title: Combined phosphate and nitrogen limitation generates a nutrient stress transcriptome favorable for arbuscular mycorrhizal symbiosis in Medicago truncatula.
abstract: Arbuscular mycorrhizal (AM) symbiosis is stimulated by phosphorus (P) limitation and contributes to P and nitrogen (N) acquisition. However, the effects of combined P and N limitation on AM formation are largely unknown. Medicago truncatula plants were cultivated in the presence or absence of Rhizophagus irregularis (formerly Glomus intraradices) in P-limited (LP), N-limited (LN) or combined P- and N-limited (LPN) conditions, and compared with plants grown in sufficient P and N. The highest AM formation was observed in LPN, linked to systemic signaling by the plant nutrient status. Plant free phosphate concentrations were higher in LPN than in LP, as a result of cross-talk between P and N. Transcriptome analyses suggest that LPN induces the activation of NADPH oxidases in roots, concomitant with an altered profile of plant defense genes and a coordinate increase in the expression of genes involved in the methylerythritol phosphate and isoprenoid-derived pathways, including strigolactone synthesis genes. Taken together, these results suggest that low P and N fertilization systemically induces a physiological state of plants favorable for AM symbiosis despite their higher P status. Our findings highlight the importance of the plant nutrient status in controlling plant-fungus interaction.
authors.affiliation: UMR 1347 Agroécologie INRA/Université de Bourgogne/Agrosup, Pôle Interactions Plantes-Microorganismes ERL CNRS 6300, 17 rue Sully, BP 86510, 21065, Dijon Cedex, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bonneau
authors.affiliation: Unité de Recherche en Génomique Végétale (URGV), UMR INRA 1165 - Université d'Evry Val d'Essonne - ERL CNRS 8196, 2 rue G. Crémieux, CP 5708, F-91057, Evry Cedex, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Huguet
authors.affiliation: UMR 1347 Agroécologie INRA/Université de Bourgogne/Agrosup, Pôle Interactions Plantes-Microorganismes ERL CNRS 6300, 17 rue Sully, BP 86510, 21065, Dijon Cedex, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Wipf
authors.affiliation: Institut Sophia Agrobiotech, UMR INRA 1355 CNRS 7254, Université de Nice-Sophia Antipolis, 400 Route des Chappes, BP 167, F-06903, Sophia Antipolis Cedex, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pauly
authors.affiliation: UMR 1347 Agroécologie INRA/Université de Bourgogne/Agrosup, Pôle Interactions Plantes-Microorganismes ERL CNRS 6300, 17 rue Sully, BP 86510, 21065, Dijon Cedex, France.
authors.forename: Hoai-Nam
authors.initials: HN
authors.lastname: Truong
mesh_terms: D004896:Erythritol / Q000031:analogs & derivatives / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D055137:Glomeromycota / Q000502:physiology; D046913:Medicago truncatula / Q000235:genetics / Q000378:metabolism* / Q000382:microbiology*; D038821:Mycorrhizae / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism*; D028061:Phosphate Transport Proteins / Q000235:genetics / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism / Q000382:microbiology; D015398:Signal Transduction / Q000235:genetics; D013312:Stress, Physiological; D013403:Sugar Phosphates / Q000235:genetics / Q000378:metabolism; D013559:Symbiosis / Q000502:physiology*; D013729:Terpenes / Q000378:metabolism; D059467:Transcriptome
chemical_list: C114232:2-C-methylerythritol 4-phosphate; D028061:Phosphate Transport Proteins; D010710:Phosphates; D010940:Plant Proteins; D013403:Sugar Phosphates; D013729:Terpenes; D010758:Phosphorus; D009584:Nitrogen; D004896:Erythritol