Panicum mosaic virus
Encyclopedia
Panicum mosaic virus is a pathogenic plant virus
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 are pathogenic to higher plants...

 noted for causing the grass
Grass
Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...

 disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

 St. Augustine Decline. It is a positive-sense ssRNA virus and the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 of the genus Panicovirus, readily spread by humans through tools such as lawn mower
Lawn mower
A lawn mower is a machine that uses a revolving blade or blades to cut a lawn at an even length.Lawn mowers employing a blade that rotates about a vertical axis are known as rotary mowers, while those employing a blade assembly that rotates about a horizontal axis are known as cylinder or reel...

 blades, but not known to be spread via biological vectors such as insects. PMV was identified in 1953, and is known to infect switchgrass
Switchgrass
Panicum virgatum, commonly known as switchgrass, is a perennial warm season bunchgrass native to North America, where it occurs naturally from 55°N latitude in Canada southwards into the United States and Mexico...

, centipedegrass and St. Augustine Grass
St. Augustine grass
St. Augustine Grass or Buffalo Grass is a warm season lawn grass that is popular for use in tropical and subtropical regions. It is a medium to high maintenance grass that forms a thick, carpetlike lawn, crowding out most weeds and other grasses.-Characteristics:St...

.

History

PMV was first observed in Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...

 in 1953. It was originally noted to infect switchgrass
Switchgrass
Panicum virgatum, commonly known as switchgrass, is a perennial warm season bunchgrass native to North America, where it occurs naturally from 55°N latitude in Canada southwards into the United States and Mexico...

 (Panicum virgatum), and was observed infecting St. Augustine Grass
St. Augustine grass
St. Augustine Grass or Buffalo Grass is a warm season lawn grass that is popular for use in tropical and subtropical regions. It is a medium to high maintenance grass that forms a thick, carpetlike lawn, crowding out most weeds and other grasses.-Characteristics:St...

 (Stenotaphrum secundatum) in Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 in 1966. The strain specific to St. Augustine Grass has since been observed in Arkansas
Arkansas
Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...

, Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

, Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...

 and South Carolina
South Carolina
South Carolina is a state in the Deep South of the United States that borders Georgia to the south, North Carolina to the north, and the Atlantic Ocean to the east. Originally part of the Province of Carolina, the Province of South Carolina was one of the 13 colonies that declared independence...

 in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, as well as in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

. Other strains have been identified infecting centipedegrass (Eremochloa ophiuroides). Foxtail millet
Foxtail millet
Foxtail millet is the second most widely planted species of millet, and the most important in East Asia. It has the longest history of cultivation among the millets, having been grown in China since sometime in the sixth millennium BC...

 (Setaria italica), white proso millet (Panicum miliaceum) and pearl millet
Pearl millet
Pearl millet is the most widely grown type of millet. Grown in Africa and the Indian subcontinent since prehistoric times, it is generally accepted that pearl millet originated in Africa and was subsequently introduced into India. The center of diversity, and suggested area of domestication, for...

 (Pennisetum glaucum) have also been used to propagate PMV and panicum mosaic satellite virus
Panicum mosaic satellite virus
Panicum mosaic satellite virus is a plant satellite virus. It only infects grasses which are infected by Panicum mosaic virus. One study found that 72% of Stenotaphrum secundatum infected with panicum mosaic virus was also infected with SPMV...

 (SPMV), and mechanical transmission can occur to maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...

 and some cultivars of common wheat
Common wheat
Common wheat, Triticum aestivum, is a cultivated wheat species.-Nomenclature and taxonomy of the variety and its cultivars:-Evolution:...

 (Triticum aestivum).

Classification

Panicum mosaic virus is the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...

 of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Panicovirus, a member of the plant virus
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 are pathogenic to higher plants...

 family
Family
In human context, a family is a group of people affiliated by consanguinity, affinity, or co-residence. In most societies it is the principal institution for the socialization of children...

 Tombusviridae
Tombusviridae
Tombusviridae is a family of single-stranded positive sense RNA plant viruses. The name is derived from the type species of the Tombusvirus genus, Tomato bushy stunt virus...

. Members of Tombusviridae are transmitted as positive sense
Sense (molecular biology)
In molecular biology and genetics, sense is a concept used to compare the polarity of nucleic acid molecules, such as DNA or RNA, to other nucleic acid molecules...

 single-stranded non-enveloped
Viral envelope
Many viruses have viral envelopes covering their protein capsids. The envelopes typically are derived from portions of the host cell membranes , but include some viral glycoproteins. Functionally, viral envelopes are used to help viruses enter host cells...

 RNA virus
RNA virus
An RNA virus is a virus that has RNA as its genetic material. This nucleic acid is usually single-stranded RNA but may be double-stranded RNA...

es, with an icosohedral capsid
Capsid
A capsid is the protein shell of a virus. It consists of several oligomeric structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The capsid encloses the genetic...

. PMV itself has a genome of 4,326 nucleotides, encapsulated into 30-nm particles by a capsid
Capsid
A capsid is the protein shell of a virus. It consists of several oligomeric structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The capsid encloses the genetic...

 protein of 26 kDa
KDA
KDA may refer to:* Karachi Development Authority* Kongsberg Defence & Aerospace* Kotelawala Defence Academy* Kramer Design Associates* Lithium diisopropylamide, KDA is the potassium analogue of lithium diisopropylamideOr kDa may refer to:...

. PMV was placed in the genus Panicovirus because of its limited monocot host range and lack of an additional 5'-ORF
Open reading frame
In molecular genetics, an open reading frame is a DNA sequence that does not contain a stop codon in a given reading frame.Normally, inserts which interrupt the reading frame of a subsequent region after the start codon cause frameshift mutation of the sequence and dislocate the sequences for stop...

. PMV is serologically
Serology
Serology is the scientific study of blood serum and other bodily fluids. In practice, the term usually refers to the diagnostic identification of antibodies in the serum...

 related to Molina streak virus and Maize mild mottle virus.

St. Augustine Decline

St. Augustine Decline (SAD) is a viral disease of St. Augustine Grass (Stenotaphrum secundatum), and is the only economically important viral disease in turf management
Turf management
Turf management or pitchcare describes the work needed to keep a sporting pitch ready for use. This article looks at the various types of sporting pitches and the type of challenges which they present....

. Research into SAD has implicated PMV, though panicum mosaic satellite virus
Panicum mosaic satellite virus
Panicum mosaic satellite virus is a plant satellite virus. It only infects grasses which are infected by Panicum mosaic virus. One study found that 72% of Stenotaphrum secundatum infected with panicum mosaic virus was also infected with SPMV...

 plays an unknown role in the disease. In SAD, grass blades taken on a mottled, chlorotic appearance, and the disease can spread across large sections of turf. Early SAD may be confused with iron chlorosis, however the latter is characterized by either uniform yellowing or characteristic yellow striping parallel to the mid-vein of the leaf.

There is no cure for SAD, and the most common solution is to replace diseased areas with disease resistant cultivar
Cultivar
A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s of St. Augustine Grass, such as Floralawn, Floratam, Raleigh and Seville. Resistant grass will crowd out diseased grass over a period of one or more years. Transmission is believed to occur by mechanical means, such as lawn mower blades.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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