Project description:Arabidopsis thaliana (Arabidopsis) encodes five DOUBLE-STRANDED RNA BINDING (DRB) proteins, DRB1 to DRB5, that predominantly act as non-catalytic cofactors for DICER-LIKE (DCL) proteins in the double-stranded RNA (dsRNA) processing stages of small RNA (sRNA) production pathways. In the nucleus, DRB1 is required for microRNA (miRNAs) processing from imperfectly dsRNA precursors by DCL1. Similarly, DRB4 is required by DCL4 for small-interfering RNAs (siRNAs) production from endogenous or exogenous perfectly dsRNA templates. DRB2 has been recently demonstrated to be required for miRNA and siRNA production in developmentally-important tissues of Arabidopsis while the requirement of either DRB3 or DRB5 in sRNA production remains unclear. Here, we analyse in parallel, the contribution of all five DRB protein family members to the global sRNA landscape of Arabidopsis floral tissues. In depth bioinformatic analysis of sRNA sequencing datasets generated from floral tissues of DRB knockout mutant (drb) plant lines, drb1, drb2, drb4, drb12, drb14, drb24, and drb35 and their comparison to the floral sRNA profile of wild-type Arabidopsis, has enabled confident assignment of the requirement of DRB1, DRB2 and DRB4 for the production of specific miRNA and siRNA subclasses in this tissue. Our analyses have additionally identified novel and/or expanded roles for DRB2 in miRNA, trans-acting siRNAs (tasiRNAs) and natural antisense transcript siRNAs (natsiRNAs) production.
Project description:A silencing signal in plants with an RNA specificity determinant moves through plasmodesmata and the phloem. To identify the mobile RNA we grafted Arabidopsis thaliana shoots to roots that would be a recipient for the silencing signal. Using high throughput sequencing as a sensitive detection method and mutants to block small RNA (sRNA) biogenesis in either source or recipient tissue, we detected endogenous and transgene specific sRNA that moved across the graft union. Surprisingly we found that the mobile endogenous sRNAs account for a substantial proportion of the sRNA in roots and we provide evidence that 24nt mobile sRNAs direct epigenetic modifications in the genome of the recipient cells. Mobile sRNA thus represents a mechanism for transmitting the specification of epigenetic modification and could affect genome defence and responses to external stimuli that have persistent effects in plants. Keywords: Small RNA Analysis, Epigenetics 34 unique samples, 15 Biological Replicates
Project description:A silencing signal in plants with an RNA specificity determinant moves through plasmodesmata and the phloem. To identify the mobile RNA we grafted Arabidopsis thaliana shoots to roots that would be a recipient for the silencing signal. Using high throughput sequencing as a sensitive detection method and mutants to block small RNA (sRNA) biogenesis in either source or recipient tissue, we detected endogenous and transgene specific sRNA that moved across the graft union. Surprisingly we found that the mobile endogenous sRNAs account for a substantial proportion of the sRNA in roots and we provide evidence that 24nt mobile sRNAs direct epigenetic modifications in the genome of the recipient cells. Mobile sRNA thus represents a mechanism for transmitting the specification of epigenetic modification and could affect genome defence and responses to external stimuli that have persistent effects in plants. Keywords: Small RNA Analysis, Epigenetics
Project description:To systematically investigate viral sRNA production and sRNA-target interaction, we sequenced sRNAs from Tobacco Rattle Virus (TRV)-infected Nicotiana benthamiana at an early (1 week post infection) and late time point (3 weeks post infection). The N. benthamiana 16c plants were infected with TGS-inducing viruses (TRV-35S and TRV-35-2M) and PTGS-inducing viruses (TRV-GFP and TRV-GFP-2M), respectively. TRV-35S is a recombinant TRV containing a 120 nt segment of the 35S promoter. Its derivative, TRV-35S-2M, carrying single nucleotide substitutions (SNS) at every 10 nt within the 120 nt 35S target segment. Same strategy was used to create recombinant TRV-GFP and TRV-GFP-2M targeting GFP coding sequence. According to SNS content, sRNAs from TRV-35S-2M/TRV-GFP-2M infected plants can be separated to yield primary (containing SNSs) and secondary sRNAs (lacking SNSs). Wild Type TRV was used along as viral infection control. Libraries were indexed during PCR amplification (16 cycles) according to the Illumina protocol. See individual sample information for specific index primers used.
Project description:To investigate how high temperature affects sRNA production during virus induced gene silencing (VIGS), we sequenced sRNAs from Tobacco Rattle Virus (TRV)-infected Nicotiana benthamiana kept at 29°C at an early (1 week post infection) and a late time point (3 weeks post infection). To compare sRNA production between virus induced transcriptional gene silencing (ViTGS) and virus induced post-translational gene silencing (ViPTGS) at 29°C, the N. benthamiana 16c plants were infected with TGS-inducing viruses (TRV-35S and TRV-35-2M) and PTGS-inducing viruses (TRV-GFP and TRV-GFP-2M). TRV-35S is a recombinant TRV containing a 120 nt segment of the 35S promoter. Its derivative, TRV-35S-2M, carrying single nucleotide substitutions (SNS) at every 10 nt within the 120 nt 35S target segment. Same strategy was used to create recombinant TRV-GFP and TRV-GFP-2M targeting GFP coding sequence. According to SNS content, sRNAs from TRV-35S-2M/TRV-GFP-2M infected plants can be separated to yield primary (containing SNSs) and secondary sRNAs (lacking SNSs). Wild Type TRV was used along as viral infection control. Libraries were indexed during PCR amplification (16 cycles) according to the Illumina protocol. See individual sample information for specific index primers used.
Project description:Potato virus Y HCPro suppression of antiviral silencing in Nicotiana benthamiana plants correlates with its ability to bind in vivo to small RNAs of 21 and 22 nucleotides in length of viral sequence
Project description:Virus infection is a process resulting in numerous molecular, cellular, and physiological changes, a wide range of which can be analyzed due to development of many high-throughput techniques. Plant RNA viruses are known to replicate in the cytoplasm; however, the roles of chloroplasts and other cellular structures in the viral replication cycle and in plant antiviral defense have been recently emphasized. Therefore, the aim of this study was to analyze the small RNAs, transcripts, proteins, and phosphoproteins affected during peanut stunt virus strain P (PSV-P)–Nicotiana benthamiana interactions with or without satellite RNA (satRNA) in the context of their cellular localization or functional connections with particular cellular compartments to elucidate the compartments most affected during pathogenesis at the early stages of infection. Moreover, the processes associated with particular cell compartments were determined. The ‘omic’ results were subjected to comparative data analyses. Transcriptomic and small RNA (sRNA)–seq data were obtained to provide new insights into PSV-P–satRNA–plant interactions, whereas previously obtained proteomic and phosphoproteomic data were used to broaden the analysis to terms associated with cellular compartments affected by virus infection. Based on the collected results, infection with PSV-P contributed to changes in the abundance of transcripts and proteins associated with various cellular compartments, including ribosomes, chloroplasts, mitochondria, the nucleus and the cytosol, and the most affected processes were photosynthesis, translation, transcription, and mRNA splicing. Furthermore, sRNA-seq and phosphoproteomic analyses indicated that kinase regulation resulted in decreases in phosphorylation levels. The kinases were associated with the membrane, cytoplasm, and nucleus components.