title: Rapid nitrogen transfer in the Sorghum bicolor-Glomus mosseae arbuscular mycorrhizal symbiosis.
abstract: We have recently identified two genes coding for ammonium transporters (AMT) in Sorghum bicolor that were induced in roots colonized by arbuscular mycorrhizal (AM) fungi. To improve our understanding of the dynamics of ammonium transport in this symbiosis, we studied the transfer of soil-ammonium-derived (15)N to S. bicolor plants via the Glomus mosseae fungal mycelium in compartmented microcosms. The (15)NH (4+)-containing hyphal compartment was inaccessible to the roots in the plant compartment. (15)N label concentrations significantly increased in plant roots and leaves already 48 h after exposure of the AM fungus to the (15)NH (4+) substrate, attesting an efficient symbiotic N transfer between the symbiotic partners and further highlighting that AM symbiosis represents an important component of plant nitrogen nutrition.
authors.affiliation: Zurich-Basel Plant Science Center; Department of Environmental Sciences, Botany; University of Basel; Basel, Switzerland.
authors.forename: Sally
authors.initials: S
authors.lastname: Koegel
authors.forename: Thomas
authors.initials: T
authors.lastname: Boller
authors.forename: Moritz F
authors.initials: MF
authors.lastname: Lehmann
authors.forename: Andres
authors.initials: A
authors.lastname: Wiemken
authors.forename: Pierre-Emmanuel
authors.initials: PE
authors.lastname: Courty
mesh_terms: D055137:Glomeromycota / Q000502:physiology*; D038821:Mycorrhizae / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D009587:Nitrogen Isotopes; D012987:Soil / Q000737:chemistry; D045868:Sorghum / Q000378:metabolism* / Q000382:microbiology*; D013559:Symbiosis; D013997:Time Factors
chemical_list: D009587:Nitrogen Isotopes; D012987:Soil; D009584:Nitrogen
keywords: 15N labeling; arbuscular mycorrhizal fungi; mycelium; nitrogen; sorghum; transfer