| nucleotide sequences from tomato leaf curl viruses from different countries: evidence for three geographically separate branches in evolution of the coat protein of whitefly-transmitted geminiviruses. | the coat protein (cp) gene-containing circular dna molecule of an isolate of tomato leaf curl geminivirus (itmlcv; 2749 nt) obtained from southern india, and the cp genes of tomato yellow leaf curl geminivirus isolates from nigeria and two regions of saudia arabia were sequenced. itmlcv dna had the same arrangement of orfs, and the same pattern of repeats in the large intergenic region as is found in in dna-a of other whitefly-transmitted geminivirus (wtgs) from the old world. however, the seque ... | 1995 | 7636485 |
| molecular cloning of indian tomato leaf curl virus genome following a simple method of concentrating the supercoiled replicative form of viral dna. | dna-a and dna-b components of the genome of a whitefly transmitted virus causing yellowing and leaf curl in tomato (itlcv) were cloned following a simple procedure for isolation of the double stranded replicative form of viral dna from infected tomato plants. the method is based on extraction of total dna from infected plants followed by concentration of the double stranded replicative form of viral dna by an alkaline denaturation procedure identical to that used for isolation of plasmid dna fro ... | 1995 | 7738150 |
| tomato leaf curl geminivirus from india has a bipartite genome and coat protein is not essential for infectivity. | genomes of two isolates of tomato leaf curl geminivirus from india (tolcv-india) have been sequenced. tolcv-india contains a and b components, both of which are required for systemic movement and symptom development. the two isolates have 94% sequence identify but one isolate gave mild symptoms in nicotiana benthamiana and tomato. the genome organization of tolcv-india is similar to other whitefly-transmitted geminiviruses (wtgs) with bipartite genomes. however, it contains an additional orf, av ... | 1995 | 7844539 |
| orf c4 of tomato leaf curl geminivirus is a determinant of symptom severity. | a tomato leaf curl virus (tlcv) mutant has been constructed in vitro that contains t-to-c replacements at nucleotides 2457 and 2463 within the c4 open reading frame (orf). the mutations destroy the two possible initiator aug codons for the c4 orf without disrupting the coding capacity of the c1 orf which entirely overlaps the c4 orf. agroinoculation of the c4 mutant tlcv into three alternative experimental hosts for the virus (datura stramonium, lycopersicon esculentum, and nicotiana tabacum) gi ... | 1994 | 7941358 |
| complete nucleotide sequence of the geminivirus tomato yellow leaf curl virus, thailand isolate. | the complete genome of a thailand isolate of the geminivirus tomato yellow leaf curl virus (tylcv-th) has been cloned and the nucleotide sequence determined. the genome consists of two dnas each slightly greater than 2700 nucleotides in length and designated a-dna and b-dna. the a-dna contains six open reading frames (orfs) capable of encoding proteins with m(r)s greater than 10k; two orfs were located on the b-dna. the predicted orfs were found at positions on the genome similar to those identi ... | 1994 | 8126446 |
| nucleotide sequence and genome organization of tomato leaf curl geminivirus. | the genome of tomato leaf curl virus (tlcv) from australia was cloned and its complete nucleotide sequence determined. it is a single circular ssdna of 2766 nucleotides containing the consensus nonanucleotide sequence present in all geminiviruses. it has six open reading frames with an organization resembling that of certain other dicotyledonous plant-infecting monopartite geminiviruses, i.e. tomato yellow leaf curl and beet curly top viruses. the regulatory sequences present indicate a bidirect ... | 1993 | 8423446 |
| mapping of the polycistronic rnas of tomato leaf curl geminivirus. | four major transcripts from infected tomato were identified and mapped onto the monopartite genome of the geminivirus tomato leaf curl virus (tlcv). the c1, c2, and c3 orfs are spanned by one transcript and a second internal rna covered c2 and c3. both these rnas have their counterparts in the dna a components of the bipartite subgroup of geminiviruses. the 5' ends of the virion-sense rnas map either side of the first in-frame aug of the v1 orf. the 3' ends of the virion-sense rnas are cotermina ... | 1993 | 8438578 |
| mutagenesis of the virion-sense open reading frames of tomato leaf curl geminivirus. | a series of frame shift, deletion, and inversion mutants in the virion-sense open reading frames (orfs) of the monopartite geminivirus tomato leaf curl virus have been constructed and their ability to replicate, produce single-stranded dna, spread, and cause symptoms in tomato plants has been investigated. disruptions in the v1 orf lead to symptomless, systemic infections with a reduced titer of all viral dna forms while interruptions in the v2 (coat protein) orf disrupted spread of the virus. m ... | 1993 | 8460471 |
| association of geminivirus infection with yellow green mosaic disease of cucumis sativus: diagnosis by nucleic acid probes. | geminivirus association with yellow mosaic disease of c. sativus has been investigated by dot/slot blot hybridization tests using nucleic acid probe derived from dna-b of indian tomato leaf curl geminivirus. the disease was transmitted experimentally on c. sativus by whitefly, bemisia tabaci. some weeds were also found to harbour geminivirus infection in dot/slot blot hybridization tests. | 1996 | 8792653 |
| plant virus dna replication processes in agrobacterium: insight into the origins of geminiviruses? | agrobacterium tumefaciens, a bacterial plant pathogen, when transformed with plasmid constructs containing greater than unit length dna of tomato leaf curl geminivirus accumulates viral replicative form dnas indistinguishable from those produced in infected plants. the accumulation of the viral dna species depends on the presence of two origins of replication in the dna constructs and is drastically reduced by introducing mutations into the viral replication-associated protein (rep or c1) orf, i ... | 1996 | 8816791 |
| the role of av2 ("precoat") and coat protein in viral replication and movement in tomato leaf curl geminivirus. | we analyzed various mutants of tomato leaf curl virus-india to investigate the role of orfs av3, av2, and coat protein (cp) in viral replication, movement, and symptom development. the results of these studies indicate that orf av3 does not encode a protein. plants inoculated with infectious dna which contained deletions in av2 developed very mild symptoms and accumulated only low levels of both single-stranded (ss) and double-stranded (ds) viral dna, whereas inoculated protoplasts accumulated b ... | 1996 | 8874500 |
| a novel subviral agent associated with a geminivirus: the first report of a dna satellite. | numerous plant rna viruses have associated with them satellite (sat) rnas that have little or no nucleotide sequence similarity to either the viral or host genomes but are completely dependent on the helper virus for replication. we report here on the discovery of a 682-nt circular dna satellite associated with tomato leaf curl geminivirus (tlcv) infection in northern australia. this is the first demonstration that satellite molecules are not limited to rna viral systems. the dna satellite (tlcv ... | 1997 | 9192696 |
| identification of the replication-associated protein binding domain within the intergenic region of tomato leaf curl geminivirus. | the geminiviral replication-associated protein (rep) is the only viral protein required for viral dna replication. tomato leaf curl virus (tlcv) rep was expressed in escherichia coli as a histidine-tagged fusion protein and purified to homogeneity in non-denaturing form. the fusion protein was used in in vitro binding experiments to identify the rep-binding elements within the origin of replication of tlcv. electrophoretic mobility shift assays demonstrated that the rep binds specifically to a 1 ... | 1998 | 9461449 |
| molecular characterization of a new whitefly-transmissible bipartite geminivirus infecting tomato in panama. | the nucleotide sequence of infectious clones of a tomato-infecting geminivirus from panama [named tomato leaf curl virus (tolcv-pan) because of symptoms produced in infected tomato (plant stunting and mild leaf curling)] was determined. tolcv-pan has a bipartite genome (dnas a and b) and computer analysis showed that the genome resembles that of other bipartite, whitefly-transmitted geminiviruses. dna a (2584 nt) and b (2542 nt) have little sequence homology other than within the common region. ... | 1998 | 9780034 |
| a phage single-stranded dna (ssdna) binding protein complements ssdna accumulation of a geminivirus and interferes with viral movement. | geminiviruses are plant viruses with circular single-stranded dna (ssdna) genomes encapsidated in double icosahedral particles. tomato leaf curl geminivirus (tolcv) requires coat protein (cp) for the accumulation of ssdna in protoplasts and in plants but not for systemic infection and symptom development in plants. in the absence of cp, infected protoplasts accumulate reduced levels of ssdna and increased amounts of double-stranded dna (dsdna), compared to accumulation in the presence of wild-ty ... | 1999 | 9882367 |
| identification of replication specificity determinants in two strains of tomato leaf curl virus from new delhi. | we used two strains of tomato leaf curl virus from new delhi to investigate specificity in replication of their cognate genomes. the strains share 94% sequence identity and are referred to as severe and mild on the basis of symptoms on tomato and tobacco. replication assays in tobacco protoplasts and plants showed that a single amino acid change, asn10 to asp in the n terminus of rep protein, determines specificity for replication of the two strains based upon its interaction with the origin of ... | 1999 | 10364296 |
| complete nucleotide sequence and the genome organization of tobacco leaf curl geminivirus from japan. | the genomic dna of tobacco leaf curl geminivirus (tlcv) from tomato plants with leaf curl disease in japan has been sequenced. the single circular dna molecule comprises 2,761 nucleotides. tlcv dna contains six open reading frames (orfs) capable of encoding proteins with a molecular weight greater than 10 k. in total nucleotide sequence comparisons with other geminiviruses, tlcv was most closely related to tomato leaf curl virus from taiwan (twtolcv) (76% identity), tomato leaf curl virus from b ... | 1999 | 10585147 |
| regulation of tomato leaf curl viral gene expression in host tissues. | the regulation of expression of the two virion-sense (v1 and v2) and four complementary-sense (c1, c2, c3, and c4) open reading frames (orfs) of tomato leaf curl virus (tlcv) was studied in both stably and transiently transformed nicotiana tabacum tissues with fusions with the beta-glucuronidase (gus) reporter gene. gus-expressing transgenic lines were obtained with each of the four complementary-sense gene-gus fusion constructs and with truncated versions of the virion-sense gene-gus fusion con ... | 2000 | 10796019 |
| a unique virus complex causes ageratum yellow vein disease. | ageratum conyzoides l., a weed species widely distributed throughout southeast asia, frequently exhibits striking yellow vein symptoms associated with infection by ageratum yellow vein virus (ayvv), a member of the geminiviridae (genus begomovirus). most begomoviruses have bipartite genomes (dnas a and b), but only a dna a has been identified for ayvv. we demonstrate that yellow vein disease of a. conyzoides results from co-infection by ayvv dna a (2,741 nt) and a circular dna that is approximat ... | 2000 | 10841581 |
| sequence parameters that determine specificity of binding of the replication-associated protein to its cognate site in two strains of tomato leaf curl virus-new delhi. | the dna binding sites for the replication-associated protein (rep) of two strains of tomato leaf curl virus from new delhi (tolcv-nde) were identified using electrophoretic mobility shift assays (emsas). the rep proteins of the two strains were found to exhibit sequence specificity in recognition of their cognate repeat motifs (iterons) in the origin, despite the fact that they share 91% sequence identity. using a series of synthetic oligonucleotides as probes in emsas, the interaction of rep pr ... | 2000 | 10915605 |
| tomato leaf curl virus from bangalore (tolcv-ban4): sequence comparison with indian tolcv isolates, detection in plants and insects, and vector relationships. | tomato leaf curl virus (tolcv) is a whitefly (bemisia tabaci) transmitted geminivirus (family geminiviridae, genus begomovirus) causing a destructive disease of tomato in many regions of india, east asia and australia. while tolcv isolates from australia and taiwan have a single genomic component (designated dna-a), those from northern india have two components (dna-a and dna-b). the tolcv isolates from southern india (bangalore) previously cloned seem to have a dna-a-like monopartite genome. we ... | 2000 | 11003471 |
| natural recombination between tomato yellow leaf curl virus-is and tomato leaf curl virus. | the complete genome sequences (2791 and 2793 nt) of isolates of tomato yellow leaf curl virus-is (tylcv-is) from spain (sp72/97) and portugal (port2/95) were determined. these isolates are closely related to tylcv-is isolates reported in japan (japan-a and japan-s) and israel (israel/mild). comparison of all sequenced isolates of tylcv-is showed that part of the genome comprising the intergenic region and the 5'-end of the rep gene of the iran and israel isolates was not closely related to that ... | 2000 | 11038394 |
| detection of tomato leaf curl geminivirus in its vector bemisia tabaci. | geminiviruses are single-stranded dna plant infecting viruses that cause major losses in important crops in tropical and subtropical countries. tomato leaf curl virus (tlcv) belonging to the genera begomovirus, is a whitefly-transmitted geminivirus that causes a severe leaf curl disease in tomato (lycopersicon esculentum). the importance of this disease has prompted a great need for a rapid identification of tlcv in its hosts and vector. polymerase chain reaction (pcr) is the most sensitive appr ... | 2000 | 11272420 |
| evidence for recombination among the tomato leaf curl virus strains/species from bangalore, india. | tomato leaf curl virus (tolcv) belongs to the begomovirus genus of the family geminiviridae. these viruses have circular single stranded dna molecules as their genome encapsidated in icosahedral geminate particles. generally the begomoviruses are bipartite with respect to their genomic composition. tolcv from south india is unique in that only dna a component has been isolated and sequenced thus far and there is no evidence for the presence of dna b component. in this communication we report the ... | 2002 | 11892687 |
| agrobacterium tumefaciens supports dna replication of diverse geminivirus types. | we have previously shown that the soil-borne plant pathogen agrobacterium tumefaciens supports the replication of tomato leaf curl geminivirus (australian isolate) (tlcv) dna. however, the reproducibility of this observation with other geminiviruses has been questioned. here, we show that replicative dna forms of three other geminiviruses also accumulate at varying levels in agrobacterium. geminiviral dna constructs that lacked the ability to replicate in agrobacterium were rendered replication- ... | 2002 | 11959128 |
| high-affinity rep-binding is not required for the replication of a geminivirus dna and its satellite. | the 682-nt satellite dna (sat-dna) of tomato leaf curl virus (tlcv) depends on the helper virus for its replication. in contrast to the strict specificity that exists in each geminivirus for its cognate replication associated protein (rep), tlcv sat-dna can utilize rep encoded by distinct geminiviruses. we have used a combination of protein-binding assays and mutagenesis to show that repeat motifs in tlcv and sat-dna are essential for rep-binding in vitro. surprisingly, mutants of tlcv and sat-d ... | 2003 | 12573580 |
| transcriptional silencing of geminiviral promoter-driven transgenes following homologous virus infection. | promoters isolated from the tomato leaf curl virus (tlcv) drive both constitutive and tissue-specific expression in transgenic tobacco. following systemic tlcv infection of plants stably expressing tlcv promoter:gus transgenes, transgene expression driven by all six tlcv promoters was silenced. silencing in the tlcv coat protein promoter:gus plants (v2:gusdeltac) was characterized in more detail. transgene silencing observed in leaf, stem, and pre-anthesis floral tissue occurred with the continu ... | 2003 | 12744514 |
| host responses to transient expression of individual genes encoded by tomato leaf curl virus. | the six open reading frames of tomato leaf curl virus (tlcv) were expressed in host nicotiana species using a tobacco mosaic virus vector. each of the genes, except that encoding the viral coat protein, produced a phenotypic effect when expressed in planta, but the corresponding untranslatable mutant genes were asymptomatic. the c1 (rep) gene invoked a hypersensitive response in nicotiana clevelandii that restricted the viral construct to sites of infection. expression of the c2 gene in n. benth ... | 2004 | 14714865 |
| phylogenetic analysis and homologies of the replicase of tomato leaf curl geminiviruses: implications for obtaining pathogen derived resistance. | geminiviruses encode a replication initiator protein, rep, which binds to iterated dna motifs functioning as essential elements for virus specific replication. rep protein gene of three isolates of whitefly transmitted geminivirus causing leaf curl disease of tomato in india were amplified, cloned and sequenced. nucleotide sequence and the derived amino acid sequence for the replicase gene of these isolates was determined and included in an analysis with the published sequences. phylogenetic rel ... | 2004 | 14976419 |
| a nac domain protein interacts with tomato leaf curl virus replication accessory protein and enhances viral replication. | geminivirus replication enhancer (ren) proteins dramatically increase the accumulation of viral dna species by an unknown mechanism. in this study, we present evidence implicating slnac1, a new member of the nac domain protein family from tomato (solanum lycopersicum), in tomato leaf curl virus (tlcv) ren function. we isolated slnac1 using yeast (saccharomyces cerevisiae) two-hybrid technology and tlcv ren as bait, and confirmed the interaction between these proteins in vitro. tlcv induces slnac ... | 2004 | 15608335 |
| replicative intermediates of tomato leaf curl virus and its satellite dnas. | several plant geminiviruses have been shown recently to utilize both rolling-circle replication (rcr) and recombination-dependent replication (rdr) strategies. a highly specific binding of the viral replication-associated protein (rep) to its cognate dna is essential for initiation of viral dna replication and for the recognition of dna components of the bipartite geminiviruses of the begomovirus genus. we have extended the replication analysis to the monopartite australian tomato leaf curl viru ... | 2005 | 15629786 |
| single-stranded dna of tomato leaf curl virus accumulates in the cytoplasm of phloem cells. | geminiviruses have been reported to replicate in, and localize to, the nuclei of host plant cells. we have investigated the tissue and intracellular distribution of the monopartite tomato leaf curl virus (tlcv) by in situ hybridization. contrary to the current understanding of geminiviral localization, single-stranded (ss) dna of tlcv accumulated in the cytoplasm. tlcv ssdna was also found in the nucleus, as was lower levels of replicative form double-stranded (ds) dna. under the same conditions ... | 2006 | 16457866 |
| analysis of silencing escape of tomato leaf curl virus: an evaluation of the role of dna methylation. | rna silencing is a sequence-specific mechanism regulating gene expression and has been used successfully for antiviral defense against rna viruses. similar strategies to develop resistance against dna containing tomato leaf curl virus (tlcv) and some other geminiviruses have been unsuccessful. to analyze this silencing escape, we transformed tomato plants with a hairpin construct from the tlcv c2 open reading frame (orf). the transgenic plants showed a strong rna silencing response, and followin ... | 2006 | 16776295 |
| identification and characterization of a host reversibly glycosylated peptide that interacts with the tomato leaf curl virus v1 protein. | monopartite geminiviruses of the genus begomovirus have two virion-sense genes, v1 and v2. v2 encodes the viral coat protein, but the function of v1 is largely unknown, although some studies suggest that it may play a role in cell-to-cell movement. yeast two-hybrid technology was used to identify possible host binding partners of v1 from tomato leaf curl virus (tlcv) to better understand its function. a protein closely related to a family of plant reversibly glycosylated peptides, designated slu ... | 2006 | 16786308 |
| characterization and transient replication of tomato leaf curl virus defective dnas. | distinct subgenomic dna species known as defective (df) dna molecules were found in plants infected with tomato leaf curl virus (tlcv). four df dnas derived from tlcv type and darwin 1 strains were found to contain large deletions that disrupt all of the viral genes required for viral replication, encapsidation and spread. however, the viral origin of replication (ori), including the replication-associated protein (rep) binding domains, was present in all four df dnas. co-agroinfection of leaf s ... | 2007 | 17347773 |
| genomic regions of tomato leaf curl virus dna satellite required for replication and for satellite-mediated delivery of heterologous dnas. | tomato leaf curl virus (tlcv) satellite dna (sat-dna) is a 682 nt, circular, single-stranded molecule that lacks an open reading frame (orf) or an apparent promoter. it contains binding motifs for the tlcv replication-associated protein, but these are dispensable for replication. to identify the regions of the sat-dna critical for replication, the entire sequence was scanned by deletion/replacement mutagenesis. transient assays using nicotiana benthamiana revealed that sequences within nt 296-35 ... | 2007 | 17554042 |
| hairpin rna-mediated strategies for silencing of tomato leaf curl virus ac1 and ac4 genes for effective resistance in plants. | rna interference (rnai) using short interfering rnas (sirnas) has been widely explored for the suppression of intracellular viral target mrnas. on the basis of our previous work with stable silencing of tomato leaf curl virus, in vivo by the antisense replicase gene (ac1) of the virus and characterizing ac4, as a small rna regulator, besides its role in pathogenicity, we used four different plasmid vector-based sirna generation strategies to silence viral genes (ac1 and ac4) of tomato leaf curl ... | 2007 | 17638528 |
| a monopartite begomovirus-associated dna beta satellite substitutes for the dna b of a bipartite begomovirus to permit systemic infection. | dna beta is a circular single-stranded satellite dna which co-infects with certain monopartite helper begomoviruses to cause economically important diseases, such as cotton leaf curl disease (clcud). dna beta encodes a single protein, betac1. tomato leaf curl new delhi virus (tolcndv) is a bipartite begomovirus in which both dna a and dna b are required for systemic infection. inoculation of tomato plants with tolcndv dna a alone induced local but not systemic infection, whereas co-inoculation w ... | 2007 | 17872543 |
| a simplified method of constructing infectious clones of begomovirus employing limited restriction enzyme digestion of products of rolling circle amplification. | most infectious clones of geminiviruses consist of (partial) tandem repeats of viral genomes in the vectors, which usually involve tedious, multi-step assemblies of genomic fragments in the construction process. a simplified procedure was devised to circumvent these problems, which employs limited restriction digestion of multimeric viral genomes produced by rolling circle amplification (rca), followed by direct cloning into appropriate vectors. the efficiency of the procedure, and infectivity o ... | 2008 | 18031835 |
| relationship between tomato yellow leaf curl viruses and the whitefly vector. | tomato yellow leaf curl virus (tylcv) and tomato leaf curl virus (tolcv) are the currently known begomoviruses in uganda. the relationship with their whiteflies (bemisia tabaci) vector and its management were not known in uganda. a direct relationship was expected between these begomoviruses and whiteflies at buwama in mpigi district of uganda. farmer practices were expected to have limited efficacy. to investigate this, a completely randomised block design was used for all trials with six treat ... | 2007 | 18396846 |
| tomato leaf curl virus satellite dna as a gene silencing vector activated by helper virus infection. | tomato leaf curl virus (tlcv) satellite dna (sat-dna) constructs containing functional segments of the cauliflower mosaic virus (camv) 35s promoter, replicate in tobacco in the presence of helper tlcv and silence gus activity in transgenic tobacco plants containing a camv 35s-gus expression cassette. we have analysed these plants for evidence of the hallmarks of silencing. the gus transcript was not detectable in the leaves of gus-silenced tobacco plants. these plants contained sirnas of approxi ... | 2008 | 18514962 |
| satellite dna beta overrides the pathogenicity phenotype of the c4 gene of tomato leaf curl virus but does not compensate for loss of function of the coat protein and v2 genes. | we have investigated the ability of satellite dna beta to complement mutations in the cp, v2 and c4 genes of the monopartite begomovirus, tomato leaf curl virus, which are potentially involved in movement. a mutation in the coat protein was not complemented by dna beta. mutations of the c4 and v2 genes attenuated and abolished symptoms, respectively. in the presence of the c4 mutant, but not the v2 mutant, dna beta induced typical symptoms, confirming that the satellite encodes a dominant sympto ... | 2008 | 18521533 |
| micrornas as biomarkers in tomato leaf curl virus (tolcv) disease. | micrornas are approximately 21- 25 nt long rna species that are critical regulators of transcriptome across the eukaryotes. growing number of evidences clearly supports their involvement in plant leaf development. tolcv infection severely affects the morphology of mature tomato leaves. to investigate the mechanism underlying the virus- host interaction, we focussed our studies on expression of micrornas and the irrespective targets under normal and tolcv infection. we have cloned myb33, arf4 hom ... | 2008 | 18776476 |
| a recessive allele (tgr-1) conditioning tomato resistance to geminivirus infection is associated with impaired viral movement. | abstract begomoviruses (the family geminiviridae) are transmitted by the whitefly bemisia tabaci and contain monopartite or bipartite circular single-stranded (ss)dna genomes. they have emerged as severe problems in the production of agricultural and horticultural crops worldwide. here, we report the identification of a tomato breeding line, fla653, that confers a high level of resistance to tomato leaf curl virus (tlcv, monopartite). genetic analysis indicated that the resistance is controlled ... | 2007 | 18943632 |
| tomato leaf curl karnataka virus from bangalore, india, appears to be a recombinant begomovirus. | abstract the genome of tomato leaf curl virus (tolcv) from bangalore, india, a whitefly-transmitted geminivirus, was cloned (pind9) and sequenced. the circular dna of 2,759 nucleotides (u38239) is organized similarly to that of other begomoviruses with monopartite genomes. comparison of the nucleotide sequence of pind9 with other tomato-associated begomoviruses from india (tomato leaf curl bangalore virus [tolcbv, z48182]) and tomato leaf curl new delhi virus-severe (tolcndv-svr, u15015) showed ... | 2002 | 18944261 |
| distribution and diversity of geminiviruses in trinidad and tobago. | abstract seven crop and eight weed species from 12 agricultural locations in trinidad and tobago were assayed for the presence of whitefly-transmitted geminiviruses (wtgs) by using dot blot hybridization and polymerase chain reaction (pcr) amplification of the n-terminal coat protein sequence with degenerate primers. the amplified fragments were cloned and analyzed by restriction enzyme digestion to determine fragment length polymorphism among the cloned fragments. representative clones were the ... | 1998 | 18944827 |
| sinaloa tomato leaf curl geminivirus: biological and molecular evidence for a new subgroup iii virus. | abstract the biological and molecular properties of sinaloa tomato leaf curl virus (stlcv) were investigated in line with the hypothesis that stlcv is a previously uncharacterized, whitefly-transmitted geminivirus from north america. stlcv causes yellow leaf curl symptoms in tomato and yellow-green foliar mottle in pepper. five species belonging to two plant families were stlcv experimental hosts. stlcv had a persistent relationship with its whitefly vector, bemisia tabaci. polymerase chain reac ... | 1998 | 18944936 |
| molecular dissection of tomato leaf curl virus resistance in tomato line ty172 derived from solanum peruvianum. | tomato yellow leaf curl virus (tylcv) is devastating to tomato (solanum lycopersicum) crops and resistant cultivars are highly effective in controlling the disease. the breeding line ty172, originating from solanum peruvianum, is highly resistant to tylcv. to map quantitative trait loci (qtls) controlling tylcv resistance in ty172, appropriate segregating populations were analyzed using 69 polymorphic dna markers spanning the entire tomato genome. results show that tylcv resistance in ty172 is c ... | 2009 | 19455299 |
| a novel shaggy-like kinase interacts with the tomato leaf curl virus pathogenicity determinant c4 protein. | tomato leaf curl virus-australia (tolcv) c4 protein has been shown to be associated with virus pathogenesis. here, we demonstrate that c4 acts as a suppressor of gene silencing. to understand the multifunctional role of c4, a novel shaggy-like kinase (slsk) from tomato, which interacts with tolcv c4 in a yeast two-hybrid assay, was isolated and interaction between these proteins was confirmed in vitro and in planta. using deletion analysis of c4, a 12 amino acid region in the c-terminal part of ... | 2009 | 19533382 |
| use of tomato leaf curl virus (tylcv) truncated rep gene sequence to engineer tylcv resistance in tomato plants. | tomato yellow leaf curl disease causes severe losses in tomato production throughout mediterranean countries including tunisia. in order to generate engineered resistance to this disease, an intron-hairpin rna construct harboring a tomato yellow leaf curl sardinia virus (tylcsv) truncated replication-associated protein (rep) gene was used to transform genotype of tomato plants. prepared transgenic plants were agro-inoculated with tunisian infectious strain of tylcsv and screened for the resistan ... | 2009 | 19537910 |
| silencing potential of viral derived rnai constructs in tomato leaf curl virus-ac4 gene suppression in tomato. | we investigated viral gene suppression in an infected tomato, by transforming it with rna inhibition (rnai) constructs derived from same viral gene. to develop rnai constructs, conserved sequences ranging from 21 to 200 nt of the viral target ac4 gene of various viruses causing the tomato leaf curl disease were chosen. the double-stranded (ds)rna producing constructs carry the sense and antisense portions of these sequences and are separated by different introns behind a constitutive promoter. w ... | 2010 | 19548101 |
| a geminiviral amplicon (va) derived from tomato leaf curl virus (tolcv) can replicate in a wide variety of plant species and also acts as a vigs vector. | the tomato leaf curl virus (tolcv) belongs to the genus begomoviridae of the family geminiviridae. the 2.7 kb dna genome of the virus encodes all the information required for viral dna replication, transcription and transmission across the plant cells. however, all of the genome sequences are not required for viral dna replication. we attempted to reveal the minimal essential region required for dna replication and stable maintenance. the phenomenon of virus induced gene silencing (vigs) has rec ... | 2009 | 19788728 |
| a new strategy for generating geminivirus resistant plants using a dna betasatellite/split barnase construct. | the betasatellite dna associated with cotton leaf curl disease contains a single orf, βc1, which is a pathogenicity determinant. deletion of the βc1 orf showed that it was not required for betasatellite replication in the presence of tomato leaf curl virus-australia (tlcv-au). a series of betasatellite/split mutant barnase gene constructs, in which a direct repeat of the bacillus amyloliquefaciens barnase gene flanked the betasatellite, were shown to replicate in tobacco in the presence of tlcv- ... | 2010 | 20813135 |
| microrna profiling of tomato leaf curl new delhi virus (tolcndv) infected tomato leaves indicates that deregulation of mir159/319 and mir172 might be linked with leaf curl disease. | tomato leaf curl virus (tolcv), a constituent of the genus begomovirus, infects tomato and other plants with a hallmark disease symptom of upward leaf curling. since micrornas (mirs) are known to control plants developmental processes, we evaluated the roles of mirnas in tomato leaf curl new delhi virus (tolcndv) induced leaf curling. | 2010 | 20973960 |
| in silico analysis reveals that several tomato microrna/microrna ∗ sequences exhibit propensity to bind to tomato leaf curl virus (tolcv) associated genomes and most of their encoded open reading frames (orfs). | tomato leaf curl virus (tolcv) is a member of family geminiviridae that constitute rapidly emerging group of phytopathogens posing threat to a large number of vegetable crops worldwide. three different genomes are found to be associated with tolcv viz., dna-a, dna-b and beta satellite dna. micrornas (mirs) are known to govern several fundamental processes in eukaryotes, including basal defense mechanisms. in animals, it has been demonstrated that certain host mirs prevent viral establishment by ... | 2010 | 21075002 |
| molecular characterization of two distinct monopartite begomoviruses infecting tomato in india. | tomato leaf curl viruses, which are the members of the genus begomovirus, have emerged as devastating pathogens worldwide causing huge economic losses and threatening production of crops like cassava, cotton, grain legumes and vegetables. even though the tolcv isolates from northern india have been shown to possess bipartite genome (designated as dna a and dna b), those from australia, taiwan and southern india have a single genomic component (dna a). we describe here the genetic diversity of tw ... | 2010 | 21092241 |
| dynamics of defense-related components in two contrasting genotypes of tomato upon infection with tomato leaf curl new delhi virus. | tomato leaf curl virus (tolcv) disease is a serious threat for tomato cultivation in the tropics and subtropics. despite serious efforts no immune commercial varieties or f(1) hybrids are available till date. in this study, the interaction between solanum lycopersicum and tolcv was characterized on molecular and biochemical basis. rna silencing mediated by short interfering rna (sirna) and reactive oxygen species (ros) has been proposed as central components of plant adaptation to several stress ... | 2011 | 22161255 |
| molecular identification of a new begomovirus associated with yellow mosaic disease of jatropha gossypifolia in india. | yellow mosaic disease was observed on jatropha gossypifolia plants growing in kathaupahadi, madhya pradesh, india, and whiteflies (bemisia tabaci) were found in the vicinity. association of a new begomovirus with yellow mosaic disease of j. gossypifolia has been detected by pcr using begomovirus dna-a-specific primers. the complete dna-a genome (~2.7 kb) of this virus isolate was amplified by rolling-circle amplification (rca) followed by digestion with bam hi. the ~2.7-kb amplicons was cloned a ... | 2011 | 21971870 |
| evolutionary and molecular aspects of indian tomato leaf curl virus coat protein. | tomato leaf curl disease (tolcd) is manifested by yellowing of leaf lamina with upward leaf curl, leaf distortion, shrinking of the leaf surface, and stunted plant growth caused by tomato leaf curl virus (tolcv). in the present study, using computational methods we explored the evolutionary and molecular prospects of viral coat protein derived from an isolate of vadodara district, gujarat (tolcgv-[vad]), india. we found that the amino acids in coat protein required for systemic infection, viral ... | 2012 | 23304121 |
| transgenic tomato plants expressing artificial micrornas for silencing the pre-coat and coat proteins of a begomovirus, tomato leaf curl new delhi virus, show tolerance to virus infection. | designing artificial micrornas (amirs) targeting the genes responsible for viral replication, transmission and symptom development after viral infection offers a promising strategy to contain the multiplication and spread of geminiviruses in host plants. here, we report the design of two amirs targeting the middle region of the av1 (coat protein) transcript (amir-av1-3) and the overlapping region of the av1 and av2 (pre-coat protein) transcripts (amir-av1-1) of a model geminivirus, tomato leaf c ... | 2012 | 23276684 |
| cotton leaf curl multan betasatellite dna as a tool to deliver and express the human b-cell lymphoma 2 (bcl-2) gene in plants. | the betasatellite dna associated with cotton leaf curl multan virus (clcumb) contains a single complementary-sense orf, βc1, which is a pathogenicity determinant. clcumb was able to replicate in plants in the presence of diverse helper geminiviruses, including tomato leaf curl virus-australia (tlcv-au), iranian isolate of tomato yellow leaf curl virus (tylcv-[ab]), and beet curly top virus (bctv-svr), and can be used as a plant gene delivery vector. to test the hypothesis that clcumb has the pot ... | 2016 | 27041273 |
| cotton leaf curl multan betasatellite as a plant gene delivery vector trans-activated by taxonomically diverse geminiviruses. | cotton leaf curl multan betasatellite (clcumb) replicates in tobacco, tomato and datura plants in the presence of the helper viruses tomato leaf curl virus-australia, iranian isolates of tomato yellow leaf curl virus, tomato leaf curl karnataka virus, and beet severe curly top virus (bsctv). infectious recombinant clcumb constructs were made in which segments of either the camv 35s or the petunia chsa promoter replaced the clcumb βc1 orf, and these were designated pbinβδc1-35s and pbinβδc1-chsa, ... | 2012 | 22476203 |
| genetic variability of cotton leaf curl betasatellite in northern india. | cotton is an important crop and its production is affected by various disease pathogens. monopartite begomovirus associated betasatellites cause cotton leaf curl disease (clcud) in northern india. in order to access the occurrence and genetic variability of cotton leaf curl betasatellites, an extensive field survey was conducted in states of rajasthan, punjab and haryana. we selected the betasatellite sequence for analysis as they are reported as important for disease severity and sequence varia ... | 2014 | 25473373 |
| spatial and temporal diversity of begomoviral complexes in papayas with leaf curl disease. | old world, monopartite begomoviruses associated with satellite dna β were observed in papaya showing symptoms of leaf curl disease sampled randomly over five years from within a radius of 250 km in north-central india. three groups of dna a sequences were evident. one group resembled chili leaf curl virus infecting tomatoes (chilcuv). another group resembled tomato leaf curl new delhi virus (tolcundv). the third group was novel (tentatively named papaya leaf crumple virus, palcrv), with less tha ... | 2012 | 22437254 |
| frequent occurrence of tomato leaf curl new delhi virus in cotton leaf curl disease affected cotton in pakistan. | cotton leaf curl disease (clcud) is the major biotic constraint to cotton production on the indian subcontinent, and is caused by monopartite begomoviruses accompanied by a specific dna satellite, cotton leaf curl multan betasatellite (clcumb). since the breakdown of resistance against clcud in 2001/2002, only one virus, the "burewala" strain of cotton leaf curl kokhran virus (clcukov-bur), and a recombinant form of clcumb have consistently been identified in cotton across the major cotton growi ... | 2016 | 27213535 |
| silencing suppressor activity of a begomovirus dna β encoded protein and its effect on heterologous helper virus replication. | dna β satellites are circular single-stranded molecules associated with some monopartite begomoviruses in the family geminiviridae. they co-infect with their helper viruses to induce severe disease in economically important crops. the βc1 protein encoded by dna β is a pathogenicity determinant and has been reported to suppress post-transcriptional gene silencing (ptgs). the βc1 proteins from various dna β molecules show low levels of amino acid sequence conservation. we show here that the βc1 fr ... | 2012 | 22504338 |
| mechanism of regulation of tomato trn1 gene expression in late infection with tomato leaf curl new delhi virus (tolcndv). | tomato leaf curl disease caused by geminiviruses is manifested by curling and puckering of leaves and thickening of veins, resembling developmental defects. this is probably due to the long-term altered regulation of expression of development related gene(s). our results show that in the infected leaves the transcript level of tornado1 (sltrn1), a gene important for cell expansion and vein formation, increased significantly. sltrn1 is transcribed from two start sites. the preferential usage of o ... | 2015 | 26706073 |
| molecular detection and partial characterization of tomato yellow leaf curl virus in sri lanka. | tomato yellow leaf curl virus (tylcv) is an important plant virus on one of the economically most important vegetable crops; tomato (lycopersicon esculentum mill.). this had not been molecularly detected before, in sri lanka. tylcv-gn-sl was isolated from apparently infected tomato plants using modified cetyltrimethyl ammonium bromide (ctab) method in gannoruwa. associated begomoviruses were detected using deng 541/deng 540 and av 494/ac 1048 primer pairs. tylcv was detected for the first time i ... | 2012 | 24205755 |
| in situ hybridization and promoter analysis reveal that cotton leaf curl multan betasatellite localizes in the phloem. | begomoviruses (the family geminiviridae) have either a monopartite or a bipartite (dna a and dna b) single-stranded dna genome. dna b contains the open reading frame for movement protein and enables some bipartite begomoviruses to invade non-phloem tissues, whereas monopartite begomoviruses are limited to the phloem. betasatellite dna replicates in association with some monopartite begomoviruses to produce severe symptoms and enhance replication of helper virus in some hosts. the cotton leaf cur ... | 2017 | 28105851 |
| characterization of non-coding dna satellites associated with sweepoviruses (genus begomovirus, geminiviridae) - definition of a distinct class of begomovirus-associated satellites. | begomoviruses (family geminiviridae) are whitefly-transmitted, plant-infecting single-stranded dna viruses that cause crop losses throughout the warmer parts of the world. sweepoviruses are a phylogenetically distinct group of begomoviruses that infect plants of the family convolvulaceae, including sweet potato (ipomoea batatas). two classes of subviral molecules are often associated with begomoviruses, particularly in the old world; the betasatellites and the alphasatellites. an analysis of swe ... | 2016 | 26925037 |
| genetic analysis to identify good combiners for tolcv resistance and yield components in tomato using interspecific hybridization. | the interspecific hybridization for tomato leaf curl virus (tolcv) resistance was carried out among 10 genetically diverse tomato genotypes (diversified by 50 ssr markers). among the 10 parents, four susceptible cultivars of solanum lycopersicum were crossed with six resistant wilds, such as s. pimpinellifolium, s. habrochaites, s. chemielewskii, s. ceraseforme, s. peruvianum and s. chilense in a line x tester mating design. all the 24 hybrids and their parents were grown in the field and glassh ... | 2014 | 25572221 |
| a novel class of dna satellites associated with new world begomoviruses. | begomoviruses (family geminiviridae) are whitefly-transmitted plant dna viruses that have been shown to be helper viruses for a number of distinct dna satellites, including betasatellites and alphasatellites. replication of the satellites interferes to some degree with replication of the helper and in some cases they affect the disease symptoms. to date, betasatellites and related molecules such as the satellite associated with tomato leaf curl virus (tolcv-sat), have only been associated with o ... | 2012 | 22330203 |
| sources and inheritance of resistance to leaf curl virus in lycopersicon. | one hundred and twenty-two varieties, lines and wild accessions of lycopersicon were screened under three different regimes during the autumn/winter season of 1982-83 and 1983-84 for resistance to tomato leaf curl virus (tlcv). l. hirsutum f. glabratum ('b6013') and l. hirsutum f. typicum ('a1904') proved to be highly resistant to tlcv in all three environments. various accessions of l. peruvianum were also highly resistant. l. pimpinellifolium ('a1921') exhibited no tlcv symptoms within 90 days ... | 1987 | 24241195 |