''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. Viruses are found in almo ...

, in the family ''

Tombusviridae ''Tombusviridae'' is a family of single-stranded positive sense RNA plant viruses. The family contains 18 genera in 3 subfamilies. The name is derived from Tomato bushy stunt virus (TBSV). Genome All viruses in the family have a non-segmente ...

''. Dianthoviruses are plant viruses. There are three species in this genus. The virus probably has a worldwide distribution, and can be transmitted via

nematodes The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (he ...

, 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 * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

Taxonomy

The genus contains the following species, listed by scientific name and followed by their common names: * ''Dianthovirus dianthi'', Carnation ringspot virus * ''Dianthovirus meliloti'', Sweet clover necrotic mosaic virus * ''Dianthovirus trifolii'', Red 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 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 electric charge, electrical charge or is electrically neutral in the statistical mean. The standard nomenclature to represent the isoelectric point is pH(I). Howe ...

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'') Research, studies are performed with Cell (biology), cells or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in ...

for about 50–70 days. Treatment with

ether In organic chemistry, ethers are a class of compounds that contain an ether group, a single oxygen atom bonded to two separate carbon atoms, each part of an organyl group (e.g., alkyl or aryl). They have the general formula , where R and R� ...

either decreases or does not alter their

infectivity In epidemiology, infectivity is the ability of a pathogen In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be refer ...

. No

lipids Lipids are a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins (such as vitamins Vitamin A, A, Vitamin D, D, Vitamin E, E and Vitamin K, K), monoglycerides, diglycerides, phospholipids, and others. The fu ...

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 that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

(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 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 genes, other functional regions of the genome such as ...

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, re ...

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