Project description:In the present study, we discover the presence of m2A in chloroplast rRNA and tRNA, as well as cytosolic tRNA, in multiple plant species. We identify six m2A-modified chloroplast tRNAs and two m2A-modified cytosolic tRNAs across different plants. Furthermore, we characterize three Arabidopsis m2A methyltransferases—RLMNL1, RLMNL2, and RLMNL3—which methylate chloroplast rRNA, chloroplast tRNA, and cytosolic tRNA, respectively. Our findings demonstrate that m2A37 promotes a relaxed conformation of tRNA, enhancing translation efficiency in chloroplast and cytosol by facilitating decoding of tandem m2A-tRNA-dependent codons. This study provides insights into the molecular function and biological significance of m2A, uncovering a layer of translation regulation in plants.
2024-02-03 | GSE127146 | GEO
Project description:Chloroplast Genome Sequencing and Comparative Genomics Analysis of Three Hypericum Species
Project description:We performed chloroplast ChIP-seq (cpChIP-seq) to identify the possible DNA-binding sites of mTERF5 in Arabidopsis thaliana. To this end, we generated transgenic Arabidopsis plants expressing mTERF5 carrying an HA tag under the control of the CaMV 35S promoter. Then, We used the polyclonal antibody (abcam, ab9110, lot GR304617-8 ) against HA tag which conjugated to ChIP-Grade protein A/G agarose (Thermo scientific, 26161, lot QJ223903) to perform cpChIP assay. The obtained chromatin immunoprecipitated DNA of chloroplasts were used to build DNA libaries for high-throughput sequencing. Finally, we showed that three potenssial DNA regions across the chloroplast genome compared to the control group were enriched by mTERF5.
Project description:In this study, we have characterized a putative chloroplast ribosome assembly factor. To elucidate transcriptional responses caused by decreased chloroplast function, we have measured the transcriptome of wild-type and knock-down seedlings.
Project description:The transition of chloroplast function from biogenesis to degeneration upon leaf senescence is critical for a plant’s fitness, as nutrient relocation from leaves to reproductive organs is achieved through this process. The optimal timing of transition should be regulated by tight coordination between chloroplast and nucleus, but the underlying mechanisms remain elusive. Here, we describe the regulatory mechanism of this transition. Chloroplast-Related LONG NONCODING RNA 1 (CHLORELLA1) is highly co-expressed with genes coding for chloroplast functionality during leaf development. Leaves of chlorella exhibit precocious senescence symptoms and a decline in the expression of chloroplast-associated genes, indicating that CHLORELLA1 plays a role in maintaining chloroplast function. Mechanistically, nucleus-encoded CHLORELLA1 transcripts are translocated into the chloroplast and contribute to the assembly of the plastid-encoded RNA polymerase (PEP) complex. At aged leaves, decreased expression of CHLORELLA1 attenuates PEP complex assembly and transcription of photosynthesis genes, possibly triggering leaf senescence. Moreover, CHLORELLA1 is directly activated by GLK1/2, master regulators of chloroplast maintenance. Our study unravels a new layer of the regulation via chloroplast-targeted lncRNA as an anterograde signal in timely decision of leaf senescence.
