A light-induced shortcut in the planktonic microbial loop
| Autor: | Stefanie Schabhüttl, Ioulia Santi, Maren Striebel, Jens C. Nejstgaard, Josep M. Gasol, Ana Gomes, Panagiotis D. Dimitriou, Stefanie Moorthi, Stella A. Berger, Peeter Laas, Stamatina Isari, Robert Ptacnik, Andrey F. Sazhin, Ayse Gazihan, Rodrigo Martínez, Radka Ptacnikova, Paraskevi Pitta, Despoina Sousoni, Soultana Zervoudaki, Kristi Altoja, Tatiana M. Tsagaraki, Albert Calbet, Sarah-Jeanne Royer |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España), German Research Foundation, European Commission |
| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
0106 biological sciences
0301 basic medicine Bacterivore Cyanobacteria Light Heterotroph Biology Photosynthesis 01 natural sciences Article 03 medical and health sciences Botany Mediterranean Sea Animals Biomass Picoplankton Ecosystem Autotrophic Processes Multidisciplinary Phototroph Ecology 010604 marine biology & hydrobiology Heterotrophic Processes biology.organism_classification Plankton 030104 developmental biology 13. Climate action Organ Specificity Predatory Behavior Microbial loop Mixotroph |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Scientific Reports |
| ISSN: | 2045-2322 |
| DOI: | 10.1038/srep29286 |
| Popis: | Ptacnik, Robert ... et al.-- 10 pages, 4 figures, 1 table, supplementary information https://dx.doi.org/10.1038/srep29286 Mixotrophs combine photosynthesis with phagotrophy to cover their demands in energy and essential nutrients. This gives them a competitive advantage under oligotropihc conditions, where nutrients and bacteria concentrations are low. As the advantage for the mixotroph depends on light, the competition between mixo- and heterotrophic bacterivores should be regulated by light. To test this hypothesis, we incubated natural plankton from the ultra-oligotrophic Eastern Mediterranean in a set of mesocosms maintained at 4 light levels spanning a 10-fold light gradient. Picoplankton (heterotrophic bacteria (HB), pico-sized cyanobacteria, and small-sized flagellates) showed the fastest and most marked response to light, with pronounced predator-prey cycles, in the high-light treatments. Albeit cell specific activity of heterotrophic bacteria was constant across the light gradient, bacterial abundances exhibited an inverse relationship with light. This pattern was explained by light-induced top-down control of HB by bacterivorous phototrophic eukaryotes (PE), which was evidenced by a significant inverse relationship between HB net growth rate and PE abundances. Our results show that light mediates the impact of mixotrophic bacterivores. As mixo- and heterotrophs differ in the way they remineralize nutrients, these results have far-reaching implications for how nutrient cycling is affected by light The experiment was financed by the European Union Seventh Framework Program MESOAQUA (FP7/2009-2013) coordinated by JCN under grant agreement no. 228224. R.P. further acknowledges financial support by the German Research Council (DFG Pt 5/3-1), JMG by Spanish project REMEI (CTM2015-70340) and AC by project PROTOS (CTM2009-08783) from the Spanish Ministry of Economy and Competitiveness |
| Databáze: | OpenAIRE |
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