Record ID No. |
1241 |
Author(s) |
Olsson,-P-A., Aarle,-I-M-van., Gavito,-M-E., Bengtson,-P., Bengtsson,G , 2005 |
Affiliation |
Microbial Ecology, Department of Ecology, Ecology Building, Lund University, SE-223 62 Lund, Sweden. |
Title |
13C incorporation into signature fatty acids as an assay for carbon allocation in arbuscular mycorrhiza |
Source. Vol.(no):Page |
Applied-and-Environmental-Microbiology. 71(5): 2592-2599p. |
Categories |
Arbuscular Mycorrhiza |
Subjects |
Biochemistry |
Sub-subjects |
Carbohydrate metabolism |
Host |
Plants |
Organism |
Glomus intraradices |
Country |
Sweden, Northern Europe |
Abstracts |
The ubiquitous arbuscular mycorrhizal fungi consume significant amounts of plant assimilated C, but this C flow has been difficult to quantify. The neutral lipid fatty acid 16:1 omega 5 is a quantitative signature for most arbuscular mycorrhizal fungi in roots and soil. We measured carbon transfer from four plant species to the arbuscular mycorrhizal fungus Glomus intraradices by estimating 13C enrichment of 16:1 omega 5 and compared it with 13C enrichment of total root and mycelial C. Carbon allocation to mycelia was detected within 1 day in monoxenic arbuscular mycorrhizal root cultures labelled with [13C]glucose. The 13C enrichment of neutral lipid fatty acid 16:1 omega 5 extracted from roots increased from 0.14% 1 day after labelling to 2.2% 7 days after labelling. The colonized roots usually were more enriched for 13C in the arbuscular mycorrhizal fungal neutral lipid fatty acid 16:1 omega 5 than for the root specific neutral lipid fatty acid 18:2 omega 6,9. We labelled plant assimilates by using 13CO2 in whole-plant experiments. The extraradical mycelium often was more enriched for 13C than was the intraradical mycelium, suggesting rapid translocation of carbon to and more active growth by the extraradical mycelium. Since there was a good correlation between 13C enrichment in neutral lipid fatty acid 16:1 omega 5 and total 13C in extraradical mycelia in different systems (r2=0.94), we propose that the total amount of labelled C in intraradical and extraradical mycelium can be calculated from the 13C enrichment of 16:1 omega 5. The method described enables evaluation of C flow from plants to arbuscular mycorrhizal fungi to be made without extraction, purification and identification of fungal mycelia. |