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Biogeosciences, 8, 3733-3745, 2011
www.biogeosciences.net/8/3733/2011/ doi:10.5194/bg-8-3733-2011 © Author(s) 2011. This work is distributed under the Creative Commons Attribution 3.0 License. |
Gradients in intact polar diacylglycerolipids across the Mediterranean Sea are related to phosphate availability
1Dept. of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, MS #4, Woods Hole, MA 02543, USA
2Université de la Méditerranée, CNRS, Laboratoire d'Océanographie Physique et Biogéochimique, UMR 6535, Centre d'Océanologie de Marseille, Campus de Luminy, Case 901, 13288 Marseille cedex 09, France
3CNRS, UMR 7621, LOMIC, Observatoire Océanologique, 66651 Banyuls/mer, France
4UPMC Univ Paris 06, UMR 7621, LOMIC, Observatoire Océanologique, 66651 Banyuls/mer, France
5INSU-CNRS, Laboratoire d'Océanologie et des Géosciences, UMR 8187, Université Lille Nord de France, ULCO, 62930 Wimereux, France
6Hellenic Centre for Marine Research, Inst. of Oceanography, 71003 Heraklion, Crete, Greece
7CNRS, UMS 2348, Observatoire Océanologique, 66651 Banyuls/mer, France
8UPMC Univ Paris 06, Laboratoire ARAGO, Observatoire Océanologique, 66651 Banyuls/mer, France
*now at: INSU-CNRS, Laboratoire d'Océanographie de Villefranche, UMR 7093, 06230 Villefranche-sur-Mer, France
**now at: Université Pierre et Marie Curie-Paris VI, Laboratoire d'Océanographie de Villefranche, UMR 7093, 06230 Villefranche-sur-Mer, France
Abstract. Intact polar membrane lipids compose a significant fraction of cellular material in plankton and their synthesis imposes a substantial constraint on planktonic nutrient requirements. As a part of the Biogeochemistry from the Oligotrophic to the Ultraoligotrophic Mediterranean (BOUM) cruise we examined the distribution of several classes of intact polar diacylglycerolipids (IP-DAGs) across the Mediterranean, and found that phospholipid concentration as a percent of total lipids correlated with phosphate concentration. In addition, the ratios of non-phosphorus lipids to phospholipids – sulfoquinovosyldiacylglycerol (SQDG) to phosphatidylglycerol (PG), and betaine lipids to phosphatidylcholine (PC) – were also found to increase from west to east across the Mediterranean. Additionally, microcosm incubations from across the Mediterranean were amended with phosphate and ammonium, and in the course of several days nutrient amendments elicited a shift in the ratios of IP-DAGs. These experiments were used to assess the relative contribution of community shifts and physiological response to the observed change in IP-DAGs across the Mediterranean. The ratio of SQDG to chlorophyll-a was also explored as an indicator of phytoplankton response to nitrogen availability. This study is the first to demonstrate the dynamic response of membrane lipid composition to changes in nutrients in a natural, mixed planktonic community.
Citation: Popendorf, K. J., Tanaka, T., Pujo-Pay, M., Lagaria, A., Courties, C., Conan, P., Oriol, L., Sofen, L. E., Moutin, T., and Van Mooy, B. A. S.: Gradients in intact polar diacylglycerolipids across the Mediterranean Sea are related to phosphate availability, Biogeosciences, 8, 3733-3745, doi:10.5194/bg-8-3733-2011, 2011.