Dataset Information

Dynamic Light Regulation of Translation Status in Arabidopsis thaliana.

ABSTRACT: Light, a dynamic environmental parameter, is an essential regulator of plant growth and development. Light-regulated transcriptional networks are well documented, whereas light-regulated post-transcriptional regulation has received limited attention. In this study, dynamics in translation of cytosolic mRNAs were evaluated at the genome-level in Arabidopsis thaliana seedlings grown under a typical light/dark diurnal regime, shifted to darkness at midday, and then re-illuminated. One-hour of unanticipated darkness reduced levels of polysomes by 17% in a manner consistent with inhibition of initiation of translation. This down-regulation of translation was reversed within 10?min of re-illumination. Quantitative comparison of the total cellular population of transcripts (the transcriptome) to those associated with one or more 80S ribosome (the translatome) identified over 1600 mRNAs that were differentially translated in response to light availability. Unanticipated darkness limited both transcription and translation of mRNAs encoding components of the photosynthetic machinery. Many mRNAs encoding proteins associated with the energy demanding process of protein synthesis were stable but sequestered in the dark, in a rapidly reversible manner. A meta-analysis determined these same transcripts were similarly and coordinately regulated in response to changes in oxygen availability. The dark and hypoxia translationally repressed mRNAs lack highly supported candidate RNA-regulatory elements but are characterized by G?+?C-rich 5'-untranslated regions. We propose that modulation of translation of a subset of cellular mRNAs functions as an energy conservation mechanism.

SUBMITTER: Juntawong P

PROVIDER: S-EPMC3355768 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Dynamic Light Regulation of Translation Status in Arabidopsis thaliana.

Juntawong Piyada P Bailey-Serres Julia J

Frontiers in plant science 20120405

Light, a dynamic environmental parameter, is an essential regulator of plant growth and development. Light-regulated transcriptional networks are well documented, whereas light-regulated post-transcriptional regulation has received limited attention. In this study, dynamics in translation of cytosolic mRNAs were evaluated at the genome-level in Arabidopsis thaliana seedlings grown under a typical light/dark diurnal regime, shifted to darkness at midday, and then re-illuminated. One-hour of unant ...[more]

PMID: 22645595

Similar Datasets

Project description:BackgroundThe majority of stress-sensitive genes responds to cold and high light in the same direction, if plants face the stresses for the first time. As shown recently for a small selection of genes of the core environmental stress response cluster, pre-treatment of Arabidopsis thaliana with a 24 h long 4 °C cold stimulus modifies cold regulation of gene expression for up to a week at 20 °C, although the primary cold effects are reverted within the first 24 h. Such memory-based regulation is called priming. Here, we analyse the effect of 24 h cold priming on cold regulation of gene expression on a transcriptome-wide scale and investigate if and how cold priming affects light regulation of gene expression.ResultsCold-priming affected cold and excess light regulation of a small subset of genes. In contrast to the strong gene co-regulation observed upon cold and light stress in non-primed plants, most priming-sensitive genes were regulated in a stressor-specific manner in cold-primed plant. Furthermore, almost as much genes were inversely regulated as co-regulated by a 24 h long 4 °C cold treatment and exposure to heat-filtered high light (800 μmol quanta m- 2 s- 1). Gene ontology enrichment analysis revealed that cold priming preferentially supports expression of genes involved in the defence against plant pathogens upon cold triggering. The regulation took place on the cost of the expression of genes involved in growth regulation and transport. On the contrary, cold priming resulted in stronger expression of genes regulating metabolism and development and weaker expression of defence genes in response to high light triggering. qPCR with independently cultivated and treated replicates confirmed the trends observed in the RNASeq guide experiment.ConclusionA 24 h long priming cold stimulus activates a several days lasting stress memory that controls cold and light regulation of gene expression and adjusts growth and defence regulation in a stressor-specific manner.

Project description:BACKGROUND: To understand transcriptional regulatory networks (TRNs), especially the coordinated dynamic regulation between transcription factors (TFs) and their corresponding target genes during development, computational approaches would represent significant advances in the genome-wide expression analysis. The major challenges for the experiments include monitoring the time-specific TFs' activities and identifying the dynamic regulatory relationships between TFs and their target genes, both of which are currently not yet available at the large scale. However, various methods have been proposed to computationally estimate those activities and regulations. During the past decade, significant progresses have been made towards understanding pollen development at each development stage under the molecular level, yet the regulatory mechanisms that control the dynamic pollen development processes remain largely unknown. Here, we adopt Networks Component Analysis (NCA) to identify TF activities over time course, and infer their regulatory relationships based on the coexpression of TFs and their target genes during pollen development. RESULTS: We carried out meta-analysis by integrating several sets of gene expression data related to Arabidopsis thaliana pollen development (stages range from UNM, BCP, TCP, HP to 0.5 hr pollen tube and 4 hr pollen tube). We constructed a regulatory network, including 19 TFs, 101 target genes and 319 regulatory interactions. The computationally estimated TF activities were well correlated to their coordinated genes' expressions during the development process. We clustered the expression of their target genes in the context of regulatory influences, and inferred new regulatory relationships between those TFs and their target genes, such as transcription factor WRKY34, which was identified that specifically expressed in pollen, and regulated several new target genes. Our finding facilitates the interpretation of the expression patterns with more biological relevancy, since the clusters corresponding to the activity of specific TF or the combination of TFs suggest the coordinated regulation of TFs to their target genes. CONCLUSIONS: Through integrating different resources, we constructed a dynamic regulatory network of Arabidopsis thaliana during pollen development with gene coexpression and NCA. The network illustrated the relationships between the TFs' activities and their target genes' expression, as well as the interactions between TFs, which provide new insight into the molecular mechanisms that control the pollen development.

Dataset Information

Dynamic Light Regulation of Translation Status in Arabidopsis thaliana.

Publications

Dynamic Light Regulation of Translation Status in Arabidopsis thaliana.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets