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.
Project description:We used high-throughput sequencing to identify conserved and nonconserved miRNAs and other short RNAs in Typha angustifolia under control and cadmium stressed condition. A total of 114 conserved miRNAs and 41 novel candidate miRNAs encoded by 66 hairpin precursors were identified in both small RNA libraries. 4 conserved and 6 novel miRNAs showed specific expression, which, combined with function of target genes, suggests that miRNAs may play a role in plant Cd stress response.These results provide a framework for further analysis of miRNAs and their role in regulating Typha angustifolia response to cadmium stress.
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.
