Giving and receiving : measuring the carbon cost of mycorrhizas in the green orchid, Goodyera repens
Direct measurement of the carbon (C) 'cost' of mycorrhizas is problematic. Although estimates have been made for arbuscular and ectomycorrhizal symbioses, these are based on incomplete budgets or indirect measurements. Furthermore, the conventional model of unidirectional plant-to-fungus C...
| Veröffentlicht in: | The New phytologist. - 1990. - 180(2008), 1 vom: 15., Seite 176-184 |
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| Weitere Verfasser: | , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2008
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Carbon Radioisotopes Carbon 7440-44-0 |
| Zusammenfassung: | Direct measurement of the carbon (C) 'cost' of mycorrhizas is problematic. Although estimates have been made for arbuscular and ectomycorrhizal symbioses, these are based on incomplete budgets or indirect measurements. Furthermore, the conventional model of unidirectional plant-to-fungus C flux is too simplistic. Net fungus-to-plant C transfer supports seedling establishment in c. 10% of plant species, including most orchids, and bidirectional C flows occur in ectomycorrhiza utilizing soil amino acids. Here, the C cost of mycorrhizas to the green orchid Goodyera repens was determined by measurement of simultaneous bidirectional fluxes of 14C labelled sources using a monoxenic system with the fungus Ceratobasidium cornigerum. Transfer of C from fungus to plant ('up-flow') occurs in the photosynthesizing orchid G. repens (max. 0.06 microg) whereas over five times more current assimilate (min. 0.355 microg) is simultaneously allocated in the reverse direction to the mycorrhizal fungus ('down-flow') after 8 d. Carbon is transferred rapidly, being detected in plant-fungal respiration within 31 h of labelling. This study provides the most complete C budget for an orchid-mycorrhizal symbiosis, and clearly shows net plant-to-fungus C flux. The rapidity of bidirectional C flux is indicative of dynamic transfer at an interfacial apoplast as opposed to reliance on digestion of fungal pelotons |
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| Beschreibung: | Date Completed 18.11.2008 Date Revised 16.04.2021 published: Print CommentIn: New Phytol. 2008;180(1):3-5. doi: 10.1111/j.1469-8137.2008.02610.x. - PMID 18811798 Citation Status MEDLINE |
| ISSN: | 0028-646X |
| DOI: | 10.1111/j.1469-8137.2008.02533.x |