Resting cell formation in the marine diatom Thalassiosira pseudonana

New Phytologist, Journal Year: 2024, Volume and Issue: 243(4), P. 1347 - 1360

Published: Feb. 25, 2024

Resting cells represent a survival strategy employed by diatoms to endure prolonged periods of unfavourable conditions. In the oceans, many sink at end their blooming season and therefore need cold dark conditions in deeper layers water column. How they survive these is largely unknown. We conducted an integrative analysis encompassing methods from histology, physiology, biochemistry, genetics reveal biological mechanism resting-cell formation model diatom Thalassiosira pseudonana. Resting-cell was triggered decrease light temperature with subsequent catabolism storage compounds. were characterised acidic viscous cytoplasm altered morphology chloroplast ultrastructure. The resting T. pseudonana energy demanding process required for biophysical alteration cytosol chloroplasts ocean as photosynthetic organisms. However, most (> 90%) germinate upon return favorable growth

Language: Английский

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A fast microbial nitrogen-assimilation technology enhances nitrogen migration and single-cell-protein production in high-ammonia piggery wastewater

Environmental Research, Journal Year: 2024, Volume and Issue: 257, P. 119329 - 119329

Published: June 6, 2024

Language: Английский

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Adaptation to Long-Term Nitrogen Starvation in a Biocrust-Derived Microalga Vischeria sp. WL1: Insights into Cell Wall Features and Desiccation Resistance

Microorganisms, Journal Year: 2025, Volume and Issue: 13(4), P. 903 - 903

Published: April 14, 2025

In drylands, microalgae dwelling in the biocrust are inevitably confronted with nitrogen deficiency and desiccation stress, despite protection afforded by soil biological complex. However, environmental adaptive features mechanisms of these remain largely unknown. this study, we explored changes a biocrust-derived unicellular microalga, Vischeria sp. WL1 (Eustigmatophyceae), face long-term deficiency. Attention was focused on alterations cell wall properties associated resistance. After exposure to deficiency, walls thickened substantially, accompanied enhanced rigidity an improvement contrast, cells cultivated under nitrogen-replete conditions were highly vulnerable stress. Additional after starvation included distinct surface sculpturing, variations monosaccharide composition, functional groups. Collectively, study provides valuable insights into survival strategies nitrogen-deficient dryland environments.

Language: Английский

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Hydrostatic pressure induces transformations in the organic matter and microbial community composition of marine snow particles

Communications Earth & Environment, Journal Year: 2023, Volume and Issue: 4(1)

Published: Oct. 14, 2023

Abstract In the hadal zone of ocean (6–11 km), characteristics sinking marine snow particles and their attached microbial communities remain elusive, despite potential importance for benthic life thriving at extreme pressures (60–110 MPa). Here, we used simulation experiments to explore how increasing pressure levels modify degradation, organic matter composition, microbiome diatom aggregates. Individual aggregates were incubated in rotating tanks which was incrementally increased simulate a descent from surface depth within 20 days. Incubations atmospheric served as controls. With pressure, respiration degradation decreased gradually ceased completely 60 MPa. Dissolved carbon leaked substantially ≥40 MPa, while lipid pigment contents moderately. Bacterial abundance remained stable >40 but bacterial community composition changed significantly 60–100 Thus, exposure reduces transforms both microbiomes particles, may seed sediments with relatively fresh particulate putative pressure-tolerant microbes.

Language: Английский

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Local adaptation of a marine diatom is governed by genome-wide changes in diverse metabolic processes

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2023, Volume and Issue: unknown

Published: Sept. 23, 2023

ABSTRACT Marine phytoplankton play essential roles in global primary production and biogeochemical cycles. Yet, the evolutionary genetic underpinnings of adaptation to complex marine coastal environments, where many environmental variables fluctuate interact, remain unclear. We combined population genomics data with experimental transcriptomics investigate genomic basis underlying a natural experiment that has played out over past 8,000 years one world’s largest brackish water bodies: colonization Baltic Sea by diatom Skeletonema marinoi . To this end, we used novel approach for protist genomics, combining target capture entire nuclear genome pooled sequencing, showed method performs well on both cultures single cells. Genotype-environment association analyses identified >3,000 genes signals selection response major gradients Sea, which apart from salinity, include marked differences temperature nutrient availability. Locally adapted were related diverse metabolic processes, including signal transduction, cell cycle, DNA methylation, maintenance homeostasis. The locally significant overlap salinity-responsive laboratory common garden experiment, suggesting salinity gradient is factor driving local S. Altogether, our show are characterized multitude gradients, driven intricate changes pathways functions.

Language: Английский

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Some fall to sleep slowly: cell biophysics and metabolism of quiescence in diatom resting cells

New Phytologist, Journal Year: 2024, Volume and Issue: 243(4), P. 1284 - 1286

Published: April 22, 2024

This article is a Commentary on Wang et al . (2024), 243 : 1347–1360.

Language: Английский

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Resting cells of Skeletonema marinoi assimilate organic compounds and respire by dissimilatory nitrate reduction to ammonium in dark, anoxic conditions

Environmental Microbiology, Journal Year: 2024, Volume and Issue: 26(4)

Published: April 1, 2024

Diatoms can survive long periods in dark, anoxic sediments by forming resting spores or cells. These have been considered dormant until recently when cells of Skeletonema marinoi were shown to assimilate nitrate and ammonium from the ambient environment conditions. Here, we show that S. also perform dissimilatory reduction (DNRA), Transmission electron microscope analyses showed chloroplasts compacted, few large mitochondria had visible cristae within Using secondary ion mass spectrometry isotope ratio combined with stable isotopic tracers, measured assimilatory processes carried out under Nitrate was both respired DNRA assimilated into biomass Cells nitrogen urea carbon acetate, which are sources dissolved organic matter produced sediments. Carbon assimilation rates corresponded turnover cellular content ranging between 469 10,000 years. Hence, diatom sustain their slowly assimilating respiring substrates environment.

Language: Английский

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Single cell dynamics and nitrogen transformations in the chain forming diatom Chaetoceros affinis

The ISME Journal, Journal Year: 2023, Volume and Issue: 17(11), P. 2070 - 2078

Published: Sept. 18, 2023

Colony formation in phytoplankton is often considered a disadvantage during nutrient limitation aquatic systems. Using stable isotopic tracers combined with secondary ion mass spectrometry (SIMS), we unravel cell-specific activities of chain-forming diatom and interactions attached bacteria. The uptake 13C-bicarbonate and15N-nitrate or 15N-ammonium was studied Chaetoceros affinis the stationary growth phase. Low cell-to-cell variance 15N-nitrate assimilation within chains prevailed early Up to 5% freshly assimilated 13C 15N detected bacteria 12 h supported bacterial C- N-growth rates up 0.026 h-1. During mid-stationary phase, chain-length decreased significantly higher solitary cells as compared that chain cells. late nitrate ceased ammonium balanced C fixation. At this stage, observed highly active neighboring inactive same chain. In N-limited regimes, remineralization N short diffusion distance between neighbors may support surviving This combination "microbial gardening" transfer represents strategy which challenges current paradigms fluxes plankton communities.

Language: Английский

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The divergent responses of salinity generalists to hyposaline stress provide insights into the colonization of freshwaters by diatoms

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 3, 2024

ABSTRACT Environmental transitions, such as the salinity divide separating marine and fresh waters, shape biodiversity over both shallow deep timescales, opening up new niches creating opportunities for accelerated speciation adaptive radiation. Understanding evolutionary genetic underpinnings behind habitat transitions is therefore a central question in biology. We used time-resolved transcriptomics to contrast hyposalinity stress responses of two ecologically important diatoms: Skeletonema marinoi has ancestry but recently invaded brackish whereas Cyclotella cryptica freshwater can withstand much broader range. S. less adept at mitigating even mild compared C. , which distinct mechanisms rapid mitigation hyposaline long-term growth low salinity. show that cellular underlying tolerance, allowed diversification across habitats worldwide, includes elements are conserved variable diatom lineage. The balance between ancestral lineage-specific environmental phytoplankton have likely shaped marine–freshwater on timescales and, contemporary will determine lineages survive adapt changing ocean conditions.

Language: Английский

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The Divergent Responses of Salinity Generalists to Hyposaline Stress Provide Insights Into the Colonisation of Freshwaters by Diatoms

Molecular Ecology, Journal Year: 2024, Volume and Issue: 33(22)

Published: Oct. 21, 2024

Environmental transitions, such as the salinity divide separating marine and fresh waters, shape biodiversity over both shallow deep timescales, opening up new niches creating opportunities for accelerated speciation adaptive radiation. Understanding genetics of environmental adaptation is central to understanding how organisms colonise subsequently diversify in habitats. We used time-resolved transcriptomics contrast hyposalinity stress responses two diatoms. Skeletonema marinoi has ancestry but recently invaded brackish waters. Cyclotella cryptica freshwater can withstand a much broader range. less adept at mitigating even mild compared cryptica, which distinct mechanisms rapid mitigation hyposaline long-term growth low salinity. show that cellular underlying tolerance, allowed diversification across habitats worldwide, includes elements are conserved variable diatom lineage. The balance between ancestral lineage-specific phytoplankton have shaped marine-freshwater transitions on evolutionary timescales and, contemporary will affect lineages survive adapt changing ocean conditions.

Language: Английский

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