Arbuscular mycorrhizal fungi can transfer substantial amounts of nitrogen to their host plant from organic material.
Nitrogen (N) capture by arbuscular mycorrhizal (AM) fungi from organic material is a recently discovered phenomenon. This study investigated the ability of two Glomus species to transfer N from organic material to host plants and examined whether the ability to capture N is related to fungal hyphal growth. Experimental microcosms had two compartments; these contained either a single plant of Plantago lanceolata inoculated with Glomus hoi or Glomus intraradices, or a patch of dried shoot material labelled with (15)N and (13)carbon (C). In one treatment, hyphae, but not roots, were allowed access to the patch; in the other treatment, access by both hyphae and roots was prevented. When allowed, fungi proliferated in the patch and captured N but not C, although G. intraradices transferred more N than G. hoi to the plant. Plants colonized with G. intraradices had a higher concentration of N than controls. Up to one-third of the patch N was captured by the AM fungi and transferred to the plant, while c. 20% of plant N may have been patch derived. These findings indicate that uptake from organic N could be important in AM symbiosis for both plant and fungal partners and that some AM fungi may acquire inorganic N from organic sources.
Leigh
Joanne
J
Department of Biology, University of York, PO Box 373, York YO10 5YW, UK.
Hodge
Angela
A
Department of Biology, University of York, PO Box 373, York YO10 5YW, UK.
Fitter
Alastair H
AH
Department of Biology, University of York, PO Box 373, York YO10 5YW, UK.
D055137:Glomeromycota / Q000378:metabolism*; D038821:Mycorrhizae / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010758:Phosphorus / Q000378:metabolism; D010943:Plantago / Q000378:metabolism*; D012987:Soil; D013559:Symbiosis
D012987:Soil; D010758:Phosphorus; D009584:Nitrogen