Hypovirus

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Hypovirus
Virus classification OOjs UI icon edit-ltr.svg
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Pisuviricota
Class: Duplopiviricetes
Order: Durnavirales
Family: Hypoviridae
Genus:Hypovirus

Hypovirus is a genus of viruses, in the family Hypoviridae. [1] Fungi serve as natural hosts. There are four species in this genus. [2] Infection reduces the virulence of its parasitic host, making it a hyperparasite useful for blight control. [1] [3]

Contents

Species

The following species are recognized by the International Committee on Taxonomy of Viruses (ICTV), all of which were found with Cryphonectria parasitica : [1] [2]

There are numerous family members affecting other plant-pathogenic fungi not yet accepted into the ICTV nomenclature. A proposal reorganizes the family into three genera. [4] The informal family Fusariviridae is the sister group. [5]

Structure

The diameter is around 50–80 nm. Genomes are linear, around 9–13kb in length. The genome has 1 or 2 open reading frames, named OrfA (not always present) and OrfB. [1] [3]

GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
HypovirusNo true capsidNon-envelopedLinearMonopartite

The genome contains no structural proteins. The virus accordingly does not bud out of the cell (see "life cycle" below). Both open reading frames of CHV1 contain a papain-like protease to the N-terminal that is autocatalyticly cleaved. OrfA (p69, P10941 ) cleaves into the p29 C7 protease and a nonessential p40 protein. OrfB ( Q04350 ) cleaves into a p48 C8 protease and the RNA replicase helicase. [3]

Life cycle

Viral replication is cytoplasmic. Replication follows the double-stranded RNA virus replication model. Double-stranded RNA virus transcription is the method of transcription. The virus exits the host cell by cell to cell movement. Fungi serve as the natural host. [1] [3]

GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
HypovirusFungiNoneCytoplasmic exchange; hyphal anastomosis Cytoplasmic exchange; hyphal anastomosisCytoplasmCytoplasmCytoplasmic exchange; hyphal anastomosis

CHV1 – Chestnut blight hypovirulence

Up to 2000, Hypovirus CHV1 was the only hypovirus found in Europe. [6] It is known for reducing the virulence of the fungus that causes chestnut blight (i.e. hypovirulence). [7] Cryphonectria parasitica, the ascomycete fungus, originated in Asia and causes the disease chestnut blight in several chestnut species (Castanea spp.). Although symptoms are mild in Asian chestnut species that have co-evolved with the fungus, they are very severe in the North American chestnut species C. dentata and also in the European sweet chestnut, C. sativa. [8] Hypovirus has been used for protection against chestnut blight in Europe since the 1970s. [6]

Related Research Articles

<span class="mw-page-title-main">Chestnut blight</span> Fungus disease of chestnut trees

The pathogenic fungus Cryphonectria parasitica is a member of the Ascomycota. This necrotrophic fungus is native to East Asia and South East Asia and was introduced into Europe and North America in the early 1900s. The fungus spread rapidly and caused significant tree loss in both regions.

<i>Totiviridae</i> Family of viruses

Totiviridae is a family of double-stranded RNA viruses. Giardia lamblia, leishmania, trichomonas vaginalis, and fungi serve as natural hosts. The name of the group derives from Latin toti which means undivided or whole. There are 28 species in this family, assigned to 5 genera.

Caulimoviridae is a family of viruses infecting plants. There are 94 species in this family, assigned to 11 genera. Viruses belonging to the family Caulimoviridae are termed double-stranded DNA (dsDNA) reverse-transcribing viruses i.e. viruses that contain a reverse transcription stage in their replication cycle. This family contains all plant viruses with a dsDNA genome that have a reverse transcribing phase in their lifecycle.

<i>Potyviridae</i> Family of viruses

Potyviridae is a family of positive-strand RNA viruses that encompasses more than 30% of known plant viruses, many of which are of great agricultural significance. The family has 12 genera and 235 species, three of which are unassigned to a genus.

<i>Tombusviridae</i> Family of viruses

Tombusviridae is a family of single-stranded positive sense RNA plant viruses. There are three subfamilies, 17 genera, and 95 species in this family. The name is derived from Tomato bushy stunt virus (TBSV).

Baltimore classification is a system used to classify viruses based on their manner of messenger RNA (mRNA) synthesis. By organizing viruses based on their manner of mRNA production, it is possible to study viruses that behave similarly as a distinct group. Seven Baltimore groups are described that take into consideration whether the viral genome is made of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), whether the genome is single- or double-stranded, and whether the sense of a single-stranded RNA genome is positive or negative.

<span class="mw-page-title-main">Mycovirus</span> Virus that infects fungi

Mycoviruses, also known as mycophages, are viruses that infect fungi. The majority of mycoviruses have double-stranded RNA (dsRNA) genomes and isometric particles, but approximately 30% have positive-sense, single-stranded RNA (+ssRNA) genomes.

<i>Totivirus</i> Genus of viruses

Totivirus is a genus of double-stranded RNA viruses in the family Totiviridae. Fungi serve as natural hosts. The name of the group derives from Latin toti which means undivided or whole. There are seven species in this genus.

<i>Alphachrysovirus</i> Genus of viruses

Alphachrysovirus is a genus of double-stranded RNA viruses. It is one of two genera in the family Chrysoviridae. They infect fungi, in particular Penicillium. Their name is derived from the Greek word chrysos which means yellow-green. There are 20 species in this genus.

<i>Partitiviridae</i> Family of viruses

Partitiviridae is a family of double-stranded RNA viruses. Plants, fungi, and protozoa serve as natural hosts. It has been suggested that they can also infect bacteria. The name comes from the Latin partitius, which means divided, and refers to the segmented genome of partitiviruses. There are five genera and 60 species in the family, 15 of which are unassigned to a genus.

Endornaviridae is a family of viruses. Plants, fungi, and oomycetes serve as natural hosts. There are 31 species in this family, assigned to 2 genera. Members of Alphaendornavirus infect plants, fungi and the oomycete Phytophthora sp., members of Betaendornavirus infect ascomycete fungi.

<i>Alphaflexiviridae</i> Family of viruses in the order Tymovirales affecting plants and fungi

Alphaflexiviridae is a family of viruses in the order Tymovirales. Plants and fungi serve as natural hosts. There are 65 species in this family, assigned to six genera. Diseases associated with this family include: mosaic and ringspot symptoms.

Ipomovirus is a genus of positive-strand RNA viruses in the family Potyviridae. Member viruses infect plants and are transmitted by whiteflies. The name of the genus is derived from Ipomoea – the generic name of sweet potato. There are seven species in this genus.

Cilevirus is a genus of viruses in the family Kitaviridae. Plants serve as natural hosts. There are two species: Citrus leprosis virus C and Citrus leprosis virus C2.

Mitovirus is a genus of positive-strand RNA viruses, in the family Mitoviridae. Fungi serve as natural hosts. There are five species in the genus.

<i>Mycoreovirus</i> Genus of viruses

Mycoreovirus is a genus of double-stranded RNA viruses in the family Reoviridae and subfamily Spinareovirinae. Fungi serve as natural hosts. Diseases associated with this genus include: hypovirulence of the fungal host. The name of the group derives from Ancient Greek myco which means fungus. There are three species in this genus.

Narnavirus is a genus of positive-strand RNA viruses in the family Narnaviridae. Fungi serve as natural hosts. There are two species in this genus. Member viruses have been shown to be required for sexual reproduction of Rhizopus microsporus. Narnaviruses have a naked RNA genome without a virion and derive their name from this feature.

Sclerodarnavirus is a genus of viruses in the order Tymovirales, in the family Alphaflexiviridae. Fungi serve as natural hosts. There is only one species in this genus: Sclerotinia sclerotiorum debilitation-associated RNA virus. Diseases associated with this genus include: hypovirulence or debilitation.

<i>Megabirnaviridae</i> Family of viruses

Megabirnaviridae is a family of double-stranded RNA viruses with one genus Megabirnavirus which infects fungi. The group name derives from member's bipartite dsRNA genome and mega that is greater genome size than families Birnaviridae and Picobirnaviridae. There is only one species in this family: Rosellinia necatrix megabirnavirus 1. Diseases associated with this family include: reduced host virulence.

Yokose virus (YOKV) is in the genus Flavivirus of the family Flaviviridae. Flaviviridae are often found in arthropods, such as mosquitoes and ticks, and may also infect humans. The genus Flavivirus includes over 50 known viruses, including Yellow Fever, West Nile Virus, Zika Virus, and Japanese Encephalitis. Yokose virus is a new member of the Flavivirus family that has only been identified in a few bat species. Bats have been associated with several emerging zoonotic diseases such as Ebola and SARS.

References

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  2. 1 2 "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 20 May 2021.
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  4. Torres-Trenas, Almudena; Cañizares, M. Carmen; García-Pedrajas, M. Dolores; Pérez-Artés, Encarnación (2020). "Molecular and Biological Characterization of the First Hypovirus Identified in Fusarium oxysporum". Frontiers in Microbiology. 10: 3131. doi: 10.3389/fmicb.2019.03131 . PMC   6992542 . PMID   32038565.
  5. "ICTV report: Hypoviridae". Ictv.global. Retrieved 31 December 2021.
  6. 1 2 Peever, Tobin; Liu, Yir-Chung; Cortese, Paolo; Milgroom, Michael (November 2000). "Variation in Tolerance and Virulence in the Chestnut Blight Fungus-Hypovirus Interaction". Applied and Environmental Microbiology. 66 (11): 4863–4869. Bibcode:2000ApEnM..66.4863P. CiteSeerX   10.1.1.504.6576 . doi:10.1128/AEM.66.11.4863-4869.2000. PMC   92392 . PMID   11055936 . Retrieved 13 August 2014.
  7. Choi, Gil (1992). "Hypovirulence of Chestnut Blight Fungus Conferred by an Infectious Viral cDNA". Science. 257 (5071): 800–803. Bibcode:1992Sci...257..800C. doi:10.1126/science.1496400. PMID   1496400.
  8. "Sweet chestnut blight (Cryphonectria parasitica)". Forestry Commission, UK. Archived from the original on 4 July 2018. Retrieved 13 August 2014.