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Geminiviridae
''Geminiviridae'' is a family of plant viruses that encode their genetic information on a circular genome of single-stranded (ss) DNA. The family contains 15 genera. Diseases associated with this family include: bright yellow mosaic, yellow mosaic, yellow mottle, leaf curling, stunting, streaks, reduced yields. They have single-stranded circular DNA genomes encoding genes that diverge in both directions from a virion strand origin of replication (i.e. geminivirus genomes are ambisense). According to the Baltimore classification they are considered class II viruses. It is the largest known family of single stranded DNA viruses. Mastrevirus and curtovirus Transmission (medicine), transmission is via various leafhopper species (e.g. maize streak virus and other African streak viruses are transmitted by ''Cicadulina mbila''), the only known topocuvirus species, ''Tomato pseudo-curly top virus'', is transmitted by the treehopper ''Micrutalis malleifera'', and begomoviruses are trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Begomovirus
''Begomovirus'' is a genus of viruses, in the family ''Geminiviridae''. They are plant viruses that as a group have a very wide host range, infecting dicotyledonous plants. Worldwide they are responsible for a considerable amount of economic damage to many important crops such as tomatoes, beans, Squash (plant), squash, cassava and cotton. There are 464 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: 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 bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mastrevirus
''Mastrevirus'' is a genus of ssDNA viruses, in the family ''Geminiviridae''. Mostly monocotyledonous plants serve as natural hosts. They are vectored by planthoppers. There are 50 species in this genus. Diseases associated with this genus include: maize streak virus: maize streak disease (MSD). Capsid proteins ''Mastreviruses'' have an unusually diverse range of capsid proteins among the Geminiviridae. While all other genera have species with essentially identical proteins (and their producing genetic sequences) among themselves, ''Mastrevirus'' has seven protein clusters and three species that each constitute their own. Structure Viruses in ''Mastrevirus'' are non-enveloped, with icosahedral geometries, and T=1 symmetry. The diameter is around 22 nm, with a length of 38 nm. Genomes are circular and non-segmented, around 2.6-2.8kb in length. Life cycle Viral replication is nuclear. Entry into the host cell is achieved by penetration into the host cell. Replication ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grablovirus
''Grablovirus'' is a genus of plant viruses 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. The family contains 15 genera. Diseases associated with this family include: bright yellow mosaic, yellow mosa ...''. The genus has three species. Taxonomy The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species: * ''Grablovirus pruni'', Prunus geminivirus A * ''Grablovirus silvestris'', Wild Vitis virus 1 * ''Grablovirus vitis'', Grapevine red blotch virus References Geminiviridae Virus genera {{virus-plant-disease-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eragrovirus
''Eragrovirus'' is a genus of viruses, 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. The family contains 15 genera. Diseases associated with this family include: bright yellow mosaic, yellow mosa ...''. Dicotyledonous plants serve as natural hosts. There is only one species in this genus: Eragrostis curvula streak virus (''Eragrovirus curvulae''). Structure Viruses in ''Eragrovirus'' are non-enveloped, with icosahedral geometries, and T=1 symmetry. Genomes are circular and non-segmented, around 3.0kb in length. Life cycle Viral replication is nuclear. Entry into the host cell is achieved by penetration into the host cell. Replication follows the ssDNA rolling circle model. DNA-templated transcription is the method of transcription. The virus exits the host cell by nuclear pore export, and tubule-guided viral movement. Dicotyledonous plants serve as the nat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curtovirus
''Curtovirus'' is a genus of ssDNA viruses, in the family ''Geminiviridae''. Dicotyledonous plants serve as natural hosts. Curtoviruses are transmitted by leafhoppers. There are three species in this genus. Diseases associated with this genus include: Curly top disease. Taxonomy The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species: * ''Curtovirus armoraciae'', Horseradish curly top virus * ''Curtovirus betae'', Beet curly top virus * ''Curtovirus spinaciae'', Spinach severe curly top virus Structure Viruses in ''Curtovirus'' are non-enveloped, with icosahedral geometries, and T=1 symmetry. The diameter is around 22 nm, with a length of 38 nm. 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 ...s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Becurtovirus
''Becurtovirus'' is a genus of viruses, 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. The family contains 15 genera. Diseases associated with this family include: bright yellow mosaic, yellow mosa ...''. Dicotyledonous plants serve as natural hosts. There are three species in this genus. Taxonomy The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species: * ''Becurtovirus betae'', Beet curly top Iran virus * ''Becurtovirus exomis'', Exomis microphylla associated virus * ''Becurtovirus spinaciae'', Spinach curly top Arizona virus Structure Viruses in ''Becurtovirus'' are non-enveloped, with icosahedral geometries, and T=1 symmetry. Genomes are circular and non-segmented, around 3.0kb in length. Life cycle Viral replication is nuclear. Entry into the host cell is achieved by penetration into the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tomato Pseudo-curly Top Virus
''Topocuvirus'' is a genus of viruses, in the family ''Geminiviridae''. Dicotyledonous plants serve as natural hosts. There is only one species in this genus: Tomato pseudo-curly top virus (''Topocuvirus solani''). Diseases associated with this genus include: vein swelling, curling of the leaves and leaf distortion. Structure Viruses in ''Topocuvirus'' are non-enveloped, with icosahedral geometries, and T=1 symmetry. The diameter is around 22 nm, with a length of 38 nm. Genomes are circular and non-segmented, around 2.86kb in length. Life cycle Viral replication is nuclear. Entry into the host cell is achieved by penetration into the host cell. Replication follows the ssDNA rolling circle model. DNA-templated transcription is the method of transcription. The virus exits the host cell by nuclear pore export, and tubule-guided viral movement. Dicotyledonous plants serve as the natural host. The virus is transmitted via a vector (treehopper Treehoppers (more precis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Begomovirus
''Begomovirus'' is a genus of viruses, in the family ''Geminiviridae''. They are plant viruses that as a group have a very wide host range, infecting dicotyledonous plants. Worldwide they are responsible for a considerable amount of economic damage to many important crops such as tomatoes, beans, Squash (plant), squash, cassava and cotton. There are 464 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: 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 bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maize Streak Virus
Maize streak virus (MSV) is a virus primarily known for causing maize streak disease (MSD) in its major host, and which also infects over 80 wild and domesticated grasses. It is an insect-transmitted pathogen of maize in the genus ''Mastrevirus'' of the family ''Geminiviridae'' that is endemic in sub-Saharan Africa and neighbouring Indian Ocean island territories such as Madagascar, Mauritius and La Reunion. The A-strain of MSV ( MSV-A) causes sporadic maize streak disease epidemics throughout the maize-growing regions of Africa. MSV was first described by the South African entomologist Claude Fuller who referred to it in a 1901 report as "mealie variegation". The development of conventionally resistant maize varieties has been a priority since the 1950s in Kenya, Nigeria, South Africa and elsewhere, with a good deal of success: however, there are several genes associated with resistance, and breeding is complex. Transgenically resistant or genetically modified maize variet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
