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Geminiviruses Drawing
''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: 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 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 ... [...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 maize pathogen 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 varietie ... [...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, cassava and cotton. 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: 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 depe ... [...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 45 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. Taxonomy The following species are recognized: *''Axonopus compressus streak virus'' (ACSV) *'' Bromus catharticus striate mosaic virus'' *'' Camellia chlorotic dwarf-associated virus'' (CaCDaV) *'' Citrus chlorotic dwarf-associated virus'' (CCDaV) *'' Chickpea chlorosis Australia virus'' *'' Chickpea chlorosis virus'' *'' Chickpea chlorotic dwarf virus'' *'' ... [...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. There are 520 species in this family, assigned to 14 genera. Diseases associated with this family include: br ...''. The genus has three species. Taxonomy The following species are recognized: *'' Grapevine red blotch virus'' *'' Prunus latent virus'' *'' Wild Vitis latent virus'' References {{Taxonbar, from=Q29002221 Geminiviridae Virus genera ... [...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. There are 520 species in this family, assigned to 14 genera. Diseases associated with this family include: br ...''. Dicotyledonous plants serve as natural hosts. There is only one species in this genus: ''Eragrostis curvula streak virus''. 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 natural host. Reference ... [...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. 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. 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 natural host. The virus is transmitted via a vector (beet leafhopper The beet leafhopper (''Circulifer tenellus''), also sometimes known ... [...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. There are 520 species in this family, assigned to 14 genera. Diseases associated with this family include: br ...''. Dicotyledonous plants serve as natural hosts. There are three species in this genus. Taxonomy The following three species are assigned to the genus: *'' Beet curly top Iran virus'' *'' Exomis microphylla latent virus'' *'' 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 host cell. Replication follows the ssDNA rolling circle model. DNA-templated transcription is the method of transcription. The virus exi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, and contains many biomolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites.Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell '' fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the "cellular building blocks" move to shape developing s. It is also common ... [...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, cassava and cotton. 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: 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 depe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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