Temporal changes in the levels of virus and betasatellite DNA in feeding on CLCuD affected cotton during the growing season.

Cotton, a key source of income for Pakistan, has suffered significantly by cotton leaf curl disease (CLCuD) since 1990. This disease is caused by a complex of phylogenetically-related begomovirus (genus , family ) species and a specific betasatellite (genus , family ), . Additionally, another DNA satellite called alphasatellite (family ), is also frequently associated.

qPCR Assay as a Tool for Examining Cotton Resistance to the Virus Complex Causing CLCuD: Yield Loss Inversely Correlates with Betasatellite, Not Virus, DNA Titer.

Cotton leaf curl disease (CLCuD) is a significant constraint to the economies of Pakistan and India. The disease is caused by different begomoviruses (genus , family ) in association with a disease-specific betasatellite. However, another satellite-like molecule, alphasatellite, is occasionally found associated with this disease complex.

Cotton leaf curl Multan betasatellite impaired ToLCNDV ability to maintain cotton leaf curl Multan alphasatellite.

Alphasatellites (family Alphasatellitidae) are circular, single-stranded (ss) DNA molecules of ~1350 nucleotide in size that have been characterized in both the Old and New Worlds. Alphasatellites have inherent ability to self-replicate, which is accomplished by a single protein, replication-associated protein (Rep). Although the precise function of alphasatellite is yet unknown, and these consider dispensable for infectivity, however, their Rep protein functions as a suppressor of host defence.

Complete genome sequence of hollyhock vein yellowing virus, a novel monopartite begomovirus infecting hollyhock in Pakistan.

Hollyhock (Alcea rosea, family Malvaceae) is an ornamental plant grown widely in gardens across South Asia. In a bed of ornamental plants near the village of Chakri (Punjab Province, Pakistan) in 2014, hollyhock plants showing two distinct symptom types were identified: yellow vein mosaic and leaf crumple. PCR amplification with universal primers amplified a begomovirus from separate nucleic acid extracts of single plants of each type but amplified a betasatellite only from the plant with the yellow vein mosaic symptoms.

Codiaeum variegatum in Pakistan harbours pedilanthus leaf curl virus and papaya leaf curl virus as well as a newly identified betasatellite.

Codiaeum variegatum (common name, garden croton) is an ornamental plant grown for its bright yellow variegated leaf morphology. Two C. variegatum plants with upward leaf curling and vein swelling symptoms were collected in Faisalabad, Pakistan.

Molecular characterization of Chickpea chlorotic dwarf virus strain D in Chickpea (Cicer arietinum) from District Dera Ismail Khan Khyber Pakhtunkhwa, Pakistan.

Chickpea chlorotic dwarf virus (CpCDV), a member of genus Mastrevirus (family Geminiviridae) is an important viral pathogen of chickpea and other legume crops in Middle East, North Africa, India and Pakistan. Among sixteen known strains of CpCDV three are known to infect legume crops in Punjab province of Pakistan. In this study diversity of CpCDV was explored in Khyber Pakhtunkhwa (KP) province of Pakistan.

Frequent occurrence of Mungbean yellow mosaic India virus in tomato leaf curl disease affected tomato in Oman.

Next generation sequencing (NGS) of DNAs amplified by rolling circle amplification from 6 tomato (Solanum lycopersicum) plants with leaf curl symptoms identified a number of monopartite begomoviruses, including Tomato yellow leaf curl virus (TYLCV), and a betasatellite (Tomato leaf curl betasatellite [ToLCB]). Both TYLCV and ToLCB have previously been identified infecting tomato in Oman. Surprisingly the NGS results also suggested the presence of the bipartite, legume-adapted begomovirus Mungbean yellow mosaic Indian virus (MYMIV).

Molecular and biological characterization of Chilli leaf curl virus and associated Tomato leaf curl betasatellite infecting tobacco in Oman.

Background: In Oman tobacco (Nicotiana tabacum; family Solanaceae) is a minor crop, which is produced only for local consumption. In 2015, tobacco plants exhibiting severe downward leaf curling, leaf thickening, vein swelling, yellowing and stunting were identified in fields of tobacco in Suhar Al-Batina region, Oman. These symptoms are suggestive of begomovirus (genus Begomovirus, family Geminiviridae) infection.

The Rep proteins encoded by alphasatellites restore expression of a transcriptionally silenced green fluorescent protein transgene in .

Alphasatellites are non-essential satellite-like components associated with geminiviruses. The precise selective advantage to a geminivirus infection of an alphasatellite remains unclear. The ability of the cotton leaf curl Multan alphasatellite (CLCuMuA)-encoded replication-associated protein (Rep) to suppress TGS was investigated by using line 16-TGS (16-TGS) harbouring a transcriptionally silenced green fluorescent protein (GFP) transgene.

Use of the cotton leaf curl Multan alphasatellite as a silencing or expression vector.

Alphasatellites, formerly known as DNA 1, are a satellite-like components associated with begomoviruses (the family Geminiviridae) that require betasatellite for symptom induction but depend on DNA-A for systemic movement. We have converted alphasatellite into gene-silencing vector (modified alphasatellite (∆DNA 1)) by deleting its A-rich region that does not affect the replication nor the movement of the helper virus. Insertion of a transgene green florescence protein (GFP) into ∆DNA 1 resulted in the silencing g of the cognate gene in Nicotiana benthamiana.

The antisense 5' end of the V2 gene confers enhanced resistance against the monopartite begomovirus cotton leaf curl Kokhran virus-Burewala strain.

Whitefly-transmitted viruses of the genus Begomovirus (the family Geminiviridae) have become a limiting factor for agricultural productivity in many warmer parts of the world. The economies of Pakistan and India have, since the early 1990s, suffered losses due to cotton leaf curl disease (CLCuD). The disease is caused by begomoviruses, the most important of which at this time is cotton leaf curl Kokhran virus strain Burewala (CLCuKoV-Bu), and a disease-specific betasatellite, cotton leaf curl Multan betasatellite (CLCuMuB).

The V2 protein encoded by a monopartite begomovirus is a suppressor of both post-transcriptional and transcriptional gene silencing activity.

Papaya leaf curl virus (PaLCuV) is a begomovirus (genus Begomovirus; family Geminiviridae) with a monopartite genome that is usually associated with beta- and alphasatellites in plants. Geminiviruses are DNA viruses with small circular genomes that occur as minichromosomes in the nucleus and are susceptible to post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS). Transient expression of the PaLCuV V2 (PV2) protein together with the green fluorescent protein (GFP) in Nicotiana benthamiana resulted in enhanced levels of GFP fluorescence and GFP mRNA, indicative of suppression of PTGS.

Transmission of cotton leaf curl disease: answer to a long-standing question.

Cotton leaf curl disease (CLCuD) has been a major constraint to cotton production across Pakistan and northwestern India since the early 1990s. The disease is caused by a number of begomoviruses, including Cotton leaf curl Multan virus (CLCuMuV), which associate with a specific host range and symptom determining betasatellite known as Cotton leaf curl Multan betasatellite (CLCuMuB). Bemisia tabaci is a complex of cryptic species that consists of numerous (> 44) morphologically indistinguishable and, at least partially, reproductively isolated species.

World Management of Geminiviruses.

Management of geminiviruses is a worldwide challenge because of the widespread distribution of economically important diseases caused by these viruses. Regardless of the type of agriculture, management is most effective with an integrated pest management (IPM) approach that involves measures before, during, and after the growing season. This includes starting with resistant cultivars and virus- and vector-free transplants and propagative plants.

Identification of a dicot infecting mastrevirus along with alpha- and betasatellite associated with leaf curl disease of spinach (Spinacia oleracea) in Pakistan.

Spinach is a common vegetable crop and very little data is available about its virus infection. Symptomatic leaves of spinach were collected during field survey. Circular DNA molecules were amplified from symptomatic samples using rolling circle amplification (RCA).

Alphasatellitidae: a new family with two subfamilies for the classification of geminivirus- and nanovirus-associated alphasatellites.

Nanoviruses and geminiviruses are circular, single stranded DNA viruses that infect many plant species around the world. Nanoviruses and certain geminiviruses that belong to the Begomovirus and Mastrevirus genera are associated with additional circular, single stranded DNA molecules (~ 1-1.4 kb) that encode a replication-associated protein (Rep).

Maintenance of Cotton Leaf Curl Multan Betasatellite by Analysis by Mutation.

Viruses of the genus (family ) are economically important phytopathogens that are transmitted plant-to-plant by the whitefly . Most Old World (OW) begomoviruses are monopartite and many of these interact with symptoms and host range determining betasatellites. (ToLCNDV) is one of only a few OW begomoviruses with a bipartite genome (components known as DNA A and DNA B).

Evaluation of carbon nanotube based copper nanoparticle composite for the efficient detection of agroviruses.

We report a biosensor that combines the construction of a three-dimensional nanocomposite with electrochemical methods for the detection of viruses in plants. This is the first report, where carbon nanotubes are used as a conductive frame to anchor highly electrolytic agglomerates of copper nanoparticles to detect agroviruses. Morphological analysis of nanocomposite revealed the presence of carbon nanotubes having a diameter of 50-100nm with copper nanoparticles of 20-100nm, attached in the form of bunches.

Diversity and Distribution of Cryptic Species of the Bemisia tabaci (Hemiptera: Aleyrodidae) complex in Pakistan.

Bemisia tabaci (Gennadius; Hempitera: Aleyrodidae) is considered to be a cryptic (sibling) species complex, the members of which exhibit morphological invariability while being genetically and behaviorally distinct. Members of the complex are agricultural pests that cause direct damage by feeding on plants, and indirectly by transmitting viruses that cause diseases leading to reduced crop yield and quality. In Pakistan, cotton leaf curl disease, caused by multiple begomovirus species, is the most economically important viral disease of cotton.

Further changes in the cotton leaf curl disease complex: an indication of things to come?

Cotton leaf curl disease (CLCuD) has been a problem for cotton production in Pakistan and India since the early 1990s. The disease is caused by begomoviruses associated with a specific satellite, the cotton leaf curl Multan betasatellite (CLCuMB). In 2001, resistance introduced into cotton was broken by a recombinant begomovirus, Cotton leaf curl Kokhran virus strain Burewala (CLCuKoV-Bur).

Real-time quantitative PCR assay for the quantification of virus and satellites causing leaf curl disease in cotton in Pakistan.

Cotton leaf curl disease (CLCuD) is the major biotic constraint to cotton production in Pakistan and northwestern India. The disease is caused by monopartite begomoviruses in association with a specific DNA satellite, Cotton leaf curl Multan betasatellite. The virus-betasatellite complex is also frequently associated with another DNA satellite-like molecule; an alphasatellite.

ICTV Virus Taxonomy Profile: Geminiviridae.

The geminiviruses are a family of small, non-enveloped viruses with single-stranded, circular DNA genomes of 2500-5200 bases. Geminiviruses are transmitted by various types of insect (whiteflies, leafhoppers, treehoppers and aphids). Members of the genus Begomovirus are transmitted by whiteflies, those in the genera Becurtovirus, Curtovirus, Grablovirus, Mastrevirus and Turncurtovirus are transmitted by specific leafhoppers, the single member of the genus Topocuvirus is transmitted by a treehopper and one member of the genus Capulavirus is transmitted by an aphid.

Capulavirus and Grablovirus: two new genera in the family Geminiviridae.

Geminiviruses are plant-infecting single-stranded DNA viruses that occur in most parts of the world. Currently, there are seven genera within the family Geminiviridae (Becurtovirus, Begomovirus, Curtovirus, Eragrovirus, Mastrevirus, Topocuvirus and Turncurtovirus). The rate of discovery of new geminiviruses has increased significantly over the last decade as a result of new molecular tools and approaches (rolling-circle amplification and deep sequencing) that allow for high-throughput workflows.

Molecular characterization of a distinct monopartite begomovirus associated with betasatellites and alphasatellites infecting Pisum sativum in Nepal.

Pea (Pisum sativum) plants exhibiting leaf distortion, yellowing, stunted growth and reduction in leaf size from Rampur, Nepal were shown to be infected by a begomovirus in association with betasatellites and alphasatellites. The begomovirus associated with the disease showed only low levels of nucleotide sequence identity (<91%) to previously characterized begomoviruses. This finding indicates that the pea samples were infected with an as yet undescribed begomovirus for which the name Pea leaf distortion virus (PLDV) is proposed.