Global and local perturbation of the tomato microRNA pathway by a trans-activated DICER-LIKE 1 mutant
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ABSTRACT:
ORGANISM(S): Solanum lycopersicum
PROVIDER: GSE51959 | GEO | 2013/11/01
SECONDARY ACCESSION(S): PRJNA225935
REPOSITORIES: GEO
Similar Datasets
Project description:DICER-like 1 (DCL1) is a major player in micro RNA (miRNA) biogenesis and accordingly, its few known loss-of-function mutants are either lethal or display arrested seedling development. Consequently, generation of dcl1 mutants by reverse genetics and functional analysis of DCL1 in late-developing organs are challenging. Here, these challenges were resolved through the unique use of trans-activated RNA interference. Global, as well as organ-specific tomato DCL1 (SlDCL1) silencing was induced by crossing the generated responder line (OP:SlDCL1IR) with the appropriate driver line. Constitutive trans-activation knocked down SlDCL1 levels by ~95%, resulting in severe abnormalities including post-germination growth arrest accompanied by decreased miRNA and 21-nucleotide small RNA levels, but prominently elevated levels of 22- nucleotide small RNAs. The elevation in the 22- nucleotide small RNAs was correlated with specific upregulation of SlDCL2b and SlDCL2d, which are likely involved in their biogenesis. Leaf- and flower-specific OP:SlDCL1IR trans-activation inhibited blade outgrowth, induced premature bud senescence and produced pale petals, respectively, emphasizing the importance of SlDCL1-dependent small RNAs in these processes. Together, our results establish OP:SlDCL1IR as an efficient tool for analyzing processes regulated by SlDCL1-mediated gene regulation in tomato. Examination of small RNA populations in control (35S:LhG4) and SlDCL1 silenced seedlings (35S>>SlDCL1IR) 2 biological replicates each
2013-11-01 | E-GEOD-51959 | biostudies-arrayexpress
Project description:DICER-like 3 (DCL3) is a major player in heterochromatic 24-nucleotide siRNA and long miRNA biogenesis and mutants have been characterized from Arabidopsis and rice. Here, a tomato DCL3 mutant was generated through the use of trans-activated artificial microRNA and characterized. Global tomato DCL3 (SlDCL3) silencing was induced by crossing the generated responder line (OP:amiRDCL3) with constitutive driver line. Constitutive trans-activation knocked down SlDCL3 levels by ~77%, resulting in dramatically decreased 24-nucleotide small RNA levels, but a significant increase in 21- and 22- nucleotide small RNAs, which was correlated with specific upregulation of SlDCL4 and SlDCL2b. Moreover, in the majority of small RNA-generating loci an almost complete overlap between the control and 35S>>amiRSlDCL3 siRNA signatures, was observed, strongly suggesting that the reduction in 24-nucleotide siRNAs was compensated by increased biogenesis of 21-22 nt siRNAs from the same genomic sequences. Collectively, these results suggest the requirement of SlDCL3 for the biogenesis of 23-24 nt sRNAs and its substitution by SlDCL4 and SlDCL2b, which function in the biogenesis of 21- and 22-nt small RNAs. In addition, differential expression between control and SlDCL3-silenced small RNAs indicated a significant reduction in the abundance of 24-nt putative long miRNAs, which was validated by northern blots, implicating SlDCL3 in their biogenesis. Examination of small RNA populations in control (35S:LhG4) and SlDCL3 silenced seedlings (35S>>amiRSlDCL3) 2 biological replicates each
2014-03-31 | E-GEOD-52265 | biostudies-arrayexpress
Project description:DICER-like 3 (DCL3) is a major player in heterochromatic 24-nucleotide siRNA and long miRNA biogenesis and mutants have been characterized from Arabidopsis and rice. Here, a tomato DCL3 mutant was generated through the use of trans-activated artificial microRNA and characterized. Global tomato DCL3 (SlDCL3) silencing was induced by crossing the generated responder line (OP:amiRDCL3) with constitutive driver line. Constitutive trans-activation knocked down SlDCL3 levels by ~77%, resulting in dramatically decreased 24-nucleotide small RNA levels, but a significant increase in 21- and 22- nucleotide small RNAs, which was correlated with specific upregulation of SlDCL4 and SlDCL2b. Moreover, in the majority of small RNA-generating loci an almost complete overlap between the control and 35S>>amiRSlDCL3 siRNA signatures, was observed, strongly suggesting that the reduction in 24-nucleotide siRNAs was compensated by increased biogenesis of 21-22 nt siRNAs from the same genomic sequences. Collectively, these results suggest the requirement of SlDCL3 for the biogenesis of 23-24 nt sRNAs and its substitution by SlDCL4 and SlDCL2b, which function in the biogenesis of 21- and 22-nt small RNAs. In addition, differential expression between control and SlDCL3-silenced small RNAs indicated a significant reduction in the abundance of 24-nt putative long miRNAs, which was validated by northern blots, implicating SlDCL3 in their biogenesis.
2014-03-31 | GSE52265 | GEO
Project description:In plants, the known microRNAs (miRNAs) are produced as ~21 nucleotide (nt) duplexes from their precursors by Dicer like 1 (DCL1). They are incorporated into Argonaute 1 (AGO1) protein to regulate target gene expression primarily through mRNA cleavage. We report here the discovery of a new class of miRNAs in the model monocot rice (Oryza sativa). These are 24 nt in length and require another member of the Dicer family, DCL3, for their biogenesis. The 24 nt long miRNAs (lmiRNAs) are loaded into AGO4 clade proteins according to hierarchical rules, depending on the upstream biogenesis machinery and the 5’ terminal nucleotide. We demonstrated that lmiRNAs direct DNA methylation at loci from which they are produced as well as in trans at their target genes and play roles in gene regulation. Considered together, our findings define a novel miRNA pathway that mediates DNA methylation. Small RNAs were prepared from Rice total extract in wide type, dcl1, dcl3, rdr2 dbsRNA mutant and AGO4a, AGO4b, and AGO16 complexes, ligated to a 3' adaptor and a 5' acceptor sequentially, and then RT-PCR amplified. PCR products were reamplified using a pair of solexa cloning primers and then provided for sequencing. For technical details, see Wu, L., Zhang, Q., Zhou, H., Ni, F., Wu, X., and Qi, Y. (2009). Rice microRNA effector complexes and targets. The Plant Cell, 21: 3421-3435.
2010-03-12 | E-GEOD-20748 | biostudies-arrayexpress
Project description:The osdcl4-1 mutant exhibits much severer developmental defects than dcl4 in Arabidopsis, suggesting that Os DCL4 may process broader substrates in rice. By deep sequencing of small RNAs from different tissues of wild types and osdcl4-1, we revealed that 21-nucleotide siRNAs were largely dependent on Os DCL4. Besides several tasiRNA loci reported in Arabidopsis and rice, over one thousand 21-nucleotide and several dozen 24-nucleotide phased siRNA (phasiRNA) clusters were identified in panicles but not in seedlings and grains. Further analyses identified two conserved 22-nucleotide motifs among the cleavage sites of the 21- and 24- phasiRNA loci, and the cleavage sites of over 90% of 21- and 24-nucleotide phasing clusters were confirmed by PARE/degradome analysis from 93-11 panicles. MiR2118 and miR2275, expressed specifically in panicles, were predicted to trigger cleavages at 21- and 24-nucleotide phasiRNA clusters, respectively. The triggers of phasiRNAs are more dependent on Os DCL4 than Os DCL1. Furthermore, the processing of 21-nucleotide phasiRNAs was largely Os DCL4-dependent, whereas the processing of 24-nucleotide phasiRNAs was slightly affected by Os DCL4, but not by Os DCL3a and Os DCL1. Our results revealed distinct roles of Os DCL4 in a novel 21- and 24-nucleotide phasiRNA biogenesis pathway in rice. Six small RNA libraries were constructed from seedlings and panicles of 93-11 (a wild-type Indica rice variety) and osdcl4-1, as well as those from Nipponbare panicles and seedlings (a wild-type Japonica rice variety).
2012-03-29 | E-GEOD-22763 | biostudies-arrayexpress
Project description:The osdcl4-1 mutant exhibits much severer developmental defects than dcl4 in Arabidopsis, suggesting that Os DCL4 may process broader substrates in rice. By deep sequencing of small RNAs from different tissues of wild types and osdcl4-1, we revealed that 21-nucleotide siRNAs were largely dependent on Os DCL4. Besides several tasiRNA loci reported in Arabidopsis and rice, over one thousand 21-nucleotide and several dozen 24-nucleotide phased siRNA (phasiRNA) clusters were identified in panicles but not in seedlings and grains. Further analyses identified two conserved 22-nucleotide motifs among the cleavage sites of the 21- and 24- phasiRNA loci, and the cleavage sites of over 90% of 21- and 24-nucleotide phasing clusters were confirmed by PARE/degradome analysis from 93-11 panicles. MiR2118 and miR2275, expressed specifically in panicles, were predicted to trigger cleavages at 21- and 24-nucleotide phasiRNA clusters, respectively. The triggers of phasiRNAs are more dependent on Os DCL4 than Os DCL1. Furthermore, the processing of 21-nucleotide phasiRNAs was largely Os DCL4-dependent, whereas the processing of 24-nucleotide phasiRNAs was slightly affected by Os DCL4, but not by Os DCL3a and Os DCL1. Our results revealed distinct roles of Os DCL4 in a novel 21- and 24-nucleotide phasiRNA biogenesis pathway in rice.
2012-03-30 | GSE22763 | GEO
Project description:Dicer enzymes function at the core of RNA silencing to defend against exogenous RNA, or as an endogenous mechanism of gene regulation. Plant DICER-LIKE4 (DCL4) performs dual functions, acting in antiviral defense, as well as in development via the biogenesis of tasiR-ARFs. These small RNAs play an essential role in the grasses and act to spatially define the expression domain of AUXIN RESPONSE FACTOR3 (ARF3) transcription factors. However, contrary to tasiR-ARFs’ essential function in development, DCL4 proteins exhibit strong evidence of recurrent adaptation typical of host factors involved in antiviral immunity. Here, we address how DCL4 balances its role in development with pressures to diversify in response to viral attack. We show that, in contrast to other tasiR-ARF biogenesis mutants, dcl4 null alleles condition an uncharacteristically mild phenotype, correlated with normal expression of select arf3 targets. Loss of DCL4 activity yields a class of 22-nt tasiR-ARF variants associated with the processing of arf3 transcripts into 22-nt secondary siRNAs by DCL1. Our findings uncover the presence of a novel DCL1-dependent siRNA pathway that bypasses the otherwise adverse developmental effects of DCL4 mutations. This novel pathway is predicted to have important implications for DCL4’s role in antiviral defense by reducing the selective constraints on DCL4 and allowing it to diversify in response to viral suppressors. Examination of small RNAs isolated from dcl4, dcl1 and double mutants in imbibed kernels of maize
2015-09-01 | E-GEOD-66986 | biostudies-arrayexpress
Project description:In Arabidopsis thaliana, four different DICER-LIKE (DCL) proteins have distinct, but partially overlapping functions in the biogenesis of microRNAs (miRNAs) and small interfering RNAs (siRNAs) from longer, non-coding precursor RNAs. To analyze the impact of different components of the small RNA (sRNA) biogenesis machinery on the transcriptome, we subjected dcl and other mutants impaired in sRNA biogenesis to whole-genome tiling array analysis. We compared both protein-coding genes and noncoding transcripts, including most pri-miRNAs, in two tissues and several stress conditions. We discovered distinct effects of dcl1, hyl1 and se mutations on the transcriptome, as well as a number of common genes affected in dcl1 and dcl2 dcl3 dcl4 triple mutants. Our results furthermore suggest that the DCL1 is not only involved in miRNA action, but can also contribute to silencing of certain transposons, apparently through an effect on DNA methylation. Together, our findings contribute to the knowledge of both specialization and overlap between different RNA silencing pathways.
2010-05-08 | GSE21685 | GEO
Project description:Maize LEAFBLADELESS1 (LBL1) and Arabidopsis SUPPRESSOR OF GENE SILENCING3 (SGS3) play orthologous roles in the biogenesis of 21 nucleotide trans-acting short-interfering RNAs (tasiRNAs). The phenotypes conditioned by mutation of lbl1 and SGS3 are, however, strikingly different, suggesting that the activities of these small RNA biogenesis components, or the tasiRNAs and their targets might not be entirely conserved. To investigate the basis for this phenotypic variation, we compared the small RNA content between wild-type and lbl1 seedling apices. We show that LBL1 affects all major classes of small RNAs, and reveal unexpected crosstalk between tasiRNA biogenesis and other small RNA pathways regulating miRNAs, retrotransposons, and DNA transposons. We further identified genomic regions generating phased siRNAs, including numerous loci generating 22-nt phased small RNAs from long hairpin RNAs or overlapping antisense transcripts not previously described in other plant species. By combining both analyses, we identified nine TAS loci, all belonging to the conserved TAS3 family. Contrary to other plant species, no TAS loci targeted by a single miRNA were identified. Information from target prediction, RNAseq, and PARE analyses identified the tasiARFs as the major functional tasiRNAs in the maize vegetative apex where they regulate expression of ARF3 homologs. As such, divergence in TAS pathways is unlikely to account for the distinct phenotypes of tasiRNA biogenesis mutants in Arabidopsis and maize. Instead, the data suggests variation in the spatiotemporal regulation of ARF3, or divergence in its function, as a plausible basis for the dramatic phenotypic differences observed upon mutation of SGS3/lbl1 in Arabidopsis and maize. An analysis of tasiRNA biogenesis, activity, and contribution to developmental phenotypes in the maize leaf. Data generated includes small RNA sequencing data and mRNA sequencing data. All data was generated in both wild type and lbl1 mutant maize leaf apices. Three replicates were generated for each genotype for the small RNA data. Two of these replicates were also used for the RNA-seq data.
2014-11-20 | E-GEOD-50557 | biostudies-arrayexpress
Project description:Maize LEAFBLADELESS1 (LBL1) and Arabidopsis SUPPRESSOR OF GENE SILENCING3 (SGS3) play orthologous roles in the biogenesis of 21 nucleotide trans-acting short-interfering RNAs (tasiRNAs). The phenotypes conditioned by mutation of lbl1 and SGS3 are, however, strikingly different, suggesting that the activities of these small RNA biogenesis components, or the tasiRNAs and their targets might not be entirely conserved. To investigate the basis for this phenotypic variation, we compared the small RNA content between wild-type and lbl1 seedling apices. We show that LBL1 affects all major classes of small RNAs, and reveal unexpected crosstalk between tasiRNA biogenesis and other small RNA pathways regulating miRNAs, retrotransposons, and DNA transposons. We further identified genomic regions generating phased siRNAs, including numerous loci generating 22-nt phased small RNAs from long hairpin RNAs or overlapping antisense transcripts not previously described in other plant species. By combining both analyses, we identified nine TAS loci, all belonging to the conserved TAS3 family. Contrary to other plant species, no TAS loci targeted by a single miRNA were identified. Information from target prediction, RNAseq, and PARE analyses identified the tasiARFs as the major functional tasiRNAs in the maize vegetative apex where they regulate expression of ARF3 homologs. As such, divergence in TAS pathways is unlikely to account for the distinct phenotypes of tasiRNA biogenesis mutants in Arabidopsis and maize. Instead, the data suggests variation in the spatiotemporal regulation of ARF3, or divergence in its function, as a plausible basis for the dramatic phenotypic differences observed upon mutation of SGS3/lbl1 in Arabidopsis and maize.
2014-11-20 | GSE50557 | GEO