Project description:Identification of new genes regulated by RDR6 and SGS3 (two genes involved in PTGS) by analysis of the transcriptome of rdr6-1 and sgs3-1 mutants compared to wild-type plants in different tissues (flower and leaves). The comparison between transcriptome of rdr6-1 and sgs3-1 mutant alleles impaired in PTGS and development (juvenile-to-adult transition) and transcriptome of rdr6-5 and sgs3-3 alleles impaired only in PTGS would allowed identification of genes involved in the developmental default (zip phenotype) of the null alleles (rdr6-1 and sgs3-1 mutants).
Project description:Identification of new genes regulated by RDR6 and SGS3 (two genes involved in PTGS) by analysis of the transcriptome of rdr6-1 and sgs3-1 mutants compared to wild-type plants in different tissues (flower and leaves). The comparison between transcriptome of rdr6-1 and sgs3-1 mutant alleles impaired in PTGS and development (juvenile-to-adult transition) and transcriptome of rdr6-5 and sgs3-3 alleles impaired only in PTGS would allowed identification of genes involved in the developmental default (zip phenotype) of the null alleles (rdr6-1 and sgs3-1 mutants). - Transcriptome of rdr6 and sgs3 mutants will be compared to the transcriptome of wild-type plants in flower and leaves. Further-more the comparison between transcriptome of rdr6-1 and sgs3-1 mutant alleles impaired in PTGS and development (juvenile-to-adult transition) and transcriptome of rdr6-5 and sgs3-3 alleles impaired only in PTGS will be done for flowers and leaves. Keywords: gene knock in (transgenic)
Project description:ra09-03_sgs - mutants versus wt - Identification of new genes regulated by SGS1 and SGS6/UBP5 (two genes involved in PTGS) by analysis of the transcriptomes of sgs1 and sgs6 mutants compared to wild-type plants in the shoots of seedlings. The comparison between the transcriptomes of sgs3, chr11, chr17 simple mutants impaired differently in PTGS and development (juvenile-to-adult transition and bolting), and the transcriptomes of the sgs3 chr11, sgs3 chr17 double mutants showed additive effects on development (juvenile-to-adult transition and bolting), which allows a better understanding of the genetic link existing between SGS3 and its potential partners, CHR11 (which interacts with SGS3 in a two-hybrid assay and BiFC) and CHR17, 2 homologous proteins of the SWI/SNF2 family. Transcriptome comparison between mutants and wild-type plants L1 in the shoots of seedlings.
Project description:ra09-03_sgs - mutants versus wt - Identification of new genes regulated by SGS1 and SGS6/UBP5 (two genes involved in PTGS) by analysis of the transcriptomes of sgs1 and sgs6 mutants compared to wild-type plants in the shoots of seedlings. The comparison between the transcriptomes of sgs3, chr11, chr17 simple mutants impaired differently in PTGS and development (juvenile-to-adult transition and bolting), and the transcriptomes of the sgs3 chr11, sgs3 chr17 double mutants showed additive effects on development (juvenile-to-adult transition and bolting), which allows a better understanding of the genetic link existing between SGS3 and its potential partners, CHR11 (which interacts with SGS3 in a two-hybrid assay and BiFC) and CHR17, 2 homologous proteins of the SWI/SNF2 family. Transcriptome comparison between mutants and wild-type plants L1 in the shoots of seedlings. 14 dye-swaps - gene knock-in (transgenic).
Project description:Post-transcriptional gene silence (PTGS) is employed in plants to shut down transgenes, invading viral genes and a certain group of endogenous genes. Meanwhile, it is not clear how the risk of expansive PTGS from endogenous genes featured by transitive siRNA production is minimized. Here we demonstrate two essential components of the SKI complex in cytoplasmic 3’-5’ mRNA decay pathway, SKI2 and SKI3, function as negative regulators of transgene PTGS in Arabidopsis. The ski2 mutants manifested severe synthetic phenotypes with a 5’-3’ exoribonuclease mutant, ein5, which were substantially suppressed by the PTGS mutants, rdr6 and ago1. RDR6 is essential for the altered gene expression in ein5 ski2 on a transcriptome-wide scale. mRNA-seq approach was used to investigate the physiological relevance veiled by the myriad developmental phenotypes in Col-0 (C), ein5-1 (e), ski2-3 (s), ein5-1 ski2-3 (es), rdr6-11 (r) and rdr6-11 ein5-1 ski2-3 (res). A number of endogenous genes, including many miRNA target genes, manifest transitive 21-22 nt siRNA production and compromised gene expression in ein5 ski2 in an RDR6-dependent manner. Taken together, our study brings to light a dual-safeguard system in preventing the expansive siRNA production by the 5’-3’ and 3’-5’ cytoplasmic mRNA decay pathways.
Project description:In plants, smRNAs are often derived from long double-stranded RNA (dsRNA) molecules synthesized by one of the six genomically-encoded RNA-dependent RNA Polymerase (RDR) proteins. However, the full complement of the RDR-dependent smRNAs and functions that these proteins and their RNA-binding co-factors play in plant RNA silencing has not been fully uncovered. To address this gap, we performed a global genomic analysis of all six RDRs and two of their co-factors to find new substrates for RDRs and targets of the resulting RDR-derived siRNAs to uncover new functions for these proteins in plants. Based on these analyses, we identified substrates for the three RDR clade proteins (RDR3 - 5), which had not been well-characterized previously. We also identified new substrates for the other three RDRs (RDR1, 2, and 6) as well as the RDR2 co-factor RNA-DIRECTED DNA METHYLATION 12 (RDM12) and the RDR6 co-factor SUPRESSOR OF GENE SILENCING 3 (SGS3). These findings revealed that the target substrates of SGS3 are not limited to those solely utilized by RDR6, but that this protein seems to be a more general co-factor for the RDR family proteins. Additionally, we found that RDR6 and SGS3 are involved in the production of smRNAs that target transcripts related to abiotic stresses including water deprivation, salt stress, and ABA response, and as expected the levels of these mRNAs are increased in rdr6 and sgs3 mutant plants. Correspondingly, plants that lack these proteins (rdr6 and sgs3 mutants) are hypersensitive to ABA treatment, tolerant to high levels of PEG8000, and have higher survival rate under salt treatment in comparison to wild-type (Col-0). In total, our analyses have provided an extremely data-rich resource for uncovering new functions of RDR-dependent RNA silencing in plants, while also revealing a previously unexplored link between the RDR6/SGS3-dependent pathway and plant abiotic stress responses.
Project description:Post-transcriptional gene silence (PTGS) is employed in plants to shut down transgenes, invading viral genes and a certain group of endogenous genes. Meanwhile, it is not clear how the risk of expansive PTGS from endogenous genes featured by transitive siRNA production is minimized. Here we demonstrate two essential components of the SKI complex in cytoplasmic 3 -5 mRNA decay pathway, SKI2 and SKI3, function as negative regulators of transgene PTGS in Arabidopsis. The ski2 mutants manifested severe synthetic phenotypes with a 5 -3 exoribonuclease mutant, ein5, which were substantially suppressed by the PTGS mutants, rdr6 and ago1. RDR6 is essential for the altered gene expression in ein5 ski2 on a transcriptome-wide scale. mRNA-seq approach was used to investigate the physiological relevance veiled by the myriad developmental phenotypes in Col-0 (C), ein5-1 (e), ski2-3 (s), ein5-1 ski2-3 (es), rdr6-11 (r) and rdr6-11 ein5-1 ski2-3 (res). A number of endogenous genes, including many miRNA target genes, manifest transitive 21-22 nt siRNA production and compromised gene expression in ein5 ski2 in an RDR6-dependent manner. Taken together, our study brings to light a dual-safeguard system in preventing the expansive siRNA production by the 5 -3 and 3 -5 cytoplasmic mRNA decay pathways. In this experiment, we did three replicates in sequencing that help increase the power in identify the differentially represented genes.The sequencing depth was also increased. Therefore we identified more siRNA-generating loci than that in previous study (GSE52408) (441 vs. 200 loci).
Project description:Background: Cytoplasmic degradation of endogenous RNAs is an integral part of RNA quality control (RQC) and often relies on the removal of the 5' cap structure and their subsequent 5M-bM-^@M-^Y to 3M-bM-^@M-^Y degradation. In parallel, many eukaryotes degrade exogenous and selected endogenous RNAs through post-transcriptional gene silencing (PTGS). In plants, PTGS depends on small interfering (si)RNAs produced after the conversion of single-stranded RNAs to double-stranded RNAs by the cellular RNA DEPENDENT RNA POLYMERASE 6 (RDR6). PTGS and RQC compete for transgene-derived RNAs, but it is unknown whether this competition also occurs for endogenous transcripts. Results: We show that that upon decapping impairment hundreds of endogenous mRNAs give rise to a new class of siRNAs, a subset of which depends on RDR6 for their production. Conclusions: Our results suggest that the decapping of aberrant endogenous RNA in P-bodies limits their entry into the PTGS pathway and prevents the subsequent deleterious consequences arising from this entry. We anticipate that the siRNAs identified in decapping mutants represent a subset of a larger ensemble of endogenous siRNAs that we coin rqc-siRNAs because they accumulate when RQC processes are impaired. Small RNA-seq experiments performed in duplicates for each condition.
Project description:Background: Cytoplasmic degradation of endogenous RNAs is an integral part of RNA quality control (RQC) and often relies on the removal of the 5' cap structure and their subsequent 5’ to 3’ degradation. In parallel, many eukaryotes degrade exogenous and selected endogenous RNAs through post-transcriptional gene silencing (PTGS). In plants, PTGS depends on small interfering (si)RNAs produced after the conversion of single-stranded RNAs to double-stranded RNAs by the cellular RNA DEPENDENT RNA POLYMERASE 6 (RDR6). PTGS and RQC compete for transgene-derived RNAs, but it is unknown whether this competition also occurs for endogenous transcripts. Results: We show that that upon decapping impairment hundreds of endogenous mRNAs give rise to a new class of siRNAs, a subset of which depends on RDR6 for their production. Conclusions: Our results suggest that the decapping of aberrant endogenous RNA in P-bodies limits their entry into the PTGS pathway and prevents the subsequent deleterious consequences arising from this entry. We anticipate that the siRNAs identified in decapping mutants represent a subset of a larger ensemble of endogenous siRNAs that we coin rqc-siRNAs because they accumulate when RQC processes are impaired.