title: The Conformation of a Plasma Membrane-Localized Somatic Embryogenesis Receptor Kinase Complex Is Altered by a Potato Aphid-Derived Effector.
abstract: Somatic embryogenesis receptor kinases (SERKs) are transmembrane receptors involved in plant immunity. Tomato (Solanum lycopersicum) carries three SERK members. One of these, SlSERK1, is required for Mi-1.2-mediated resistance to potato aphids (Macrosiphum euphorbiae). Mi-1.2 encodes a coiled-coil nucleotide-binding leucine-rich repeat protein that in addition to potato aphids confers resistance to two additional phloem-feeding insects and to root-knot nematodes (Meloidogyne spp.). How SlSERK1 participates in Mi-1.2-mediated resistance is unknown, and no Mi-1.2 cognate pest effectors have been identified. Here, we study the mechanistic involvement of SlSERK1 in Mi-1.2-mediated resistance. We show that potato aphid saliva and protein extracts induce the Mi-1.2 defense marker gene SlWRKY72b, indicating that both saliva and extracts contain a Mi-1.2 recognized effector. Resistant tomato cultivar Motelle (Mi-1.2/Mi-1.2) plants overexpressing SlSERK1 were found to display enhanced resistance to potato aphids. Confocal microscopy revealed that Mi-1.2 localizes at three distinct subcellular compartments: the plasma membrane, cytoplasm, and nucleus. Coimmunoprecipitation experiments in these tomato plants and in Nicotiana benthamiana transiently expressing Mi-1.2 and SlSERK1 showed that Mi-1.2 and SlSERK1 colocalize only in a microsomal complex. Interestingly, bimolecular fluorescence complementation analysis showed that the interaction of Mi-1.2 and SlSERK1 at the plasma membrane distinctively changes in the presence of potato aphid saliva, suggesting a model in which a constitutive complex at the plasma membrane participates in defense signaling upon effector binding.
authors.affiliation: Department of Nematology (H.-C.P., S.M., I.K.), Graduate Program in Botany and Plant Sciences (H.-C.P., I.K.), Institute for Integrative Genome Biology and Center for Plant Cell Biology (G.R.H., I.K.), University of California, Riverside, California 92521; and Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1012 WX Amsterdam, The Netherlands (F.L.W.T.).
authors.forename: Hsuan-Chieh
authors.initials: HC
authors.lastname: Peng
authors.affiliation: Department of Nematology (H.-C.P., S.M., I.K.), Graduate Program in Botany and Plant Sciences (H.-C.P., I.K.), Institute for Integrative Genome Biology and Center for Plant Cell Biology (G.R.H., I.K.), University of California, Riverside, California 92521; and Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1012 WX Amsterdam, The Netherlands (F.L.W.T.).
authors.forename: Sophie
authors.identifier: 0000-0002-6023-6897
authors.initials: S
authors.lastname: Mantelin
authors.affiliation: Department of Nematology (H.-C.P., S.M., I.K.), Graduate Program in Botany and Plant Sciences (H.-C.P., I.K.), Institute for Integrative Genome Biology and Center for Plant Cell Biology (G.R.H., I.K.), University of California, Riverside, California 92521; and Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1012 WX Amsterdam, The Netherlands (F.L.W.T.).
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Hicks
authors.affiliation: Department of Nematology (H.-C.P., S.M., I.K.), Graduate Program in Botany and Plant Sciences (H.-C.P., I.K.), Institute for Integrative Genome Biology and Center for Plant Cell Biology (G.R.H., I.K.), University of California, Riverside, California 92521; and Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1012 WX Amsterdam, The Netherlands (F.L.W.T.) f.l.w.takken@uva.nl isgouhi.kaloshian@ucr.edu.
authors.forename: Frank L W
authors.identifier: 0000-0003-2655-3108
authors.initials: FL
authors.lastname: Takken
authors.affiliation: Department of Nematology (H.-C.P., S.M., I.K.), Graduate Program in Botany and Plant Sciences (H.-C.P., I.K.), Institute for Integrative Genome Biology and Center for Plant Cell Biology (G.R.H., I.K.), University of California, Riverside, California 92521; and Molecular Plant Pathology, Swammerdam Institute for Life Sciences, University of Amsterdam, 1012 WX Amsterdam, The Netherlands (F.L.W.T.) f.l.w.takken@uva.nl isgouhi.kaloshian@ucr.edu.
authors.forename: Isgouhi
authors.initials: I
authors.lastname: Kaloshian
mesh_terms: D000818:Animals; D001042:Aphids / Q000737:chemistry* / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism*; D006790:Host-Parasite Interactions; D019476:Insect Proteins / Q000494:pharmacology*; D018551:Solanum lycopersicum / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012463:Saliva / Q000737:chemistry; D014026:Nicotiana / Q000235:genetics
chemical_list: D019476:Insect Proteins; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; D011494:Protein Kinases