Biological nitrogen fixation by alternative nitrogenases in boreal cyanolichens: importance of molybdenum availability and implications for current biological nitrogen fixation estimates
| Autor: | Jolanta Miadlikowska, Darcy L. McRose, Anne M. L. Kraepiel, Romain Darnajoux, Xinning Zhang, François Lutzoni, Jean-Philippe Bellenger |
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| Rok vydání: | 2016 |
| Předmět: |
Nostoc
010504 meteorology & atmospheric sciences Lichens Physiology Plant Science Peltigera aphthosa Cyanobacteria 01 natural sciences Cyanolichen Nitrogen Fixation Botany Nitrogenase Lichen Symbiosis Nitrogen cycle 0105 earth and related environmental sciences Molybdenum Sweden biology Nitrogen Isotopes Ecology Discriminant Analysis Vanadium 04 agricultural and veterinary sciences biology.organism_classification 040103 agronomy & agriculture Nitrogen fixation Cyanobiont Linear Models 0401 agriculture forestry and fisheries Environmental Pollution |
| Zdroj: | The New phytologist. 213(2) |
| ISSN: | 1469-8137 |
| Popis: | Cryptogamic species and their associated cyanobacteria have attracted the attention of biogeochemists because of their critical roles in the nitrogen cycle through symbiotic and asymbiotic biological fixation of nitrogen (BNF). BNF is mediated by the nitrogenase enzyme, which, in its most common form, requires molybdenum at its active site. Molybdenum has been reported as a limiting nutrient for BNF in many ecosystems, including tropical and temperate forests. Recent studies have suggested that alternative nitrogenases, which use vanadium or iron in place of molybdenum at their active site, might play a more prominent role in natural ecosystems than previously recognized. Here, we studied the occurrence of vanadium, the role of molybdenum availability on vanadium acquisition and the contribution of alternative nitrogenases to BNF in the ubiquitous cyanolichen Peltigera aphthosa s.l. We confirmed the use of the alternative vanadium-based nitrogenase in the Nostoc cyanobiont of these lichens and its substantial contribution to BNF in this organism. We also showed that the acquisition of vanadium is strongly regulated by the abundance of molybdenum. These findings show that alternative nitrogenase can no longer be neglected in natural ecosystems, particularly in molybdenum-limited habitats. |
| Databáze: | OpenAIRE |
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