FN Archimer Export Format PT J TI Growth and phosphorus uptake by the toxic dinoflagellate Alexandrium catenella (dinophyceae) in response to phosphate limitation BT AF JAUZEIN, Cecile LABRY, Claire YOUENOU, Agnes QUERE, Julien DELMAS, Daniel COLLOS, Yves AS 1:2;2:3;3:3;4:3;5:3;6:1; FF 1:PDG-DOP-LER-LERLR;2:PDG-DOP-DCB-DYNECO-PELAGOS;3:PDG-DOP-DCB-DYNECO-PELAGOS;4:PDG-DOP-DCB-DYNECO-PELAGOS;5:PDG-DOP-DCB-DYNECO-PELAGOS;6:; C1 Univ Montpellier 2, CNRS, IFREMER, Lab Ecosyst Lagunaires,UMR 5119,IRD, F-34095 Montpellier 5, France. IFREMER, Lab LER LR, F-34203 Sete, France. IFREMER, Ctr Brest, Lab DYNECO Pelagos, F-29280 Plouzane, France. C2 UNIV MONTPELLIER, FRANCE IFREMER, FRANCE IFREMER, FRANCE SI SETE BREST SE PDG-DOP-LER-LERLR PDG-DOP-DCB-DYNECO-PELAGOS IN WOS Ifremer jusqu'en 2018 copubli-france copubli-univ-france IF 2.239 TC 28 UR https://archimer.ifremer.fr/doc/00015/12641/9570.pdf LA English DT Article DE ;Alexandrium catenella;alkaline phosphatase;limitation;phosphorus;semicontinuous cultures AB Alexandrium catenella (Whedon et Kof.) Balech has exhibited seasonal recurrent blooms in the Thau lagoon (South of France) since first reported in 1995. Its appearance followed a strong decrease (90%) in phosphate (PO(4)3-) concentrations in this environment over the 1970-1995 period. To determine if this dinoflagellate species has a competitive advantage in PO(4)3--limited conditions in terms of nutrient acquisition, semicontinuous cultures were carried out to characterize phosphorus (P) uptake by A. catenella cells along a P-limitation gradient using different dilution rates (DRs). Use of both inorganic and organic P was investigated from measurements of 33PO(4)3- uptake and alkaline phosphatase activity (APA), respectively. P status was estimated from cellular P and carbon contents (Q(P) and Q(C)). Shifts in trends of Q(P)/Q(C) and Q(P) per cell (Q(P center dot cell-1)) along the DR gradient allowed the definition of successive P-stress thresholds for A. catenella cells. The maximal uptake rate of 33PO(4)3- increased strongly with the decrease in DR and the decrease in Q(P)/Q(C), displaying physiological acclimations to PO(4)3- limitation. Concerning maximal APA per cell, the observation of an all-or-nothing pattern along the dilution gradient suggests that synthesis of AP was induced and maximized at the cellular scale as soon as PO(4)3- limitation set in. APA variations revealed that the synthesis of AP was repressed over a PO(4)3- threshold between 0.4 and 1 mu M. As lower PO(4)3- concentrations are regularly observed during A. catenella blooms in Thau lagoon, a significant portion of P uptake by A. catenella cells in the field may come from organic compounds. PY 2010 PD OCT SO Journal Of Phycology SN 0022-3646 PU Wiley-blackwell Publishing, Inc VL 46 IS 5 UT 000282378200009 BP 926 EP 936 DI 10.1111/j.1529-8817.2010.00878.x ID 12641 ER EF