Transcript responses of lipid accumulation in Auxenochlorella pyrenoidosa to varying nitrogen deprivation
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ABSTRACT:
ORGANISM(S): Auxenochlorella pyrenoidosa
PROVIDER: GSE233967 | GEO | 2023/06/06
REPOSITORIES: GEO
Similar Datasets
Project description:Transcript responses of lipid accumulation in Auxenochlorella pyrenoidosa to varying nitrogen deprivation
| PRJNA979124 | ENA
Project description:Chlamydomonas reinhardtii forms lipid droplets rich in triacylglycerols when nutrient-deprived. To begin studying the mechanisms underlying this process, N-deprivation was used to induce triacylglycerol accumulation and changes in developmental programs such as gametogenesis. Comparative global analysis of transcripts under induced and non-induced conditions was applied as a first approach to study molecular changes that promote or accompany triacylglycerol accumulation in cells encountering a new nutrient environment. Towards this goal, high-throughput sequencing technology was employed to generate large numbers of expressed sequence tags of 8 biologically independent libraries (6 Illumina libraries, 2 454 libraries), four for each condition, N-replete and N-deprived, that allowed a statistically sound comparison of expression levels under the two tested conditions. Inferences on metabolism based on transcriptional analysis can only be indirect but were supported in parts by biochemical experiments. N-deprivation led to a marked redirection of metabolism as the carbon source acetate was no longer converted to cell building blocks by the glyoxylate cycle and gluconeogensis, but funneled directly into fatty acid biosynthesis. Protein biosynthesis and photosynthesis were down-regulated and genes of gametogenesis activated. A notable finding was that the genes encoding photosynthetic accessory PSBS proteins of currently unclear function in C. reinhardtii were strongly expressed following N-deprivation, providing a clue to their physiological role. Lipase-encoding genes were found to be some of the most regulated following N-deprivation, suggesting a remodeling of membranes under these conditions. The data provided here represent a rich source for the exploration of the mechanism of oil accumulation in microalgae. Examining N-replete and N-deprived conditions. Three biological replicates each condition.
2010-09-24 | E-GEOD-24365 | biostudies-arrayexpress
Project description:Understanding gene expression re-programming in response to limiting nitrogen (N) conditions is crucial for ongoing progress towards the development of crop varieties with improved nitrogen use efficiency. We analyzed expression data obtained from leaves and roots of rice plants adapted to sufficient and limiting nitrate as well as after shifting them to low (reduction) and sufficient (induction) nitrate conditions.
2015-03-25 | GSE61370 | GEO
Project description:Drastic alteration in macronutrients causes large changes in gene expression in the photosynthetic unicellular alga Chlamydomonas reinhardtii. Preliminary data suggested that cells follow a biphasic response to this change hinging on the initiation of lipid accumulation, and we hypothesized that drastic repatterning of metabolism also followed this biphasic modality. To test this hypothesis, transcriptomic, proteomic, and metabolite changes that occur under nitrogen (N) deprivation were analyzed. Eight sampling times were selected covering the progressive slowing of growth and induction of oil synthesis between 4 and 6 h after N deprivation. Results of the combined, systems-level investigation indicated that C. reinhardtii cells sense and respond on a large scale within 30 min to a switch to N-deprived conditions turning on a largely gluconeogenic metabolic state, which then transitions to a glycolytic stage between 4 and 6 h after N depletion. This nitrogen-sensing system is transduced to carbon- and nitrogen-responsive pathways, leading to down-regulation of carbon assimilation and chlorophyll biosynthesis, and an increase in nitrogen metabolism and lipid biosynthesis. For example, the expression of nearly all the enzymes for assimilating nitrogen from ammonium, nitrate, nitrite, urea, formamide/acetamide, purines, pyrimidines, polyamines, amino acids and proteins increased significantly. Although arginine biosynthesis enzymes were also rapidly up-regulated, arginine pool size changes and isotopic labeling results indicated no increased flux through this pathway.
2015-06-17 | PXD002377 | Pride
Project description:To investigate the mechanism by which the microalgae-yeast co-culture system promotes wastewater denitrification. We concluded that microalgae and yeast exhibit a mutually beneficial relationship in the co-culture system. Microalgae nitrogen metabolism can be influenced by both miRNA and mRNA, and the presence of yeast stimulates gene expression in microalgae.
2023-07-12 | GSE231399 | GEO
Project description:Identification of the earliest transcriptional responses of adult Arabidopsis plant roots towards N-deprivation. Hydroponically grown Plants (35 days old) were 5 days adapted to nitrate or ammonium,respectively, as sole N-source to detect N-form specific transcripts.
2016-05-31 | GSE73903 | GEO
Project description:Identification of the earliest transcriptional responses of adult Arabidopsis plant roots towards N-deprivation. Hydroponically grown Plants (35 days old) were 5 days adapted to nitrate or ammonium,respectively, as sole N-source to detect N-form specific transcripts. 24 Samples: 2 Pre-Treatments (5 Day adaptation to 3mM Ammonium/Nitrate) x 3 sampling time-points (0min, 15 min, 180 min) x 3 independent replications per time-point + 6 additional controls (2 x 15min, 1x 180min per Pre-Treatment)
2016-05-31 | E-GEOD-73903 | biostudies-arrayexpress
Project description:Transcriptome of A. fumigatus shifted from ammoniumtartrate to different nitrogen sources and incubated for a defined time was compared. After 16h preculture, the fungus was transferred into fresh medium containing ammonium tartrate, sodium nitrate, proline or bsa as nitrogen source. After 1h, fungus was reisolated, RNA was prepared from fungus, transcriptome was assessed and used for further analysis.
2011-10-30 | GSE30384 | GEO
Project description:As global temperatures climb to historic highs, the far-reaching effects of climate change have impacted agricultural nutrient availability. This has extended to low latitude oceans, where a deficit in both nitrogen and phosphorus stores has led to dramatic decreases in carbon sequestration in oceanic phytoplankton. Although Chlamydomonas reinhardtii, a freshwater model green alga, has shown drastic systems-level alterations following nitrogen deprivation, the mechanism(s) through which these alterations are triggered and regulated are unclear. This study examined the role of reversible oxidative signaling in the nitrogen stress response of C. reinhardtii. Using oxidized cysteine resin-assisted capture enrichment coupled with label-free quantitative proteomics, 7,889 unique oxidized cysteine thiol identifiers were quantified, with 231 significantly changing peptides from 184 proteins following 2 h of nitrogen deprivation. These results demonstrate proteins affected by oxidation involved in nitrogen assimilation, amino acid metabolism, photosynthesis, and other metabolic processes. An enhanced role of non-damaging oxidative pathways is observed throughout the photosynthetic apparatus that provides a framework for further analysis in phototrophs.
2020-06-28 | PXD019491 | Pride
Project description:Chlamydomonas reinhardtii forms lipid droplets rich in triacylglycerols when nutrient-deprived. To begin studying the mechanisms underlying this process, N-deprivation was used to induce triacylglycerol accumulation and changes in developmental programs such as gametogenesis. Comparative global analysis of transcripts under induced and non-induced conditions was applied as a first approach to study molecular changes that promote or accompany triacylglycerol accumulation in cells encountering a new nutrient environment. Towards this goal, high-throughput sequencing technology was employed to generate large numbers of expressed sequence tags of 8 biologically independent libraries (2 454 libraries, 6 Illumina libraries), four for each condition, N-replete and N-deprived, that allowed a statistically sound comparison of expression levels under the two tested conditions. Inferences on metabolism based on transcriptional analysis can only be indirect but were supported in parts by biochemical experiments. N-deprivation led to a marked redirection of metabolism as the carbon source acetate was no longer converted to cell building blocks by the glyoxylate cycle and gluconeogensis, but funneled directly into fatty acid biosynthesis. Protein biosynthesis and photosynthesis were down-regulated and genes of gametogenesis activated. A notable finding was that the genes encoding photosynthetic accessory PSBS proteins of currently unclear function in C. reinhardtii were strongly expressed following N-deprivation, providing a clue to their physiological role. Lipase-encoding genes were found to be some of the most regulated following N-deprivation, suggesting a remodeling of membranes under these conditions. The data provided here represent a rich source for the exploration of the mechanism of oil accumulation in microalgae. Examing N-replete and N-deprived conditions. One biological replicate each condition.
2010-09-24 | E-GEOD-24366 | biostudies-arrayexpress