Mycelial uptake, translocation and assimilation of N-15-labeled nitrogen by ectomycorrhizal Pinus sylvestris plants

Summary, in English

Mycolial uptake, translocation and assimilation of 15N-labelled ammonium was followed in Pinus sylvestris plants infected with the ectomycorrhizal fungus. Paxillus involutus. The distribution of labelled compounds within the systems was examined using gas chromatography / mass spectrometry. Labelled nitrogen was incorporated into a range of free amino acids in the fungal mycelium, the principal sinks being alanine and glutamatelglutamine. Levels of 15 N enrichment declined throughout the transport pathway from 30-45% in the mycelium a~d mycorrhlzal root lips to 3-11% in the plant shoots. A significant proportion of the total assimilated nitrogen (27%) was incorporated into

proteinaceous material and the proportion of label present in this fraction increased from 27% in the mycelium to 32% and 58% in the plant roots and needles respectively. The protein-incorporated amino acids showed a wider spectrum of labelling with significant amounts of 15N incorporated into valine, isoleucine, phenylalanine and lysine.

• Author: R.D. Finlay; H. Ek; G. Odham; Bengt Söderström
• Department/s: MEMEG; Microbial Ecology
• Publishing year: 1990
• Language: English
• Pages: 133-137
• Publication/Series: Agriculture, Ecosystems & Environment
• Volume: 28
• Issue: 1-4
• Links: http://www.sciencedirect.com/science/article/pii/016788099090028C
• Document type: Journal article
• Publisher: Elsevier
• Topic: Biological Sciences
• Status: Published
• Research group: Microbial Ecology
• ISBN/ISSN/Other: ISSN: 1873-2305