Ontology highlight
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PROVIDER: PRJNA1207614 | ENA |
REPOSITORIES: ENA
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Project description:Atrazine is one of the most commonly used herbicide and has been frequently detected in estuarine and offshore waters worldwide. As a photosystem Ⅱ inhibitor, atrazine may inhibit phytoplankton from fixating of CO2 and alter its carbon metabolism, which will undoubtedly have negative effect on the primary productivity and carbon sequestration capacity of coastal waters. However, the existing reports mainly focused on agriculture and freshwater ecosystems and are mostly toxicity test with high-dose of atrazine, which have little concern about the negative effects of atrazine on the carbon metabolism of phytoplankton and can’t reflect the actual toxic situation in offshore water. Diatoms are widely distributed in freshwater and oceans and contribute at least 20% of the global CO2 assimilation, which is an ideal model group to assess the ecological risk of atrazine. Here we present a comprehensive analysis of the physiological and genome-wide gene expression characteristics of the diatom P. tricornutum Pt-1 (CCMP 2561) treated with environmental dose of atrazine at different stress stages.
2020-12-12 | GSE112478 | GEO
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: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:Emiliania huxleyi: Cellular cascades induced by bacterial algicides Interactions between phytoplankton and bacteria play a central role in mediating oceanic biogeochemical cycling and microbial trophic structure in the ocean. The intricate relationships between these two domains of life are mediated via excreted molecules that facilitate communication and determine competitive outcomes. Yet, despite their predicted importance, identifying these secreted compounds and understanding their ecological significance has remained a challenge. Research in the Whalen Lab endeavors to (i) identify those bacterially-derived chemical signaling compounds (i.e. infochemicals) that mediate phytoplankton population dynamics, and (ii) determine the underlying physiological processes that contribute to phytoplankton tolerance or susceptibility to these compounds. Recently, the Whalen lab isolated an alkylquinolone-signaling molecule with known quorum sensing function from the globally distributed marine γ-proteobacteria, Pseudoalteromonas sp. capable of inducing species-specific phytoplankton mortality. This research was the first to suggest quorum sensing compounds have expanded and previously unrecognized ecological roles in regulating primary production and phytoplankton bloom dynamics. We are now investigating in how this alkylquinolone induces phytoplankton mortality via transcriptomic profiling and diagnostic biochemical analysis. Complementary to this transcriptomic examination, we will complete whole-cell proteomic approach to identify those phytoplankton proteins crucial in competitive interactions with bacterial infochemicals, but whose functions may not yet be known. With this proteomic approach in parallel to our transcriptomic investigation, we can establish a better understanding of the eukaryotic macromolecular targets and cellular cascades induced in response to bacterial algicides like alkylquinolones. With the knowledge gained from both approaches we can begin to address how these ?keystone molecules? influence population dynamics and community composition of phytoplankton and bacteria in field-based experiments with the goal of defining a new mechanistic framework for how bacterially derived signaling molecules influence biogeochemical cycles. D= DMSO - control treatment L= low 1 nm HHG additions M= medium 10 nm HHG additions H= high 100 nm HHG additions Each treatment had 4 biological replicates A-D
2019-02-15 | PXD011559 | Pride
Project description:Emiliania huxleyi: Cellular cascades induced by bacterial algicides Interactions between phytoplankton and bacteria play a central role in mediating oceanic biogeochemical cycling and microbial trophic structure in the ocean. The intricate relationships between these two domains of life are mediated via excreted molecules that facilitate communication and determine competitive outcomes. Yet, despite their predicted importance, identifying these secreted compounds and understanding their ecological significance has remained a challenge. Research in the Whalen Lab endeavors to (i) identify those bacterially-derived chemical signaling compounds (i.e. infochemicals) that mediate phytoplankton population dynamics, and (ii) determine the underlying physiological processes that contribute to phytoplankton tolerance or susceptibility to these compounds. Recently, the Whalen lab isolated an alkylquinolone-signaling molecule with known quorum sensing function from the globally distributed marine γ-proteobacteria, Pseudoalteromonas sp. capable of inducing species-specific phytoplankton mortality. This research was the first to suggest quorum sensing compounds have expanded and previously unrecognized ecological roles in regulating primary production and phytoplankton bloom dynamics. We are now investigating in how this alkylquinolone induces phytoplankton mortality via transcriptomic profiling and diagnostic biochemical analysis. Complementary to this transcriptomic examination, we will complete whole-cell proteomic approach to identify those phytoplankton proteins crucial in competitive interactions with bacterial infochemicals, but whose functions may not yet be known. With this proteomic approach in parallel to our transcriptomic investigation, we can establish a better understanding of the eukaryotic macromolecular targets and cellular cascades induced in response to bacterial algicides like alkylquinolones. With the knowledge gained from both approaches we can begin to address how these ?keystone molecules? influence population dynamics and community composition of phytoplankton and bacteria in field-based experiments with the goal of defining a new mechanistic framework for how bacterially derived signaling molecules influence biogeochemical cycles. D= DMSO - control treatment L= low 1 nm HHG additions M= medium 10 nm HHG additions H= high 100 nm HHG additions Each treatment had 4 biological replicates A-D
2020-01-07 | PXD011560 | Pride
Project description:Atrazine is an agricultural herbicide used throughout the Midwestern United States that frequently contaminates potable water supplies resulting in human exposure. Using the zebrafish model system, an embryonic atrazine exposure was previously reported to decrease spawning rates with an increase in progesterone and ovarian follicular atresia in adult females. In addition, alterations in genes associated with distinct molecular pathways of the endocrine system were observed in brain and gonad tissue of the adult females and males. Current hypotheses for mechanistic changes in the developmental origins of health and disease include genetic (e.g., copy number alterations) or epigenetic (e.g., DNA methylation) mechanisms. As such, in the current study we investigated whether an atrazine exposure would generate copy number alterations (CNAs) in the zebrafish genome. A zebrafish fibroblast cell line was used to limit detection to CNAs caused by the chemical exposure. First, cells were exposed to a range of atrazine concentrations and a crystal violet assay was completed, showing confluency decreased by ~60% at 46.3 µM. Cells were then exposed to 0, 0.463, 4.63, or 46.3 µM atrazine and array comparative genomic hybridization completed. Results showed 34, 21, and 44 CNAs in the 0.463, 4.63, and 46.3µM treatments, respectively. Furthermore, CNAs were associated with previously reported gene expression alterations in adult male and female zebrafish. This study demonstrates that atrazine exposure can generate CNAs that are linked to gene expression alterations observed in adult zebrafish exposed to atrazine during embryogenesis providing a mechanism of the developmental origins of atrazine endocrine disruption.
2017-02-20 | GSE93635 | GEO
Project description:The increased urban pressures are often associated with specialization of microbial communities. Microbial communities being a critical player in the geochemical processes, makes it important to identify key environmental parameters that influence the community structure and its function.In this proect we study the influence of land use type and environmental parameters on the structure and function of microbial communities. The present study was conducted in an urban catchment, where the metal and pollutants levels are under allowable limits. The overall goal of this study is to understand the role of engineered physicochemical environment on the structure and function of microbial communities in urban storm-water canals.
2014-12-22 | GSE64286 | GEO
Project description:The increased urban pressures are often associated with specialization of microbial communities. Microbial communities being a critical player in the geochemical processes, makes it important to identify key environmental parameters that influence the community structure and its function.In this proect we study the influence of land use type and environmental parameters on the structure and function of microbial communities. The present study was conducted in an urban catchment, where the metal and pollutants levels are under allowable limits. The overall goal of this study is to understand the role of engineered physicochemical environment on the structure and function of microbial communities in urban storm-water canals. Microbial community structure was determined using PhyoChio (G3)
2014-12-22 | GSE64368 | GEO