Arabidopsis thaliana
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA178113 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Background: The majority of plant transposable elements (TEs) are found in a silenced state that is epigenetically propagated by the maintenance of symmetrical DNA methylation. TE methylation is established and reinforced by a mechanism of RNA-dependent DNA methylation, which is dependent on transcription of the PolIV RNA polymerase. Recently, a pathway has been described that initiates de novo DNA methylation dependent on components of the RNAi post-transcriptional silencing pathway, independent of PolIV. To define the function of this new pathway, we have focused on the RDR6 protein, which plays a central role in the pathway we refer to as RDR6-dependent RNA-directed DNA Methylation (RDR6-RdDM). Methods: We have sequenced total small RNAs from wild-type and three mutant genotypes: ddm1, ddm1/rdr6, and rdr6. Conclusions: We demonstrate that RDR6-RdDM utilizes 21 and 22 nucleotide siRNAs to de novo methylate actively transcribing TEs. In addition, we find that the RDR6-RdDM pathway functions in the efficient initiation and re-establishment of TE transcriptional silencing, while it is not necessary to maintain trans-generational epigenetic silencing. Examination of flower bud small RNAs from wild-type and 3 mutant genotypes
2013-04-11 | E-GEOD-41755 | biostudies-arrayexpress
Project description:This set consists of small RNAs sequenced from two replicates of wildtype and two replicates of RDR6-15 knockout Arabidopsis thaliana Col-0 leaf samples. RDR6 is required for the production of tasRNAs (trans-acting small RNAS) and so tags associated with the tasRNA loci should be severely down-regulated or absent in the knockout compared to wildtype. The set can thus be used as containing known true positives for testing differential expression detection methods.
2010-11-22 | GSE16959 | GEO
Project description:Background: The majority of plant transposable elements (TEs) are found in a silenced state that is epigenetically propagated by the maintenance of symmetrical DNA methylation. TE methylation is established and reinforced by a mechanism of RNA-dependent DNA methylation, which is dependent on transcription of the PolIV RNA polymerase. Recently, a pathway has been described that initiates de novo DNA methylation dependent on components of the RNAi post-transcriptional silencing pathway, independent of PolIV. To define the function of this new pathway, we have focused on the RDR6 protein, which plays a central role in the pathway we refer to as RDR6-dependent RNA-directed DNA Methylation (RDR6-RdDM). Methods: We have sequenced total small RNAs from wild-type and three mutant genotypes: ddm1, ddm1/rdr6, and rdr6. Conclusions: We demonstrate that RDR6-RdDM utilizes 21 and 22 nucleotide siRNAs to de novo methylate actively transcribing TEs. In addition, we find that the RDR6-RdDM pathway functions in the efficient initiation and re-establishment of TE transcriptional silencing, while it is not necessary to maintain trans-generational epigenetic silencing.
2013-04-11 | GSE41755 | GEO
Project description:This set consists of small RNAs sequenced from two replicates of wildtype and two replicates of RDR6-15 knockout Arabidopsis thaliana Col-0 leaf samples. RDR6 is required for the production of tasRNAs (trans-acting small RNAS) and so tags associated with the tasRNA loci should be severely down-regulated or absent in the knockout compared to wildtype. The set can thus be used as containing known true positives for testing differential expression detection methods. Examination of smRNA in 2 replicates wildtype and 2 replicates RDR6-15 knockout
2010-11-22 | E-GEOD-16959 | biostudies-arrayexpress
Project description:Secondary metabolites are involved in the plant stress response. Among these are scopolin and its active form scopoletin, which are coumarin derivatives associated with reactive oxygen species scavenging and pathogen defence. Here we show that in Arabidopsis thaliana, scopolin accumulation can be induced in the root by osmotic stress and in the leaf by low temperature stress. A genetic screen for altered scopolin levels in Arabidopsis thaliana identified a mutant compromised for scopolin accumulation in response to stress; the lesion was present in a homologue of THO1, the product of which contributes to the THO/TREX complex. The THO/TREX complex contributes to RNA silencing, supposedly by trafficking precursors of small RNAs. Mutants carrying defective THO and RDR6 genes were impaired with respect to scopolin accumulation in response to stress, suggesting a mechanism based on RNA silencing like the transacting small interfering RNA pathway which requires THO/TREX and RDR6 function.
2018-02-05 | MTBLS389 | MetaboLights
Project description:The Arabidopsis genome contains a highly complex and abundant population of small RNAs, and many of the endogenous siRNAs are dependent on RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) for their biogenesis. By analyzing an rdr2 loss-of-function mutant using two different parallel sequencing technologies, MPSS and 454, we characterized the complement of miRNAs expressed in Arabidopsis inflorescence to considerable depth. Nearly all known miRNAs were enriched in this mutant and we identified 13 new miRNAs, all of which were relatively low abundance and constitute new families. Trans-acting siRNAs (ta-siRNAs) were even more highly enriched. Computational and gel blot analyses suggested that the minimal number of miRNAs in Arabidopsis is approximately 155. The size profile of small RNAs in rdr2 reflected enrichment of 21-nt miRNAs and other classes of siRNAs like ta-siRNAs, and a significant reduction in 24-nt heterochromatic siRNAs. Other classes of small RNAs were found to be RDR2-independent, particularly those derived from long inverted repeats and a subset of tandem repeats. The small RNA populations in other Arabidopsis small RNA biogenesis mutants were also examined; a dcl2/3/4 triple mutant showed a similar pattern to rdr2, whereas dcl1-7 and rdr6 showed reductions in miRNAs and ta-siRNAs consistent with their activities in the biogenesis of these types of small RNAs. Deep sequencing of mutants provides a genetic approach for the dissection and characterization of diverse small RNA populations and the identification of low abundance miRNAs. Keywords: small RNA sequences generated by 454 sequencing
2006-09-08 | GSE5343 | GEO
Project description:In plants, transposons and non-protein-coding repeats are epigenetically silenced by CG and non-CG methylation. This pattern of methylation is mediated in part by small RNAs and two specialized RNA polymerases, Pol IV and Pol V, in a process called RNA-directed DNA methylation. By contrast, many protein-coding genes transcribed by Pol II contain in their gene bodies exclusively CG methylation that is independent of small RNAs and Pol IV/Pol V activities. It is unclear how the different methylation machineries distinguish between transposons and genes. Here we report on a group of atypical genes that display in their coding region a transposon-like methylation pattern, which is associated with gene silencing in sporophytic tissues. We performed a methylation-sensitive amplification polymorphism analysis to search for targets of RNA-directed DNA methylation in Arabidopsis thaliana and identified several members of a gene family encoding cysteine-rich peptides (CRPs). We also examined small RNA abundance at individual CRP genes in the wild type plant, nrpd1, and rdr2 mutant plants.
2012-11-22 | E-GEOD-34207 | biostudies-arrayexpress
Project description:In plants, decapping prevents RDR6-dependent production of small interfering RNAs from endogenous mRNAs
| PRJNA272807 | ENA
Project description:Plant small RNAs (sRNAs) regulate key physiological mechanisms through post-transcriptional and transcriptional silencing of gene expression. sRNAs fall into two major categories: those that are reliant on RNA Dependent RNA Polymerases (RDRs) for biogenesis and those that aren’t. Known RDR-dependent sRNAs include phased and repeat-associated short interfering RNAs, while known RDR-independent sRNAs are primarily microRNAs (miRNAs) and other hairpin-derived sRNAs. In this study, we produced and analyzed sRNA-seq libraries produced from rdr1/rdr2/rdr6 triple mutant plants. We found 58 previously annotated MIRNA loci that were dependent on RDR function, casting doubt on their classification as MIRNAs. We also found 38 RDR-independent sRNA clusters that were not MIRNAs or otherwise hairpin-derived. These 38 sRNA loci have novel biogenesis mechanisms, and frequently arise from protein-coding genes. Altogether, our analysis suggests that these 38 sRNA loci represent one or more new types of sRNA loci in Arabidopsis thaliana.
2018-04-09 | GSE105262 | GEO
Project description:Arabidopsis Argonaute4, Argonaute6 and Argonaute9 associated small RNAs
| PRJNA116171 | ENA