title: A role for diatom-like silicon transporters in calcifying coccolithophores.
abstract: Biomineralization by marine phytoplankton, such as the silicifying diatoms and calcifying coccolithophores, plays an important role in carbon and nutrient cycling in the oceans. Silicification and calcification are distinct cellular processes with no known common mechanisms. It is thought that coccolithophores are able to outcompete diatoms in Si-depleted waters, which can contribute to the formation of coccolithophore blooms. Here we show that an expanded family of diatom-like silicon transporters (SITs) are present in both silicifying and calcifying haptophyte phytoplankton, including some globally important coccolithophores. Si is required for calcification in these coccolithophores, indicating that Si uptake contributes to the very different forms of biomineralization in diatoms and coccolithophores. Significantly, SITs and the requirement for Si are absent from highly abundant bloom-forming coccolithophores, such as Emiliania huxleyi. These very different requirements for Si in coccolithophores are likely to have major influence on their competitive interactions with diatoms and other siliceous phytoplankton.
authors: Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, UK.
authors: Grażyna M
authors: GM
authors: Durak
authors: Department of Biology and Marine Biology, University of North Carolina Wilmington, 601 South College Road, Wilmington, North Carolina, 28403-5915, USA.
authors: Alison R
authors: AR
authors: Taylor
authors: Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, UK.
authors: Charlotte E
authors: CE
authors: Walker
authors: Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France.
authors: Ian
authors: I
authors: Probert
authors: Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France.
authors: Colomban
authors: C
authors: de Vargas
authors: Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France.
authors: Stephane
authors: S
authors: Audic
authors: Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, UK.
authors: Declan
authors: D
authors: Schroeder
authors: Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, UK.|School of Ocean and Earth Sciences, University of Southampton, National Oceanography Centre, Southampton SO14 3ZH, UK.
authors: Colin
authors: C
authors: Brownlee
authors: Marine Biological Association, The Laboratory, Citadel Hill, Plymouth, Devon PL1 2PB, UK.
authors: Glen L
authors: GL
authors: Wheeler
mesh_terms: D002113:Calcification, Physiologic; D017377:Diatoms / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D020869:Gene Expression Profiling; D058087:Haptophyta / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D010839:Phytoplankton; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012623:Seawater / Q000737:chemistry; D012825:Silicon / Q000378:metabolism*
chemical_list: D026901:Membrane Transport Proteins; D012825:Silicon