Aphid Protected from Pathogen by Endosymbiont

• Published in: Science (American Association for the Advancement of Science) Vol. 310; no. 5755; p. 1781
• Main Authors: Scarborough, Claire L, Ferrari, Julia, Godfray, H. C. J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 16.12.2005; The American Association for the Advancement of Science
• Subjects: Acyrthosiphon pisum; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Aphids - microbiology; Aphids - physiology; Autoecology; bacteria; Biological and medical sciences; Brevia; disease resistance; Endosymbionts; Endosymbiosis; Enterobacteriaceae - genetics; Enterobacteriaceae - physiology; entomopathogenic fungi; Entomophthorales - pathogenicity; Entomophthorales - physiology; Erynia neoaphidis; Fundamental and applied biological sciences. Psychology; Fungi; Insects; Molecular Sequence Data; mutualism; Mycoses; Parasite hosts; Pathogens; Peas; Plant pathology; Protozoa. Invertebrata; Regiella insecticola; Spores, Fungal - physiology; sporulation; Symbionts; Symbiosis; Symbiosis; Host parasite relation; Aphidoidea; Animal microorganism relation; Insecta; Zoopathogen; Symbiont; Acyrthosiphon pisum; Fungi; Parasitoid; Sensitivity resistance; Entomophagous; Homoptera; Arthropoda; Pathogenic; Aphididae; Bacteria; Defense mechanism; Invertebrata; Interspecific relation; Thallophyta
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1120180

Aphids are associated with several facultative bacterial endosymbionts that may influence their interactions with other organisms. We show here that one of the three most common facultative symbionts of pea aphid (Acyrthosiphon pisum), the bacterium Regiella insecticola, has a major effect on host resistance to a fungal pathogen. Experimental establishment of the bacterium in uninfected aphid clones led to higher survival after fungal attack. The bacteria also increased the aphid's inclusive fitness, because the presence of the symbiont reduced the probability of fungal sporulation on aphid cadavers, hence lowering the rate of transmission of the disease to nearby related aphids.