Incorporation of zinc into the frustule of the freshwater diatom Stephanodiscus hantzschii

Jaccard, Thomas; Ariztegui, Daniel; Wilkinson, Kevin J.

doi:10.1016/j.chemgeo.2009.04.016

Cited by 31 publications

(17 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, the cellular concentrations of Zn and Fe in the imaged cell are comparable to those measured on single diatom cells collected from two pristine regions of the ocean (17-19) (Table S1). While cellular Mn concentration is fourfold greater in the imaged cell than in oceanic diatom cells, it is also 20-fold less than reported for another freshwater diatom grown in culture at environmentally realistic Mn 2þ and Zn 2þ concentrations (20). Because C. meneghiniana is common to rivers and lakes in which trace elements are far more abundant than in the open ocean, our findings are likely relevant to these natural conditions.…”

Section: Resultsmentioning

confidence: 59%

Quantitative 3D elemental microtomography ofCyclotella meneghinianaat 400-nm resolution

Jonge

Holzner

Baines

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

156

102

View full text Add to dashboard Cite

X-ray fluorescence tomography promises to map elemental distributions in unstained and unfixed biological specimens in three dimensions at high resolution and sensitivity, offering unparalleled insight in medical, biological, and environmental sciences. X-ray fluorescence tomography of biological specimens has been viewed as impractical-and perhaps even impossible for routine application-due to the large time required for scanning tomography and significant radiation dose delivered to the specimen during the imaging process. Here, we demonstrate submicron resolution X-ray fluorescence tomography of a whole unstained biological specimen, quantifying three-dimensional distributions of the elements Si, P, S, Cl, K, Ca, Mn, Fe, Cu, and Zn in the freshwater diatom Cyclotella meneghiniana with 400-nm resolution, improving the spatial resolution by over an order of magnitude. The resulting maps faithfully reproduce cellular structure revealing unexpected patterns that may elucidate the role of metals in diatom biology and of diatoms in global element cycles. With anticipated improvements in data acquisition and detector sensitivity, such measurements could become routine in the near future.diatom | trace element distributions | X-ray fluorescence tomography A ccurate descriptions of elemental distributions within cells are required to address a wide range of key questions in the medical, biological, and environmental sciences. Element distributions can provide clues regarding biochemical function and indicate mechanisms by which trace elements act as carcinogens at the cellular level (1). Interactions between cells, such as pathogenicity, can be understood as a competition between host and parasite for critical trace elements (2). In the environmental sciences, the location of elements within cells can affect how those elements are accumulated up food chains (3). On a global scale, elemental composition of planktonic algae-particularly those prone to sink from surface waters-determines in part the amount of carbon that can be fixed by the ocean and, thus, the potential for storage of atmospheric CO 2 within deep waters (4).Scanning X-ray fluorescence microprobes have been used to map 2D projected elemental distributions over length scales ranging from under 1 μm to tens of millimetres, covering cells, small multicellular organisms, and larger sectioned specimens. The resolution and sensitivity of X-ray fluorescence microprobes extends below 60 nm (5) and several thousand atoms (6). Although single-atom sensitivity at Ångström length-scales has been demonstrated in the electron microscope (7) and single-molecule sensitivity in the range of 20 nm by optical fluorescence methods (8), the high penetration of X-rays suits them ideally to the investigation of trace elements in whole, unsectioned biological systems without staining.The interpretation of 2D projected elemental maps of 3D structures can be ambiguous. X-ray fluorescence tomography (9) promises unambiguous localization of elements. It has been used to obtain virt...

show abstract

Section: Resultsmentioning

confidence: 59%

Quantitative 3D elemental microtomography ofCyclotella meneghinianaat 400-nm resolution

Jonge

Holzner

Baines

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

156

102

View full text Add to dashboard Cite

show abstract

“…This would imply that the oceanic cycle of Zn is dominated by uptake into and regeneration from diatom siliceous tests, which are regenerated more slowly during sinking through the water column than intracellular organic matter (Zhao et al, 2014). However, the vast majority of Zn in diatoms is associated with N and P in organic tissues (Twining & Baines, 2013;Twining et al, 2004Twining et al, , 2015 and not diatom opal (1-3% of total cellular Zn inventory; Ellwood & Hunter, 2000;Jaccard et al, 2009), and thus, Zn should be regenerated from this organic matter in the upper ocean alongside P rather than opal-derived Si (Twining et al, 2014). A more recent hypothesis suggests that the strong Zn-Si correlation across the major oceans is instead explained by extreme drawdown of Zn and Si relative to P by diatoms in the surface Southern Ocean, and it is the lateral transport and modification of these Zn-and Si-depleted waters that sets the unusual Zn-Si-P stoichiometry in global nutricline waters (Ellwood, 2008;Vance et al, 2017;Weber et al, 2018;Wyatt et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Biogeochemical Cycling of Dissolved Zinc in the Western Arctic (Arctic GEOTRACES GN01)

Jensen

Wyatt

Twining

et al. 2019

Global Biogeochemical Cycles

View full text Add to dashboard Cite

The biogeochemical cycling of dissolved zinc (dZn) was investigated in the Western Arctic along the U.S. GEOTRACES GN01 section. Vertical profiles of dZn in the Arctic are strikingly different than the classic “nutrient‐type” profile commonly seen in the Atlantic and Pacific Oceans, instead exhibiting higher surface concentrations (~1.1 nmol/kg), a shallow subsurface absolute maximum (~4–6 nmol/kg) at 200 m coincident with a macronutrient maximum, and low deep water concentrations (~1.3 nmol/kg) that are homogeneous (sp.) with depth. In contrast to other ocean basins, typical inputs such as rivers, atmospheric inputs, and especially deep remineralization are insignificant in the Arctic. Instead, we demonstrate that dZn distributions in the Arctic are controlled primarily by (1) shelf fluxes following the sediment remineralization of high Zn:C and Zn:Si cells and the seaward advection of those fluxes and (2) mixing of dZn from source waters such as the Atlantic and Pacific Oceans rather than vertical biological regeneration of dZn. This results in both the unique profile shapes and the largely decoupled relationship between dZn and Si found in the Arctic. We found a weak dZn:Si regression in the full water column (0.077 nmol/μmol, r2 = 0.58) that is higher than the global slope (0.059 nmol/μmol, r2 = 0.94) because of the shelf‐derived halocline dZn enrichments. We hypothesize that the decoupling of Zn:Si in Western Arctic deep waters results primarily from a past ventilation event with unique preformed Zn:Si stoichiometries.

show abstract

“…Dissolution experiments show that the Zn/Si released through time is constant for a given opal sample, indicating that the Zn content of diatom frustrules is homogeneous [ Ellwood and Hunter , 2000a; Hendry and Rickaby , 2008]. Field tests support the laboratory findings, and show that (Zn/Si) opal and the Zn isotopic composition of diatom opal also relates to trace metal availability, which is often coupled with biological productivity and nutrient uptake in regions such as the Southern Ocean [ Jaccard et al , 2009; Hendry and Rickaby , 2008; Andersen et al , 2011]. Sediment trap and core top studies show (Zn/Si) opal signatures are transferred faithfully to sediments [ Hendry and Rickaby , 2008], such that (Zn/Si) opal is a useful paleoproxy, especially in the Southern Ocean where carbonate‐based proxies are poorly preserved.…”

Section: Introductionmentioning

confidence: 88%

“…The zinc content of diatom frustrules (normalized to silicon, (Zn/Si) opal ), with careful cleaning and preparation, can be used as a paleoproxy for past micronutrient concentrations [e.g., Ellwood and Hunter , 1999, 2000a, 2000b; Hendry and Rickaby , 2008; Andersen et al , 2011]. Laboratory cultures of both marine and freshwater diatoms show a relationship between (Zn/Si) opal and biologically available free Zn 2+ ions [ Ellwood and Hunter , 2000a; Jaccard et al , 2009]. Dissolution experiments show that the Zn/Si released through time is constant for a given opal sample, indicating that the Zn content of diatom frustrules is homogeneous [ Ellwood and Hunter , 2000a; Hendry and Rickaby , 2008].…”

Section: Introductionmentioning

confidence: 99%

Changes in micronutrient supply to the surface Southern Ocean (Atlantic sector) across the glacial termination

Hendry¹,

Rickaby

Allen

2011

Geochem. Geophys. Geosyst.

View full text Add to dashboard Cite

[1] Major deepwater masses upwell and reach the surface in the Southern Ocean, forming an important conduit supplying nutrients and micronutrients to the surface and playing a key role in the regulation of global climate through ocean-atmosphere gas exchange. Here, we reconstruct changes in micronutrient distribution in this region in response to past changes in upwelling, oceanic mixing, and sea-ice seasonality. We present two downcore (Zn/Si) opal records from the Scotia Sea and Drake Passage region, which we interpret in the context of micronutrient distribution in the Atlantic sector of the Southern Ocean over the last glacial termination. Previous work shows that micronutrient availability in the surface waters in the South Atlantic appear to be controlled dominantly by upwelling and mixing of micronutrient rich deepwaters, which are additionally fuelled by the terrestrial sediment sources of the Scotia Arc and South Georgia. This is supported by our reconstructions, which show micronutrient availability to the west of the Scotia Arc and South Georgia are consistently lower than to the east over the last glacial termination due to downstream transport and mixing into surface waters of continentally derived material in the Antarctic Circumpolar Current. Micronutrient availability in this region was at a minimum from 20 to 25 ky BP, coinciding with maximum sea-ice coverage, and increased due to an expansion of the seasonal sea-ice zone and increased mixing of subsurface waters. Our findings are consistent with largely diminished upwelling of micronutrients during the maximum glacial extent, and reduced mixing due to the presence of persistent sea-ice. During the deglacial there was an increase in micronutrient availability, as well as other nutrients and inorganic carbon, within the Antarctic Circumpolar Current as a result of an increase in deep oceanic upwelling, mixing and strengthened zonal transport.

show abstract

Incorporation of zinc into the frustule of the freshwater diatom Stephanodiscus hantzschii

Cited by 31 publications

References 32 publications

Quantitative 3D elemental microtomography ofCyclotella meneghinianaat 400-nm resolution

Quantitative 3D elemental microtomography ofCyclotella meneghinianaat 400-nm resolution

Biogeochemical Cycling of Dissolved Zinc in the Western Arctic (Arctic GEOTRACES GN01)

Changes in micronutrient supply to the surface Southern Ocean (Atlantic sector) across the glacial termination

Contact Info

Product

Resources

About