin, showing a remarkable predominance of Serratia and Clostridium species, which switched from asymptomatic gut symbionts to hemocoelic pathogens. These experimental results demonstrate the important contribution of host enteric flora in B. thuringiensis-killing activity and provide a sound foundation for developing new insect control strategies aimed at enhancing the impact of biocontrol agents by reducing the immunocompetence of the host. |
| Databáze: | OpenAIRE |
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