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Jean-michel Lett - One of the best experts on this subject based on the ideXlab platform.
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Tomato leaf curl Kunene virus: a novel tomato-infecting Monopartite begomovirus from Namibia
Archives of Virology, 2020Co-Authors: Jean-michel Lett, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Jocelin Ncho, Vera Cauwer, Rolf BeckerAbstract:This is the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomato with symptoms of tomato (yellow) leaf curl disease collected in northwestern Namibia, which we provisionally name “tomato leaf curl Kunene virus”. The DNA-A-like nucleotide sequence shares the highest nucleotide sequence identity (82.8%) with tobacco leaf curl Zimbabwe virus (ToLCZWV). Phylogenetic analysis confirmed its affiliation with Old World Monopartite begomoviruses. The discovery of a new begomovirus in a vegetable plant in Namibia highlights the importance of maintaining epidemiological surveillance in southern Africa.
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Evaluation of the main epidemiological parameters associated with the emergence of PepYVMLV in Burkina Faso
2019Co-Authors: Alassane Ouattara, Fidèle Tiendrebeogo, Pierre Lefeuvre, Nicolas Barro, Nathalie Becker, Marie-murielle Hoareau, Agathe Allibert, Frédéric Chiroleu, Gael Thébaud, Jean-michel LettAbstract:Solanaceous crops fields are severely affected by the emerging virus Pepper yellow vein Mali virus (PepYVMLV) in West Africa. It belongs to the genus Begomovirus (family Geminiviridae) and is transmitted by Bemisia tabaci. African begomoviruses described on crops are mainly Monopartite (DNA-A component), except cassava-infecting bipartite begomoviruses (DNA-A and DNA-B components). Up to now, the PepYVMLV was described as a Monopartite Begomovirus. In order to better understand the epidemiology of this virus in West Africa, particularly in Burkina Faso, two surveys were undertaken in the whole country and 1,614 solanaceous plants were collected to be checked for the presence of the virus. The deep characterization allowed to discover the presence of a typical DNA-B associated with the pepper yellow vein disease. This DNA-B is different from those of currently described cassava mosaic Geminiviruses. The discovery of the association of a newly described DNA-B component with the PepYVMLV also leads to the study of the epidemiological parameters of this co-infection. Although this association is relaxed, we demonstrated that disease virulence, viral accumulation and transmission by Bemisia tabaci were increased in co-infection with the DNA-B component. All these factors are probably related to the success of this association in the field. Because of the extreme severity of the resulting disease, the dispersal of this new DNA-B component at a larger scale would represent a major threat to tomato and pepper cultivation in Burkina Faso, Africa and the world in general.
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Tomato leaf curl Mahé virus: a novel tomato-infecting Monopartite begomovirus from the Seychelles.
Archives of virology, 2018Co-Authors: Sarah Scussel, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Ravi Moustache, Hélène Delatte, Jean-michel LettAbstract:This is the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomato with symptoms of tomato (yellow) leaf curl disease collected in the Seychelles. The DNA-A-like nucleotide sequences share the highest nucleotide sequence identity (84%) with tomato leaf curl Anjouan virus (ToLCAnjV) from the Comoros islands. Phylogenetic analysis confirmed its recombinant nature and its relationship to Old World Monopartite and bipartite begomoviruses. This discovery of a new member of a species confirms the high genetic diversity of begomoviruses in the south-western Indian Ocean islands.
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Tomato leaf curl Burkina Faso virus: a novel tomato-infecting Monopartite begomovirus from Burkina Faso.
Archives of virology, 2017Co-Authors: Alassane Ouattara, Fidèle Tiendrebeogo, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Edgard Valentin Traoré, Nicolas Barro, Oumar Traoré, Jean-michel LettAbstract:In this report, we present the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomatoes collected in Burkina Faso and presenting with symptoms of tomato leaf curl disease. We propose the tentative name “tomato leaf curl Burkina Faso virus’’ (ToLCBFV). DNA-A-like nucleotide sequence of ToLCBFV shares the highest nucleotide sequence identity (85%) with the pepper yellow vein Mali virus (PepYVMLV). Phylogenetic analysis confirmed the affiliation of ToLCBFV to Old World Monopartite begomoviruses. This discovery of a new species confirms the existence of high genetic diversity in Monopartite begomoviruses in sub-Saharan Africa and particularly in West Africa.
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Differential disease phenotype of begomoviruses associated with tobacco leaf curl disease in Comoros
Archives of virology, 2011Co-Authors: Magalie Thierry, Pierre Lefeuvre, Murielle Hoareau, Hélène Delatte, Frédéric Péréfarres, Bernard Reynaud, Darren P. Martin, Jean-michel LettAbstract:In the 2000s, tobacco plantations on the Comoros Islands were afflicted with a previously unobserved tobacco leaf curl disease characterised by symptoms of severe leaf curling and deformation. Previous molecular characterization of potential viral pathogens revealed a complex of African Monopartite tobacco leaf curl begomovirus (TbLCVs). Our molecular investigation allowed the characterization of a new Monopartite virus involved in the disease: tomato leaf curl Namakely virus (ToLCNamV). Agroinoculation experiments indicated that TbLCVs and tomato leaf curl viruses (ToLCVs) can infect both tomato and tobacco but that infectivity and symptom expression fluctuate depending on the virus and the plant cultivar combination.
Murielle Hoareau - One of the best experts on this subject based on the ideXlab platform.
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Tomato leaf curl Kunene virus: a novel tomato-infecting Monopartite begomovirus from Namibia
Archives of Virology, 2020Co-Authors: Jean-michel Lett, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Jocelin Ncho, Vera Cauwer, Rolf BeckerAbstract:This is the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomato with symptoms of tomato (yellow) leaf curl disease collected in northwestern Namibia, which we provisionally name “tomato leaf curl Kunene virus”. The DNA-A-like nucleotide sequence shares the highest nucleotide sequence identity (82.8%) with tobacco leaf curl Zimbabwe virus (ToLCZWV). Phylogenetic analysis confirmed its affiliation with Old World Monopartite begomoviruses. The discovery of a new begomovirus in a vegetable plant in Namibia highlights the importance of maintaining epidemiological surveillance in southern Africa.
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Tomato leaf curl Mahé virus: a novel tomato-infecting Monopartite begomovirus from the Seychelles.
Archives of virology, 2018Co-Authors: Sarah Scussel, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Ravi Moustache, Hélène Delatte, Jean-michel LettAbstract:This is the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomato with symptoms of tomato (yellow) leaf curl disease collected in the Seychelles. The DNA-A-like nucleotide sequences share the highest nucleotide sequence identity (84%) with tomato leaf curl Anjouan virus (ToLCAnjV) from the Comoros islands. Phylogenetic analysis confirmed its recombinant nature and its relationship to Old World Monopartite and bipartite begomoviruses. This discovery of a new member of a species confirms the high genetic diversity of begomoviruses in the south-western Indian Ocean islands.
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Tomato leaf curl Burkina Faso virus: a novel tomato-infecting Monopartite begomovirus from Burkina Faso.
Archives of virology, 2017Co-Authors: Alassane Ouattara, Fidèle Tiendrebeogo, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Edgard Valentin Traoré, Nicolas Barro, Oumar Traoré, Jean-michel LettAbstract:In this report, we present the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomatoes collected in Burkina Faso and presenting with symptoms of tomato leaf curl disease. We propose the tentative name “tomato leaf curl Burkina Faso virus’’ (ToLCBFV). DNA-A-like nucleotide sequence of ToLCBFV shares the highest nucleotide sequence identity (85%) with the pepper yellow vein Mali virus (PepYVMLV). Phylogenetic analysis confirmed the affiliation of ToLCBFV to Old World Monopartite begomoviruses. This discovery of a new species confirms the existence of high genetic diversity in Monopartite begomoviruses in sub-Saharan Africa and particularly in West Africa.
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Differential disease phenotype of begomoviruses associated with tobacco leaf curl disease in Comoros
Archives of virology, 2011Co-Authors: Magalie Thierry, Pierre Lefeuvre, Murielle Hoareau, Hélène Delatte, Frédéric Péréfarres, Bernard Reynaud, Darren P. Martin, Jean-michel LettAbstract:In the 2000s, tobacco plantations on the Comoros Islands were afflicted with a previously unobserved tobacco leaf curl disease characterised by symptoms of severe leaf curling and deformation. Previous molecular characterization of potential viral pathogens revealed a complex of African Monopartite tobacco leaf curl begomovirus (TbLCVs). Our molecular investigation allowed the characterization of a new Monopartite virus involved in the disease: tomato leaf curl Namakely virus (ToLCNamV). Agroinoculation experiments indicated that TbLCVs and tomato leaf curl viruses (ToLCVs) can infect both tomato and tobacco but that infectivity and symptom expression fluctuate depending on the virus and the plant cultivar combination.
Rob W Briddon - One of the best experts on this subject based on the ideXlab platform.
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Transgenic expression of the Agrobacterium tumefaciens single-stranded DNA binding protein VirE2 provides resistance to both bipartite and Monopartite betasatellite-associated begomoviruses in Nicotiana benthamiana
Physiological and Molecular Plant Pathology, 2020Co-Authors: Sumaira Yousaf, Rob W Briddon, Shahid Mansoor, Imran Amin, Ghulam Rasool, Muhammad SaeedAbstract:Abstract Viruses of the genus Begomovirus (family Geminiviridae) are a threat to agriculture and food security throughout the warmer parts of the world. Begomoviruses are transmitted by the whitefly Bemisia tabaci and have genomes consisting of one (Monopartite) or two (bipartite) circular, single-stranded (ss) DNA molecules. Most Monopartite begomoviruses also associate with host range and symptom exacerbating satellites known as betasatellites. Cotton leaf curl Kokhran virus (CLCuKoV), in association with the betasatellite cotton leaf curl Multan betasatellite (CLCuMuB), is one of a number of viruses that cause cotton leaf curl disease in southern Asia. Tomato leaf curl New Delhi virus (ToLCNDV) is a bipartite begomovirus widespread on the Indian subcontinent that has recently also been identified in North Africa and southern Europe and causes problems in a number of crops including cotton and tomato. The Agrobacterium tumefaciens virulence protein VirE2 has ssDNA binding activity. Nicotiana benthamiana was transformed with a construct for the expression of VirE2 to assess its potential to impart resistance to begomoviruses. Plants of three VirE2 transgenic lines showed attenuated symptoms when infected with either CLCuKoV, CLCuKoV with CLCuMuB or ToLCNDV relative to the severe symptoms induced in non-transformed plants. Presence of the betasatellite was found to reduce the effectiveness of the resistance imparted byVirE2. There was a marked reduction in the accumulation of viral/betasatellite DNA for both viruses as detected by Southern hybridization. The results indicate that VirE2 shows promise in efforts to develop non-conventional, broad spectrum resistance against begomoviruses, being active against Monopartite and bipartite begomoviruses. Efforts should now focus on investigating VirE2 resistance in crop plants, with a view to developing commercially useful resistant lines.
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Identification of Chilli leaf curl virus associated with tomato leaf curl betasatellite infecting Mentha in Oman
Canadian Journal of Plant Pathology, 2019Co-Authors: Muhammad Shafiq Shahid, Amir Raza, Abdullah M. Al-sadi, Rob W BriddonAbstract:Mint (Mentha sp.; family: Lamiaceae) plants showing yellowing and stunting symptoms from Salalah, Dhofar region, Oman were shown to be infected by a Monopartite begomovirus (family: Geminiviridae)....
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pepper leaf curl lahore virus requires the dna b component of tomato leaf curl new delhi virus to cause leaf curl symptoms
Virology Journal, 2010Co-Authors: Muhammad Shafiq, Rob W Briddon, Shaheen Asad, Yusuf Zafar, Shahid MansoorAbstract:Background Begomoviruses are whitefly-transmitted geminiviruses with genomes that consist of either two components (known as DNA A and DNA B) or a single component (homologous to the DNA A component of bipartite begomoviruses). Monopartite begomoviruses are often associated with a symptom-modulating DNA satellite (collectively known as betasatellites). Both bipartite and Monopartite begomoviruses with associated satellites have previously been identified in chillies showing leaf curl symptoms in Pakistan.
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Characterization of begomovirus components from a weed suggests that begomoviruses may associate with multiple distinct DNA satellites
Virus genes, 2010Co-Authors: M. Mubin, Rob W Briddon, Muhammad Shafiq Shahid, Muhammad Tahir, Shahid MansoorAbstract:A begomovirus disease complex associated with Sonchus arvensis, a common weed in Pakistan was studied using cloning, nucleic acid sequencing and phylogenetic analysis. The complex associated with this weed consists of a Monopartite begomovirus and several distinct betasatellites and alphasatellites. The Monopartite begomovirus associated with yellow vein disease of Sonchus arvensis showed 95-99% nucleotide sequence identity with Alternanthera yellow vein virus (AlYVV) reported from China, Vietnam and India. Two betasatellites were isolated from S. arvensis: one sharing between 91.4 and 95.3% nucleotide sequence identity with isolates of Ageratum yellow leaf curl betasatellite (AYLCB), and the other sharing between 78.2 and 99.9% identity with isolates of Cotton leaf curl Multan betasatellite (CLCuMB). Two alphasatellites were identified: one was homologous to Potato leaf curl alphasatellite (PotLCuA), while the other was closely related to Hibiscus leaf curl alphasatellite (HLCuA). Thus, AlYVV in S. arvensis is associated with satellites shown previously to be associated with other begomoviruses in Pakistan. Our results suggest that Monopartite begomoviruses may associate with distinct satellites that are prevalent in the region.
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The hypersensitive response induced by the V2 protein of a Monopartite begomovirus is countered by the C2 protein
Molecular plant pathology, 2010Co-Authors: M. Mubin, Rob W Briddon, Imran Amin, Luqman Amrao, Shahid MansoorAbstract:A functional analysis of the V2 protein of two Monopartite begomoviruses, Papaya leaf curl virus (PaLCuV) and Cotton leaf curl Kokhran virus (CLCuKoV), has been performed. Expression of the V2 gene from a Potato virus X (PVX) vector resulted in severe leaf curling followed by a hypersensitive response (HR) in Nicotiana benthamiana and N. tabacum, demonstrating that the V2 protein is a pathogenicity determinant and a target of host defence responses. Agroinfiltration of a PVX vector expressing the V2 protein resulted in cell death in the infiltrated area. Subsequently, a systemic HR developed that was associated with the long-distance spread of the virus and led to the death of the plant. V2 amino acid sequences encompassing a conserved putative protein kinase C (PKC) phosphorylation motif were shown to be essential for the elicitation of cell death. In co-inoculation experiments, the transient expression of the C2 protein of PaLCuV or Cotton leaf curl Multan virus under the control of the Cauliflower mosaic virus 35S promoter inhibited the HR induced by V2 in the agroinfiltrated area. These findings demonstrate that the V2 protein of Monopartite begomoviruses is a pathogenicity determinant and induces an HR that can be suppressed by the C2 protein. The induction and suppression of HR have been demonstrated previously in bipartite begomoviruses and our results extend this to Monopartite begomoviruses.
Pierre Lefeuvre - One of the best experts on this subject based on the ideXlab platform.
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Tomato leaf curl Kunene virus: a novel tomato-infecting Monopartite begomovirus from Namibia
Archives of Virology, 2020Co-Authors: Jean-michel Lett, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Jocelin Ncho, Vera Cauwer, Rolf BeckerAbstract:This is the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomato with symptoms of tomato (yellow) leaf curl disease collected in northwestern Namibia, which we provisionally name “tomato leaf curl Kunene virus”. The DNA-A-like nucleotide sequence shares the highest nucleotide sequence identity (82.8%) with tobacco leaf curl Zimbabwe virus (ToLCZWV). Phylogenetic analysis confirmed its affiliation with Old World Monopartite begomoviruses. The discovery of a new begomovirus in a vegetable plant in Namibia highlights the importance of maintaining epidemiological surveillance in southern Africa.
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Evaluation of the main epidemiological parameters associated with the emergence of PepYVMLV in Burkina Faso
2019Co-Authors: Alassane Ouattara, Fidèle Tiendrebeogo, Pierre Lefeuvre, Nicolas Barro, Nathalie Becker, Marie-murielle Hoareau, Agathe Allibert, Frédéric Chiroleu, Gael Thébaud, Jean-michel LettAbstract:Solanaceous crops fields are severely affected by the emerging virus Pepper yellow vein Mali virus (PepYVMLV) in West Africa. It belongs to the genus Begomovirus (family Geminiviridae) and is transmitted by Bemisia tabaci. African begomoviruses described on crops are mainly Monopartite (DNA-A component), except cassava-infecting bipartite begomoviruses (DNA-A and DNA-B components). Up to now, the PepYVMLV was described as a Monopartite Begomovirus. In order to better understand the epidemiology of this virus in West Africa, particularly in Burkina Faso, two surveys were undertaken in the whole country and 1,614 solanaceous plants were collected to be checked for the presence of the virus. The deep characterization allowed to discover the presence of a typical DNA-B associated with the pepper yellow vein disease. This DNA-B is different from those of currently described cassava mosaic Geminiviruses. The discovery of the association of a newly described DNA-B component with the PepYVMLV also leads to the study of the epidemiological parameters of this co-infection. Although this association is relaxed, we demonstrated that disease virulence, viral accumulation and transmission by Bemisia tabaci were increased in co-infection with the DNA-B component. All these factors are probably related to the success of this association in the field. Because of the extreme severity of the resulting disease, the dispersal of this new DNA-B component at a larger scale would represent a major threat to tomato and pepper cultivation in Burkina Faso, Africa and the world in general.
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Tomato leaf curl Mahé virus: a novel tomato-infecting Monopartite begomovirus from the Seychelles.
Archives of virology, 2018Co-Authors: Sarah Scussel, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Ravi Moustache, Hélène Delatte, Jean-michel LettAbstract:This is the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomato with symptoms of tomato (yellow) leaf curl disease collected in the Seychelles. The DNA-A-like nucleotide sequences share the highest nucleotide sequence identity (84%) with tomato leaf curl Anjouan virus (ToLCAnjV) from the Comoros islands. Phylogenetic analysis confirmed its recombinant nature and its relationship to Old World Monopartite and bipartite begomoviruses. This discovery of a new member of a species confirms the high genetic diversity of begomoviruses in the south-western Indian Ocean islands.
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Tomato leaf curl Burkina Faso virus: a novel tomato-infecting Monopartite begomovirus from Burkina Faso.
Archives of virology, 2017Co-Authors: Alassane Ouattara, Fidèle Tiendrebeogo, Pierre Lefeuvre, Sohini Claverie, Murielle Hoareau, Edgard Valentin Traoré, Nicolas Barro, Oumar Traoré, Jean-michel LettAbstract:In this report, we present the first description of the complete genome sequence of a new Monopartite begomovirus isolated from tomatoes collected in Burkina Faso and presenting with symptoms of tomato leaf curl disease. We propose the tentative name “tomato leaf curl Burkina Faso virus’’ (ToLCBFV). DNA-A-like nucleotide sequence of ToLCBFV shares the highest nucleotide sequence identity (85%) with the pepper yellow vein Mali virus (PepYVMLV). Phylogenetic analysis confirmed the affiliation of ToLCBFV to Old World Monopartite begomoviruses. This discovery of a new species confirms the existence of high genetic diversity in Monopartite begomoviruses in sub-Saharan Africa and particularly in West Africa.
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Differential disease phenotype of begomoviruses associated with tobacco leaf curl disease in Comoros
Archives of virology, 2011Co-Authors: Magalie Thierry, Pierre Lefeuvre, Murielle Hoareau, Hélène Delatte, Frédéric Péréfarres, Bernard Reynaud, Darren P. Martin, Jean-michel LettAbstract:In the 2000s, tobacco plantations on the Comoros Islands were afflicted with a previously unobserved tobacco leaf curl disease characterised by symptoms of severe leaf curling and deformation. Previous molecular characterization of potential viral pathogens revealed a complex of African Monopartite tobacco leaf curl begomovirus (TbLCVs). Our molecular investigation allowed the characterization of a new Monopartite virus involved in the disease: tomato leaf curl Namakely virus (ToLCNamV). Agroinoculation experiments indicated that TbLCVs and tomato leaf curl viruses (ToLCVs) can infect both tomato and tobacco but that infectivity and symptom expression fluctuate depending on the virus and the plant cultivar combination.
Shahid Mansoor - One of the best experts on this subject based on the ideXlab platform.
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Association of cotton leaf curl Multan betasatellite and Ageratum conyzoides symptomless alphasatellite with tomato leaf curl New Delhi virus in Luffa cylindrica in Pakistan
Australasian Plant Pathology, 2020Co-Authors: Ifrah Anwar, Imran Amin, Hanan Arif Bukhari, Nazia Nahid, Kamran Rashid, Shabnum Shaheen, Khadim Hussain, Shahid MansoorAbstract:Luffa plants showing symptoms of begomovirus infection were collected from Vehari, Punjab in 2016. RCA and PCR amplifications of begomovirus genomic components showed the presence of a typical Old World bipartite begomovirus Tomato leaf curl New Delhi virus (ToLCNDV). Interestingly, Ageratum conyzoides symptomless alphasatellite and CLCuMB were also found associated with bipartite begomoviruses in the same host, however, no Monopartite begomovirus was detected. To the best of our knowledge, this is the first report of ToLCNDV with associated satellites infecting L. cylindrica in Pakistan. The importance of begomovirus extended host range with different combinations of associated satellites has been discussed.
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Transgenic expression of the Agrobacterium tumefaciens single-stranded DNA binding protein VirE2 provides resistance to both bipartite and Monopartite betasatellite-associated begomoviruses in Nicotiana benthamiana
Physiological and Molecular Plant Pathology, 2020Co-Authors: Sumaira Yousaf, Rob W Briddon, Shahid Mansoor, Imran Amin, Ghulam Rasool, Muhammad SaeedAbstract:Abstract Viruses of the genus Begomovirus (family Geminiviridae) are a threat to agriculture and food security throughout the warmer parts of the world. Begomoviruses are transmitted by the whitefly Bemisia tabaci and have genomes consisting of one (Monopartite) or two (bipartite) circular, single-stranded (ss) DNA molecules. Most Monopartite begomoviruses also associate with host range and symptom exacerbating satellites known as betasatellites. Cotton leaf curl Kokhran virus (CLCuKoV), in association with the betasatellite cotton leaf curl Multan betasatellite (CLCuMuB), is one of a number of viruses that cause cotton leaf curl disease in southern Asia. Tomato leaf curl New Delhi virus (ToLCNDV) is a bipartite begomovirus widespread on the Indian subcontinent that has recently also been identified in North Africa and southern Europe and causes problems in a number of crops including cotton and tomato. The Agrobacterium tumefaciens virulence protein VirE2 has ssDNA binding activity. Nicotiana benthamiana was transformed with a construct for the expression of VirE2 to assess its potential to impart resistance to begomoviruses. Plants of three VirE2 transgenic lines showed attenuated symptoms when infected with either CLCuKoV, CLCuKoV with CLCuMuB or ToLCNDV relative to the severe symptoms induced in non-transformed plants. Presence of the betasatellite was found to reduce the effectiveness of the resistance imparted byVirE2. There was a marked reduction in the accumulation of viral/betasatellite DNA for both viruses as detected by Southern hybridization. The results indicate that VirE2 shows promise in efforts to develop non-conventional, broad spectrum resistance against begomoviruses, being active against Monopartite and bipartite begomoviruses. Efforts should now focus on investigating VirE2 resistance in crop plants, with a view to developing commercially useful resistant lines.
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pepper leaf curl lahore virus requires the dna b component of tomato leaf curl new delhi virus to cause leaf curl symptoms
Virology Journal, 2010Co-Authors: Muhammad Shafiq, Rob W Briddon, Shaheen Asad, Yusuf Zafar, Shahid MansoorAbstract:Background Begomoviruses are whitefly-transmitted geminiviruses with genomes that consist of either two components (known as DNA A and DNA B) or a single component (homologous to the DNA A component of bipartite begomoviruses). Monopartite begomoviruses are often associated with a symptom-modulating DNA satellite (collectively known as betasatellites). Both bipartite and Monopartite begomoviruses with associated satellites have previously been identified in chillies showing leaf curl symptoms in Pakistan.
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Characterization of begomovirus components from a weed suggests that begomoviruses may associate with multiple distinct DNA satellites
Virus genes, 2010Co-Authors: M. Mubin, Rob W Briddon, Muhammad Shafiq Shahid, Muhammad Tahir, Shahid MansoorAbstract:A begomovirus disease complex associated with Sonchus arvensis, a common weed in Pakistan was studied using cloning, nucleic acid sequencing and phylogenetic analysis. The complex associated with this weed consists of a Monopartite begomovirus and several distinct betasatellites and alphasatellites. The Monopartite begomovirus associated with yellow vein disease of Sonchus arvensis showed 95-99% nucleotide sequence identity with Alternanthera yellow vein virus (AlYVV) reported from China, Vietnam and India. Two betasatellites were isolated from S. arvensis: one sharing between 91.4 and 95.3% nucleotide sequence identity with isolates of Ageratum yellow leaf curl betasatellite (AYLCB), and the other sharing between 78.2 and 99.9% identity with isolates of Cotton leaf curl Multan betasatellite (CLCuMB). Two alphasatellites were identified: one was homologous to Potato leaf curl alphasatellite (PotLCuA), while the other was closely related to Hibiscus leaf curl alphasatellite (HLCuA). Thus, AlYVV in S. arvensis is associated with satellites shown previously to be associated with other begomoviruses in Pakistan. Our results suggest that Monopartite begomoviruses may associate with distinct satellites that are prevalent in the region.
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The hypersensitive response induced by the V2 protein of a Monopartite begomovirus is countered by the C2 protein
Molecular plant pathology, 2010Co-Authors: M. Mubin, Rob W Briddon, Imran Amin, Luqman Amrao, Shahid MansoorAbstract:A functional analysis of the V2 protein of two Monopartite begomoviruses, Papaya leaf curl virus (PaLCuV) and Cotton leaf curl Kokhran virus (CLCuKoV), has been performed. Expression of the V2 gene from a Potato virus X (PVX) vector resulted in severe leaf curling followed by a hypersensitive response (HR) in Nicotiana benthamiana and N. tabacum, demonstrating that the V2 protein is a pathogenicity determinant and a target of host defence responses. Agroinfiltration of a PVX vector expressing the V2 protein resulted in cell death in the infiltrated area. Subsequently, a systemic HR developed that was associated with the long-distance spread of the virus and led to the death of the plant. V2 amino acid sequences encompassing a conserved putative protein kinase C (PKC) phosphorylation motif were shown to be essential for the elicitation of cell death. In co-inoculation experiments, the transient expression of the C2 protein of PaLCuV or Cotton leaf curl Multan virus under the control of the Cauliflower mosaic virus 35S promoter inhibited the HR induced by V2 in the agroinfiltrated area. These findings demonstrate that the V2 protein of Monopartite begomoviruses is a pathogenicity determinant and induces an HR that can be suppressed by the C2 protein. The induction and suppression of HR have been demonstrated previously in bipartite begomoviruses and our results extend this to Monopartite begomoviruses.
