The influence of external nitrogen on carbon allocation to Glomus intraradices in monoxenic arbuscular mycorrhiza
Author
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.
Publishing year
2005
Language
English
Pages
677-686
Publication/Series
New Phytologist
Volume
168
Issue
3
Links
Document type
Journal article
Publisher
Wiley-Blackwell
Topic
- Ecology
Keywords
- GiPT
- metabolic activity
- mycorrhiza (AM) cultures
- monoxenic atbuscular
- phosphorus (P)
- carbon allocation
- nitrogen (N)
- phosphate transporter
Status
Published
Research group
- Microbial Ecology
- Plant Biology
ISBN/ISSN/Other
- ISSN: 1469-8137