''Begomovirus'' is a genus of

virus 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 ...

es, in the family ''

Geminiviridae ''Geminiviridae'' is a family of plant viruses that encode their genetic information on a circular genome of single-stranded (ss) DNA. There are 520 species in this family, assigned to 14 genera. Diseases associated with this family include: bri ...

''. They 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 ...

that as a group have a very wide host range, infecting

dicotyledonous The dicotyledons, also known as dicots (or, more rarely, dicotyls), are one of the two groups into which all the flowering plants (angiosperms) were formerly divided. The name refers to one of the typical characteristics of the group: namely, t ...

plants. Worldwide they are responsible for a considerable amount of economic damage to many important crops such as

tomato 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 ...

es,

bean A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes th ...

squash Squash may refer to: Sports * Squash (sport), the high-speed racquet sport also known as squash racquets * Squash (professional wrestling), an extremely one-sided match in professional wrestling * Squash tennis, a game similar to squash but pla ...

cassava ''Manihot esculenta'', common name, commonly called cassava (), manioc, or yuca (among numerous regional names), is a woody shrub of the spurge family, Euphorbiaceae, native to South America. Although a perennial plant, cassava is extensively ...

and

cotton Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus ''Gossypium'' in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor perce ...

. There are 445 species in this genus.

Morphology

Virus particles are non-enveloped. The nucleocapsid is 38 nanometers (nm) long and 15–22 nm in diameter. While particles have basic icosahedral symmetry, they consist of two incomplete icosahedra—missing one vertex—joined together. There are 22 capsomeres per nucleocapsid.

Genome

Single stranded closed circular DNA. Many begomoviruses have a bipartite

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 ...

: this means that the genome is segmented into two segments (referred to as DNA A and DNA B) that are packaged into separate particles. Both segments are generally required for successful symptomatic infection in a host cell but DNA B is dependent for its replication upon DNA A, which can in some begomoviruses apparently cause normal infections on its own. Begomovirus (6260190377)

The DNA A segment typically encodes five to six proteins including replication protein Rep, coat protein and transport and/or regulatory proteins. This component is homologous to the genomes of all other geminiviruses. The proteins encoded on it are required for replication (Rep), control of gene expression, overcoming host defenses,

encapsidation {{Short pages monitor