Project description:The coordination of chloroplast and nuclear genome status are critical for plant cell function, but the mechanism remain largely unclear. In this study, we report that Arabidopsis thaliana CHLOROPLAST AND NUCLEUS DUAL-LOCALIZED PROTEIN 1 (CND1) maintains genome stability in both the chloroplast and the nucleus.
Project description:The coordination of chloroplast and nuclear genome status are critical for plant cell function, but the mechanism remain largely unclear. In this study, we report that Arabidopsis thaliana CHLOROPLAST AND NUCLEUS DUAL-LOCALIZED PROTEIN 1 (CND1) maintains genome stability in both the chloroplast and the nucleus.
Project description:The regulator for chloroplast biogenesis (rcb) mutant was identified as a mutant defective in phytochrome-mediated chloroplast biogenesis. The rcb mutant has long hypocotyl and albino phenotypes. RCB initiates chloroplast biogenesis in the nucleus by promoting the degradation of the master repressors for chloroplast biogenesis, the PIFs (Phytochrome Interacting Factors). To understand how RCB regulates the expression of PIF-regulated genes, we performed genome-wide expression analysis of RCB-dependent genes using a rcb-10 null allele.
Project description:Deep sequencing provided evidence that a novel subset of small RNAs were derived from the chloroplast genome of Chinese cabbage (Brassica rapa) and Arabidopsis (Ler). The chloroplast small RNAs (csRNAs) include those derived from mRNA, rRNA, tRNA and intergenic RNA. The rRNA-derived csRNA were preferentially located at the 3â-ends of the rRNAs, while the tRNA-derived csRNAs were mainly located at 5â-termini of the tRNAs. After heat treatment, the abundance of csRNAs decreased in chinese cabbage seedlings, except those of 24 nt in length. The novel heat-responsive csRNAs and their locations in the chloroplast were verified by Northern blotting. The regulation of some csRNAs to the putative target genes were identified by real-time PCR. Our results indicated that high temperature regulated the production of some csRNAs, which may have potential roles in transcriptional or post-transcriptional regulation, and affected putative target genes expression in chloroplast.
Project description:Identification of target transcripts for the putative chloroplast RNA binding protein CFM2 in Zea mays. CFM2 was immunoprecipitated from a chloroplast extract. Chloroplast extracts were prepared from WT tissue. RNA from the pellet and from the supernatant for each pulldown was labelled with different fluoro-dyes and hybridized onto an array covering the complete maize chloroplast genome. Messages enriched in the immunoprecipitate from WT tissue are likely targets for CFM2.
Project description:Identification of target transcripts for the putative chloroplast RNA binding protein CRP1 in Zea mays. CRP1 was immunoprecipitated from a chloroplast extract. Chloroplast extracts were prepared from WT and CRP1-deficient tissue. RNA from the pellet and from the supernatant for each pulldown was labelled with different fluoro-dyes and hybridized onto an array covering the complete maize chloroplast genome. Messages enriched in the immunoprecipitate from WT tissue, but not enriched in mutant tissue are likely targets for CRP1.
Project description:Analysis of the genome wide response of wild type and two mutant arabidopsis thaliana seedlings to norflurazon Keywords: Genome wide response to inhibition of chloroplast development
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.
