title: Sustained NIK-mediated antiviral signalling confers broad-spectrum tolerance to begomoviruses in cultivated plants.
abstract: Begomovirus-associated epidemics currently threaten tomato production worldwide due to the emergence of highly pathogenic virus species and the proliferation of a whitefly B biotype vector that is adapted to tomato. To generate an efficient defence against begomovirus, we modulated the activity of the immune defence receptor nuclear shuttle protein (NSP)-interacting kinase (NIK) in tomato plants; NIK is a virulence target of the begomovirus NSP during infection. Mutation of T474 within the kinase activation loop promoted the constitutive activation of NIK-mediated defences, resulting in the down-regulation of translation-related genes and the suppression of global translation. Consistent with these findings, transgenic lines harbouring an activating mutation (T474D) were tolerant to the tomato-infecting begomoviruses ToYSV and ToSRV. This phenotype was associated with reduced loading of coat protein viral mRNA in actively translating polysomes, lower infection efficiency and reduced accumulation of viral DNA in systemic leaves. Our results also add some relevant insights into the mechanism underlying the NIK-mediated defence. We observed that the mock-inoculated T474D-overexpressing lines showed a constitutively infected wild-type transcriptome, indicating that the activation of the NIK-mediated signalling pathway triggers a typical response to begomovirus infection. In addition, the gain-of-function mutant T474D could sustain an activated NIK-mediated antiviral response in the absence of the virus, further confirming that phosphorylation of Thr-474 is the crucial event that leads to the activation of the kinase.
authors: Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil.|National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Otávio J B
authors: OJB
authors: Brustolini
authors: Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil.|National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Joao Paulo B
authors: JPB
authors: Machado
authors: National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Jorge A
authors: JA
authors: Condori-Apfata
authors: Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil.|National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Daniela
authors: D
authors: Coco
authors: Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil.|National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Michihito
authors: M
authors: Deguchi
authors: Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil.|National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Virgílio A P
authors: VAP
authors: Loriato
authors: National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Welison A
authors: WA
authors: Pereira
authors: National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Poliane
authors: P
authors: Alfenas-Zerbini
authors: National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Francisco M
authors: FM
authors: Zerbini
authors: National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.|Embrapa Vegetables, Brasília, DF, Brazil.
authors: Alice K
authors: AK
authors: Inoue-Nagata
authors: Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil.|National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Anesia A
authors: AA
authors: Santos
authors: Howard Hughes Medical Institute and Plant Biology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.
authors: Joanne
authors: J
authors: Chory
authors: Departamento de Zootecnia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors: Fabyano F
authors: FF
authors: Silva
authors: Departamento de Bioquímica e Biologia Molecular, Bioagro, Viçosa, MG, Brazil.|National Institute of Science and Technology in Plant-Pest Interactions, Bioagro, Viçosa, MG, Brazil.
authors: Elizabeth P B
authors: EPB
authors: Fontes
mesh_terms: D053839:Begomovirus / Q000502:physiology*; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000502:physiology / Q000821:virology*; D009154:Mutation; D010935:Plant Diseases / Q000276:immunology / Q000821:virology*; D057865:Plant Immunity; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000235:genetics; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D014764:Viral Proteins; D017346:Protein Serine-Threonine Kinases
keywords: NIK; NSP-interacting kinase; begomovirus; leucine-rich repeats receptor-like kinase; nuclear shuttle protein; tomato-infecting begomoviruses