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S. K. Pahuja - One of the best experts on this subject based on the ideXlab platform.
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Role of 2,4-D and BAP in in vitro regeneration of Cyamopsis species
International Journal of Research, 2018Co-Authors: Anju Ahlawat, Hans Raj Dhingra, S. K. PahujaAbstract:With the objective to optimize medium receipe and cultural conditions for plant regeneration in Cyamopsis species viz. C. tetragonoloba cv. HG 563, C . serrata and C. Senegalensis . Different explants viz. cotyledon, hypocotyls, cotyledonary node measuring 4-5mm obtained from asceptically grown seedlings were inoculated on the surface of culture medium. Embryo explants were excised from surface sterilized 10 day old green pods taken from net house and three explants per flask were cultured. Direct shoot regeneration from hypocotyls was observed in medium adjuncted with 1mg/l BAP in C. serrata. Cotyledonary node produced multiple shoot on MS medium supplemented with 2mg/l BAP. C. senegalensis showed direct multiple shoot formation only from hypocotyl explants in medium supplemented with 1mg/l BAP. Maximum callus induction from cotyledon explant was evident in C. serrata and C. senegalensis on MS medium with B5 vitamins and supplemented 2, 4-D (2mg/l). Hypocotyl explants of all the tested species of Cyamopsis showed very good callus induction response in media supplemented with 2mg/l 2, 4-D. Half strength MS + NAA(2mg/l) was the best for rooting of shoots in C. tetragonoloba while ½ MS with 0.5 mg/l and 1 mg/l IBA supported best rooting in C. senegalensis and C. serrata . C. tetragonoloba showed flowering in MS medium adjuncted with NAA (2mg/l) with BAP (2mg/l) from shoots obtained from cotyledonary node explant after 80-90 days of inoculation. In vitro regenerated plantlets were successfully transferred to paper cups.Micropropagation of C. serrata and C. senegalensis on the above media will help to produce true to type plants and reduce dependence on seeds for plant production.
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African Journal of Agricultural
2016Co-Authors: Anju Ahlawat, S. K. Pahuja, H. R. DhingraAbstract:Studies on interspecific hybridization in Cyamopsis specie
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Review Mutagenesis in Guar [Cyamopsis tetragonoloba (L.) Taub.]
2015Co-Authors: R. N. Arora, S. K. PahujaAbstract:Guar or clusterbean [Cyamopsis tetragonoloba (L.) Taub.] (2n=14) is a multipurpose legume crop, grown for feed, green fodder, vegetable, green manuring, and grain purposes. Mutagenesis is a powerful tool for creating variation in a crop like guar where exploitable and favourable genetic variability is very meager. Various types of manifestations such as recip-rocal translocations, trisomics, reduction in seed germination, seedling survival, pollen fertility, seed yield, number of seeds per pod, and pod length have been reported in the materials treated with mutagens and their progenies. Additionally, some researchers have observed increase in peduncle length, plant height, and number of clusters, number of pods per cluster, number of pods, seed yield, protein content, gum content and early maturity in the mutated material. The doses of 100 to 200 kR have been quoted to be lethal. The application of chemical mutagens like EMS, hydroxyl amine, hydrazine hydrate, ki-tazin, saturn, sodium nitrate, NMU, and sodium azide have generated chlorophyll mutations, profuse vegetative growth, single stem, regular pod bearing, changed leaf texture or shape and pod size, late flowering, changes in seed colour, determi-nate and spreading growth habit etc. Heterophylly in guar has also been reported. The effect of hybridization and mutagenesis on the inheritance of various morphological traits in guar has also been studied. Further research and understanding on muta-tion induction is needed to generate more desirable genetic variability for traits of economic importance to develop better ideotypes in guar
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In vitro callus formation in cultivated and wild species of Cyamopsis
African Journal of Biotechnology, 2013Co-Authors: Anju Ahlawat, Hans Raj Dhingra, S. K. PahujaAbstract:2,4-Dichlorophenoxy acetic acid (2, 4-D) and benzylaminopurine (BAP) induced callusing from cotyledons in all three species of Cyamopsis . The maximum callus induction from cotyledon explant was evident in Cyamopsis serrata and Cyamopsis senegalensis on a medium supplemented with 2,4-D (2 mg/l). On the other hand, Cyamopsis tetragonoloba showed poor callus formation on the same medium. The callus however, proliferated well on Murashige and Skoog (MS) medium adjuncted with naphthalene acetic acid (NAA) (2 mg/l) + BAP (2 mg/l). Hypocotyl of all the tested species of Cyamopsis showed very good callus induction response in the medium supplemented with 2 mg/l 2,4-D. As the concentration of BAP increased from (1 mg/l) to (2 mg/l) in combination with NAA (2 mg/l) callus formation was also increased. From cotyledonary node explant, when NAA (2 mg/l) is combined with BAP (1 mg/l), then good callusing was observed in C. serrata whereas no callusing was found in other species. 2,4-D induce callusing in all the three species of Cyamopsis at (2mg/l) concentration and both the wild species have more callus formation then cultivated species. In C. serrate , good callusing was observed at BAP (1 mg/l) from immature embryo explant. When the concentration of NAA is increased to 1 mg/l and concentration of BAP is decreased with 0.5 mg/l, response was decreased in wild species of C. senegalensis whereas no change in response was found in the other two species. Keywords : Callus induction, cluster bean ( Cyamopsis tetragonoloba ), Cyamopsis serrata, Cyamopsis senegalensis . African Journal of Biotechnology Vol. 12(30), pp. 4813-4818
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Studies on interspecific hybridization in Cyamopsis species
African Journal of Agricultural Research, 2013Co-Authors: Anju Ahlawat, S. K. Pahuja, Hans Raj DhingraAbstract:Reproductive characters of three species of Cyamopsis were studied to find out barriers to interspecific crosses between Cyamopsis tetragonoloba × Cyamopsis serrata and C. tetragonoloba × C. senegalensiswhich may serve as a stepping stone for development of extra early varieties of guar. Pollen grains of C. tetragonoloba and C. senegalensis showed more than 95% of viability while those of C. serrata had 87% viability. Nutritive requirement for in vitro germination of pollen revealed that pollen of C. tetragonoloba required 25% sucrose + 100 ppm boric acid + 300 ppm calcium nitrate while C. senegalensis pollen needed 35% sucrose with same basal medium. On the other hand, C. serrata pollen required 35% maltose + 6% PEG 6000 along with above dose of boric acid and calcium nitrate. Moreover, pollen germination in C. serrata was initiated after 30 h of incubation and its pollen tubes were slow growing attaining 174.7 µm length in 48 h. The length of style of C. tetragonoloba and C. serrata was nearly identical (2.6 mm) while C. senegalensispossessed longest style (3.8 mm). Interspecific hybridization between C. tetragonoloba x C. serrata was successful through the use of stub smeared with pollen germination medium (PGM) and as a consequence 10.43% of pod setting was observed. Colour and shape of hybrid seeds was similar to the female parent (C. tetragonoloba), hybrid plants showed early flowering just like male parent (C. serrata) whereas the plant height was intermediate between the two parents. Key words: Interspecific hybrids, pollen, in vitro germination, stub pollination, in vivo tube growth.
Anju Ahlawat - One of the best experts on this subject based on the ideXlab platform.
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Role of 2,4-D and BAP in in vitro regeneration of Cyamopsis species
International Journal of Research, 2018Co-Authors: Anju Ahlawat, Hans Raj Dhingra, S. K. PahujaAbstract:With the objective to optimize medium receipe and cultural conditions for plant regeneration in Cyamopsis species viz. C. tetragonoloba cv. HG 563, C . serrata and C. Senegalensis . Different explants viz. cotyledon, hypocotyls, cotyledonary node measuring 4-5mm obtained from asceptically grown seedlings were inoculated on the surface of culture medium. Embryo explants were excised from surface sterilized 10 day old green pods taken from net house and three explants per flask were cultured. Direct shoot regeneration from hypocotyls was observed in medium adjuncted with 1mg/l BAP in C. serrata. Cotyledonary node produced multiple shoot on MS medium supplemented with 2mg/l BAP. C. senegalensis showed direct multiple shoot formation only from hypocotyl explants in medium supplemented with 1mg/l BAP. Maximum callus induction from cotyledon explant was evident in C. serrata and C. senegalensis on MS medium with B5 vitamins and supplemented 2, 4-D (2mg/l). Hypocotyl explants of all the tested species of Cyamopsis showed very good callus induction response in media supplemented with 2mg/l 2, 4-D. Half strength MS + NAA(2mg/l) was the best for rooting of shoots in C. tetragonoloba while ½ MS with 0.5 mg/l and 1 mg/l IBA supported best rooting in C. senegalensis and C. serrata . C. tetragonoloba showed flowering in MS medium adjuncted with NAA (2mg/l) with BAP (2mg/l) from shoots obtained from cotyledonary node explant after 80-90 days of inoculation. In vitro regenerated plantlets were successfully transferred to paper cups.Micropropagation of C. serrata and C. senegalensis on the above media will help to produce true to type plants and reduce dependence on seeds for plant production.
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African Journal of Agricultural
2016Co-Authors: Anju Ahlawat, S. K. Pahuja, H. R. DhingraAbstract:Studies on interspecific hybridization in Cyamopsis specie
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In vitro callus formation in cultivated and wild species of Cyamopsis
African Journal of Biotechnology, 2013Co-Authors: Anju Ahlawat, Hans Raj Dhingra, S. K. PahujaAbstract:2,4-Dichlorophenoxy acetic acid (2, 4-D) and benzylaminopurine (BAP) induced callusing from cotyledons in all three species of Cyamopsis . The maximum callus induction from cotyledon explant was evident in Cyamopsis serrata and Cyamopsis senegalensis on a medium supplemented with 2,4-D (2 mg/l). On the other hand, Cyamopsis tetragonoloba showed poor callus formation on the same medium. The callus however, proliferated well on Murashige and Skoog (MS) medium adjuncted with naphthalene acetic acid (NAA) (2 mg/l) + BAP (2 mg/l). Hypocotyl of all the tested species of Cyamopsis showed very good callus induction response in the medium supplemented with 2 mg/l 2,4-D. As the concentration of BAP increased from (1 mg/l) to (2 mg/l) in combination with NAA (2 mg/l) callus formation was also increased. From cotyledonary node explant, when NAA (2 mg/l) is combined with BAP (1 mg/l), then good callusing was observed in C. serrata whereas no callusing was found in other species. 2,4-D induce callusing in all the three species of Cyamopsis at (2mg/l) concentration and both the wild species have more callus formation then cultivated species. In C. serrate , good callusing was observed at BAP (1 mg/l) from immature embryo explant. When the concentration of NAA is increased to 1 mg/l and concentration of BAP is decreased with 0.5 mg/l, response was decreased in wild species of C. senegalensis whereas no change in response was found in the other two species. Keywords : Callus induction, cluster bean ( Cyamopsis tetragonoloba ), Cyamopsis serrata, Cyamopsis senegalensis . African Journal of Biotechnology Vol. 12(30), pp. 4813-4818
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Studies on interspecific hybridization in Cyamopsis species
African Journal of Agricultural Research, 2013Co-Authors: Anju Ahlawat, S. K. Pahuja, Hans Raj DhingraAbstract:Reproductive characters of three species of Cyamopsis were studied to find out barriers to interspecific crosses between Cyamopsis tetragonoloba × Cyamopsis serrata and C. tetragonoloba × C. senegalensiswhich may serve as a stepping stone for development of extra early varieties of guar. Pollen grains of C. tetragonoloba and C. senegalensis showed more than 95% of viability while those of C. serrata had 87% viability. Nutritive requirement for in vitro germination of pollen revealed that pollen of C. tetragonoloba required 25% sucrose + 100 ppm boric acid + 300 ppm calcium nitrate while C. senegalensis pollen needed 35% sucrose with same basal medium. On the other hand, C. serrata pollen required 35% maltose + 6% PEG 6000 along with above dose of boric acid and calcium nitrate. Moreover, pollen germination in C. serrata was initiated after 30 h of incubation and its pollen tubes were slow growing attaining 174.7 µm length in 48 h. The length of style of C. tetragonoloba and C. serrata was nearly identical (2.6 mm) while C. senegalensispossessed longest style (3.8 mm). Interspecific hybridization between C. tetragonoloba x C. serrata was successful through the use of stub smeared with pollen germination medium (PGM) and as a consequence 10.43% of pod setting was observed. Colour and shape of hybrid seeds was similar to the female parent (C. tetragonoloba), hybrid plants showed early flowering just like male parent (C. serrata) whereas the plant height was intermediate between the two parents. Key words: Interspecific hybrids, pollen, in vitro germination, stub pollination, in vivo tube growth.
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In vitro Regeneration of Wild species of Guar (Cyamopsis serrata and Cyamopsis senegalensis)
Journal of Krishi Vigyan, 2013Co-Authors: Anju Ahlawat, Hans Raj Dhingra, Jagbir Singh DhankarAbstract:Wild relatives of Cyamopsis i.e. C. serrata is an early maturing (40–50 days), slow growing and branched species, while the other species i.e. C. senegalensis is a slow growing annual herb and matures in 120–130 days. Both these wild relatives possess some desirable attributes like drought resistance, photo-and thermo-insensitivity and disease resistance.
Savithri, Handanahal S. - One of the best experts on this subject based on the ideXlab platform.
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Sesbania Mosaic Virus (SeMV) Infectious Clone: Possible Mechanism of 3 ` and 5 ` End Repair and Role of Polyprotein Processing in Viral Replication
PUBLIC LIBRARY SCIENCE, 2012Co-Authors: Govind Kunduri, Mäkinen Kristiina, Savithri, Handanahal S.Abstract:Sesbania mosaic virus (SeMV) is a positive stranded RNA virus belonging to the genus Sobemovirus. Construction of an infectious clone is an essential step for deciphering the virus gene functions in vivo. Using Agrobacterium based transient expression system we show that SeMV icDNA is infectious on Sesbania grandiflora and Cyamopsis tetragonoloba plants. The efficiency of icDNA infection was found to be significantly high on Cyamopsis plants when compared to that on Sesbania grandiflora. The coat protein could be detected within 6 days post infiltration in the infiltrated leaves. Different species of viral RNA (double stranded and single stranded genomic and subgenomic RNA) could be detected upon northern analysis, suggesting that complete replication had taken place. Based on the analysis of the sequences at the genomic termini of progeny RNA from SeMV icDNA infiltrated leaves and those of its 3' and 5' terminal deletion mutants, we propose a possible mechanism for 3' and 5' end repair in vivo. Mutation of the cleavage sites in the polyproteins encoded by ORF 2 resulted in complete loss of infection by the icDNA, suggesting the importance of correct polyprotein processing at all the four cleavage sites for viral replication. Complementation analysis suggested that ORF 2 gene products can act in trans. However, the trans acting ability of ORF 2 gene products was abolished upon deletion of the N-terminal hydrophobic domain of polyprotein 2a and 2ab, suggesting that these products necessarily function at the replication site, where they are anchored to membranes
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Sesbania mosaic virus (SeMV) infectious clone: possible mechanism of 3′ and 5′ end repair and role of polyprotein processing in viral replication
'Public Library of Science (PLoS)', 2012Co-Authors: Govind Kunduri, Mäkinen Kristiina, Savithri, Handanahal S.Abstract:Sesbania mosaic virus (SeMV) is a positive stranded RNA virus belonging to the genus Sobemovirus. Construction of an infectious clone is an essential step for deciphering the virus gene functions in vivo. Using Agrobacterium based transient expression system we show that SeMV icDNA is infectious on Sesbania grandiflora and Cyamopsis tetragonoloba plants. The efficiency of icDNA infection was found to be significantly high on Cyamopsis plants when compared to that on Sesbania grandiflora. The coat protein could be detected within 6 days post infiltration in the infiltrated leaves. Different species of viral RNA (double stranded and single stranded genomic and subgenomic RNA) could be detected upon northern analysis, suggesting that complete replication had taken place. Based on the analysis of the sequences at the genomic termini of progeny RNA from SeMV icDNA infiltrated leaves and those of its 3′ and 5′ terminal deletion mutants, we propose a possible mechanism for 3′ and 5′ end repair in vivo. Mutation of the cleavage sites in the polyproteins encoded by ORF 2 resulted in complete loss of infection by the icDNA, suggesting the importance of correct polyprotein processing at all the four cleavage sites for viral replication. Complementation analysis suggested that ORF 2 gene products can act in trans. However, the trans acting ability of ORF 2 gene products was abolished upon deletion of the N-terminal hydrophobic domain of polyprotein 2a and 2ab, suggesting that these products necessarily function at the replication site, where they are anchored to membranes
Hans Raj Dhingra - One of the best experts on this subject based on the ideXlab platform.
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Role of 2,4-D and BAP in in vitro regeneration of Cyamopsis species
International Journal of Research, 2018Co-Authors: Anju Ahlawat, Hans Raj Dhingra, S. K. PahujaAbstract:With the objective to optimize medium receipe and cultural conditions for plant regeneration in Cyamopsis species viz. C. tetragonoloba cv. HG 563, C . serrata and C. Senegalensis . Different explants viz. cotyledon, hypocotyls, cotyledonary node measuring 4-5mm obtained from asceptically grown seedlings were inoculated on the surface of culture medium. Embryo explants were excised from surface sterilized 10 day old green pods taken from net house and three explants per flask were cultured. Direct shoot regeneration from hypocotyls was observed in medium adjuncted with 1mg/l BAP in C. serrata. Cotyledonary node produced multiple shoot on MS medium supplemented with 2mg/l BAP. C. senegalensis showed direct multiple shoot formation only from hypocotyl explants in medium supplemented with 1mg/l BAP. Maximum callus induction from cotyledon explant was evident in C. serrata and C. senegalensis on MS medium with B5 vitamins and supplemented 2, 4-D (2mg/l). Hypocotyl explants of all the tested species of Cyamopsis showed very good callus induction response in media supplemented with 2mg/l 2, 4-D. Half strength MS + NAA(2mg/l) was the best for rooting of shoots in C. tetragonoloba while ½ MS with 0.5 mg/l and 1 mg/l IBA supported best rooting in C. senegalensis and C. serrata . C. tetragonoloba showed flowering in MS medium adjuncted with NAA (2mg/l) with BAP (2mg/l) from shoots obtained from cotyledonary node explant after 80-90 days of inoculation. In vitro regenerated plantlets were successfully transferred to paper cups.Micropropagation of C. serrata and C. senegalensis on the above media will help to produce true to type plants and reduce dependence on seeds for plant production.
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In vitro callus formation in cultivated and wild species of Cyamopsis
African Journal of Biotechnology, 2013Co-Authors: Anju Ahlawat, Hans Raj Dhingra, S. K. PahujaAbstract:2,4-Dichlorophenoxy acetic acid (2, 4-D) and benzylaminopurine (BAP) induced callusing from cotyledons in all three species of Cyamopsis . The maximum callus induction from cotyledon explant was evident in Cyamopsis serrata and Cyamopsis senegalensis on a medium supplemented with 2,4-D (2 mg/l). On the other hand, Cyamopsis tetragonoloba showed poor callus formation on the same medium. The callus however, proliferated well on Murashige and Skoog (MS) medium adjuncted with naphthalene acetic acid (NAA) (2 mg/l) + BAP (2 mg/l). Hypocotyl of all the tested species of Cyamopsis showed very good callus induction response in the medium supplemented with 2 mg/l 2,4-D. As the concentration of BAP increased from (1 mg/l) to (2 mg/l) in combination with NAA (2 mg/l) callus formation was also increased. From cotyledonary node explant, when NAA (2 mg/l) is combined with BAP (1 mg/l), then good callusing was observed in C. serrata whereas no callusing was found in other species. 2,4-D induce callusing in all the three species of Cyamopsis at (2mg/l) concentration and both the wild species have more callus formation then cultivated species. In C. serrate , good callusing was observed at BAP (1 mg/l) from immature embryo explant. When the concentration of NAA is increased to 1 mg/l and concentration of BAP is decreased with 0.5 mg/l, response was decreased in wild species of C. senegalensis whereas no change in response was found in the other two species. Keywords : Callus induction, cluster bean ( Cyamopsis tetragonoloba ), Cyamopsis serrata, Cyamopsis senegalensis . African Journal of Biotechnology Vol. 12(30), pp. 4813-4818
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Studies on interspecific hybridization in Cyamopsis species
African Journal of Agricultural Research, 2013Co-Authors: Anju Ahlawat, S. K. Pahuja, Hans Raj DhingraAbstract:Reproductive characters of three species of Cyamopsis were studied to find out barriers to interspecific crosses between Cyamopsis tetragonoloba × Cyamopsis serrata and C. tetragonoloba × C. senegalensiswhich may serve as a stepping stone for development of extra early varieties of guar. Pollen grains of C. tetragonoloba and C. senegalensis showed more than 95% of viability while those of C. serrata had 87% viability. Nutritive requirement for in vitro germination of pollen revealed that pollen of C. tetragonoloba required 25% sucrose + 100 ppm boric acid + 300 ppm calcium nitrate while C. senegalensis pollen needed 35% sucrose with same basal medium. On the other hand, C. serrata pollen required 35% maltose + 6% PEG 6000 along with above dose of boric acid and calcium nitrate. Moreover, pollen germination in C. serrata was initiated after 30 h of incubation and its pollen tubes were slow growing attaining 174.7 µm length in 48 h. The length of style of C. tetragonoloba and C. serrata was nearly identical (2.6 mm) while C. senegalensispossessed longest style (3.8 mm). Interspecific hybridization between C. tetragonoloba x C. serrata was successful through the use of stub smeared with pollen germination medium (PGM) and as a consequence 10.43% of pod setting was observed. Colour and shape of hybrid seeds was similar to the female parent (C. tetragonoloba), hybrid plants showed early flowering just like male parent (C. serrata) whereas the plant height was intermediate between the two parents. Key words: Interspecific hybrids, pollen, in vitro germination, stub pollination, in vivo tube growth.
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In vitro Regeneration of Wild species of Guar (Cyamopsis serrata and Cyamopsis senegalensis)
Journal of Krishi Vigyan, 2013Co-Authors: Anju Ahlawat, Hans Raj Dhingra, Jagbir Singh DhankarAbstract:Wild relatives of Cyamopsis i.e. C. serrata is an early maturing (40–50 days), slow growing and branched species, while the other species i.e. C. senegalensis is a slow growing annual herb and matures in 120–130 days. Both these wild relatives possess some desirable attributes like drought resistance, photo-and thermo-insensitivity and disease resistance.
Govind Kunduri - One of the best experts on this subject based on the ideXlab platform.
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Sesbania Mosaic Virus (SeMV) Infectious Clone: Possible Mechanism of 3 ` and 5 ` End Repair and Role of Polyprotein Processing in Viral Replication
PUBLIC LIBRARY SCIENCE, 2012Co-Authors: Govind Kunduri, Mäkinen Kristiina, Savithri, Handanahal S.Abstract:Sesbania mosaic virus (SeMV) is a positive stranded RNA virus belonging to the genus Sobemovirus. Construction of an infectious clone is an essential step for deciphering the virus gene functions in vivo. Using Agrobacterium based transient expression system we show that SeMV icDNA is infectious on Sesbania grandiflora and Cyamopsis tetragonoloba plants. The efficiency of icDNA infection was found to be significantly high on Cyamopsis plants when compared to that on Sesbania grandiflora. The coat protein could be detected within 6 days post infiltration in the infiltrated leaves. Different species of viral RNA (double stranded and single stranded genomic and subgenomic RNA) could be detected upon northern analysis, suggesting that complete replication had taken place. Based on the analysis of the sequences at the genomic termini of progeny RNA from SeMV icDNA infiltrated leaves and those of its 3' and 5' terminal deletion mutants, we propose a possible mechanism for 3' and 5' end repair in vivo. Mutation of the cleavage sites in the polyproteins encoded by ORF 2 resulted in complete loss of infection by the icDNA, suggesting the importance of correct polyprotein processing at all the four cleavage sites for viral replication. Complementation analysis suggested that ORF 2 gene products can act in trans. However, the trans acting ability of ORF 2 gene products was abolished upon deletion of the N-terminal hydrophobic domain of polyprotein 2a and 2ab, suggesting that these products necessarily function at the replication site, where they are anchored to membranes
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Sesbania mosaic virus (SeMV) infectious clone: possible mechanism of 3′ and 5′ end repair and role of polyprotein processing in viral replication
'Public Library of Science (PLoS)', 2012Co-Authors: Govind Kunduri, Mäkinen Kristiina, Savithri, Handanahal S.Abstract:Sesbania mosaic virus (SeMV) is a positive stranded RNA virus belonging to the genus Sobemovirus. Construction of an infectious clone is an essential step for deciphering the virus gene functions in vivo. Using Agrobacterium based transient expression system we show that SeMV icDNA is infectious on Sesbania grandiflora and Cyamopsis tetragonoloba plants. The efficiency of icDNA infection was found to be significantly high on Cyamopsis plants when compared to that on Sesbania grandiflora. The coat protein could be detected within 6 days post infiltration in the infiltrated leaves. Different species of viral RNA (double stranded and single stranded genomic and subgenomic RNA) could be detected upon northern analysis, suggesting that complete replication had taken place. Based on the analysis of the sequences at the genomic termini of progeny RNA from SeMV icDNA infiltrated leaves and those of its 3′ and 5′ terminal deletion mutants, we propose a possible mechanism for 3′ and 5′ end repair in vivo. Mutation of the cleavage sites in the polyproteins encoded by ORF 2 resulted in complete loss of infection by the icDNA, suggesting the importance of correct polyprotein processing at all the four cleavage sites for viral replication. Complementation analysis suggested that ORF 2 gene products can act in trans. However, the trans acting ability of ORF 2 gene products was abolished upon deletion of the N-terminal hydrophobic domain of polyprotein 2a and 2ab, suggesting that these products necessarily function at the replication site, where they are anchored to membranes
