Unknown,Transcriptomics,Genomics,Proteomics

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Characterization of the complete genome sequence of Barley yellow striate mosaic virus reveals an overprinted ancillary gene encoding a small hydrophobic protein

ABSTRACT: In the recent years, RNA silencing has been studied extensively to be a conserved regulatory process in plants. In the antiviral silencing, the intermediate double-stranded RNA form during the replication of RNA viruses were recognized and processed into abundant of overlapping viral siRNA (viRNAs). Accordingly, the cloned viRNAs could be conversely assembled into some contigs of viruses, which is recently exploited for identifying new viruses and their genome sequences.To obtain rapidly the complete genome sequence of BYSMV, we carried out deep sequencing of small RNAs from healthy and BYSMV infected wheat, respectively. Thirteen contigs were assembled from the overlapping viRNAs only present in the infected wheat but not in the healthy wheat. The results of BLAST showed that ten contigs shared about 96% identity with the reported L gene of BYSMV isolate Zanjan-1. Viral assembly from the BYSMV infected wheat plants to obtain the full lengh genome and characterise the viral siRNAs

ORGANISM(S): Triticum aestivum

SUBMITTER: Xian-Bing Wang

PROVIDER: E-GEOD-61565 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Project description:Wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) are type members of Tritimovirus and Poacevirus genera, respectively, in the family Potyviridae, and are transmitted by wheat curl mites. Co-infection of these two viruses causes synergistic interaction with increased virus accumulation and disease severity in wheat. In this study, we examined the effects of synergistic interaction between WSMV and TriMV on endogenous small (s) RNAs and virus-specific small interfering RNAs (vsiRNAs) in susceptible (Arapahoe) and temperature-sensitive resistant (Mace) wheat cultivars at 27C and 18C. Single- and double-infections in wheat caused a shift in the profile of endogenous sRNAs from 24 nt being the most predominant in healthy plants to 21 nt in infected wheat. Additionally, we report high-resolution vsiRNA maps of WSMV and TriMV in singly- and doubly-infected wheat cultivars Arapahoe and Mace at 18C and 27C. Massive amounts of 21 and 22 nt vsiRNA reads were accumulated in Arapahoe at both temperatures and in Mace at 27C but not at 18C. The plus- and minus-sense vsiRNAs were distributed throughout the genomic RNAs in Arapahoe at both temperature regimens and in Mace at 27C, although some regions of genomic RNAs serve as hot-spots with an excessive number of vsiRNAs. The positions of vsiRNA peaks were conserved among wheat cultivars Arapahoe and Mace, suggesting that Dicer-like enzymes of susceptible and resistant wheat cultivars are similarly accessed the genomic RNAs of WSMV and TriMV. Additionally, several cold-spot regions were found in the genomes of TriMV and WSMV with no or a few vsiRNAs, indicating that certain regions of WSMV and TriMV genomes are not accessible to Dicer-like enzymes. The high-resolution map of endogenous and vsiRNAs from wheat cultivars synergistically infected with WSMV and TriMV at two temperature regimens form a foundation for understanding the virus-host interactions, effect of synergistic interactions on host defense mechanisms, and virus resistance mechanisms in wheat. Small RNA was sequenced from two wheat cultivars (Mace and Araphahoe), at two temperatures 18C and 27C, for healthy (control/uninfected), infected with wheat streak mosaic virus (WSMV), infected with Triticum mosaic virus (TriMV), and a double-infecttion of WSMV and TriMV.

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.

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Characterization of the complete genome sequence of Barley yellow striate mosaic virus reveals an overprinted ancillary gene encoding a small hydrophobic protein

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