scholarly journals Facilitative and synergistic interactions between fungal and plant viruses

2020 ◽  
Vol 117 (7) ◽  
pp. 3779-3788 ◽  
Author(s):  
Ruiling Bian ◽  
Ida Bagus Andika ◽  
Tianxing Pang ◽  
Ziqian Lian ◽  
Shuang Wei ◽  
...  
Keyword(s):  
Pathogenic Fungus ◽  
Plant Viruses ◽  
Virus Infections ◽  
In Planta ◽  
Symbiotic Relationships ◽  
Synergistic Interactions ◽  
Ssrna Virus ◽  
Facilitative Interactions ◽  
Fungal Viruses ◽  
Cryphonectria Hypovirus

Plants and fungi are closely associated through parasitic or symbiotic relationships in which bidirectional exchanges of cellular contents occur. Recently, a plant virus was shown to be transmitted from a plant to a fungus, but it is unknown whether fungal viruses can also cross host barriers and spread to plants. In this study, we investigated the infectivity of Cryphonectria hypovirus 1 (CHV1, family Hypoviridae), a capsidless, positive-sense (+), single-stranded RNA (ssRNA) fungal virus in a model plant, Nicotiana tabacum. CHV1 replicated in mechanically inoculated leaves but did not spread systemically, but coinoculation with an unrelated plant (+)ssRNA virus, tobacco mosaic virus (TMV, family Virgaviridae), or other plant RNA viruses, enabled CHV1 to systemically infect the plant. Likewise, CHV1 systemically infected transgenic plants expressing the TMV movement protein, and coinfection with TMV further enhanced CHV1 accumulation in these plants. Conversely, CHV1 infection increased TMV accumulation when TMV was introduced into a plant pathogenic fungus, Fusarium graminearum. In the in planta F. graminearum inoculation experiment, we demonstrated that TMV infection of either the plant or the fungus enabled the horizontal transfer of CHV1 from the fungus to the plant, whereas CHV1 infection enhanced fungal acquisition of TMV. Our results demonstrate two-way facilitative interactions between the plant and fungal viruses that promote cross-kingdom virus infections and suggest the presence of plant–fungal-mediated routes for dissemination of fungal and plant viruses in nature.

scholarly journals Molecular Characterization of a Novel Single-stranded RNA Virus, ChRV1, Isolated From the Plant Pathogenic Fungus Colletotrichum Higginsianum

2021 ◽  
Author(s):  
Hong Liu ◽  
Hui Wang ◽  
Xun Lu ◽  
Qian Zhou
Keyword(s):  
Rna Virus ◽  
Pathogenic Fungus ◽  
Gc Content ◽  
Plant Viruses ◽  
Open Reading Frames ◽  
Phytopathogenic Fungus ◽  
Plant Pathogenic Fungus ◽  
Rdrp Domain ◽  
Colletotrichum Higginsianum ◽  
Ssrna Virus

Abstract In this study, a novel single-stranded RNA virus was isolated from the plant pathogenic fungus, Colletotrichum higginsianum strain HTC-5, named “Colletotrichum higginsianum ssRNA virus 1” (ChRV1). The complete genome of ChRV1 is 3850 bp in length with a GC content of 52 % and encodes two in-frame open reading frames (ORFs): ORF1 (smaller) and ORF2 (larger). ORF1 encodes a protein with highest similarity to proteins encoded by Phoma matteucciicola RNA virus 1 (PmRV1, 47.99% identity) and Periconia macrospinosa ambiguivirus 1 (PmAV1, 50.73% identity). ORF2 encodes a protein with a conserved RNA-dependent RNA polymerase (RdRp) domain with similarity to RdRps of PmRV1 (61.41% identity) and PmAV1 (60.61% identity), which are unclassified (+)ssRNA mycoviruses reported recently. Phylogenetic analysis of the RdRp domain suggested that ChRV1 grouped together with PmRV1, PmAV1 and other unclassified (+)ssRNA mycoviruses, and had a distant relationship to invertebrate viruses and plant viruses of the family Tombusviridae. This is the first report of a novel (+)ssRNA virus infecting the phytopathogenic fungus C. higginsianum.

scholarly journals Repeat elements organize 3D genome structure and mediate transcription in the filamentous fungusEpichloë festucae

2018 ◽  
Author(s):  
David J Winter ◽  
Austen RD Ganley ◽  
Carolyn A Young ◽  
Ivan Liachko ◽  
Christopher L Schardl ◽  
...  
Keyword(s):  
Genome Structure ◽  
Regulation Of Gene Expression ◽  
Three Dimensional ◽  
Structural Features ◽  
Dimensional Structure ◽  
In Planta ◽  
Repeat Elements ◽  
Symbiotic Relationships ◽  
3D Genome ◽  
Transcriptional Changes

AbstractStructural features of genomes, including the three-dimensional arrangement of DNA in the nucleus, are increasingly seen as key contributors to the regulation of gene expression. However, studies on how genome structure and nuclear organization influence transcription have so far been limited to a handful of model species. This narrow focus limits our ability to draw general conclusions about the ways in which three-dimensional structures are encoded, and to integrate information from three-dimensional data to address a broader gamut of biological questions. Here, we generate a complete and gapless genome sequence for the filamentous fungus,Epichloë festucae. Coupling it with RNAseq and HiC data, we investigate how the structure of the genome contributes to the suite of transcriptional changes that anEpichloëspecies needs to maintain symbiotic relationships with its grass host. Our results reveal a unique “patchwork” genome, in which repeat-rich blocks of DNA with discrete boundaries are interspersed by gene-rich sequences. In contrast to other species, the three-dimensional structure of the genome is anchored by these repeat blocks, which act to isolate transcription in neighbouring gene-rich regions. Genes that are differentially expressed in planta are enriched near the boundaries of these repeat-rich blocks, suggesting that their three-dimensional orientation partly encodes and regulates the symbiotic relationship formed by this organism.

scholarly journals Detection of Viruses in Sweetpotato from Honduras and Guatemala Augmented by Deep-Sequencing of Small-RNAs

Plant Disease ◽  
2012 ◽  
Vol 96 (10) ◽  
pp. 1430-1437 ◽  
Author(s):  
M. Kashif ◽  
S. Pietilä ◽  
K. Artola ◽  
R. A. C. Jones ◽  
A. K. Tugume ◽  
...  
Keyword(s):  
Sweet Potato ◽  
Virus Strain ◽  
Deep Sequencing ◽  
Ipomoea Batatas ◽  
Plant Viruses ◽  
Virus Infections ◽  
Potato Leaf ◽  
Wide Range ◽  
Virus C ◽  
Small Rna Deep Sequencing

Sweetpotato (Ipomoea batatas) plants become infected with over 30 RNA or DNA viruses in different parts of the world but little is known about viruses infecting sweetpotato crops in Central America, the center of sweetpotato domestication. Small-RNA deep-sequencing (SRDS) analysis was used to detect viruses in sweetpotato in Honduras and Guatemala, which detected Sweet potato feathery mottle virus strain RC and Sweet potato virus C (Potyvirus spp.), Sweet potato chlorotic stunt virus strain WA (SPCSV-WA; Crinivirus sp.), Sweet potato leaf curl Georgia virus (Begomovirus sp.), and Sweet potato pakakuy virus strain B (synonym: Sweet potato badnavirus B). Results were confirmed by polymerase chain reaction and sequencing of the amplicons. Four viruses were detected in a sweetpotato sample from the Galapagos Islands. Serological assays available to two of the five viruses gave results consistent with those obtained by SRDS, and were negative for six additional sweetpotato viruses tested. Plants coinfected with SPCSV-WA and one to two other viruses displayed severe foliar symptoms of epinasty and leaf malformation, purpling, vein banding, or chlorosis. The results suggest that SRDS is suitable for use as a universal, robust, and reliable method for detection of plant viruses, and especially useful for determining virus infections in crops infected with a wide range of unrelated viruses.

scholarly journals Plant Virus Metagenomics: Advances in Virus Discovery

2015 ◽  
Vol 105 (6) ◽  
pp. 716-727 ◽  
Author(s):  
Marilyn J. Roossinck ◽  
Darren P. Martin ◽  
Philippe Roumagnac
Keyword(s):  
Nucleic Acids ◽  
Deep Sequencing ◽  
Plant Virus ◽  
Virus Disease ◽  
Plant Viruses ◽  
Wild Plants ◽  
Cultivated Plants ◽  
Virus Discovery ◽  
Virus Infections ◽  
Virus Like Particles

In recent years plant viruses have been detected from many environments, including domestic and wild plants and interfaces between these systems—aquatic sources, feces of various animals, and insects. A variety of methods have been employed to study plant virus biodiversity, including enrichment for virus-like particles or virus-specific RNA or DNA, or the extraction of total nucleic acids, followed by next-generation deep sequencing and bioinformatic analyses. All of the methods have some shortcomings, but taken together these studies reveal our surprising lack of knowledge about plant viruses and point to the need for more comprehensive studies. In addition, many new viruses have been discovered, with most virus infections in wild plants appearing asymptomatic, suggesting that virus disease may be a byproduct of domestication. For plant pathologists these studies are providing useful tools to detect viruses, and perhaps to predict future problems that could threaten cultivated plants.

scholarly journals Genome-wide alternative splicing profiling in the fungal plant pathogen Sclerotinia sclerotiorum during the colonization of diverse host families

2020 ◽  
Author(s):  
Heba M. M. Ibrahim ◽  
Stefan Kusch ◽  
Marie Didelon ◽  
Sylvain Raffaele
Keyword(s):  
Alternative Splicing ◽  
Sclerotinia Sclerotiorum ◽  
Plant Pathogen ◽  
Host Plants ◽  
Higher Plants ◽  
Pathogenic Fungus ◽  
Differentially Expressed ◽  
Cell Protein ◽  
In Planta ◽  
Alternative Transcripts

AbstractSclerotinia sclerotiorum is a notorious generalist plant pathogen that threatens more than 600 host plants including wild and cultivated species. The molecular bases underlying the broad compatibility of S. sclerotiorum with its hosts is not fully elucidated. In contrast to higher plants and animals, alternative splicing (AS) is not well studied in plant pathogenic fungi. AS is a common regulated cellular process that increases cell protein and RNA diversity. In this study, we annotated spliceosome genes in the genome of S. sclerotiorum and characterized their expression in vitro and during the colonization of six host species. Several spliceosome genes were differentially expressed in planta, suggesting that AS was altered during infection. Using stringent parameters, we identified 1,487 S. sclerotiorum genes differentially expressed in planta and exhibiting alternative transcripts. The most common AS events during the colonization of all plants were retained introns and alternative 3′ receiver site. We identified S. sclerotiorum genes expressed in planta for which (i) the relative accumulation of alternative transcripts varies according to the host being colonized and (ii) alternative transcripts harbor distinct protein domains. This notably included 42 genes encoding predicted secreted proteins showing high confidence AS events. This study indicates that AS events are taking place in the plant pathogenic fungus S. sclerotiorum during the colonization of host plants and could generate functional diversity in the repertoire of proteins secreted by S. sclerotiorum during infection.

scholarly journals Discovery and Community Dynamics of Novel ssRNA Mycoviruses in the Conifer Pathogen Heterobasidion parviporum

2021 ◽  
Vol 12 ◽  
Author(s):  
Suvi Sutela ◽  
Tuula Piri ◽  
Eeva J. Vainio
Keyword(s):  
Community Dynamics ◽  
Viral Infections ◽  
Population Analysis ◽  
Virus Infections ◽  
Ssrna Virus ◽  
Forest Region ◽  
Forest Sites ◽  
High Prevalence ◽  
Small Rna Deep Sequencing ◽  
First Time

Heterobasidion species are highly destructive basidiomycetous conifer pathogens of the Boreal forest region. Earlier studies have revealed dsRNA virus infections of families Curvulaviridae and Partitiviridae in Heterobasidion strains, and small RNA deep sequencing has also identified infections of Mitoviridae members in these fungi. In this study, the virome of Heterobasidion parviporum was examined for the first time by RNA-Seq using total RNA depleted of rRNA. This method successfully revealed new viruses representing two established (+)ssRNA virus families not found earlier in Heterobasidion: Narnaviridae and Botourmiaviridae. In addition, we identified the presence of a recently described virus group tentatively named “ambiviruses” in H. parviporum. The H. parviporum isolates included in the study originated from experimental forest sites located within 0.7 km range from each other, and a population analysis including 43 isolates was conducted at one of the experimental plots to establish the prevalence of the newly identified viruses in clonally spreading H. parviporum individuals. Our results indicate that viral infections are considerably more diverse and common among Heterobasidion isolates than known earlier and include ssRNA viruses with high prevalence and interspecies variation.

scholarly journals Antiviral RISC mainly targets viral mRNA but not genomic RNA of tospovirus

2021 ◽  
Vol 17 (7) ◽  
pp. e1009757
Author(s):  
Hao Hong ◽  
Chunli Wang ◽  
Ying Huang ◽  
Min Xu ◽  
Jiaoling Yan ◽  
...  
Keyword(s):  
Tobacco Rattle Virus ◽  
Plant Viruses ◽  
Genomic Rna ◽  
In Planta ◽  
Viral Mrnas ◽  
Genomic Rnas ◽  
N Protein ◽  
Viral Nucleocapsid

Antiviral RNA silencing/interference (RNAi) of negative-strand (-) RNA plant viruses (NSVs) has been studied less than for single-stranded, positive-sense (+)RNA plant viruses. From the latter, genomic and subgenomic mRNA molecules are targeted by RNAi. However, genomic RNA strands from plant NSVs are generally wrapped tightly within viral nucleocapsid (N) protein to form ribonucleoproteins (RNPs), the core unit for viral replication, transcription and movement. In this study, the targeting of the NSV tospoviral genomic RNA and mRNA molecules by antiviral RNA-induced silencing complexes (RISC) was investigated, in vitro and in planta. RISC fractions isolated from tospovirus-infected N. benthamiana plants specifically cleaved naked, purified tospoviral genomic RNAs in vitro, but not genomic RNAs complexed with viral N protein. In planta RISC complexes, activated by a tobacco rattle virus (TRV) carrying tospovirus NSs or Gn gene fragments, mainly targeted the corresponding viral mRNAs and hardly genomic (viral and viral-complementary strands) RNA assembled into RNPs. In contrast, for the (+)ssRNA cucumber mosaic virus (CMV), RISC complexes, activated by TRV carrying CMV 2a or 2b gene fragments, targeted CMV genomic RNA. Altogether, the results indicated that antiviral RNAi primarily targets tospoviral mRNAs whilst their genomic RNA is well protected in RNPs against RISC-mediated cleavage. Considering the important role of RNPs in the replication cycle of all NSVs, the findings made in this study are likely applicable to all viruses belonging to this group.

scholarly journals Impact of Abiotic Stresses on Plant Virus Transmission by Aphids

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 216 ◽  
Author(s):  
Manuella van Munster
Keyword(s):  
Climate Change ◽  
Abiotic Stresses ◽  
Plant Pathogens ◽  
Plant Defence ◽  
Virus Transmission ◽  
Plant Viruses ◽  
Research Field ◽  
Viral Transmission ◽  
In Planta ◽  
Elevated Atmospheric Co2

Plants regularly encounter abiotic constraints, and plant response to stress has been a focus of research for decades. Given increasing global temperatures and elevated atmospheric CO2 levels and the occurrence of water stress episodes driven by climate change, plant biochemistry, in particular, plant defence responses, may be altered significantly. Environmental factors also have a wider impact, shaping viral transmission processes that rely on a complex set of interactions between, at least, the pathogen, the vector, and the host plant. This review considers how abiotic stresses influence the transmission and spread of plant viruses by aphid vectors, mainly through changes in host physiology status, and summarizes the latest findings in this research field. The direct effects of climate change and severe weather events that impact the feeding behaviour of insect vectors as well as the major traits (e.g., within-host accumulation, disease severity and transmission) of viral plant pathogens are discussed. Finally, the intrinsic capacity of viruses to react to environmental cues in planta and how this may influence viral transmission efficiency is summarized. The clear interaction between biotic (virus) and abiotic stresses is a risk that must be accounted for when modelling virus epidemiology under scenarios of climate change.

scholarly journals Effects of Irrigation Methods and Water Regimes on Occurrences of Cucumo- And Poty- Viruses in Watermelon

2016 ◽  
Vol 4 (3) ◽  
pp. 108
Author(s):  
Kehinde Titilope Kareem ◽  
Adebayo Olubukola Oke ◽  
Kayode Stephen Are ◽  
Oluwafolake Adenike Akinbode ◽  
Ayodele Olumide Adelana
Keyword(s):  
Mosaic Virus ◽  
Yield Loss ◽  
Plant Viruses ◽  
Watermelon Mosaic Virus ◽  
Virus Infections ◽  
Cmv Infection ◽  
Mean Values ◽  
Water Regimes ◽  
Irrigation Methods ◽  
Basin Irrigation

The response of watermelon to Cucumber mosaic virus (CMV) and Watermelon mosaic virus (WMV) under different irrigation methods and water regimes (WRs) was investigated. Watermelon varieties; Kaolak and Sugar baby were irrigated using either sprinkler or basin at 50%, 70% and 100% WRs during the dry season. Results showed that at 3 and 5 weeks after planting (WAP) total irrigation at 100% water regime (WR100) produced the tallest plants with basin irrigation. Mean values of 15.68 cm and 15.85 cm were obtained from Kaolak and Sugar baby respectively with basin irrigation at WR100. However, irrigation at WR50 produced shorter plants with fewer leaves. Complete yield loss was recorded on the field due to severe virus infection. Mixed virus infections were evident in some of the treatments but basin irrigation at WR70 and WR100 had no mix infection of CMV and WMV. Also, varieties were not susceptible to CMV infection at WR70 and WR100 when basin irrigation was used. However, the most severe CMV infection occurred in Sugar baby at WR50 using sprinkler irrigation with virus titre of 1.29. The two varieties were susceptible to WMV irrespective of the irrigation method or WR. The highest WMV titre was 2.88 obtained from Sugar baby at WR50. Total irrigation produced plants with good agronomic parameters compared with deficit irrigation. However, complete yield loss was recorded as a result of either single or double virus infections. Therefore, virus prevention and breeding for virus resistance are best approaches for the control of plant viruses.     

scholarly journals Toll-like receptor 7 suppresses virus replication in neurons but does not affect viral pathogenesis in a mouse model of Langat virus infection

2013 ◽  
Vol 94 (2) ◽  
pp. 336-347 ◽  
Author(s):  
David G. Baker ◽  
Tyson A. Woods ◽  
Niranjan B. Butchi ◽  
Timothy M. Morgan ◽  
R. Travis Taylor ◽  
...  
Keyword(s):  
Virus Infection ◽  
Virus Replication ◽  
Type I ◽  
Toll Like Receptor ◽  
Virus Infections ◽  
Ssrna Virus ◽  
Langat Virus ◽  
The Central Nervous System ◽  
Interferon Responses ◽  
Deficient Mice

Toll-like receptor 7 (TLR7) recognizes guanidine-rich viral ssRNA and is an important mediator of peripheral immune responses to several ssRNA viruses. However, the role that TLR7 plays in regulating the innate immune response to ssRNA virus infections in specific organs such as the central nervous system (CNS) is not as clear. This study examined the influence of TLR7 on the neurovirulence of Langat virus (LGTV), a ssRNA tick-borne flavivirus. TLR7 deficiency did not substantially alter the onset or incidence of LGTV-induced clinical disease; however, it did significantly affect virus levels in the CNS with a log10 increase in virus titres in brain tissue from TLR7-deficient mice. This difference in virus load was also observed following intracranial inoculation, indicating a direct effect of TLR7 deficiency on regulating virus replication in the brain. LGTV-induced type I interferon responses in the CNS were not dependent on TLR7, being higher in TLR7-deficient mice compared with wild-type controls. In contrast, induction of pro-inflammatory cytokines including tumour necrosis factor, CCL3, CCL4 and CXCL13 were dependent on TLR7. Thus, although TLR7 is not essential in controlling LGTV pathogenesis, it is important in controlling virus infection in neurons in the CNS, possibly by regulating neuroinflammatory responses.

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