Transcriptome profiling of the Chlamydomonas reinhardtii phot mutant
Ontology highlight
ABSTRACT:
ORGANISM(S): Chlamydomonas reinhardtii
PROVIDER: GSE227473 | GEO | 2023/03/21
REPOSITORIES: GEO
Similar Datasets
Project description:Linear tetrapyrrole (bilin)-based phytochrome sensors optimize photosynthetic light capture by mediating massive gene reprogramming in land plants, yet surprisingly, many sequenced chlorophyte (green) algae lack phytochrome genes. Previous studies on the heme oxygenase (hmox1) mutant of Chlamydomonas reinhardtii suggest that bilin biosynthesis in plastids is needed for regulation of a limited nuclear gene network implicated in oxygen detoxification during dark to light transitions. The hmox1 mutant is unable to grow photoautotrophically and poorly acclimates to increased illumination even in the presence of acetate. Here we show that these phenotypes reflect the reduced accumulation of PSI reaction centers as well as a loss of PSI and PSII antennae complexes during photoacclimation. Phenotypically, the hmox1 mutant is similar to the chlorophyll biosynthesis mutants, gun4, crd1 and cth1. However, many of the hmox1 phenotypes can be rescued by the application of exogenous biliverdin IXα, the bilin product of HMOX1; this rescue is independent of photosynthesis but strongly dependent upon blue light. RNA-Seq comparisons of hmox1, 4A+ wild type and two genetically complemented lines also reveal that bilins restore regulation of a small network of photosynthesis-associated nuclear genes. These include genes responsible for chlorophyll biosynthesis (CHLI1/2), PSI light-harvesting (LHCA4) and naphthoquinone metabolism (MEN2), all of which show reduced photoinduction in the hmox1 mutant. We propose that a bilin-based, blue light sensory system is responsible for the maintenance of a functional photosynthetic apparatus in light-grown C. reinhardtii. This critical and possibly ancestral role for bilins may be responsible for retention of bilin biosynthesis in all eukaryotic photosynthetic species.
2019-01-24 | GSE77388 | GEO
Project description:Here, we report a transcriptomics analysis on a day in the life of Chlamydomonas reinhardtii. Cultures of this unicellular alga were grown in photobioreactors on a 12 h light / 12 h dark cycle. Samples were collected at regular intervals and subjected to a transcriptomics analysis by RNA-Seq.
2019-01-03 | GSE112394 | GEO
Project description:We used Chlamydomonas microarray v2.0 to compare the time course expression profiles of two Chlamydomonas reinhardtii strains: wild-type WT and the high hydrogen producing mutant Stm6Glc4 during sulfur starvation induced hydrogen production. Major cellular reorganizations in photosynthetic apparatus, sulfur and carbon metabolism upon H2 production were confirmed as common to both strains. More importantly, our results pointed out factors which lead to the higher hydrogen production in the mutant including higher light sensitivity and lower competitions with hydrogenase by alternative electron sinks. Under S-starvation induced H2 producing conditions the induction of LHCSR3, a chlorophyll binding protein involving in non photochemical quenching, was significantly lower in Stm6Glc4 resulting in significant higher photodamage to photosystem II. Consequently, Stm6Glc4 had a shorter aerobic phase, consumed less starch reserves, and produced H2 earlier at higher rates than WT. We also showed that the loss of mitochondrial DNA-binding protein MOC1 in both knockdown and knockout mutant resulted in higher light sensitivity and improved H2 yield. Furthermore, by comparing our data with previously published ‘omics’ data, we were able to identify genes that responded specifically to either sulfur starvation, anaerobiosis or hydrogen production as well as to provide a more complete picture of S-deprived H2 production in the green alga C. reinhardtii.
2011-11-30 | GSE30252 | GEO
Project description:We used Chlamydomonas microarray v2.0 to compare the time course expression profiles of two Chlamydomonas reinhardtii strains: wild-type WT and the high hydrogen producing mutant Stm6Glc4 during sulfur starvation induced hydrogen production. Major cellular reorganizations in photosynthetic apparatus, sulfur and carbon metabolism upon H2 production were confirmed as common to both strains. More importantly, our results pointed out factors which lead to the higher hydrogen production in the mutant including higher light sensitivity and lower competitions with hydrogenase by alternative electron sinks. Under S-starvation induced H2 producing conditions the induction of LHCSR3, a chlorophyll binding protein involving in non photochemical quenching, was significantly lower in Stm6Glc4 resulting in significant higher photodamage to photosystem II. Consequently, Stm6Glc4 had a shorter aerobic phase, consumed less starch reserves, and produced H2 earlier at higher rates than WT. We also showed that the loss of mitochondrial DNA-binding protein MOC1 in both knockdown and knockout mutant resulted in higher light sensitivity and improved H2 yield. Furthermore, by comparing our data with previously published ‘omics’ data, we were able to identify genes that responded specifically to either sulfur starvation, anaerobiosis or hydrogen production as well as to provide a more complete picture of S-deprived H2 production in the green alga C. reinhardtii. A total of 33 microarray hydridizations were performed covering samples taken during the course of S deprivation induced H2 producction. The samples included 4 time points in the high hydrogen producing mutant Stm6Glc4 (taken at 16, 28, 52 and 76h) and 6 time points in the wildtype CC-406 (taken at 16, 28, 52, 68, 92, 116h). Samples from each time point were compared directly with the sample taken prior to S starvation from the corresponding strain. Three biological replicates were tested at each time point.
2011-11-30 | E-GEOD-30252 | biostudies-arrayexpress
Project description:time course following a low light to high light shift
| PRJNA87061 | ENA
Project description:Comparison of gene expression for Chlamydomonas cells grown for 0h, 48h, 72h, 96h in sulfur depleted media
2014-09-08 | E-MTAB-1329 | biostudies-arrayexpress
Project description:Here, we report on the transcriptome of the organelles of the micro-alga, Chlamydomonas reinhardtii, sampled under a number of different conditions. The preparation of the RNA-Seq libraries and their analysis were performed using protocols optimized for organellar transcripts. Samples include growth in media +/– Fe, growth in media +/– Cu, diurnal growth samples collected in dark and light, and the sexual cycle.
2017-11-27 | GSE101944 | GEO
Project description:To investigate how acetate and high light stress affect gene expression in Chlamydomonas reinhardtii, RNAseq data from a timeline of cultures subjected to high light and different carbon sources was analyzed.
2023-03-21 | GSE227281 | GEO
Project description:DCL3 is the main processor of miRNA precursors in Chlamydomonas reinhardtii. Because of that, and in order identify mRNA targets of miRNA-guided slicer complexes, we used RNAseq of the transcriptome in dcl3 mutant and parental lines.
2016-08-28 | E-MTAB-3852 | biostudies-arrayexpress
Project description:Phosphorus (P) is an essential nutrient that is limiting in many environments. When P is scarce organisms employ strategies for conservation of internal stores, and to efficiently scavenge P from their external surroundings. In this study we investigated the acclimation response of Chlamydomonas reinhardtii to P deficiency, comparing the transcriptional profiles of P starved wild-type cells to the P replete condition. RNA was prepared from P-containing or P-deprived logarithmic growth phase cells and subjected to RNA-Seq analysis. During the 24 hours after the imposition of P starvation we observed that from the 407 significantly changing genes (> 2 fold change, corrected p-value < 0.05) in the wild-type 317 genes were up-regulated, in average 8.36-fold, and 90 genes were down-regulated by 3.43-fold, in average. Many of the upregulated genes encoded enzymes involved in specific responses to P starvation, including PHOX, encoding the major secreted alkaline phosphatase, and multiple putative, high-efficiency phosphate transporter genes. More general responses included the up-regulation of genes involved in photoprotective processes (LHCSR3, LHCSR1, LHCBM9, PTOX1) and genes involved in protein modification and degradation. Down-regulated mRNAs indicated an early stage of the reduction of chloroplast ribosomal proteins, which are considered to be a reservoir for P in the cell. Chlamydomonas reinhardtii strain 21 gr (CC1690, wild-type) grown in TAP medium (Harris 1989) in a rotary incubator (200 rpm) at 25 M-BM-0C in continuous light (70 M-BM-5mol m-2 s-1). For 24 hours, either 1.1 mM phosphate or 0 mM were provided with the growth media. P deprivation was achieved by washing cells twice in midlogarithmic growth phase with liquid TAP medium without P (TAP-P) and cells were resuspended at a density of 2.5 mg/ml Chlorophyll in TAP or TAP-P. Cell aliquots were collected for mRNA isolation 24 h after being transferred either to TAP or TAP-P medium.
2014-04-05 | E-GEOD-56505 | biostudies-arrayexpress