The influence of external nitrogen on carbon allocation to Glomus intraradices in monoxenic arbuscular mycorrhiza
Författare
Summary, in English
The influence of external nitrogen (N) on carbon (C) allocation and processes related to phosphorus (P) metabolism were studied in monoxenic arbuscular mycorrhiza (AM) cultures of Daucus carota. Fungal hyphae of Glomus intraradices proliferated from colonized roots growing on solid medium into C-free liquid minimal medium with two different N and P levels. Furthermore, we exposed the colonized roots to high or low N availability and then studied the mycelial development. Roots were provided with C-13-glucose in order to follow the C allocation. The mycelium was analysed for phosphatase activity and transcription levels of two nutrient regulated genes. High N availability to the monoxenic AM root reduced the C allocation to the AM fungus while N availability to the mycelium was important for the upregulation of the fungal inorganic phosphorus (Pi)-transporter GiPT. We found that N availability can regulate nutritional processes in arbuscular mycorrhiza. We conclude that negative impacts of N on AM abundance are caused by reduced C allocation from the plant. Upregulation of the fungal Pi-transporter GiPT indicated that increased N availability might induce P limitation in the mycelium.
Publiceringsår
2005
Språk
Engelska
Sidor
677-686
Publikation/Tidskrift/Serie
New Phytologist
Volym
168
Issue
3
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Wiley-Blackwell
Ämne
- Ecology
Nyckelord
- GiPT
- metabolic activity
- mycorrhiza (AM) cultures
- monoxenic atbuscular
- phosphorus (P)
- carbon allocation
- nitrogen (N)
- phosphate transporter
Status
Published
Forskningsgrupp
- Microbial Ecology
- Plant Biology
ISBN/ISSN/Övrigt
- ISSN: 1469-8137