title: The Salivary Protein Repertoire of the Polyphagous Spider Mite Tetranychus urticae: A Quest for Effectors.
abstract: The two-spotted spider mite Tetranychus urticae is an extremely polyphagous crop pest. Alongside an unparalleled detoxification potential for plant secondary metabolites, it has recently been shown that spider mites can attenuate or even suppress plant defenses. Salivary constituents, notably effectors, have been proposed to play an important role in manipulating plant defenses and might determine the outcome of plant-mite interactions. Here, the proteomic composition of saliva from T. urticae lines adapted to various host plants-bean, maize, soy, and tomato-was analyzed using a custom-developed feeding assay coupled with nano-LC tandem mass spectrometry. About 90 putative T. urticae salivary proteins were identified. Many are of unknown function, and in numerous cases belonging to multimembered gene families. RNAseq expression analysis revealed that many genes coding for these salivary proteins were highly expressed in the proterosoma, the mite body region that includes the salivary glands. A subset of genes encoding putative salivary proteins was selected for whole-mount in situ hybridization, and were found to be expressed in the anterior and dorsal podocephalic glands. Strikingly, host plant dependent expression was evident for putative salivary proteins, and was further studied in detail by micro-array based genome-wide expression profiling. This meta-analysis revealed for the first time the salivary protein repertoire of a phytophagous chelicerate. The availability of this salivary proteome will assist in unraveling the molecular interface between phytophagous mites and their host plants, and may ultimately facilitate the development of mite-resistant crops. Furthermore, the technique used in this study is a time- and resource-efficient method to examine the salivary protein composition of other small arthropods for which saliva or salivary glands cannot be isolated easily.
authors.affiliation: From the ‡Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Gent, Belgium.|§Department of Evolutionary Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands.
authors.forename: Wim
authors.initials: W
authors.lastname: Jonckheere
authors.affiliation: From the ‡Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Gent, Belgium; wannes.dermauw@ugent.be gerben.menschaert@UGent.be thomas.vanleeuwen@ugent.be.
authors.forename: Wannes
authors.identifier: http://orcid.org/0000-0003-4612-8969
authors.initials: W
authors.lastname: Dermauw
authors.affiliation: ¶Department of Biology, The University of Western Ontario, London, ON, Canada N6A5B7.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Zhurov
authors.affiliation: §Department of Evolutionary Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands.
authors.forename: Nicky
authors.identifier: http://orcid.org/0000-0001-7874-9765
authors.initials: N
authors.lastname: Wybouw
authors.affiliation: ‖UGCT - Woodlab-UGent, Department of Forest and Water Management, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Gent, Belgium.
authors.forename: Jan
authors.identifier: http://orcid.org/0000-0003-2939-5408
authors.initials: J
authors.lastname: Van den Bulcke
authors.affiliation: **Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands.|‡‡Department of Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Villarroel
authors.affiliation: §§Department of Biology, University of Utah, Salt Lake City 257 South 1400 East Utah 84112.
authors.forename: Robert
authors.initials: R
authors.lastname: Greenhalgh
authors.affiliation: ¶Department of Biology, The University of Western Ontario, London, ON, Canada N6A5B7.|¶¶Instituto de Ciencias de la Vid y el Vino, 26006 Logrono, Spain.
authors.forename: Mike
authors.initials: M
authors.lastname: Grbić
authors.affiliation: **Department of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands.
authors.forename: Rob C
authors.initials: RC
authors.lastname: Schuurink
authors.affiliation: From the ‡Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Gent, Belgium.
authors.forename: Luc
authors.initials: L
authors.lastname: Tirry
authors.affiliation: ‖‖Center for Proteomics (CFP), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium.|Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium.
authors.forename: Geert
authors.identifier: http://orcid.org/0000-0002-0661-931X
authors.initials: G
authors.lastname: Baggerman
authors.affiliation: §§Department of Biology, University of Utah, Salt Lake City 257 South 1400 East Utah 84112.|Center for Cell and Genome Science, University of Utah, Salt Lake City 257 South 1400 East Utah 84122.
authors.forename: Richard M
authors.identifier: http://orcid.org/0000-0002-1470-301X
authors.initials: RM
authors.lastname: Clark
authors.affiliation: ‡‡Department of Population Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands.
authors.forename: Merijn R
authors.initials: MR
authors.lastname: Kant
authors.affiliation: Department of Plant Systems Biology, VIB, B-9052 Gent, Belgium.|Department of Plant Biotechnology and Bioinformatics, Ghent University, B-9052 Gent, Belgium.
authors.forename: Bartel
authors.initials: B
authors.lastname: Vanholme
authors.affiliation: Department of Mathematical Modelling, Statistics and Bioinformatics, Ghent University, Coupure links 653, 9000 Gent, Belgium wannes.dermauw@ugent.be gerben.menschaert@UGent.be thomas.vanleeuwen@ugent.be.
authors.forename: Gerben
authors.identifier: http://orcid.org/0000-0002-7575-2085
authors.initials: G
authors.lastname: Menschaert
authors.affiliation: From the ‡Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Coupure links 653, 9000 Gent, Belgium; wannes.dermauw@ugent.be gerben.menschaert@UGent.be thomas.vanleeuwen@ugent.be.|§Department of Evolutionary Biology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, the Netherlands.
authors.forename: Thomas
authors.identifier: http://orcid.org/0000-0003-4651-830X
authors.initials: T
authors.lastname: Van Leeuwen
mesh_terms: D000818:Animals; D060829:Arthropod Proteins / Q000378:metabolism; D002853:Chromatography, Liquid; D018556:Crops, Agricultural / Q000235:genetics / Q000469:parasitology*; D005786:Gene Expression Regulation; D058507:Host Specificity; D006790:Host-Parasite Interactions; D040901:Proteomics / Q000379:methods*; D012471:Salivary Proteins and Peptides / Q000235:genetics / Q000378:metabolism*; D017423:Sequence Analysis, RNA / Q000379:methods; D053719:Tandem Mass Spectrometry; D040102:Tetranychidae / Q000378:metabolism / Q000502:physiology*; D014018:Tissue Distribution
chemical_list: D060829:Arthropod Proteins; D012471:Salivary Proteins and Peptides