title: Recently fixed carbon allocation in strawberry plants and concurrent inorganic nitrogen uptake through arbuscular mycorrhizal fungi.
abstract: Most crop species form a symbiotic association with arbuscular mycorrhizal (AM) fungi, receiving plant photosynthate and exchanging nutrients from the soil. The plant carbon (C) allocation to AM fungi and the nitrogen feedback are rarely studied together. In this study, a dual (13)CO2 and (15)NH4(15)NO3 pulse labeling experiment was carried out to determine the allocation of recent photosynthates to mycorrhizal hyphae and the translocation of N absorbed by hyphae to strawberry plants. Plants were grown in pots in which a 50 μm mesh net allowed the physical separation of the mycorrhizal hyphae from the roots in one portion of the pot. An inorganic source of (15)N was added to the hyphal compartment at the same time of the (13)CO2 pulse labeling. One and seven days after pulse labeling, the plants were destructively harvested and the amount of the recently fixed carbon (C) and of the absorbed N was determined. (13)C allocated to belowground organs such as roots and mycorrhizal hyphae accounted for an average of 10%, with 4.3% allocated to mycorrhizal hyphae within the first 24h after the pulse labeling. Mycorrhizae absorbed labeled inorganic nitrogen, of which almost 23% was retained in the fungal mycelium. The N uptake was linearly correlated with the (13)C fixed by the plants suggesting a positive correlation between a plant photosynthetic rate and the hyphal absorption capacity.
authors.affiliation: Faculty of Science and Technology, Free University of Bozen-Bolzano Piazza Università 5, 39100 Bolzano, BZ, Italy. Electronic address: Elisabetta.Tome@natec.unibz.it.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Tomè
authors.affiliation: Faculty of Science and Technology, Free University of Bozen-Bolzano Piazza Università 5, 39100 Bolzano, BZ, Italy. Electronic address: Massimo.Tagliavini@unibz.it.
authors.forename: Massimo
authors.initials: M
authors.lastname: Tagliavini
authors.affiliation: Faculty of Science and Technology, Free University of Bozen-Bolzano Piazza Università 5, 39100 Bolzano, BZ, Italy. Electronic address: Francesca.Scandellari@unibz.it.
authors.forename: Francesca
authors.initials: F
authors.lastname: Scandellari
mesh_terms: D018533:Biomass; D002244:Carbon / Q000378:metabolism*; D057486:Carbon Cycle; D002245:Carbon Dioxide / Q000378:metabolism; D002247:Carbon Isotopes; D035264:Flowers / Q000378:metabolism; D031985:Fragaria / Q000378:metabolism*; D005638:Fruit / Q000378:metabolism; D025301:Hyphae / Q000378:metabolism; D007553:Isotope Labeling; D038821:Mycorrhizae / Q000502:physiology*; D009584:Nitrogen / Q000378:metabolism*; D063245:Plant Development
chemical_list: D002247:Carbon Isotopes; D002245:Carbon Dioxide; D002244:Carbon; D009584:Nitrogen
keywords: Dual-labeling experiment; Fragaria x ananassa; Hyphal N uptake; Photosynthetic capacity; Stable isotopes