title: Subcellular tracking reveals the location of dimethylsulfoniopropionate in microalgae and visualises its uptake by marine bacteria.
abstract: Phytoplankton-bacteria interactions drive the surface ocean sulfur cycle and local climatic processes through the production and exchange of a key compound: dimethylsulfoniopropionate (DMSP). Despite their large-scale implications, these interactions remain unquantified at the cellular-scale. Here we use secondary-ion mass spectrometry to provide the first visualization of DMSP at sub-cellular levels, tracking the fate of a stable sulfur isotope (34S) from its incorporation by microalgae as inorganic sulfate to its biosynthesis and exudation as DMSP, and finally its uptake and degradation by bacteria. Our results identify for the first time the storage locations of DMSP in microalgae, with high enrichments present in vacuoles, cytoplasm and chloroplasts. In addition, we quantify DMSP incorporation at the single-cell level, with DMSP-degrading bacteria containing seven times more34S than the control strain. This study provides an unprecedented methodology to label, retain, and image small diffusible molecules, which can be transposable to other symbiotic systems.
authors.affiliation: AIMS@JCU, James Cook University, Townsville, Australia.|Australian Institute of Marine Science, Townsville, Australia.|Climate Change Cluster, University of Technology Sydney, Sydney, Australia.|ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia.|College of Science and Engineering, James Cook University, Townsville, Australia.
authors.forename: Jean-Baptiste
authors.identifier: 0000-0002-7508-0004
authors.initials: JB
authors.lastname: Raina
authors.affiliation: The Centre for Microscopy Characterisation and Analysis, The University of Western Australia, Crawley, Australia.|Oceans Institute, The University of Western Australia, Crawley, Australia.
authors.forename: Peta L
authors.initials: PL
authors.lastname: Clode
authors.affiliation: Mark Wainwright Analytical Centre, University of New South Wales, Kensington, Australia.
authors.forename: Soshan
authors.initials: S
authors.lastname: Cheong
authors.affiliation: The Centre for Microscopy Characterisation and Analysis, The University of Western Australia, Crawley, Australia.|School of Earth and Environment, The University of Western Australia, Crawley, Australia.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Bougoure
authors.affiliation: The Centre for Microscopy Characterisation and Analysis, The University of Western Australia, Crawley, Australia.
authors.forename: Matt R
authors.initials: MR
authors.lastname: Kilburn
authors.affiliation: The Centre for Microscopy Characterisation and Analysis, The University of Western Australia, Crawley, Australia.
authors.forename: Anthony
authors.initials: A
authors.lastname: Reeder
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia.|Research School of Biology, Australian National University, Canberra, Australia.
authors.forename: Sylvain
authors.identifier: 0000-0002-4145-9243
authors.initials: S
authors.lastname: Forêt
authors.affiliation: Trace and Environmental DNA Laboratory, Department of Environment and Agriculture, Curtin University, Perth, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Stat
authors.affiliation: Australian Institute of Marine Science, Townsville, Australia.
authors.forename: Victor
authors.initials: V
authors.lastname: Beltran
authors.affiliation: Australian Institute of Marine Science, Townsville, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Thomas-Hall
authors.affiliation: Australian Institute of Marine Science, Townsville, Australia.
authors.forename: Dianne
authors.initials: D
authors.lastname: Tapiolas
authors.affiliation: AIMS@JCU, James Cook University, Townsville, Australia.|Australian Institute of Marine Science, Townsville, Australia.
authors.forename: Cherie M
authors.initials: CM
authors.lastname: Motti
authors.affiliation: Mark Wainwright Analytical Centre, University of New South Wales, Kensington, Australia.
authors.forename: Bill
authors.initials: B
authors.lastname: Gong
authors.affiliation: Climate Change Cluster, University of Technology Sydney, Sydney, Australia.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Pernice
authors.affiliation: Mark Wainwright Analytical Centre, University of New South Wales, Kensington, Australia.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Marjo
authors.affiliation: Climate Change Cluster, University of Technology Sydney, Sydney, Australia.
authors.forename: Justin R
authors.initials: JR
authors.lastname: Seymour
authors.affiliation: AIMS@JCU, James Cook University, Townsville, Australia.|ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Australia.|College of Science and Engineering, James Cook University, Townsville, Australia.
authors.forename: Bette L
authors.initials: BL
authors.lastname: Willis
authors.affiliation: Australian Institute of Marine Science, Townsville, Australia.|College of Science and Engineering, James Cook University, Townsville, Australia.
authors.forename: David G
authors.initials: DG
authors.lastname: Bourne
mesh_terms: D059001:Aquatic Organisms / Q000737:chemistry* / Q000378:metabolism*; D001419:Bacteria / Q000737:chemistry* / Q000378:metabolism*; D007553:Isotope Labeling; D058086:Microalgae / Q000737:chemistry* / Q000378:metabolism*; D018629:Spectrometry, Mass, Secondary Ion; D013452:Sulfonium Compounds / Q000032:analysis*; D013460:Sulfur Isotopes / Q000032:analysis
chemical_list: D013452:Sulfonium Compounds; D013460:Sulfur Isotopes; C068078:dimethylpropiothetin
keywords: NanoSIMS; ToF-SIMS; biogeochemical cycling; dmsp; ecology; infectious disease; microbiology; nanosims; phytoplankton-bacteria; phytoplankton-bacteria interaction; stable isotope labelling; sulfur cycle; symbiosis