''Dianthovirus'' is a genus of

viruses A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

, in the family '' Tombusviridae''. Dianthoviruses are

plant viruses Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses can be pathogenic to higher plants. M ...

. There are three species in this genus. The virus probably has a worldwide distribution, and can be transmitted via nematodes, by mechanical inoculation, by grafting of plants and by contact between infected hosts with previously uninfected

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

Taxonomy

The genus contains the following species: * '' Carnation ringspot virus'' * ''

Red clover necrotic mosaic virus Red is the color at the long wavelength end of the visible spectrum of light, next to orange and opposite violet. It has a dominant wavelength of approximately 625–740 nanometres. It is a primary color in the RGB color model and a secondar ...

'' * '' Sweet clover necrotic mosaic virus''

Structure

Viruses in ''Dianthovirus'' are non-enveloped, with icosahedral and spherical geometries, a “hexagonal” appearance, and T=3 symmetry. The diameter is around 28-34 nm. Genomes are linear and segmented, bipartite, around 11.3-1.4kb in length. The

buoyant density Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the pr ...

in CsCl of virions is between 1.363 and 1.366 g cm-3. They have a sedimentation coefficient of 126-132-135 S20w. The pH of their

isoelectric point The isoelectric point (pI, pH(I), IEP), is the pH at which a molecule carries no net electrical charge or is electrically neutral in the statistical mean. The standard nomenclature to represent the isoelectric point is pH(I). However, pI is also u ...

is 4.5. The virions become inactive from about 80-90 °C and are inactive above those temperatures. They are viable

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

for about 50–70 days. Treatment with

ether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be c ...

either decreases or does not alter their infectivity. No

lipids Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...

have so far been reported.

Life cycle

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 -1 ribosomal frameshifting. 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.

Genome

These viruses have segmented, bipartite genomes that are linear, positive-sense, single-stranded

RNA Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...

(1). These genomes are about 5300 nucleotides in length (1). They have a methylated cap at the 5'-end whose sequence type is m7GpppA (1). The

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...

also codes for non-structural

proteins Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

as well as structural proteins (1). Three non-structural proteins have been found (1).

References

External links

Viralzone: Dianthovirus

ICTV
{{Taxonbar, from=Q5271721 Tombusviridae Virus genera