2015NWPAC
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB24154 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The spring bloom in the North Atlantic develops over a few weeks in response to the physical stabilization of the nutrient replete water column and is one of the biggest biological signals on earth. The composition of the phytoplankton assemblage during the spring bloom of 2008 was evaluated, using a microarray, on the basis of functional genes that encode key enzymes in nitrogen and carbon assimilation in eukaryotic and prokaryotic phytoplankton. Oligonucleotide archetype probes representing RuBisCO, nitrate reductase and nitrate transporter genes from major phytoplankton classes detected a diverse assemblage. For RuBisCO, the archetypes with strongest signals represented known phytoplankton groups, but for the nitrate related genes, the major signals were not closely related to any known phytoplankton sequences. Most of the assemblage's components exhibited consistent temporal/spatial patterns. Yet, the strongest archetype signals often showed quite different patterns, indicating different ecological responses by the main players. The most abundant phytoplankton genera identified previously by microscopy, however, were not well represented on the microarray. The lack of sequence data for well-studied species, and the inability to identify organisms associated with functional gene sequences in the environment, still limits our understanding of phytoplankton ecology even in this relatively well-studied system.
2016-05-11 | GSE81262 | GEO
Project description:we characterized the microbial communities and proteomes of POC collected from the twilight zone at three contrasting sites in the northwest Pacific Ocean using a metaproteomic approach.Particle-attached bacteria, Alteromonadales, Rhodobacterales and Enterobacteriales, were the major remineralizers of POC in the twilight zone.
2021-03-24 | PXD014630 | Pride
Project description:Marine phytoplankton are a diverse group of photoautotrophic organisms and key mediators in the global carbon cycle. Phytoplankton physiology and biomass accumulation are closely tied to mixed layer depth, but the intracellular metabolic pathways activated in response to changing mixed layer depths remain unexplored. Here, metatranscriptomics was used to characterize the phytoplankton community response to a mixed layer shallowing from 233 meters to 5 meters over the course of two days during the late spring in the Northwest Atlantic. Most phytoplankton genera downregulated core photosynthesis, carbon storage, and carbon fixation genes as the system transitioned from a deep to a shallow mixed layer and shifted towards catabolism of stored carbon ic pathways supportive of rapid cell growth. In contrast, phytoplankton genera exhibited divergent transcriptional strategies for photosystem light harvesting complex genes during this transition. Active infection, taken as the ratio of virus to host transcripts, increased in the Bacillariophyta (diatom) phylum and decreased in the Chlorophyta (green algae) phylum upon mixed layer shallowing. A conceptual model is proposed to provide ecophysiological context for our findings, in which light limitation during deep mixing induces populations into a transcriptional state which maximizes interrupts the oscillating levels of transcripts related to photosynthesis, carbon storage, and carbon fixation found in shallow mixed layers with relatively higher growth rates. We propose that upon sensing high light levels during mixed layer shallowing, phytoplankton resume diel oscillation of core sets of genes enabling photoprotection, biosynthesis and cell replication. Our findings highlight the shared and unique transcriptional response strategies within phytoplankton communities acclimating to the dynamic light environment associated with transient deep mixing and shallowing events during the annual North Atlantic bloom.
2023-03-22 | GSE208287 | GEO
Project description:Projected responses of ocean net primary productivity (NPP) to climate change are highly uncertain. The climate sensitivity of phytoplankton nutrient limitation in the low-latitude Pacific plays a crucial role, but field measurements are insufficient to provide suitable constraints. Here we quantify two decades of nutrient limitation in the Equatorial Pacific with satellite observations. Using field nutrient addition experiments, proteomics, and above-water hyperspectral radiometry, we demonstrate that physiological responses of phytoplankton to iron limitation led to ~3-fold increases in chlorophyll-normalized phytoplankton fluorescence. Extension to the >18-year satellite fluorescence record showed that Equatorial Pacific iron limitation was robust to changes in physical forcing through multiple El Niño–Southern Oscillation cycles, despite coherent fluctuations in limitation strength. In contrast, these iron limitation changes were overestimated 2-fold by a state-of-the-art climate model. Such synoptic constraints provide a powerful new approach for benchmarking the realism of model NPP projections to climate changes.
2023-06-26 | PXD030610 | Pride
Project description:In summer 2014, we conducted experiments to determine the effects of different N substrates on phytoplankton communities in the North Pacific Ocean and in the transition zone of the California Current and gyre (Shilova, Mills et al., 2017). Samples were incubated with nitrate, ammonium, urea, and filtered deep water (FDW) for 48 hours (T48). Two treatments added iron, alone (Fe) or with a mix of N substrates (N+Fe), to determine the effects of Fe on the utilization of N substrates. All treatments resulted in changes in phytoplankton cell abundances and photosynthetic activity at both locations, with differences between phytoplankton groups. Prochlorococcus had large increases in biomass in response to ammonium and urea, while both eukaryotic phytoplankton and Synechococcus had only modest biomass increases in response to N+Fe and FDW. Moreover, distinct physiological responses were observed within sub-populations of Prochlorococcus and Synechococcus. In order to understand the variable responses to N substrates among phytoplankton groups and sub-populations in the California Current transition zone, the present work examines transcriptional changes that occurred 24 h after the substrates were added. Specifically, we hypothesize that transcription changes at 24 h indicate which phytoplankton taxa are N-limited, and thus help explain changes in cell abundances and photosynthetic activity by individual phytoplankton groups observed at 48 h. Furthermore, we hypothesize that the diversity in physiological responses within Prochlorococcus and Synechococcus are evident in the transcriptional responses measured at sub-population resolution.
2020-04-12 | GSE130464 | GEO
Project description:Sequencing the metatranscriptome can provide information about the response of organisms to varying environmental conditions. We present a methodology for obtaining random whole-community mRNA from a complex microbial assemblage using Pyrosequencing. The metatranscriptome had, with minimum contamination by ribosomal RNA, significant coverage of abundant transcripts, and included significantly more potentially novel proteins than in the metagenome. Keywords: metatranscriptome, mesocosm, ocean acidification This experiment is part of a much larger experiment. We have produced 4 454 metatranscriptomic datasets and 6 454 metagenomic datasets. These were derived from 4 samples. The experiment is an ocean acidification mesocosm set up in a Norwegian Fjord in 2006. We suspended 6 bags containing 11,000 L of sea water in a Coastal Fjord and then we bubbled CO2 through three of these bags to simulate ocean acidification conditions in the year 2100. The other three bags were bubbled with air. We then induced a phytoplankton bloom in all six bags and took measurements and performed analyses of phytoplankton, bacterioplankton and physiochemical characteristics over a 22 day period. We took water samples from the peak of the phytoplankton bloom and following the decline of the phytoplankton bloom to analyses using 454 metagenomics and 454 metatranscriptomics. Day 1, High CO2 Bag and Day 1, Present Day Bag, refer to the metatranscriptomes from the peak of the bloom. Day 2, High CO2 Bag and Day 2, Present Day Bag, refer to the metatranscriptomes following the decline of the bloom. Obviously High CO2 refers to the ocean acidification mesocosm and Present Day refers to the control mesocosm. Raw data for both the metagenomic and metatranscriptomic components are available at NCBI's Short Read Archive at ftp://ftp.ncbi.nlm.nih.gov/sra/Studies/SRP000/SRP000101
2008-02-08 | E-GEOD-10119 | biostudies-arrayexpress
Project description:The Pacific Northwest Udall Center
| PRJNA485596 | ENA
Project description:The Pacific Northwest Udall Center
| PRJNA485597 | ENA