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:Proplastid-to-chloroplast transitconversion during early plant development involves exintensive genome replication and nucleoid structurale changes of the nucleoid during plant early development. In addition, and the nucleoid distribution shifts from ring-shaped assemblies near the inner- envelope to thylakoids-anchored punctate structures., while the regulatoryThe mechanisms underlying this massive reorganization are still missingnot known. Here we report that the glycerophospholipid phosphatidylethanolamine (PE) governs early chloroplast genome replication and nucleoid biogenesis. Genetic screens revealed that Through genetic screening, we found mutations ofin the phosphatidylserine decarboxylase PSD1 can relieve the transcription-replication conflicts (TRCs) in thea chloroplast R-loop accumulation mutant atrnh1c. PSD1 is thea chloroplast inner- envelope-localized protein that required for PE synthesis. PE reduction leads to decreased replication speed and TRCs stresses, resulting in fewer less R-loops and DNA breaks. We also show that PE physically interacts with replication-related proteins and nucleic acids, promotes DNA replication and nucleoid concentration in the inner- envelope during early seedling development, accomplishing proplastid-to-chloroplast transition. Together, our results reveal a previously unknowndiscovered lipid-involvbased mechanism for genome maintenance and nucleoid- biogenesis, and open up a new horizonsuggest a role for lipids in participating genomeome regulation events.