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Metarhizium brunneum infection dynamics differ at the cuticle interface of susceptible and tolerant morphs of Galleria mellonella
- Source :
- Virulence, article-version (VoR) Version of Record, Virulence, Vol 10, Iss 1, Pp 999-1012 (2019)
- Publication Year :
- 2019
- Publisher :
- Taylor & Francis, 2019.
-
Abstract
- In order for entomopathogenic fungi to colonize an insect host, they must first attach to, and penetrate, the cuticle layers of the integument. Herein, we explored the interactions between the fungal pathogen Metarhizium brunneum ARSEF 4556 and two immunologically distinct morphs, melanic (M) and non-melanic (NM), of the greater wax moth Galleria mellonella. We first interrogated the cuticular compositions of both insect morphs to reveal substantial differences in their physiochemical properties. Enhanced melanin accumulation, fewer hydrocarbons, and higher L-dihydroxyphenylalanine (DOPA) decarboxylase activity were evident in the cuticle of the M larvae. This “hostile” terrain proved challenging for M. brunneum – reflected in poor conidial attachment and germination, and elevated expression of stress-associated genes (e.g., Hsp30, Hsp70). Lack of adherence to the cuticle impacted negatively on the speed of kill and overall host mortality; a dose of 107 conidia killed ~30% of M larvae over a 12-day period, whereas a 100-fold lower dose (105 conidia) achieved a similar result for NM larvae. Candidate gene expression patterns between the insect morphs indicated that M larvae are primed to “switch-on” immunity-associated genes (e.g., phenoloxidase) within 6–12 h of conidia exposure and can sustain a “defense” response. Critically, M. brunneum responds to the distinct physiochemical cues of both hosts and adjusts the expression of pathogenicity-related genes accordingly (e.g., Pr2, Mad1, Mad2). We reveal previously uncharacterized mechanisms of attack and defence in fungal-insect antibiosis.
- Subjects :
- Microbiology (medical)
Entomopathogenic fungi
animal structures
media_common.quotation_subject
Cuticle
Immunology
Insect
melanization
Biology
Microbiology
lcsh:Infectious and parasitic diseases
03 medical and health sciences
host-pathogen interactions
lcsh:RC109-216
030304 developmental biology
media_common
Innate immunity
0303 health sciences
030306 microbiology
Host (biology)
fungi
entomopathogenic fungi
biology.organism_classification
Galleria mellonella
The integument
Infectious Diseases
comic_books
Metarhizium brunneum
Parasitology
Infection dynamics
cuticle
comic_books.character
Research Article
Research Paper
Subjects
Details
- Language :
- English
- ISSN :
- 21505608 and 21505594
- Volume :
- 10
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Virulence
- Accession number :
- edsair.doi.dedup.....d1b6ce68ab52ddbf6c9007c6d52fbdab