Tobacco mosaic virus (TMV) is a positive-sense single-stranded RNA virus species in the genus Tobamovirus that infects a wide range of plants, especially tobacco and other members of the family Solanaceae. The infection causes characteristic patterns, such as "mosaic"-like mottling and discoloration on the leaves. TMV was the first virus to be discovered. Although it was known from the late 19th century that a non-bacterial infectious disease was damaging tobacco crops, it was not until 1930 that the infectious agent was determined to be a virus. It is the first pathogen identified as a virus. The virus was crystallised by Wendell Meredith Stanley. It has a similar size to the largest synthetic molecule, known as PG5.
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 vascular plants.
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.
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).
Brome mosaic virus (BMV) is a small, positive-stranded, icosahedral RNA plant virus belonging to the genus Bromovirus, family Bromoviridae, in the Alphavirus-like superfamily.
Tomato bushy stunt virus (TBSV) is a virus of the tombusvirus family. It was first reported in tomatoes in 1935 and primarily affects vegetable crops, though it is not generally considered an economically significant plant pathogen. Depending upon the host, TBSV causes stunting of growth, leaf mottling, and deformed or absent fruit. The virus is likely to be soil-borne in the natural setting, but can also be transmitted mechanically, for example through contaminated cutting tools. TBSV has been used as a model system in virology research on the life cycle of plant viruses, particularly in experimental infections of the model host plant Nicotiana benthamiana.
Tenuivirus is a plant virus genus belonging to Phenuiviridae family in the order Bunyavirales. These plant viruses cause diseases in their host plants. Typical symptoms are chlorotic stripes on the affected leaves. This group of viruses make viral inclusions in infected cells which can be used to diagnose infection.
Take-all is a plant disease affecting the roots of grass and cereal plants in temperate climates caused by the fungus Gaeumannomyces tritici. All varieties of wheat and barley are susceptible. It is an important disease in winter wheat in Western Europe particularly, and is favoured by conditions of intensive production and monoculture.
Powdery scab is a disease of potato tubers. It is caused by the cercozoan Spongospora subterranea f. sp. subterranea and is widespread in potato growing countries. Symptoms of powdery scab include small lesions in the early stages of the disease, progressing to raised pustules containing a powdery mass. These can eventually rupture within the tuber periderm. The powdery pustules contain resting spores that release anisokont zoospores to infect the root hairs of potatoes or tomatoes. Powdery scab is a cosmetic defect on tubers, which can result in the rejection of these potatoes. Potatoes which have been infected can be peeled to remove the infected skin and the remaining inside of the potato can be cooked and eaten.
Barley yellow mosaic virus is plant pathogenic virus that causes the yellow mosaic disease of barley. Its shape is categorized as being flexuous filamentous, with lengths of 275 and 550 nanometers. The virus has a limited host range, and barley appears to be the only known susceptible host. The virus is transmitted via Polymyxa graminis, which is a plasmodiophorid protist, through the resting spores that survive in the soil, and eventually zoospores. Eastern Asia is the most affected region, but the virus can be found worldwide. Current agricultural practices have been ineffective at eliminating the virus, but breeding resistance appears to be the only way to help reduce the disease.
Cucumber mosaic virus (CMV) is a plant pathogenic virus in the family Bromoviridae. This virus has a worldwide distribution and a very wide host range, having the reputation of the widest host range of any known plant virus. It can be transmitted from plant to plant both mechanically by sap and by aphids in a stylet-borne fashion. It can also be transmitted in seeds and by the parasitic weeds, Cuscuta sp. (dodder).
Panicum mosaic virus (PMV) is a positive-sense single-stranded RNA viral pathogen that infects plant species in the panicoid tribe of the grass family, Poaceae. The pathogen was first identified in Kansas in 1953 and most commonly causes disease on select cultivars of turf grass, switchgrass, and millet. The disease most commonly associated with the panicum mosaic virus pathogen is St. Augustine Decline Syndrome, which infects species of turf grass and causes chlorotic mottling. In addition to St. Augustine Decline, panicum mosaic virus is responsible for chlorotic streaking and mild green mosaicking in select cultivars of switchgrass and millet.
Potato mop-top virus (PMTV) is a plant pathogenic virus transmitted through the vector Spongospora subterranea that affects potatoes. PMTV belongs to family of Virgaviridae, and the genus Pomovirus. The virus was first identified in 1966 by Calvert and Harrison in Britain, and is now reported in many other potato cultivating regions of the world including U.S.A., Canada, China, Pakistan, Japan, South American countries and many parts of Europe. Many disease management systems have been found to be ineffective against the virus, although a combination of sanitation and vector controls seems to work well.
Wheat streak mosaic virus (WSMV) is a plant pathogenic virus of the family Potyviridae that infects plants in the family Poaceae, especially wheat ; it is globally distributed and vectored by the wheat curl mite, particularly in regions where wheat is widely grown. First described in Nebraska in 1922, stunted growth and the eponymous “streaks” of yellowed, non-uniform discoloration are characteristic of WSMV infection. As it has been known to cause 100% crop mortality, WSMV is a subject of ongoing scientific research.
Fig mosaic emaravirus (FMV) is a segmented, negative sense, single-stranded RNA virus that is determined to be the causal agent of fig mosaic disease (FMD) in fig plants, Ficus carica. It is a member of the genus Emaravirus and order Bunyavirales and is transmitted mainly by the eriophyid mite Aceria ficus. FMV can cause a range of symptoms varying in severity, including leaf chlorosis, deformity, and mosaic or discoloration patterns, as well as premature fruit drop.
Melon necrotic spot virus (MNSV) is a virus that belongs to the genus Gammacarmovirus of the family Tombusviridae. It has been observed in several countries of the Americas, Africa, Asia, and Europe. It is considered to be an endemic virus in greenhouses and field productions of Cucurbitaceae crops, including melon, cucumber, and watermelon. MNSV is mainly spread through infected soil, seedlings, insects, and by the root-inhabiting fungus vector Olpidium bornovanus. Symptoms vary between Curbitaceae crops, but generally consist of chlorosis, brown necrotic lesions, leaf wilt, fruit decay, and plant death. Management of the disease consists of preventing infection by rotating fields and crops, steam sterilization, and disposal of infected plants. Also, treated seeds with heat or chemicals are efficient in preventing infection. MNSV is important in melon plants as it causes vast economical damage worldwide reducing significant yields.
Cocoa necrosis virus (CoNV) is a plant pathogenic virus of the genus nepovirus that infects Theobroma cacao en natura causing cacao necrosis disease. CoNV is considered synonymous with Strain S of cacao swollen shoot virus. Unlike Cacao swollen shoot virus, it is not transmitted by mealybugs nor vectored by aphids, beetles, or leafhoppers that also commonly infest cacao. It is serologically, distantly related to Tomato black ring virus and very distantly related to Grapevine chrome mosaic virus.
Carnation Italian Ringspot Virus (CIRV) is a plant virus that impacts carnation plants. These flowers are a popular choice in ornamental flower arrangements. This article will provide an overview of CIRV. This will include the history of the virus, information on transmission, symptoms, and characteristics, and research about how it relates to plant physiology.
The Blueberry mosaic associated ophiovirus (B1MaV) is a plant virus which infects blueberry plants, causing a discoloration of the leaves of the plants in a mosaic-like pattern. The disease is found in blueberry plants in many regions of North America, as well as South America, Europe, New Zealand, and South Africa. Within these regions the virus is most often found in high blueberry-yielding areas, but can be spread to other locations. Blueberry mosaic associatedophiovirus is one of seven species in the genus Ophiovirus. It is a member of the Aspiviridae family, in the Serpentovirales order, and in the Milnevircetes class. The Ophioviridae viruses are characterized by a flexible and elongated nucleocapsid that is composed mostly of filamentous structures and is helically symmetrical. It also has a non-enveloped protein capsid that is capable of coiling around itself allowing for a super-coiled structure and the helical symmetry. The virus has the potential to be symptomatic or asymptomatic within plants causing the display of symptoms in only a few plants, but the ability to transmit the virus unknowingly in many plants. B1MaV often remains asymptomatic for long periods of time after initial infection allowing for blind transmission.
Viral diseases of potato are a group of diseases caused by different types of Viruses that affect potato crops worldwide and, although they do not affect human or animal health since they are viruses that only infect vegetables, they are a source of great economic losses annually. About 28 viruses have been reported infecting potato crops. However, potato virus X (PVX), potato virus Y (PVY), and potato leafroll virus (PLRV) are the most important viruses worldwide. Some others are of economic importance only in some regions. Such is the case of potato virus M (PVM) in some Asian and European countries.
