title: Independent Effects of a Herbivore's Bacterial Symbionts on Its Performance and Induced Plant Defences.
abstract: It is well known that microbial pathogens and herbivores elicit defence responses in plants. Moreover, microorganisms associated with herbivores, such as bacteria or viruses, can modulate the plant's response to herbivores. Herbivorous spider mites can harbour different species of bacterial symbionts and exert a broad range of effects on host-plant defences. Hence, we tested the extent to which such symbionts affect the plant's defences induced by their mite host and assessed if this translates into changes in plant resistance. We assessed the bacterial communities of two strains of the common mite pestTetranychus urticae. We found that these strains harboured distinct symbiotic bacteria and removed these using antibiotics. Subsequently, we tested to which extent mites with and without symbiotic bacteria induce plant defences in terms of phytohormone accumulation and defence gene expression, and assessed mite oviposition and survival as a measure for plant resistance. We observed that the absence/presence of these bacteria altered distinct plant defence parameters and affected mite performance but we did not find indications for a causal link between the two. We argue that although bacteria-related effects on host-induced plant defences may occur, these do not necessarily affect plant resistance concomitantly.
authors.affiliation: Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands. hstauda@gmail.com.
authors.forename: Heike
authors.initials: H
authors.lastname: Staudacher
authors.affiliation: Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands. B.C.J.Schimmel@uva.nl.
authors.forename: Bernardus C J
authors.initials: BC
authors.lastname: Schimmel
authors.affiliation: Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands. m.lamers@erasmusmc.nl.
authors.forename: Mart M
authors.initials: MM
authors.lastname: Lamers
authors.affiliation: Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands. N.R.Wybouw@uva.nl.
authors.forename: Nicky
authors.initials: N
authors.lastname: Wybouw
authors.affiliation: Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands. A.T.Groot@uva.nl.|Max Planck Institute for Chemical Ecology, Hans-Knöll-Straβe 8, 07745 Jena, Germany. A.T.Groot@uva.nl.
authors.forename: Astrid T
authors.initials: AT
authors.lastname: Groot
authors.affiliation: Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands. M.Kant@uva.nl.
authors.forename: Merijn R
authors.initials: MR
authors.lastname: Kant
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects*; D005260:Female; D060434:Herbivory / Q000187:drug effects; D018551:Solanum lycopersicum / Q000276:immunology / Q000382:microbiology* / Q000469:parasitology*; D008297:Male; D009068:Movement; D010937:Plant Growth Regulators / Q000032:analysis; D016019:Survival Analysis; D013559:Symbiosis / Q000187:drug effects; D040102:Tetranychidae / Q000187:drug effects / Q000502:physiology*
chemical_list: D000900:Anti-Bacterial Agents; D010937:Plant Growth Regulators
keywords: Cardinium; Spiroplasma; Tetranychus urticae; Wolbachia; plant defence; plant–herbivore interaction; symbiosis