Project description:The experiment was conducted to examine the influence of non-chloroplast genomes rearangements on chloroplast transcription in cucumber
Project description:The genus Flaveria has been extensively used as a model to study the evolution of C4 photosynthesis as it contains both C3 and C4 species as well as a number of species that exhibit intermediate types of photosynthesis. The current phylogenetic tree of the Flaveria genus contains 21 of the 23 known Flaveria species and has been constructed using a combination of morphologicial data and three non-coding DNA sequences (nuclear encoded ETS, ITS and chloroplast encoded trnl-F). However, recent studies have suggested that phylogenetic trees inferred using a small number of molecular sequences may often be incorrect. Moreover, studies in other genera have often shown substantial differences between trees inferred using morphological data and those using molecular sequence. To provide new insight into the phylogeny of the genus Flaveria we utilize RNA-Seq data to construct a multi-gene concatenated phylogenetic tree of 17 Flaveria species. Furthermore, we use this new data to identify 14 C4 specific non-synonymous mutation sites, 12 of which (86%) can be independently verified by public sequence data. We propose that the data collection method provided in this study can be used as a generic method for facilitating phylogenetic tree reconstruction in the absence of reference genomes for the target species. 18 Flaveria sample including 11 species are sequenced, other three samples were also sequenced as out-group. In all, 21 samples.
Project description:The genus Flaveria has been extensively used as a model to study the evolution of C4 photosynthesis as it contains both C3 and C4 species as well as a number of species that exhibit intermediate types of photosynthesis. The current phylogenetic tree of the Flaveria genus contains 21 of the 23 known Flaveria species and has been constructed using a combination of morphologicial data and three non-coding DNA sequences (nuclear encoded ETS, ITS and chloroplast encoded trnl-F). However, recent studies have suggested that phylogenetic trees inferred using a small number of molecular sequences may often be incorrect. Moreover, studies in other genera have often shown substantial differences between trees inferred using morphological data and those using molecular sequence. To provide new insight into the phylogeny of the genus Flaveria we utilize RNA-Seq data to construct a multi-gene concatenated phylogenetic tree of 17 Flaveria species. Furthermore, we use this new data to identify 14 C4 specific non-synonymous mutation sites, 12 of which (86%) can be independently verified by public sequence data. We propose that the data collection method provided in this study can be used as a generic method for facilitating phylogenetic tree reconstruction in the absence of reference genomes for the target species.
2015-01-08 | GSE54339 | GEO
Project description:Chloroplast genomes
| PRJNA473238 | ENA
Project description:Complete sequence of the chloroplast genome of Asarum sieboldii Miq.
Project description:Chloroplast biogenesis represents a crucial step in seedling development, and is essential for the transition to autotrophic growth in plants. This light-controlled process relies on the transcription of nuclear and plastid genomes that drives the effective assembly and regulation of the photosynthetic machinery. Here we reveal a novel regulation level for this process by showing the involvement of chromatin remodelling in the coordination of nuclear and plastid gene expression for proper chloroplast biogenesis and function. The two Arabidopsis homologs of the yeast EPL1 proteins, core components of the NuA4 histone acetyl-transferase complex, are essential for the correct assembly and performance of chloroplasts. EPL1 proteins are necessary for the coordinated expression of nuclear genes encoding most of the components of chloroplast transcriptional machinery, specifically promoting H4K5Ac deposition in these loci. These data unveil a key participation of epigenetic regulatory mechanisms in the coordinated expression of the nuclear and plastid genomes.
Project description:Transcription profiling of Brassica rapa, Brassica oleracea and Brassica napus I and II The nuclear genomes of the resynthesised B. napus lines should be identical but, as one (B. napus I) involved a cross of B. oleracea onto B. rapa, and the other (B. napus II) involved a cross of B rapa onto B. oleracea, they differ in cytoplasm, and hence contain different chloroplast and mitochondrial genomes. Four-condition experiment, comparison of transcription profiles of the genomes. Four biological replicates were used, independently grown and harvested. One replicate per array.
Project description:Chloroplasts are organelles responsible for photosynthesis. They originated form a procaryotic ancestor in the process of endosymbiosis and contain their own genomes. The chloroplast genome is packaged into a chromatin-like structure known as the nucleoid. The internal arrangement of the nucleoid, molecular mechanisms of DNA packaging and connection of the nucleoid structure to gene expression remain poorly understood. We show that Arabidopsis thaliana chloroplast nucleoids have a unique organization driven by DNA binding to the thylakoid membranes. Membrane association of specific DNA regions is correlated with high levels of transcription, high protein occupancy and reduced DNA accessibility. Genes with low levels of transcription are further away from the membranes, have lower protein occupancy and higher DNA accessibility. Gene-specific disruption of transcription in sigma factor mutants causes a corresponding reduction in membrane association, indicating that RNA polymerase activity causes DNA tethering to the membranes. We propose that transcription organizes the chloroplast nucleoid into a transcriptionally active membrane-associated core and a less active Periphery.