Machlomovirus | |
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Virus classification ![]() | |
(unranked): | Virus |
Realm: | Riboviria |
Kingdom: | Orthornavirae |
Phylum: | Kitrinoviricota |
Class: | Tolucaviricetes |
Order: | Tolivirales |
Family: | Tombusviridae |
Subfamily: | Procedovirinae |
Genus: | Machlomovirus |
Machlomovirus is a genus of plant viruses, in the family Tombusviridae . Plants serve as natural hosts. There is only one species in this genus: Maize chlorotic mottle virus [1] [2] (MCMV), which causes significant losses in maize production worldwide. [3] MCMV was first identified in the U.S. state of Kansas causing maize lethal necrosis disease/MLN/corn lethal necrosis, a severe disease that negatively affects all stages of development for maize plants. [4]
Viruses in Machlomovirus are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry. The diameter is around 28-34 nm. Genomes are linear, around 4–5.4kb in length. [1] [5]
Genus | Structure | Symmetry | Capsid | Genomic arrangement | Genomic segmentation |
---|---|---|---|---|---|
Machlomovirus | Icosahedral | T=3 | Non-enveloped | Linear | Monopartite |
Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription, using the premature termination model of subgenomic RNA transcription is the method of transcription. Translation takes place by leaky scanning, and suppression of termination. The virus exits the host cell by tubule-guided viral movement. Plants serve as the natural host. Transmission routes are mechanical, seed borne, and contact. [1] Even a small incidence of seed transmission is problematic: Although Kimani et al. 2021 finds MCMV to be almost incapable of successfully making the jump from contaminated seed to infecting a seedling, even a small infected proportion of a field will infect the entire field (via vector) unless quickly removed. [6]
Genus | Host details | Tissue tropism | Entry details | Release details | Replication site | Assembly site | Transmission |
---|---|---|---|---|---|---|---|
Machlomovirus | Plants | None | Viral movement; mechanical inoculation | Viral movement | Cytoplasm | Cytoplasm | Mechanical: contact; seed |
This virus can be transmitted by six species of leaf beetle: cereal leaf beetle (Oulema melanopus), the red-headed flea beetle ( Systena frontalis ), corn flea beetle ( Chaetocnema pulicaria ), southern corn rootworm ( Diabrotica undecimpunctata ), northern corn rootworm ( D. longicornis ) and western corn rootworm ( D. virgifera virgifera ). It can also be transmitted by the corn thrips, Frankliniella williamsi . [7]
A satellite is a subviral agent that depends on the coinfection of a host cell with a helper virus for its replication. Satellites can be divided into two major classes: satellite viruses and satellite nucleic acids. Satellite viruses, which are most commonly associated with plants, are also found in mammals, arthropods, and bacteria. They encode structural proteins to enclose their genetic material, which are therefore distinct from the structural proteins of their helper viruses. Satellite nucleic acids, in contrast, do not encode their own structural proteins, but instead are encapsulated by proteins encoded by their helper viruses. The genomes of satellites range upward from 359 nucleotides in length for satellite tobacco ringspot virus RNA (STobRV).
Closteroviridae is a family of viruses. Plants serve as natural hosts. There are four genera and 59 species in this family, seven of which are unassigned to a genus. Diseases associated with this family include: yellowing and necrosis, particularly affecting the phloem.
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).
Tobamovirus is a genus of positive-strand RNA viruses in the family Virgaviridae. Many plants, including tobacco, potato, tomato, and squash, serve as natural hosts. Diseases associated with this genus include: necrotic lesions on leaves. The name Tobamovirus comes from the host and symptoms of the first virus discovered.
Potyvirus is a genus of positive-strand RNA viruses in the family Potyviridae. Plants serve as natural hosts. Like begomoviruses, members of this genus may cause significant losses in agricultural, pastoral, horticultural, and ornamental crops. More than 200 species of aphids spread potyviruses, and most are from the subfamily Aphidinae. The genus contains 190 species and potyviruses account for about thirty percent of all currently known plant viruses.
Closterovirus, also known as beet yellows viral group, is a genus of viruses, in the family Closteroviridae. Plants serve as natural hosts. There are 17 species in this genus. Diseases associated with this genus include: yellowing and necrosis, particularly affecting the phloem. This genus has a probably worldwide distribution and includes among other viral species the Beet yellows virus and Citrus tristeza virus, rather economically important plant diseases. At least some species require vectors such as aphids or mealybugs for their transmission from plant to plant.
Cowpea chlorotic mottle virus, known by the abbreviation CCMV, is a virus that specifically infects the cowpea plant, or black-eyed pea. The leaves of infected plants develop yellow spots, hence the name "chlorotic". Similar to its "brother" virus, Cowpea mosaic virus (CPMV), CCMV is produced in high yield in plants. In the natural host, viral particles can be produced at 1–2 mg per gram of infected leaf tissue. Belonging to the bromovirus genus, cowpea chlorotic mottle virus (CCMV) is a small spherical plant virus. Other members of this genus include the brome mosaic virus (BMV) and the broad bean mottle virus (BBMV).
Ilarvirus is a genus of positive-strand RNA viruses in the family Bromoviridae. Plants serve as natural hosts. There are 22 species in this genus.
Benyvirus is a genus of viruses, in the family Benyviridae. Plants serve as natural hosts. There are four species in this genus. Diseases associated with this genus include: BNYVV: rhizomania.
Sadwavirus is a genus of viruses in the order Picornavirales, in the family Secoviridae. Plants serve as natural hosts. There are three subgenera and five species in this genus. Diseases associated with this genus include: satsuma dwarf virus disease which causes spoon-shaped leaves on citrus tree. Symptoms are enations, multiple flushing, stunting or dwarfing, reduction in number and size of leaves and fruits. The name of this genus comes from one of its species: Satsuma dwarf virus.
Sobemovirus is a genus of non-enveloped, positive-strand RNA viruses which infect plants. Plants serve as natural hosts. There are 21 species in this genus. Diseases associated with this genus include: mosaics and mottles.
Carlavirus, formerly known as the "Carnation latent virus group", is a genus of viruses in the order Tymovirales, in the family Betaflexiviridae. Plants serve as natural hosts. There are 53 species in this genus. Diseases associated with this genus include: mosaic and ringspot symptoms.
Trichovirus is a genus of viruses in the order Tymovirales, in the family Betaflexiviridae. Plants, specifically angiosperms such as pome fruits, citrus, and pear, serve as natural hosts for this plant pathogen. There are seven species in this genus.
Maize lethal necrosis disease is a viral disease affecting maize (corn) predominantly in East Africa, Southeast Asia and South America, which was recognised in 2010. It is caused by simultaneous infection with two viruses, MCMoV and any of several Potyviridae.
Badnavirus is a genus of viruses, in the family Caulimoviridae order Ortervirales. Plants serve as natural hosts. There are 67 species in this genus. Diseases associated with this genus include: CSSV: leaf chlorosis, root necrosis, red vein banding in young leaves, small mottled pods, and stem/root swelling followed by die-back. Infection decreases yield by 25% within one year, 50% within two years and usually kills trees within 3–4 years.
Bromovirus is a genus of viruses, in the family Bromoviridae. Plants serve as natural hosts. There are six species in this genus.
Foveavirus is a genus of viruses in the order Tymovirales, in the family Betaflexiviridae. Plants serve as natural hosts. There are eight species in this genus. Diseases associated with this genus include: mosaic and ringspot symptoms.
Polerovirus is a genus of viruses, in the family Solemoviridae. Plants serve as natural hosts. There are 26 species in this genus. Diseases associated with this genus include: PLRV causes prominent rolling of the leaves of potato and a stiff upright habit of the plants; necrosis of the phloem and accumulation of carbohydrates in the leaves.
Torradovirus is a genus of viruses in the order Picornavirales, in the family Secoviridae. Plants serve as natural hosts. There are six species in this genus. Diseases associated with this genus include: torrado disease: severe necrosis of leaves and fruits.
Waikavirus is a genus of viruses in the order Picornavirales, in the family Secoviridae. Plants, poaceae, cyperaceae, and gramineae serve as natural hosts. There are four species in this genus. Diseases associated with this genus include: MCDV: plant stunting and chlorotic striping of tertiary leaf veins in maize.