Dataset Information

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

ABSTRACT: We have investigated short and small RNAs (sRNAs) that were bound to a biologically active hexahistidine-tagged Potato virus Y (PVY) HCPro suppressor of silencing, expressed from a heterologous virus vector in Nicotiana benthamiana plants, and purified under non-denaturing conditions. We found that RNAs in purified preparations were differentially enriched in sRNAs of 21 and to a much lesser extent of 22 nucleotides (nt) in length and of viral sequence (vsRNAs) when compared to those found in a control plant protein background bound to the nickel resin in the absence of HCPro, or in a purified alanine substitution HCPro mutant (HCPro mutB) control that lacked suppressor of silencing activity. In both controls, sRNAs were composed almost entirely by molecules of plant sequence, indicating that the resin-bound protein background had no affinity for vsRNAs, and also that HCPro mutB failed to bind to vsRNAs. Therefore, PVY HCPro suppressor activity correlated with its ability to bind to 21 and 22 nt vsRNAs. HCPro constituted at least 54 % of the total protein content in purified preparations and we were able to calculate its contribution to the 21 and the 22 nt pool of sRNAs present in the purified samples and its binding strength relative to the background. We also found that in the 21 nt vsRNAs of the HCPro preparation 5´ terminal adenines were overrepresented relative to the controls, but not in vsRNAs of other sizes or of plant sequence.

ORGANISM(S): Nicotiana benthamiana

PROVIDER: GSE71921 | GEO | 2017/03/31

SECONDARY ACCESSION(S): PRJNA292454

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:In response to infection, viral genomes are processed by Dicer-like (DCL) ribonuclease proteins into viral small RNAs (vsRNAs) of discrete sizes. vsRNAs are then used as guides for silencing the viral genome. The profile of vsRNAs produced during the infection process has been extensively studied for some group of viruses. However, nothing is known for members of the economically important family Luteoviridae, a group of phloem-restricted viruses. Here, the population of vsRNAs from cotton plants infected with Cotton leafroll dwarf virus (CLRDV), a member of the genus Polerovirus, family Luteoviridae, is characterized.Deep sequencing of small RNAs (sRNAs) from CLRDV-infected cotton leaves was performed. Results showed 21-nt to 24-nt long vsRNAs matching all the viral genome, with a higher frequency of matches in the 3M-CM-"M-BM-^@M-BM-^Y region. Equivalent amounts of sense and antisense vsRNAs were found, and the 22-nt long small RNA class was the most prominent one. Looking for cotton Dcl transcripts levels during infection, we could observe that Dcl4 seems to be up-regulated, while Dcl2 seems to be down-regulated.This is the first report on the profile of sRNAs coming from a plant infected with a member of the family Luteoviridae. Our sequence data strongly suggest that virus-derived double-stranded RNA functions as one of the main precursors of vsRNAsOur results indicate that secondary structures of the viral RNAs are not the main source of the viRNAs observed, as suggested for other viruses. Judging by the profiled size classes, all cotton DCLs might be working to silence the virus. The possible causes for the unexpected high accumulation of 22-nt viRNAvsRNAs are discussed. CLRDV is the causal agent of worldwide cotton pathology named Cotton blue disease. Our results are an important contribution for understanding the molecular mechanisms involved in this and related diseases. Total RNA obtained from leaves of the cotton plant 5 days post-infection with Cotton leafrol dawrf virus (CLRDV) compared to not-infected control.

Project description:In Oxytricha, the somatic genome is responsible for vegetative growth, while the germline contributes DNA to the next sexual generation. Somatic nuclear development eliminates all transposons and other so-called "junk DNA", which constitute ~95% of the germline. We demonstrate that Piwi-interacting small RNAs (piRNAs) from the maternal nucleus can specify genomic regions for retention in this process. Oxytricha piRNAs map primarily to the somatic genome, representing the ~5% of the germline that is retained. Furthermore, injection of synthetic piRNAs corresponding to normally-deleted regions leads to their retention in subsequent generations. Our findings highlight small RNAs (sRNAs) as powerful transgenerational carriers of epigenetic information for genome programming. The backcross study here shows that the mating between an IES+ strain with the wild-type stain produces corresponding IES-containing sRNAs at 19 hr, and we provided the mapping to and the sequences of the specific loci of interest in the submission. As a control, wild-type cells do not produce such IES-containing sRNAs, and this analysis can be pulled out from the GSE35018 study since we provided mapping to the whole genome. The purpose of the 20 hr total sRNA sequencing study here is to show that the class of 27 nt sRNA is the major species of total sRNAs in Oxytricha at 20 hr, which we sequenced previously from Otiwi1-associated sRNAs at 12, 19, 23, and 30 hr (GSE35018). In addition, there is a less abundant class of small RNAs of 21-22 nt. These two classes are obvious by simply plotting the length distribution of the sRNA sequences. We sequenced sRNAs from Contig22226.0 IES1+ strain backcrossed to wild-type parental strain at 19hr post-mixing, and found corresponding IES-containing sRNAs. As a control, wild-type cells do not produce such IES-containing sRNAs (see GSE35018). Total RNA from the backcrossing at 19hr were isolated with mirVana small RNA extraction kit (Ambion), and directly used for making Illumina sRNA libraries. Oxytricha total small RNA (sRNA) sequencing at 20 hr post conjugation shows that a class of 27 nt, 5'-U sRNAs dominates the sRNA population at 20 hr, and this class of sRNAs associate with Otiwi1 (see GSE35018 for Otiwi1-interacting sRNAs in Oxytricha). In addition, a much less abundant class of 21-22 nt sRNAs is present according to the length distribution.

Dataset Information

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

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure