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Multiple integrated metabolic strategies allow foraminiferan protists to thrive in anoxic marine sediments.

ABSTRACT: Oceanic deoxygenation is increasingly affecting marine ecosystems; many taxa will be severely challenged, yet certain nominally aerobic foraminifera (rhizarian protists) thrive in oxygen-depleted to anoxic, sometimes sulfidic, sediments uninhabitable to most eukaryotes. Gene expression analyses of foraminifera common to severely hypoxic or anoxic sediments identified metabolic strategies used by this abundant taxon. In field-collected and laboratory-incubated samples, foraminifera expressed denitrification genes regardless of oxygen regime with a putative nitric oxide dismutase, a characteristic enzyme of oxygenic denitrification. A pyruvate:ferredoxin oxidoreductase was highly expressed, indicating the capability for anaerobic energy generation during exposure to hypoxia and anoxia. Near-complete expression of a diatom's plastid genome in one foraminiferal species suggests kleptoplasty or sequestration of functional plastids, conferring a metabolic advantage despite the host living far below the euphotic zone. Through a unique integration of functions largely unrecognized among "typical" eukaryotes, benthic foraminifera represent winning microeukaryotes in the face of ongoing oceanic deoxygenation.

SUBMITTER: Gomaa F

PROVIDER: S-EPMC8153729 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature

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Multiple integrated metabolic strategies allow foraminiferan protists to thrive in anoxic marine sediments.

Gomaa Fatma F Utter Daniel R DR Powers Christopher C Beaudoin David J DJ Edgcomb Virginia P VP Filipsson Helena L HL Hansel Colleen M CM Wankel Scott D SD Zhang Ying Y Bernhard Joan M JM

Science advances 20210526 22

Oceanic deoxygenation is increasingly affecting marine ecosystems; many taxa will be severely challenged, yet certain nominally aerobic foraminifera (rhizarian protists) thrive in oxygen-depleted to anoxic, sometimes sulfidic, sediments uninhabitable to most eukaryotes. Gene expression analyses of foraminifera common to severely hypoxic or anoxic sediments identified metabolic strategies used by this abundant taxon. In field-collected and laboratory-incubated samples, foraminifera expressed deni ...[more]

PMID: 34039603

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Multiple integrated metabolic strategies allow foraminiferan protists to thrive in anoxic marine sediments.

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Multiple integrated metabolic strategies allow foraminiferan protists to thrive in anoxic marine sediments.

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