Tobacco etch virus (TEV) is a

plant virus 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. ...

in the genus ''

Potyvirus ''Potyvirus'' is a genus of positive-strand RNA viruses in the family ''Potyviridae''. Plants serve as natural hosts. The genus is named after member virus ''potato virus Y''. Potyviruses account for about thirty percent of the currently known ...

'' and family ''

Potyviridae ''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 ...

''. Like other members of the genus ''Potyvirus'', TEV has a monopartite

positive-sense In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context ...

, single-stranded RNA genome surrounded by a

capsid A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may ...

made from a single viral encoded protein. The virus is a filamentous particle that measures about 730 nm in length. It is transmissible in a non-persistent manner by more than 10 species of

aphids Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A t ...

including ''

Myzus persicae ''Myzus persicae'', known as the green peach aphid, greenfly, or the peach-potato aphid, is a small green aphid belonging to the order Hemiptera. It is the most significant aphid pest of peach trees, causing decreased growth, shrivelling of the ...

''. It also is easily transmitted by mechanical means but is not known to be transmitted by seeds.

Host range

This virus infects many species of

Solanaceae The Solanaceae , or nightshades, are a family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spices, weeds, and orn ...

. Agriculturally important crops that it infects include several species of ''

Capsicum ''Capsicum'' () is a genus of flowering plants in the Solanum, nightshade family Solanaceae, native to Americas, the Americas, cultivated worldwide for their chili pepper or bell pepper fruit. Etymology and names The generic name may come f ...

'' (i.e. '' C. annuum'', '' C. frutescens''), tomato (''

Lycopersicon esculentum The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word , ...

''), and

tobacco Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...

(''

Nicotiana ''Nicotiana'' () is a genus of herbaceous plants and shrubs in the Family (biology), family Solanaceae, that is Native plant, indigenous to the Americas, Australia, Southwestern Africa and the South Pacific. Various ''Nicotiana'' species, common ...

spp.''). It also infects many

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

weed species that can act as virus reservoirs for susceptible agricultural crops. These weed species include ''

Solanum nigrum ''Solanum nigrum'', the European black nightshade or simply black nightshade or blackberry nightshade, is a species of flowering plant in the genus ''Solanum'', native to Eurasia and introduced in the Americas, Australasia, and South Africa. Ripe ...

'' (nightshade), '' S. aculeatissimum'' (soda apple), ''

Chenopodium album ''Chenopodium album'' is a fast-growing weedy annual plant in the genus ''Chenopodium''. Though cultivated in some regions, the plant is elsewhere considered a weed. Common names include lamb's quarters, melde, goosefoot, wild spinach and fat-h ...

'' (pigweed), ''

Datura stramonium ''Datura stramonium'', known by the common names thorn apple, jimsonweed (jimson weed), devil's snare, or devil's trumpet, is a poisonous flowering plant of the nightshade family Solanaceae. It is a species belonging to the ''Datura'' genus a ...

'' (jimson weed), ''

Linaria canadensis ''Nuttallanthus canadensis'', the blue toadflax, Canada toadflax, or old-field toadflax, is a species of '' Nuttallanthus'' in the family Plantaginaceae, native to eastern North America from Ontario east to Nova Scotia and south to Texas and Flo ...

'' (blue toadflax), and ''

Physalis ''Physalis'' (, , , , from φυσαλλίς ''phusallís'' "bladder") is a genus of approximately 75 to 90 flowering plants in the Solanum, nightshade family (biology), family (Solanaceae), which are native to the Americas and Australasia. At l ...

spp.'' (ground cherry). Thus, recommendations for the control of this virus include the control of weeds in and around susceptible solanaceous crops.

Signs and symptoms

Symptoms seen on plants infected with this virus can vary depending on the plant. However typical symptoms include vein clearing, mottling, and necrotic lines or etching. Symptoms can occur on leaves and fruit and the plants can become stunted. Like other potyviruses, TEV makes viral inclusions that can be seen in the light microscope if properly stained. This particular potyvirus makes two kinds of inclusions that can be diagnostic in a known host. One of the inclusions is the cylindrical inclusions found in the cytoplasm of infected cells and the second inclusion is found in the nucleus. Neither inclusion type stains in the nucleic acid stain (AzureA).
Inclusions of tobacco etch virus in various hosts.

Geographic distribution

TEV appears to be a virus that evolved in the

New World The term ''New World'' is often used to mean the majority of Earth's Western Hemisphere, specifically the Americas."America." ''The Oxford Companion to the English Language'' (). McArthur, Tom, ed., 1992. New York: Oxford University Press, p. 3 ...

. It has been reported in Canada, the United States (including Hawaii), Mexico and Puerto Rico in North America and in Venezuela in South America.

Beyond plant disease

Potyvirus RNA codes for at least seven different proteins. One of them is a protease. The TEV protease is a highly site-specific protease that biochemists have used to their advantage to create a

protein purification Protein purification is a series of processes intended to isolate one or a few proteins from a complex mixture, usually cells, tissues or whole organisms. Protein purification is vital for the specification of the function, structure and interact ...

system by incorporating TEV protease's recognition site into protein purification tags. A gene construct is created containing the protein of interest fused to a TEV protease recognition site, followed by an

affinity tag Protein tags are peptide sequences genetically grafted onto a recombinant protein. Tags are attached to proteins for various purposes. They can be added to either end of the target protein, so they are either C-terminus or N-terminus specific or a ...

, such as a

polyhistidine-tag A polyhistidine-tag is an amino acid motif in proteins that typically consists of at least six histidine (''His'') residues, often at the N- or C-terminus of the protein. It is also known as hexa histidine-tag, 6xHis-tag, His6 tag, by the US trad ...

. Following

affinity chromatography Affinity chromatography is a method of separating a biomolecule from a mixture, based on a highly specific macromolecular binding interaction between the biomolecule and another substance. The specific type of binding interaction depends on the ...

, the purified protein is then treated with TEV protease. TEV protease cleaves at its recognition site, removing the affinity tag. This allows for affinity purification of proteins that are not well-behaved when fused to protein tags.

References

External links

Tobacco Etch Virus (Pepper Diseases)Tobacco Etch Virus (Tomato Diseases)Descriptions of Plant Viruses (DPV)
{{DEFAULTSORT:Tobacco Etch Virus Viral plant pathogens and diseases Potyviruses