The Experts below are selected from a list of 1473 Experts worldwide ranked by ideXlab platform
A. R. R. Cruz - One of the best experts on this subject based on the ideXlab platform.
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rnai based enhanced resistance to Cowpea severe mosaic virus and Cowpea Aphid borne mosaic virus in transgenic Cowpea
Plant Pathology, 2014Co-Authors: A. R. R. Cruz, Francisco J. L. AragãoAbstract:Cowpea (Vigna unguiculata) is one of the most important legumes cultivated in many parts of the world. The diseases caused by Cowpea severe mosaic virus (CPSMV) and Cowpea Aphid-borne mosaic virus (CABMV) are considered among the most important constraints on yield and quality, especially in Latin America and Africa. Here, the concept of using an RNA interference construct to silence the CPSMV proteinase cofactor gene and the CABMV coat protein gene is explored, in order to generate resistant transgenic Cowpea plants. Ten Cowpea transgenic lines were produced, presenting a normal phenotype and transferring the transgene to the next generation. Plants were tested for resistance to both CABMV and CPSMV by mechanical co-inoculation. Seven lines presented milder symptoms when compared to the control and three lines presented enhanced resistance to both viruses. Northern analyses were carried out to detect the transgene-derived small interfering RNA (siRNA) in leaves and revealed no correlation between siRNA levels and virus resistance. Additionally, in the symptomless resistant lines the resistance was homozygosis-dependent. Only homozygous plants remained uninfected while hemizygous plants presented milder symptoms.
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RNAi‐based enhanced resistance to Cowpea severe mosaic virus and Cowpea Aphid‐borne mosaic virus in transgenic Cowpea
Plant Pathology, 2013Co-Authors: A. R. R. Cruz, Francisco J. L. AragãoAbstract:Cowpea (Vigna unguiculata) is one of the most important legumes cultivated in many parts of the world. The diseases caused by Cowpea severe mosaic virus (CPSMV) and Cowpea Aphid-borne mosaic virus (CABMV) are considered among the most important constraints on yield and quality, especially in Latin America and Africa. Here, the concept of using an RNA interference construct to silence the CPSMV proteinase cofactor gene and the CABMV coat protein gene is explored, in order to generate resistant transgenic Cowpea plants. Ten Cowpea transgenic lines were produced, presenting a normal phenotype and transferring the transgene to the next generation. Plants were tested for resistance to both CABMV and CPSMV by mechanical co-inoculation. Seven lines presented milder symptoms when compared to the control and three lines presented enhanced resistance to both viruses. Northern analyses were carried out to detect the transgene-derived small interfering RNA (siRNA) in leaves and revealed no correlation between siRNA levels and virus resistance. Additionally, in the symptomless resistant lines the resistance was homozygosis-dependent. Only homozygous plants remained uninfected while hemizygous plants presented milder symptoms.
Thierry Candresse - One of the best experts on this subject based on the ideXlab platform.
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Sequence of the 3′-terminal region of a Zimbabwe isolate of Cowpea Aphid-borne mosaic virus (CABMV)
Archives of Virology, 1996Co-Authors: I. Sithole-niang, T. Nyathi, D. P. Maxwell, Thierry CandresseAbstract:The 3'-terminal 1221 nucleotides of a Zimbabwe isolate of Cowpea Aphid-borne mosaic potyvirus (CABMV) genome have been sequenced. The sequence comprises an open reading frame (ORF) of 990 nucleotides and a 3' non-coding-region of 231 nucleotides followed by a poly-A. The ORF has high similarity to NIb and coat proteins (CP) of potyviruses. A potential CP Q/S cleavage site was identified, yielding a CP of 30.5 kDa containing 275 amino acids. The CABMV sequence is closely related to that of South African passiflora virus (SAPV) which should therefore be regarded as a strain of CABMV.
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Sequence of the 3'-terminal region of a Zimbabwe isolate of Cowpea Aphid-borne mosaic virus (CABMV)
Archives of Virology, 1996Co-Authors: I. Sithole-niang, T. Nyathi, D. P. Maxwell, Thierry CandresseAbstract:The 3prime-terminal 1221 nucleotides of a Zimbabwe isolate of Cowpea Aphid-borne mosaic potyvirus (CABMV) genome have been sequenced. The sequence comprises an open reading frame (ORF) of 990 nucleotides and a 3prime non-coding-region of 231 nucleotides followed by a poly-A. The ORF has high similarity to NIb and coat proteins (CP) of potyviruses. A potential CP Q/S cleavage site was identified, yielding a CP of 30.5 kDa containing 275 amino acids. The CABMV sequence is closely related to that of South African passiflora virus (SAPV) which should therefore be regarded as a strain of CABMV.
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sequence of the 3 terminal region of a zimbabwe isolate of Cowpea Aphid borne mosaic virus cabmv
Archives of Virology, 1996Co-Authors: I Sitholeniang, T. Nyathi, D. P. Maxwell, Thierry CandresseAbstract:The 3'-terminal 1221 nucleotides of a Zimbabwe isolate of Cowpea Aphid-borne mosaic potyvirus (CABMV) genome have been sequenced. The sequence comprises an open reading frame (ORF) of 990 nucleotides and a 3' non-coding-region of 231 nucleotides followed by a poly-A. The ORF has high similarity to NIb and coat proteins (CP) of potyviruses. A potential CP Q/S cleavage site was identified, yielding a CP of 30.5 kDa containing 275 amino acids. The CABMV sequence is closely related to that of South African passiflora virus (SAPV) which should therefore be regarded as a strain of CABMV.
Francisco J. L. Aragão - One of the best experts on this subject based on the ideXlab platform.
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rnai based enhanced resistance to Cowpea severe mosaic virus and Cowpea Aphid borne mosaic virus in transgenic Cowpea
Plant Pathology, 2014Co-Authors: A. R. R. Cruz, Francisco J. L. AragãoAbstract:Cowpea (Vigna unguiculata) is one of the most important legumes cultivated in many parts of the world. The diseases caused by Cowpea severe mosaic virus (CPSMV) and Cowpea Aphid-borne mosaic virus (CABMV) are considered among the most important constraints on yield and quality, especially in Latin America and Africa. Here, the concept of using an RNA interference construct to silence the CPSMV proteinase cofactor gene and the CABMV coat protein gene is explored, in order to generate resistant transgenic Cowpea plants. Ten Cowpea transgenic lines were produced, presenting a normal phenotype and transferring the transgene to the next generation. Plants were tested for resistance to both CABMV and CPSMV by mechanical co-inoculation. Seven lines presented milder symptoms when compared to the control and three lines presented enhanced resistance to both viruses. Northern analyses were carried out to detect the transgene-derived small interfering RNA (siRNA) in leaves and revealed no correlation between siRNA levels and virus resistance. Additionally, in the symptomless resistant lines the resistance was homozygosis-dependent. Only homozygous plants remained uninfected while hemizygous plants presented milder symptoms.
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RNAi‐based enhanced resistance to Cowpea severe mosaic virus and Cowpea Aphid‐borne mosaic virus in transgenic Cowpea
Plant Pathology, 2013Co-Authors: A. R. R. Cruz, Francisco J. L. AragãoAbstract:Cowpea (Vigna unguiculata) is one of the most important legumes cultivated in many parts of the world. The diseases caused by Cowpea severe mosaic virus (CPSMV) and Cowpea Aphid-borne mosaic virus (CABMV) are considered among the most important constraints on yield and quality, especially in Latin America and Africa. Here, the concept of using an RNA interference construct to silence the CPSMV proteinase cofactor gene and the CABMV coat protein gene is explored, in order to generate resistant transgenic Cowpea plants. Ten Cowpea transgenic lines were produced, presenting a normal phenotype and transferring the transgene to the next generation. Plants were tested for resistance to both CABMV and CPSMV by mechanical co-inoculation. Seven lines presented milder symptoms when compared to the control and three lines presented enhanced resistance to both viruses. Northern analyses were carried out to detect the transgene-derived small interfering RNA (siRNA) in leaves and revealed no correlation between siRNA levels and virus resistance. Additionally, in the symptomless resistant lines the resistance was homozygosis-dependent. Only homozygous plants remained uninfected while hemizygous plants presented milder symptoms.
Maria Lucia Carneiro Vieira - One of the best experts on this subject based on the ideXlab platform.
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genetic transformation of passionflower and evaluation of r1 and r2 generations for resistance to Cowpea Aphid borne mosaic virus
Plant Disease, 2011Co-Authors: Alessandra Cristina B A Monteirohara, Jorge Alberto Marques Rezende, Maria Lucia Carneiro Vieira, A S Jadao, Beatriz Madalena Januzzi Mendes, Flavio Trevisan, A P O A Mello, L M M Meletti, Sonia Maria De Stefano PiedadeAbstract:Monteiro-Hara, A. C. B. A., Jadao, A. S., Mendes, B. M. J., Rezende, J. A. M., Trevisan, F., Mello, A. P. O. A., Vieira, M. L. C., Meletti, L. M. M., and Piedade, S. M. De S. 2011. Genetic transformation of passionflower and evaluation of R1 and R2 generations for resistance to Cowpea Aphid borne mosaic virus. Plant Dis. 95:1021-1025. We report on the production and evaluation of passionflower transgenic lines for resistance to Cowpea Aphid borne mosaic virus (CABMV). Genetic transformation was done using Agrobacterium tumefaciens and transgene integration was confirmed by Southern blot analyses, resulting in nine transgenic lines for ‘IAC 275’ and three for ‘IAC 277’. Transgenic lines were clonally propagated and evaluated for resistance to CABMV. After the third inoculation, under higher inoculum pressure, only propagated plants of the transgenic line T16 remained asymptomatic, indicating a high resistance to infection with CABMV. This transgenic line was self-pollinated and the R1 generation was evaluated together with the R1 generation of another resistant transgenic line (T2) identified previously. Plants were inoculated with CABMV by means of viruliferous Myzus nicotianae. All 524 T2R1 plants became infected, whereas 13 of 279 T16R1 remained asymptomatic after four successive inoculations. A T16R2 generation was obtained and plants were inoculated with CABMV mechanically or by Aphids. After successive inoculations, 118 of 258 plants were symptomless, suggesting that the resistance to CABMV was maintained in the plant genome as the homozygous condition was achieved. Five selected resistant T16R2 plants which contained the capsid protein gene are being crossed for further analyses. Brazil is the world’s largest producer of passion fruit, with an estimated planted area of 44,300 ha and fruit yield of 615,196 t (12). Yellow passion fruit (Passiflora edulis f. flavicarpa) is the predominant species (98%), with the remaining area (2%) planted with sweet passion fruit (P. alata). However, this production is threatened by several pathogens, including the Potyvirus sp. Cowpea Aphid borne mosaic virus (CABMV) (4,23,24), which was previously misidentified as Passion fruit woodiness virus (6,7). The disease caused by CABMV was first detected in Brazil in the late 1970s in the State of Bahia (6), and then spread throughout the country (3,7,11,16). The virus is transmitted in a nonpersistent manner by several Aphid species, and also mechanically, during pruning. The disease causes severe yield losses and reduces the orchard lifespan by approximately half (13). The control of passion fruit woodiness disease in passionflower orchards is problematic. All cultivars of yellow and sweet passion fruit are susceptible to infection, and chemical vector control is usually inefficient because of the nonpersistent manner of transmission. Cross protection with mild strains of the virus have also failed to control the disease (26). Recently, two Brazilian hybrids (BRS Ouro Vermelho and BRS Sol do Cerrado) tolerant to this disease were introduced into the market but are still being evaluated by growers (http://www.cpac.embrapa.br/maracuja/inicio/). In Brazil, at present, several cultural practices have been recommended to minimize the problems associated with CABMV in passionflower orchards. These include the use of virus-free seedlings for new plantings, eradication of old and abandoned orchards before starting new crops, care during pruning operations to prevent mechanical transmission of the virus, avoidance of leguminous plants which may harbor the virus in the proximity of the orchard, and roguing of diseased plants by means of systematic inspections during the first 5 months after transplanting (11,13).
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Screening of Passiflora species for reaction to Cowpea Aphid-borne mosaic virus reveals an immune wild species
Scientia Agricola, 2009Co-Authors: S. C. Maciel, Daniel Hiroshi Nakano, Jorge Alberto Marques Rezende, Maria Lucia Carneiro VieiraAbstract:Cowpea Aphid-borne mosaic virus (CABMV) is a potyvirus that causes the most serious virus disease of passion fruit crops in Brazil. It is transmitted by several species of Aphids in a non-persistent, non-circulative manner. The reaction of 16 species of Passiflora to infection by mechanical inoculation with four Brazilian isolates of CABMV was evaluated under greenhouse conditions. Only P. suberosa, a wild species, was resistant to infection by all virus isolates, in two independent assays. P. suberosa grafted onto infected P. edulis f. flavicarpa did not develop symptoms; neither was the virus detected by RT-PCR in the upper leaves, suggesting that this species is immune to CABMV.
Jorge Alberto Marques Rezende - One of the best experts on this subject based on the ideXlab platform.
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Alternative hosts of Cowpea Aphid-borne mosaic virus (CABMV) in sesame (Sesamum indicum) crops grown in Paraguay
Tropical Plant Pathology, 2013Co-Authors: Luis R. González-segnana, Jorge Alberto Marques Rezende, A P O A Mello, Arnaldo Esquivel Fariña, Diego D. González, Elliot W. KitajimaAbstract:Sesame (Sesamum indicum L.) production in Paraguay has been severely affected by infection with Cowpea Aphid-borne mosaic virus (CABMV), which causes a disease known locally as ka'are. Because very little is known about the epidemiology of this disease, a survey was performed in fields surrounding affected sesame plantations to identify CABMV-infected plants that may be acting as sources of inoculum. Samples from 48 plant species (symptomatic or asymptomatic, mostly spontaneous and a few cultivated) belonging to 17 families were evaluated by biological and serological assays. In a few select cases, confirmation of the infection was achieved by RT-PCR. The following species were found to be naturally infected by CABMV: Amaranthus hybridus, Arachis hypogaea, Crotalaria incana, Crotalaria juncea, Crotalaria spectabilis, and Vigna unguiculata. The absence of resistant/tolerant sesame cultivars along with the ineffectiveness of disease control through the chemical control of Aphid vectors indicates that the only alternative available for disease management at present is the elimination and/or reduction of the sources of inoculum immediately before starting new plantations.
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genetic transformation of passionflower and evaluation of r1 and r2 generations for resistance to Cowpea Aphid borne mosaic virus
Plant Disease, 2011Co-Authors: Alessandra Cristina B A Monteirohara, Jorge Alberto Marques Rezende, Maria Lucia Carneiro Vieira, A S Jadao, Beatriz Madalena Januzzi Mendes, Flavio Trevisan, A P O A Mello, L M M Meletti, Sonia Maria De Stefano PiedadeAbstract:Monteiro-Hara, A. C. B. A., Jadao, A. S., Mendes, B. M. J., Rezende, J. A. M., Trevisan, F., Mello, A. P. O. A., Vieira, M. L. C., Meletti, L. M. M., and Piedade, S. M. De S. 2011. Genetic transformation of passionflower and evaluation of R1 and R2 generations for resistance to Cowpea Aphid borne mosaic virus. Plant Dis. 95:1021-1025. We report on the production and evaluation of passionflower transgenic lines for resistance to Cowpea Aphid borne mosaic virus (CABMV). Genetic transformation was done using Agrobacterium tumefaciens and transgene integration was confirmed by Southern blot analyses, resulting in nine transgenic lines for ‘IAC 275’ and three for ‘IAC 277’. Transgenic lines were clonally propagated and evaluated for resistance to CABMV. After the third inoculation, under higher inoculum pressure, only propagated plants of the transgenic line T16 remained asymptomatic, indicating a high resistance to infection with CABMV. This transgenic line was self-pollinated and the R1 generation was evaluated together with the R1 generation of another resistant transgenic line (T2) identified previously. Plants were inoculated with CABMV by means of viruliferous Myzus nicotianae. All 524 T2R1 plants became infected, whereas 13 of 279 T16R1 remained asymptomatic after four successive inoculations. A T16R2 generation was obtained and plants were inoculated with CABMV mechanically or by Aphids. After successive inoculations, 118 of 258 plants were symptomless, suggesting that the resistance to CABMV was maintained in the plant genome as the homozygous condition was achieved. Five selected resistant T16R2 plants which contained the capsid protein gene are being crossed for further analyses. Brazil is the world’s largest producer of passion fruit, with an estimated planted area of 44,300 ha and fruit yield of 615,196 t (12). Yellow passion fruit (Passiflora edulis f. flavicarpa) is the predominant species (98%), with the remaining area (2%) planted with sweet passion fruit (P. alata). However, this production is threatened by several pathogens, including the Potyvirus sp. Cowpea Aphid borne mosaic virus (CABMV) (4,23,24), which was previously misidentified as Passion fruit woodiness virus (6,7). The disease caused by CABMV was first detected in Brazil in the late 1970s in the State of Bahia (6), and then spread throughout the country (3,7,11,16). The virus is transmitted in a nonpersistent manner by several Aphid species, and also mechanically, during pruning. The disease causes severe yield losses and reduces the orchard lifespan by approximately half (13). The control of passion fruit woodiness disease in passionflower orchards is problematic. All cultivars of yellow and sweet passion fruit are susceptible to infection, and chemical vector control is usually inefficient because of the nonpersistent manner of transmission. Cross protection with mild strains of the virus have also failed to control the disease (26). Recently, two Brazilian hybrids (BRS Ouro Vermelho and BRS Sol do Cerrado) tolerant to this disease were introduced into the market but are still being evaluated by growers (http://www.cpac.embrapa.br/maracuja/inicio/). In Brazil, at present, several cultural practices have been recommended to minimize the problems associated with CABMV in passionflower orchards. These include the use of virus-free seedlings for new plantings, eradication of old and abandoned orchards before starting new crops, care during pruning operations to prevent mechanical transmission of the virus, avoidance of leguminous plants which may harbor the virus in the proximity of the orchard, and roguing of diseased plants by means of systematic inspections during the first 5 months after transplanting (11,13).
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Screening of Passiflora species for reaction to Cowpea Aphid-borne mosaic virus reveals an immune wild species
Scientia Agricola, 2009Co-Authors: S. C. Maciel, Daniel Hiroshi Nakano, Jorge Alberto Marques Rezende, Maria Lucia Carneiro VieiraAbstract:Cowpea Aphid-borne mosaic virus (CABMV) is a potyvirus that causes the most serious virus disease of passion fruit crops in Brazil. It is transmitted by several species of Aphids in a non-persistent, non-circulative manner. The reaction of 16 species of Passiflora to infection by mechanical inoculation with four Brazilian isolates of CABMV was evaluated under greenhouse conditions. Only P. suberosa, a wild species, was resistant to infection by all virus isolates, in two independent assays. P. suberosa grafted onto infected P. edulis f. flavicarpa did not develop symptoms; neither was the virus detected by RT-PCR in the upper leaves, suggesting that this species is immune to CABMV.
