Data/hora: 06/06/2024 03:41:54

Provedor de dados: | 5
País: | France
Título: | Regulation of the Phytoplankton Heme b Iron Pool During the North Atlantic Spring Bloom
Autores: | Louropoulou, Evangelia; Gledhill, Martha; Browningi, Thomas J.; Desai, Dhwani K.; Barraqueta, Jan-lukas Menzel; Tonnard, Manon; Sarthou, Geraldine; Planquette, Helene; Bowie, Andrew R.; Schmitz, Ruth A.; Laroche, Julie; Achterberg, Eric P.
Data: | 2019-07
Ano: | 2019
Palavras-chave: | Heme b; North Atlantic; Phytoplankton; Diatoms; Iron; Limitation; GEOTRACES; GEOVIDE.
Resumo: | Heme b is an iron-containing co-factor in hemoproteins. Heme b concentrations are low (&lt; 1 pmol L-1) in iron limited phytoplankton in cultures and in the field. Here, we determined heme b in marine particulate material (&gt; 0.7 mu m) from the North Atlantic Ocean (GEOVIDE cruise - GEOTRACES section GA01), which spanned several biogeochemical regimes. We examined the relationship between heme b abundance and the microbial community composition, and its utility for mapping iron limited phytoplankton. Heme b concentrations ranged from 0.16 to 5.1 pmol L-1 (median = 2.0 pmol L-1, n = 62) in the surface mixed layer (SML) along the cruise track, driven mainly by variability in biomass. However, in the Irminger Basin, the lowest heme b levels (SML: median = 0.53 pmol L-1, n = 12) were observed, whilst the biomass was highest (particulate organic carbon, median = 14.2 mu mol L-1, n = 25; chlorophyll a: median = 2.0 nmol L-1, n = 23) pointing to regulatory mechanisms of the heme b pool for growth conservation. Dissolved iron (DFe) was not depleted (SML: median = 0.38 nmol L-1, n = 11) in the Irminger Basin, but large diatoms (Rhizosolenia sp.) dominated. Hence, heme b depletion and regulation is likely to occur during bloom progression when phytoplankton class-dependent absolute iron requirements exceed the available ambient concentration of DFe. Furthermore, high heme b concentrations found in the Iceland Basin and Labrador Sea (median = 3.4 pmol L-1, n = 20), despite having similar DFe concentrations to the Irminger Basin, were attributed to an earlier growth phase of the extant phytoplankton populations. Thus, heme b provides a snapshot of the cellular activity in situ and could both be used as indicator of iron limitation and contribute to understanding phytoplankton adaptation mechanisms to changing iron supplies.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00508/61940/66029.pdf

https://archimer.ifremer.fr/doc/00508/61940/66030.zip

DOI:10.3389/fmicb.2019.01566

https://archimer.ifremer.fr/doc/00508/61940/

Editor: | Frontiers Media Sa
Formato: | application/pdf
Fonte: | Frontiers In Microbiology (1664-302X) (Frontiers Media Sa), 2019-07 , Vol. 10 , N. 1566 , P. 16p.

Fonte:

info:eu-repo/semantics/openAccess

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