FN Archimer Export Format PT J TI Intraspecific variability in membrane proteome, cell growth, and morphometry of the invasive marine neurotoxic dinoflagellate Alexandrium pacificum grown in metal-contaminated conditions BT AF Chetouhi, Cherif Masseret, Estelle Satta, Cecilia Teodora Balliau, Thierry Laabir, Mohamed Jean, Natacha AS 1:1;2:2;3:3;4:4;5:2;6:1; FF 1:;2:;3:;4:;5:;6:; C1 Mediterranean Institute of Oceanography, Equipe Microbiologie Environnementale et Biotechnologie, UM 110 CNRS/IRD Aix-Marseille Université, Université de Toulon, CS 60584, 83 041 Toulon Cedex 9, France Marbec, University of Montpellier, IRD, Ifremer, CNRS, 34 095 Montpellier Cedex 5, France University of Sassari, via Piandanna 4, Agenzia Regionale per la Ricerca in Agricoltura, Loc. Bonassai, Olmedo, 07 100 Sassari, Italy PAPPSO-GQE-Le Moulon, INRA, Université Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91 190 Gif-sur-Yvette, France C2 UNIV TOULON, FRANCE UNIV MONTPELLIER, FRANCE UNIV SASSARI, ITALY INRA, FRANCE UM MARBEC IN WOS Cotutelle UMR copubli-france copubli-europe copubli-univ-france IF 7.963 TC 6 UR https://archimer.ifremer.fr/doc/00606/71802/70290.pdf LA English DT Article DE ;Alexandrium pacificum;Harmful algal bloom;Proteomics;Membrane pmteome;Trace metals AB Over the past decades, the occurrence, distribution and intensity of harmful algal blooms involving the dinoflagellate Alexandrium pacificum have increased in marine coastal areas disturbed by anthropogenic inputs. This invasive species produces saxitoxin, which causes the paralytic shellfish poisoning syndrome in humans upon consumption of contaminated seafood. Blooms of A. pacificum have been reported in metal-contaminated coastal ecosystems, suggesting some ability of these microorganisms to adapt to and/or resist in metal stress conditions. This study seeks to characterize the modifications in membrane proteomes (by 2-D electrophoresis coupled to LC-MS/MS), cell growth and morphometry (measured with an inverted microscope), in response to metal stress (addition of Zn2+, Pb2+, Cu2+ and Cd2+), in two Mediterranean A. pacificum strains: SG C10-3 and TAR C5-4F, respectively isolated from the Santa Giusta Lagoon (Sardinia, Italy) and from the Tarragona seaport (Spain), both metal-contaminated ecosystems. In the SG C10-3 cultures grown in a metal cocktail, cell growth was significantly delayed, and cell size increased (22% of 37.5 μm cells after 25 days of growth). Conversely, no substantial change was observed for cell growth or cell size in the TAR C5-4F cultures grown in a metal cocktail (P > 0.10), thus indicating intraspecific variability in the responses of A. pacificum strains to metal contamination. Regardless of the conditions tested, the total number of proteins constituting the membrane proteome was significantly higher for TAR C5-4F than for SG C10-3, which may help TAR C5-4F to thrive better in contaminated conditions. For both strains, the total number of proteins constituting the membrane proteomes was significantly lower in response to metal stress (29% decrease in the SG C10-3 proteome: 82 ± 12 proteins for controls, and 58 ± 12 in metal-contaminated cultures; 17% decrease in the TAR C5-4F proteome: 101 ± 8 proteins for controls, and 84 ± 5 in metal-contaminated cultures). Moreover, regardless of the strain, proteins with significantly modified expression in response to stress were mainly down-regulated (representing 45% of the proteome for SG C10-3 and 38% for TAR C5-4F), clearly showing the harmful effects of the metals. Protein down-regulation may affect cell transport (actin and phospholipid scramblase in SG C10-3), photosynthesis (RUBISCO in SG C10-3, light-harvesting protein in TAR C5-4F, and high-CO2-inducing periplasmic protein in both strains), and finally energy metabolism (ATP synthase in both strains). However, other modifications in protein expression may confer to these A. pacificum strains a capacity for adaptation and/or resistance to metal stress conditions, for example by (i) limiting the metal entry through the plasma membrane of the SG C10-3 cells (via the down-regulation of scramblase) and/or (ii) reducing the oxidative stress generated by metals in SG C10-3 and TAR C5-4F cells (due to down-regulation of ATP-synthase). PY 2020 PD MAY SO Science Of The Total Environment SN 0048-9697 PU Elsevier BV VL 715 UT 000518409900077 DI 10.1016/j.scitotenv.2020.136834 ID 71802 ER EF