title: Arbuscular mycorrhizal symbiosis limits foliar transcriptional responses to viral infection and favors long-term virus accumulation.
abstract: Tomato (Solanum lycopersicum) can establish symbiotic interactions with arbuscular mycorrhizal (AM) fungi, and can be infected by several pathogenic viruses. Here, we investigated the impact of mycorrhization by the fungus Glomus mosseae on the Tomato spotted wilt virus (TSWV) infection of tomato plants by transcriptomic and hormones level analyses. In TSWV-infected mycorrhizal plants, the AM fungus root colonization limited virus-induced changes in gene expression in the aerial parts. The virus-responsive upregulated genes, no longer induced in infected mycorrhizal plants, were mainly involved in defense responses and hormone signaling, while the virus-responsive downregulated genes, no longer repressed in mycorrhizal plants, were involved in primary metabolism. The presence of the AM fungus limits, in a salicylic acid-independent manner, the accumulation of abscissic acid observed in response to viral infection. At the time of the molecular analysis, no differences in virus concentration or symptom severity were detected between mycorrhizal and nonmycorrhizal plants. However, in a longer period, increase in virus titer and delay in the appearance of recovery were observed in mycorrhizal plants, thus indicating that the plant's reaction to TSWV infection is attenuated by mycorrhization.
authors: Istituto di Virologia Vegetale, Torino, Italy. l.miozzi@ivv.cnr.it
authors: Laura
authors: L
authors: Miozzi
authors: Marco
authors: M
authors: Catoni
authors: Valentina
authors: V
authors: Fiorilli
authors: Philip M
authors: PM
authors: Mullineaux
authors: Gian Paolo
authors: GP
authors: Accotto
authors: Luisa
authors: L
authors: Lanfranco
mesh_terms: D000040:Abscisic Acid / Q000032:analysis / Q000378:metabolism; D018533:Biomass; D003517:Cyclopentanes / Q000032:analysis / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D055137:Glomeromycota / Q000235:genetics / Q000502:physiology*; D018551:Solanum lycopersicum / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D038821:Mycorrhizae / Q000235:genetics / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins / Q000032:analysis / Q000378:metabolism; D010641:Phenotype; D010935:Plant Diseases / Q000382:microbiology*; D010937:Plant Growth Regulators / Q000032:analysis / Q000378:metabolism*; D018515:Plant Leaves / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D018517:Plant Roots / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D018520:Plant Shoots / Q000235:genetics / Q000382:microbiology / Q000502:physiology; D020156:Salicylic Acid / Q000032:analysis / Q000378:metabolism; D015398:Signal Transduction; D013559:Symbiosis; D013997:Time Factors; D017865:Tospovirus / Q000502:physiology*; D059467:Transcriptome; D015854:Up-Regulation / Q000235:genetics
chemical_list: D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; C011006:jasmonic acid; D000040:Abscisic Acid; D020156:Salicylic Acid