title: Local and systemic N signaling are involved in Medicago truncatula preference for the most efficient Sinorhizobium symbiotic partners.
abstract: • Responses of the Medicago truncatula-Sinorhizobium interaction to variation in N₂-fixation of the bacterial partner were investigated. • Split-root systems were used to discriminate between local responses, at the site of interaction with bacteria, and systemic responses related to the whole plant N status. • The lack of N acquisition by a half-root system nodulated with a nonfixing rhizobium triggers a compensatory response enabling the other half-root system nodulated with N₂-fixing partners to compensate the local N limitation. This response is mediated by a stimulation of nodule development (number and size) and involves a systemic signaling mechanism related to the plant N demand. In roots co-infected with poorly and highly efficient strains, partner choice for nodule formation was not modulated by the plant N status. However, the plant N demand induced preferential expansion of nodules formed with the most efficient partners when the symbiotic organs were functional. The response of nodule expansion was associated with the stimulation of symbiotic plant cell multiplication and of bacteroid differentiation. • A general model where local and systemic N signaling mechanisms modulate interactions between Medicago truncatula and its Sinorhizobium partners is proposed.
authors.affiliation: INRA, USC 1242, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|IRD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|CIRAD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|SupAgro, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|UM2, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.
authors.forename: Gisèle
authors.initials: G
authors.lastname: Laguerre
authors.affiliation: INRA, USC 1242, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|IRD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|CIRAD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|SupAgro, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|UM2, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Heulin-Gotty
authors.affiliation: INRA, USC 1242, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|IRD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|CIRAD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|SupAgro, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|UM2, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Brunel
authors.affiliation: INRA, USC 1242, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|IRD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|CIRAD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|SupAgro, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|UM2, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Klonowska
authors.affiliation: INRA, USC 1242, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|IRD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|CIRAD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|SupAgro, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|UM2, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Le Quéré
authors.affiliation: INRA, UMR 5004, Biochimie et Physiologie Moléculaire des Plantes, F-34000 Montpellier, France.|CNRS, Biochimie et Physiologie Moléculaire des Plantes, F-34000 Montpellier, France.|SupAgro, Biochimie et Physiologie Moléculaire des Plantes, F-34000 Montpellier, France.|UM2, Biochimie et Physiologie Moléculaire des Plantes, F-34000 Montpellier, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Tillard
authors.affiliation: INRA, USC 1242, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|IRD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|CIRAD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|SupAgro, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|UM2, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.
authors.forename: Yves
authors.initials: Y
authors.lastname: Prin
authors.affiliation: INRA, USC 1242, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|IRD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|CIRAD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|SupAgro, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|UM2, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Cleyet-Marel
authors.affiliation: INRA, USC 1242, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|IRD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|CIRAD, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|SupAgro, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.|UM2, UMR 113, Symbioses Tropicales et Méditerranéennes, F-34000 Montpellier, France.
authors.forename: Marc
authors.initials: M
authors.lastname: Lepetit
mesh_terms: D018533:Biomass; D046913:Medicago truncatula / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology*; D009584:Nitrogen / Q000172:deficiency / Q000378:metabolism* / Q000494:pharmacology; D009586:Nitrogen Fixation / Q000187:drug effects; D053204:Root Nodules, Plant / Q000187:drug effects / Q000382:microbiology / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects; D020579:Sinorhizobium / Q000187:drug effects / Q000502:physiology*; D013559:Symbiosis / Q000187:drug effects / Q000502:physiology*
chemical_list: D009584:Nitrogen