Project description:How plants control the transition to flowering in response to ambient temperature is only beginning to be understood. In Arabidopsis thaliana, the MADS-box transcription factor genes FLOWERING LOCUS M (FLM) and SHORT VEGETATIVE PHASE (SVP) have key roles in this process. FLM is subject to temperature-dependent alternative splicing, producing two splice variants, FLM-M-NM-2 and FLM-M-NM-4, which compete for interaction with the floral repressor SVP. The SVP/FLM-M-NM-2 complex is predominately formed at low temperatures and prevents precocious flowering. In contrast, the competing SVP FLM-M-NM-4 complex is impaired in DNA binding and acts as a dominant negative activator of flowering at higher temperatures. Our results demonstrate the importance of temperature-dependent alternative splicing in modulating the timing of the floral transition in response to environmental change. ChIP-seq A. thaliana FLM (3 replicates for gFLM and 2 replicates for FLM splice variants)
Project description:How plants control the transition to flowering in response to ambient temperature is only beginning to be understood. In Arabidopsis thaliana, the MADS-box transcription factor genes FLOWERING LOCUS M (FLM) and SHORT VEGETATIVE PHASE (SVP) have key roles in this process. FLM is subject to temperature-dependent alternative splicing, producing two splice variants, FLM-β and FLM-δ, which compete for interaction with the floral repressor SVP. The SVP/FLM-β complex is predominately formed at low temperatures and prevents precocious flowering. In contrast, the competing SVP FLM-δ complex is impaired in DNA binding and acts as a dominant negative activator of flowering at higher temperatures. Our results demonstrate the importance of temperature-dependent alternative splicing in modulating the timing of the floral transition in response to environmental change.
Project description:Ambient temperature dependent flowering time is an important feature that is required for plants to reproduce in various environmental conditions. The rising global temperature poses a significant challenge to the growth and reproduction of plants. In Arabidopsis thaliana, FLM-β, a major splicing isoform of the flowering repressor gene FLOWERING LOCUS M, is down-regulated in response to increasing temperature and represents a critical mechanism for plants to respond to temperature changes. However, it is unknown how the transcript level of FLM-β is down-regulated. Here we identify an RRM domain-containing protein, UBA2C, as a previously uncharacterized flowering repressor by forward genetic screening. We demonstrate that UBA2C directly binds to FLM chromatin and facilitates FLM transcription predominantly by inhibiting the histone H3K27 trimethylation, a histone mark related to transcriptional repression. At FLM chromatin, the histone H3K27 trimethylation is enhanced in response to increasing temperatures. Depletion of UBA2C weakens the response of FLM transcription and H3K27 trimethylation to temperature changes. UBA2C forms multiple puncta in the nucleus and the number of puncta increases with increasing temperatures. UBA2C contains a prion-like domain (PrLD) that is responsible for forming puncta in the nucleus in vivo. These results not only identify a previously unknown flowering-time regulator but also reveal the mechanism by which the regulator controls flowering time in response to temperature changes.
Project description:Ambient temperature dependent flowering time is an important feature that is required for plants to reproduce in various environmental conditions. The rising global temperature poses a significant challenge to the growth and reproduction of plants. In Arabidopsis thaliana, FLM-β, a major splicing isoform of the flowering repressor gene FLOWERING LOCUS M, is down-regulated in response to increasing temperature and represents a critical mechanism for plants to respond to temperature changes. However, it is unknown how the transcript level of FLM-β is down-regulated. Here we identify an RRM domain-containing protein, UBA2C, as a previously uncharacterized flowering repressor by forward genetic screening. We demonstrate that UBA2C directly binds to FLM chromatin and facilitates FLM transcription predominantly by inhibiting the histone H3K27 trimethylation, a histone mark related to transcriptional repression. At FLM chromatin, the histone H3K27 trimethylation is enhanced in response to increasing temperatures. Depletion of UBA2C weakens the response of FLM transcription and H3K27 trimethylation to temperature changes. UBA2C forms multiple puncta in the nucleus and the number of puncta increases with increasing temperatures. UBA2C contains a prion-like domain (PrLD) that is responsible for forming puncta in the nucleus in vivo. These results not only identify a previously unknown flowering-time regulator but also reveal the mechanism by which the regulator controls flowering time in response to temperature changes.
Project description:Downregulations of TCAM1P-004 and RP11-598D14.1 were frequently observed in HCC tumors as compared to adjacent non-tumor tissues. To further study the molecular functions of TCAM1P-004 and RP11-598D14.1, we attempted to identify the gene targets regulated by either lncRNAs. Knockdown of TCAM1P-004 or RP11-598D14.1 were achieved by transduction of lentivirus carrying respective shRNAs in non-tumor hepatocyte MIHA cells. Diffferentially expressed genes after knockdown of the lncRNAs were compared to cells tranduced with lentivirus carrying scramble shRNAs.
Project description:To further understand the gene expression characteristics of Pseudomonas aeruginosa PAO1, we have applied whole genome microarray expression profiling as a discovery platform to specify the temperature dependent expression of PAO1 genome at soil and human body temperature. We selected 28°C as temperature representative of the soil niche and 37°C for human body. The results from the temperature dependent transcriptome analysis are consistent to our previous published data that the phzM, ptsP and lasI genes expression is upregulated at 37°C [11]. The comparison analysis of the M18 genome expressional profiles at 28°C and 37°C indicated a total of 596 genes expressed in a temperature dependent manner over two fold.
Project description:To further understand the gene expression characteristics of originating biocontrol strain Pseudomonas aeruginosa M18, we have applied whole genome microarray expression profiling as a discovery platform to to specify the temperature dependent expression of M18 genome at rhizosphere and human body temperature. We selected 28°C as temperature representative of the rhizosphere niches and 37°C for human body. The results from the temperature dependent transcriptome analysis are consistent to our previous published data that the phzM, ptsP and lasI genes expression is upregulated at 37°C. The comparison analysis of the M18 genome expressional profiles at 28°C and 37°C indicated a total of 605 gene expressed in a temperature dependent manner over about two fold at 28°C compared that at 37°C, covering 10.6% genes in M18 whole genome.
Project description:To further understand the gene expression characteristics of Pseudomonas aeruginosa PAO1, we have applied whole genome microarray expression profiling as a discovery platform to specify the temperature dependent expression of PAO1 genome at soil and human body temperature. We selected 28°C as temperature representative of the soil niche and 37°C for human body. The results from the temperature dependent transcriptome analysis are consistent to our previous published data that the phzM, ptsP and lasI genes expression is upregulated at 37°C [11]. The comparison analysis of the M18 genome expressional profiles at 28°C and 37°C indicated a total of 596 genes expressed in a temperature dependent manner over two fold. Cells were grown to OD600=5.0-6.0 (late exponential phase) in LB medium at 28℃ and 37℃, respectively. Three independent experiments were performed at each time.