| differential interactions among strains of tomato aspermy virus and satellite rnas of cucumber mosaic virus. | tomato and tobacco plants were inoculated with either of two strains of tomato aspermy virus, 1-tav or v-tav, and each of six isolates of cucumber mosaic virus satellite rna (cmv-satrna), b1, b2, b3, ix, or wl2. ribonuclease protection assays, used to detect total satrna and encapsidated satrna, revealed that g-satrna generated new satellite rna not of the inoculated sequence. the other cmv-satrnas were compared for their ability (1) to replicate, (2) to modulate symptoms, (3) to reduce tav accu ... | 1992 | 1370738 |
| role of an upstream open reading frame in the translation of polycistronic mrnas in plant cells. | the influence of an upstream small open reading frame (urf) on the translation of two consecutive coding regions on an eukaryotic mrna was studied. the cis effects of leader length, urf length, the sequences of the urf and neighboring regions, and the trans effects of the cauliflower mosaic virus transactivator (tav) were analyzed. translation efficiency of the immediate downstream open reading frame (orf) decreased with increasing urf length. short urfs did not drastically inhibit translation o ... | 1992 | 1508670 |
| nucleotide sequence analyses of peanut stunt cucumovirus rnas 1 and 2. | the nucleotide sequences of the rnas 1 and 2 of the peanut stunt virus strain j (psv-j) were determined and compared with those of the cucumber mosaic virus strain y (cmv-y, subgroup i), strain q (cmv-q, subgroup ii) and the tomato aspermy virus strain v (tav-v) at both the nucleotide and protein levels. rna 1 of psv-j consists of 3355 nucleotides (nt) and has one large open reading frame (orf) which can encode the putative 1a protein of mr 112025. psv-j rna 1 and the 1a protein are 65 to 73% id ... | 1992 | 1545224 |
| insect-mediated transmission of mixed and reassorted cucumovirus genomic rnas. | transmissions of virus using the aphid myzus persicae were performed using plants co-infected with two cucumoviruses, tomato aspermy virus (v-tav) and cucumber mosaic virus (m-cmv). five of the aphid-transmitted progeny viruses (3.7%) induced symptoms distinct from those induced by either parental virus. northern blot hybridization analysis of encapsidated rnas from these novel progeny demonstrated that all of the rna profiles were characteristic of pseudo-recombinants, i.e. viruses with reassor ... | 1992 | 1645147 |
| cucumber mosaic virus satellite rna (y strain): analysis of sequences which affect yellow mosaic symptoms on tobacco. | plants infected with cucumber mosaic virus (cmv) (kin strain) produce a mild mosaic disease on tobacco whereas infections of cmv with satellite rna (strain y) cause a severe yellow mosaic. analysis of recombinant and mutant forms of satellite rna identified a site (nucleotides 185/186) in the y satellite rna that affects the ability to induce the yellow mosaic in combination with cmv but not with tomato aspermy virus. the location of this site with respect to other mutations in the satellite rna ... | 1990 | 1698919 |
| replication of cucumber mosaic virus satellite rna in vitro by an rna-dependent rna polymerase from virus-infected tobacco. | an rna-dependent rna polymerase purified from tobacco infected with cucumber mosaic virus catalyzes the synthesis of (-) and (+) strands of the viral satellite rna, carna 5, but fails to replicate the satellite rna of peanut stunt virus (psv). the enzyme replicates the genomic rnas of the three principal cucumoviruses cmv, psv and tomato aspermy virus (tav) with varying efficiencies. the specificity with which cmv rdrp replicates different sequence-unrelated rna templates suggests that the site ... | 1991 | 1720399 |
| evolutionary relationships in the cucumoviruses: nucleotide sequence of tomato aspermy virus rna 1. | rna 1 of the v strain of tomato aspermy virus (tav) consists of 3410 nucleotides and contains one open reading frame (orf) of 2982 nucleotides, resembling rna 1 of cucumber mosaic virus (cmv) strains q and fny (68% and 66% identical, respectively) and of brome mosaic virus (bmv) (41% identical). in comparisons between amino acid sequences, three conserved regions (n-terminal, c-terminal and central) between tav and each cmv were found. the n- and c-terminal regions were also conserved with bmv, ... | 1991 | 1895056 |
| nucleotide sequence of rna 3 of peanut stunt cucumovirus. | the nucleotide sequence of the rna 3 of the peanut stunt virus strain j (psv-j) was determined and compared with those of the cucumber mosaic virus strain y (cmv-y, subgroup i) and the tomato aspermy virus strain c (tav-c) at both the nucleotide and protein levels. the rna 3 of psv-j consists of 2186 nucleotides and has two large open reading frames (orfs). by analogy to other tripartite plant viruses, it is presumed that the first orf (867 nucleotides) codes for the 3a protein and the second or ... | 1991 | 1926787 |
| tomato aspermy virus has an evolutionary relationship with other tripartite rna plant viruses. | the entire rna 3 (2214 nucleotides) of a chrysanthemum isolate of tomato aspermy virus (c-tav) has been cloned and its sequence determined. c-tav possesses two open reading frames which encode a 3a protein (277 amino acids) and a coat protein (229 amino acids). computer-assisted comparisons were made between c-tav rna 3 and its predicted protein sequences and those of two other tripartite rna viruses, cucumber mosaic virus (cmv) and brome mosaic virus (bmv). results from this study suggest that ... | 1991 | 1990057 |
| nucleotide sequence of tomato aspermy virus rna 2. | rna 2 of the v strain of tomato aspermy virus (tav) consists of 3074 nucleotides and contains one open reading frame of 2487 nucleotides. thus, it resembles rna 2 of cucumber mosaic virus (cmv) strains q and fny (62% identical to both), brome mosaic virus (42% identical) and cowpea chlorotic mottle virus (40% identical). in comparisons between amino acid sequences, three different regions of similarity could be distinguished. these were the central part (amino acids 224 to 757 for v-tav), which ... | 1991 | 2016592 |
| induction of tobacco chlorosis by certain cucumber mosaic virus satellite rnas is specific to subgroup ii helper strains. | two satellite (sat) rnas of cucumber mosaic virus (cmv), b2- and wl3-sat rnas, which induce systemic chlorosis on tobacco, were inoculated onto tobacco with a number of cmv strains. systemic chlorosis was observed only when these satellite rnas were associated with subgroup ii cmv strains. infection of tobacco with various pseudorecombinants of subgroup i and ii cmv strains, together with wl3- or b2-sat rna, suggests that chlorosis is associated with rna 2 of subgroup ii cmv strains. chlorosis w ... | 1990 | 2330677 |
| comparative study of virion structure, protein composition and genomic dna of three ascovirus isolates. | the virions of three ascoviruses isolated from the noctuids heliothis zea, spodoptera frugiperda and trichoplusia ni were compared with respect to their size and structure, protein composition and the size and relatedness of their dnas. the virions of the isolates from h. zea (hav) and t. ni (tav) were allantoid in shape (400 x 130 nm), enveloped and contained an inner particle which appeared to have an internal lipid bilayer surrounding the dna core. the virions of the s. frugiperda isolate (sa ... | 1990 | 2391498 |
| subcellular localization of chrysanthemum aspermy virus in tobacco and chrysanthemum leaf tissue. | | 1970 | 4192142 |
| biophysical and biochemical properties of tomato aspermy virus. | | 1973 | 4735035 |
| [serological studies on the behavior of tomato aspermy virus in chrysanthemum indicum l]. | | 1967 | 5632365 |
| complex interactions among several nucleotide positions determine phenotypes defective for long-distance transport in the satellite rna of cucumber mosaic virus. | ix-satrna is a cmv-satrna necrogenic on tomato that is defective for long-distance systemic movement when coinoculated in tobacco with v-tav. to analyze the determinants for this defective phenotype, full-length cdna clones of ix-satrna and of the closely related, nondefective i17n-satrna were obtained. infectious transcripts from these clones (ix5-satrna and i17n1-satrna) had the same phenotypes as the original satrnas and differed only in four positions: positions 20 (ix5, c; i17n1, u), 102 (i ... | 1994 | 7510433 |
| mapping helper virus functions for cucumber mosaic virus satellite rna with pseudorecombinants derived from cucumber mosaic and tomato aspermy viruses. | p-tav is a strain of tomato aspermy virus (tav) able to efficiently support the systemic accumulation of some (i.e., b2-satrna) but not of other (i.e., ix-satrna) strains of the satellite rna (satrna) of cucumber mosaic virus (cmv) in both tobacco and in tomato. as reported for v-tav, the failure to support the systemic accumulation of ix-satrna seems to be due to an inefficient support of its systemic movement. pseudorecombinants obtained by the exchange of rnas 1 + 2 between p-tav and trk7-cmv ... | 1994 | 7526544 |
| variation in the hypervariable region of cucumber mosaic virus satellite rnas is affected by the helper virus and the initial sequence context. | the d satellite rna (sat rna) of cucumber mosaic virus (cmv) was previously shown to contain a region of hypervariability around nucleotide 230, in wild-type populations and in cdna clones and progeny of one such clone (pdsat4) after passage with the subgroup i strain fny-cmv. this hypervariable region (hvr) consists of a series of consecutive a and/or u residues. we found that variability is also generated in the hvr of transcript derived from pdsat4 after passage with the subgroup ii strain ls ... | 1995 | 7530401 |
| genetic analysis of helper virus-specific selective amplification of cucumber mosaic virus satellite rnas. | satellite rnas (sat-rnas) are small molecular parasites associated with a number of plant rna viruses. the cucumber mosaic virus (cmv) sat-rnas are ca. 335 nucleotides and have evolved to produce a large number of closely related sat-rnas. different cucumoviruses can act as helper viruses in the amplification of cmv sat-rnas. we have found that different helper viruses show a preference for a particular sat-rna in a mixed infection. in this study the specificity of wl47 sat-rna amplification by ... | 1995 | 7536251 |
| preliminary x-ray diffraction analysis of crystals of tomato aspermy virus (tav). | tomato aspermy virus (tav) is a member of the t = 3 cucumovirus group, and the chrysanthemum strain (c-tav) has been crystallized in a form suitable for x-ray structural analysis. the crystals, which grow in 14-17% ethanol at ph 8.5, are of orthorhombic space group i222 with unit cell dimensions of a = 295.1 a, b = 320.5 a, and c = 383.6 a. there are two t = 3 virus particles in the unit cell, which means that they must be centered at 0,0,0 and 1/2, 1/2, 1/2 with icosahedral 222 symmetry element ... | 1995 | 7784430 |
| nucleotide sequence and infectious in vitro transcripts of rna 3 of tomato aspermy virus pepper isolate. | the nucleotide sequence of a cdna clone corresponding to the entire rna 3 of a pepper isolate of tomato aspermy cucumovirus (p-tav) was determined. the 2222 nucleotides (nt) long rna 3 is dicistronic and codes a 3a (280 amino acids) and a coat protein (cp, 218 amino acids). the nucleotide sequence of p-tav rna 3 shows a high sequence identity (99%) with that of c-tav rna 3 and the amino acid sequences of the 3a and the coat proteins between these two tav strains are also very similar. the transc ... | 1994 | 7985413 |
| increase in the relative fitness of a plant virus rna associated with its recombinant nature. | a recombination event at the 3' end of rna 3 in a pseudorecombinant virus (c1c2t3) having rnas 1 and 2 from trk7-cucumber mosaic virus (cmv) and rna 3 from p-tomato aspermy virus (tav) was detected by ribonuclease protection assay (rpa). sequence analysis of the 3' end of rna 3 of c1c2t3 and of its parental cmv and tav strains showed that rna 3 of c1c2t3 had a hybrid nature in which most of the 3' noncoding region (3' ncr), including the whole 3' terminal trna-like structure, was derived from cm ... | 1994 | 8053160 |
| expression of homologous and heterologous viral coat protein-encoding genes using recombinant di rna from cymbidium ringspot tombusvirus. | defective interfering (di) rna of cymbidium ringspot tombusvirus (cyrsv) was tested as a potential rna vector. the coat protein-encoding gene (cp) of the same virus or of the unrelated tomato aspermy cucumovirus (tav) was inserted in a biologically active clone of cyrsv di-3 rna. both homologous and heterologous cp genes were inserted into di-3 cdna clone in two different positions. the cyrsv cp was expressed only in the leaves which were inoculated with di-3cpwt plus cp-less mutant helper virus ... | 1994 | 8125295 |
| specificity of replicase-mediated resistance to cucumber mosaic virus. | plants transformed with a nucleotide sequence coding for a truncated rna 2 replicase gene of the subgroup i strain of cucumber mosaic virus, fny-cmv, are resistant to cucumber mosaic disease. two resistant lines representing independent transformations in the original study have been propagated, and their progeny have been examined. resistance to fny-cmv was genetically integrated and was retained in the r4 generation. fourteen subgroup i cmv strains, 6 strains uncharacterized as to subgroup, an ... | 1994 | 8184532 |
| nucleotide sequence of rna 3 of the british type isolate (blencowe strain) of tomato aspermy virus. | the complete sequence of rna 3 of the blencowe, british (b) isolate of tomato aspermy virus (tav) is presented. the rna 3 of tav-b is dicistronic, encoding the putative movement protein 3a and the capsid protein. | 1994 | 8209425 |
| molecular dissection of the cauliflower mosaic virus translation transactivator. | the cauliflower mosaic virus (camv) transactivator (tav) is a complex protein that appears to be involved in many aspects of the virus life cycle. one of its roles is to control translation from the polycistronic camv 35s rna. here we report a molecular dissection of tav in relation to its ability to enhance dicistronic translation in transient expression experiments. we have identified a protein domain that is responsible and sufficient for that activity. this 'minitav domain' consists of only ... | 1993 | 8344266 |
| conservation of dna sequence in the predicted major late promoter regions of selected mastadenoviruses. | the major late promoter (mlp) of the subgroup c human adenoviruses is a preeminent model for the study of the mechanisms of basal and activated transcription, both in vivo and in vitro. however, while the structure and function of the human virus mlp has been the subject of extensive investigation, the conservation of the various promoter elements among the adenoviruses from different species has not been examined. conservation of specific elements would strongly suggest the importance and unive ... | 1996 | 8661390 |
| an interspecies hybrid rna virus is significantly more virulent than either parental virus. | cucumber mosaic cucumovirus (cmv) infects a very wide range of plant species (>1000 species). we recently demonstrated that a previously undescribed gene (2b) encoded by rna 2 of the tripartite rna genome of cmv is required for systemic virus spread and disease induction in its hosts. herein we report that when this cmv gene is replaced by its homologue from tomato aspermy cucumovirus (tav), the resultant hybrid virus is significantly more virulent, induces earlier onset of systemic symptoms, an ... | 1996 | 8755497 |
| mixed-subunit capsids can be assembled in vitro with coat protein subunits from two cucumoviruses. | virus particles were reassembled in vitro from tomato aspermy virus strain v (v-tav) rna and a mixture of subunits prepared from v-tav and 35s-labelled cucumber mosaic virus strain t (t-cmv). immunodiffusion tests showed that the reassembled particles reacted with polyclonal antisera raised against both v-tav and t-cmv. radioactivity was found in the precipitin line formed between the reassembled particles and antiserum raised against t-cmv as well as in the precipitin line formed between the re ... | 1995 | 9049344 |
| two novel subgenomic rnas derived from rna 3 of tomato aspermy cucumovirus. | two abundant subgenomic rnas, designated rna 3b and rna 5, were found to be associated with the v strain of tomato aspermy cucumovirus (v-tav). sequence determination showed that the 3'-terminal 323 nucleotides (nt) of rna 3b was identical to rna 5, whereas its 5'-terminal 163 nt was a direct repeat (one nt difference) of the 5'-half of rna 5, and that both rnas are completely homologous to the 3'-terminal untranslated region of tav rna 3. tav rnas 3b and 5 were also detected in the infection of ... | 1997 | 9049398 |
| biological properties of pseudorecombinant and recombinant strains created with cucumber mosaic virus and tomato aspermy virus. | cucumber mosaic virus (cmv) and tomato aspermy virus (tav) are closely related cucumoviruses. we have made pseudorecombinant viruses in which the rnas 3 of these two viruses have been exchanged and recombinant viruses containing chimeric rna 3 molecules, in which the coat proteins and the 3'-end regions of cmv and tav have been exchanged, giving rise to recombinants designated rt3 and tr3. the replication properties and the cell-to-cell and long-distance movement patterns of these pseudorecombin ... | 1997 | 9094632 |
| plasmid vector for cloning infectious cdnas from plant rna viruses: high infectivity of cdna clones of tomato aspermy cucumovirus. | an improved version of the previously obtained cloning vector pcass was constructed by partially duplicating the 35s promoter used to drive the transient transcription of cloned viral cdnas. full-length cdnas of the three genomic rnas of tomato aspermy cucumovirus (tav) cloned in this improved pcass (designated pcass2) gave a 3-fold higher infectivity in two plant species tested than the same cdnas cloned in pcass1 with only a single 35s promoter. host range, symptoms, morphology of viral partic ... | 1997 | 9152439 |
| rnas 4a and 5 are present in tomato aspermy virus and both subgroups of cucumber mosaic virus. | primer extension analysis was used to determine the presence of rnas 4a and 5 in tomato aspermy virus (tav) and both subgroups of cucumber mosaic virus (cmv). rnas 4a and 5 were detected in tav and all cmv strains (representative of both subgroups) that were analysed, except for one subgroup i cmv strain which lacked detectable rna 5. in subgroup ii cmv strains the rna 5 population was found to consist of two sequence variants. comparison of the rna 5 sequences from tav and cmv indicated that ta ... | 1997 | 9229015 |
| some indian strains of cucumber mosaic virus (cmv) lacking satellite rna. | virus strains isolated from ocimum sanctum and zinnia elegans were identified as cucumber mosaic virus (cmv) strains on the basis of non-persistant aphid transmission, 28 nm particles, 26 kda coat protein subunits and serological relationships with cmv and chrysanthemum aspermy virus. the strains showed some biological, serological and satellite rna based differentiation with other cmv strains isolated earlier from chrysanthemum, petunia and tobacco. | 1997 | 9475049 |
| template-independent repair of the 3' end of cucumber mosaic virus satellite rna controlled by rnas 1 and 2 of helper virus. | rna viruses which do not have a poly(a) tail or a trna-like structure for the protection of their vulnerable 3' termini may have developed a different strategy to maintain their genome integrity. we provide evidence that deletions of up to 7 nucleotides from the 3' terminus of cucumber mosaic cucumovirus (cmv) satellite rna (satrna) were repaired in planta in the presence of the helper virus (hv) cmv. sequence comparison of 3'-end-repaired satrna progenies, and of satrna and hv rna, suggested th ... | 1998 | 9573276 |
| evolution of a quadripartite hybrid virus by interspecific exchange and recombination between replicase components of two related tripartite rna viruses. | cucumber mosaic virus (cmv) and tomato aspermy virus (tav) belong to the cucumovirus genus. they have a tripartite genome consisting of single-stranded rnas, designated 1, 2, and 3. previous studies have shown that viable pseudorecombinants could be created in vitro by reciprocal exchanges between cmv and tav rna 3, but exchanges of rnas 1 and 2 were replication deficient. when we coinoculated cmv rnas 2 and 3 along with tav rnas 1 and 2 onto nicotiana benthamiana, a hybrid quadripartite virus a ... | 1998 | 9724730 |
| a novel capsid expression strategy for thosea asigna virus (tetraviridae). | this paper presents evidence that thosea asigna virus (tav) has a unique capsid expression strategy and is a member of the nudaurelia beta-like genus of the tetraviridae. electron microscopy of tav particles indicated a 38 nm, t = 4 icosahedral capsid similar in structure to that of nudaurelia beta virus (nbetav). tav particles have a buoyant density of 1.296 g/cm3 in cscl and consist of two capsid proteins of 56 and 6 kda. the virus genome contains a genomic rna molecule of 6.5 kb and a subgeno ... | 1999 | 10423156 |
| pcr for specific detection of haemorrhagic enteritis virus of turkeys, an avian adenovirus. | a hexon gene based pcr was developed for specific amplification of dna sequences from the haemorrhagic enteritis virus (hev) of turkeys. the hexon genes of different avian adenoviruses were compared for primer construction. two regions with low sequence homology between hev and fowl adenovirus (fav) hexon genes were selected for primer localisation. in correlation with the known sequence data a fragment of 1647 bp was amplified from a live vaccine and spleens of turkeys suffering from haemorrhag ... | 1999 | 10488779 |
| recombination between genomic rnas of two cucumoviruses under conditions of minimal selection pressure. | recombination is considered to play a key role in rna virus evolution; however, little is known about its occurrence under natural conditions. we inoculated tobacco plants with wild-type strains of two closely related cucumovirus species: cucumber mosaic virus (cmv) and tomato aspermy virus (tav). rna from the inoculated leaves of doubly-infected plants was tested for the presence of recombination events in an 0.8-kb central portion of the viral rna3. using a sensitive and specific rt-pcr proced ... | 1999 | 10544102 |
| rt-pcr detection and identification of three species of cucumoviruses with a genus-specific single pair of primers. | reverse transcription and polymerase chain reaction (rt-pcr) was used for detection and identification of three cucumoviruses (cucumber mosaic virus, cmv; peanut stunt virus, psv; tomato aspermy virus, tav) in various plants sources with a single pair of primers, designed as cptall-3 and cptall-5. the pair of cucumovirus genus-specific primers that flank the coat protein gene were designed and used to amplify a dna fragment of approximately ranging from 938 to 966 bp. the rt-pcr with the set of ... | 1999 | 10598084 |
| synthesis of (-)-strand rna from the 3' untranslated region of plant viral genomes expressed in transgenic plants upon infection with related viruses. | when expressed in transgenic tobacco plants, transgene mrna that includes the 3' untranslated region (3' utr) of lettuce mosaic virus served as template for synthesis of complementary (-)-strand rna following an infection by tobacco etch virus, tobacco vein mottle virus or pepper mottle virus, but not when infected with cucumber mosaic virus. deletion of the 3' utr from the transgene abolished the synthesis of (-)-strand transcripts. similar results were obtained in transgenic tobacco plants exp ... | 2000 | 10725441 |
| analysis of the capsid processing strategy of thosea asigna virus using baculovirus expression of virus-like particles. | thosea asigna virus (tav), a putative member of the genus betatetravirus of the family tetraviridae, is predicted to have a novel capsid expression strategy compared with other characterized tetraviruses. the capsid precursor protein is cleaved twice to generate three proteins. two of the proteins, l (58.3 kda) and s (6.8 kda), are incorporated into the tav virion. the third, non-structural protein, produced from the n terminus of the precursor protein, is up to 17 kda in size and is of unknown ... | 2001 | 11125178 |
| ribosome shunt is essential for infectivity of cauliflower mosaic virus. | cauliflower mosaic virus (camv) is a dna-containing pararetrovirus replicating by means of reverse transcription of a terminally redundant pregenomic 35s rna that is also used as a polycistronic mrna. the leader of 35s rna is long, highly structured, and contains multiple short orfs (sorfs), which strongly interfere with the ribosome scanning process. translation of this rna is initiated by a ribosome shunt mechanism, in which ribosomes translate the most 5'-proximal short orf (sorf a), then ski ... | 2001 | 11158565 |
| a plant viral "reinitiation" factor interacts with the host translational machinery. | the cauliflower mosaic virus transactivator, tav, controls translation reinitiation of major open reading frames on polycistronic rna. we show here that tav function depends on its association with polysomes and eukaryotic initiation factor eif3 in vitro and in vivo. tav physically interacts with eif3 and the 60s ribosomal subunit. two proteins mediating these interactions were identified: eif3g and 60s ribosomal protein l24. transient expression of eif3g and l24 in plant protoplasts strongly af ... | 2001 | 11572778 |
| the brome mosaic virus rna3 intergenic replication enhancer folds to mimic a trna tpsic-stem loop and is modified in vivo. | the genome of brome mosaic virus (bmv), a positive-strand rna virus in the alphavirus-like superfamily, consists of three capped, messenger-sense rnas. rna1 and rna2 encode viral replication proteins 1a and 2a, respectively. rna3 encodes the 3a movement protein and the coat protein, which are essential for systemic infection in plants but dispensable for rna3 replication in plants and yeast. a subset of the 250-base intergenic region (igr), the replication enhancer (re), contains all cis-acting ... | 2001 | 11720293 |
| separation methods for tricyclic antiviral drugs. | a review of the published analytical methodology for the tricyclic antiviral (tav) drugs is presented. while amantadine and rimantadine are the only two approved drugs for the prophylaxis and treatment of the influenza a virus, amantadine has also been approved for the treatment of parkinson's disease. in addition, a few structurally related compounds are finding important clinical applications in other central nervous system-related disorders. to effectively evaluate the pharmacokinetics, biotr ... | 2001 | 11817035 |
| a comparative analysis of the avirulence and translational transactivator functions of gene vi of cauliflower mosaic virus. | the primary function associated at present with the gene vi product of cauliflower mosaic virus (camv) is that of a translational transactivator (tav). in this capacity, it alters the host translational machinery to allow reinitiation of translation of other camv genes on the polycistronic 35s rna of camv. in addition, the gene vi protein can elicit a specific type of plant defense response called the hypersensitive response (hr) in nicotiana edwardsonii. in this study, we have adapted the agroi ... | 2002 | 11886242 |
| generation of infectious cdna clones of a korean strain of tomato aspermy virus. | infectious full-length cdna clones of the korean strain of tomato aspermy cucumovirus (kc-tav) were constructed using a long-template reverse transcription-polymerase chain reaction. the in vitro rna transcripts, which were produced using t7 rna polymerase from full-length cdnas, could systemically infect the nicotiana tabacum cv. xanti-nc plants and induce systemic symptoms on the upper leaves that are similar to the wildtype kc-tav. the complete nucleotide sequences of genomic rnas of kc-tav w ... | 2002 | 11911475 |
| the structure of tomato aspermy virus by x-ray crystallography. | the three-dimensional structure of tomato aspermy virus (tav) has been solved by x-ray crystallography and refined to an r factor of 0.218 for 3.4-40 a data (effective resolution of 4a). molecular replacement, using cucumber mosaic virus (smith et al., 2000), provided phases for the initial maps used for model building. the coat protein of the 280 a diameter virion has the canonical "swiss roll" beta-barrel topology with a distinctive amino-terminal alpha-helix directed into the interior of the ... | 2002 | 12406691 |
| the palm subdomain-based active site is internally permuted in viral rna-dependent rna polymerases of an ancient lineage. | template-dependent polynucleotide synthesis is catalyzed by enzymes whose core component includes a ubiquitous alphabeta palm subdomain comprising a, b and c sequence motifs crucial for catalysis. due to its unique, universal conservation in all rna viruses, the palm subdomain of rna-dependent rna polymerases (rdrps) is widely used for evolutionary and taxonomic inferences. we report here the results of elaborated computer-assisted analysis of newly sequenced replicases from thosea asigna virus ... | 2002 | 12421558 |
| differential induction of symptoms in arabidopsis by p6 of cauliflower mosaic virus. | the gene vi protein (p6) of cauliflower mosaic virus (camv) functions as a virulence factor in crucifers by eliciting chlorotic symptoms in infected plants. the ability to induce chlorosis has been associated previously with p6 through gene-swapping experiments between strains and through the development of transgenic plants that express p6. the primary role that has been identified for p6 in the camv infection cycle is to modify the host translation machinery to facilitate the translation of th ... | 2003 | 12580280 |
| rna recombination between cucumoviruses: possible role of predicted stem-loop structures and an internal subgenomic promoter-like motif. | we previously analyzed hybrids of cucumber mosaic virus (cmv) and tomato aspermy virus (tav) that contained cmv rna2 with the 3'-terminal sequence from tav rna2. in this article, we scrutinized the rna3 molecules in these hybrid viruses by northern hybridization and rt-pcr and found some recombinant cmv rna3 molecules and various recombinant rna4 molecules whose 3'-termini were derived from tav rna1 or 2. sequence analyses revealed that most of the crossover sites for recombination were located ... | 2003 | 12620800 |
| the 2b protein of cucumoviruses has a role in promoting the cell-to-cell movement of pseudorecombinant viruses. | pseudorecombinant viruses (i.e., those containing a reassorted genome of closely related multipartite viruses) are often not as competitive as the parental viruses. the role of the 2b gene in hypervirulence and maintenance of a progressive infection was assessed in a pseudorecombinant virus formed between rnas 1 plus 2 of cucumber mosaic virus (cmv) and rna 3 of tomato aspermy virus (tav). the presence of rna 3 of tav was found to affect the level of rna accumulation but not the level of virulen ... | 2003 | 12650457 |
| dissection of cauliflower mosaic virus transactivator/viroplasmin reveals distinct essential functions in basic virus replication. | cauliflower mosaic virus (camv) transactivator/viroplasmin (tav) is an essential multifunctional viral protein. dissection of tav by deletion mutagenesis revealed that the central region is essential for camv replication in single cells but that the n- and c-terminal parts are not. strains with mutations in the central region were defective in the translational transactivator function and could be complemented by coexpressing gag (capsid protein precursor) and pol (polyprotein with protease, rev ... | 2003 | 12857928 |
| molecular anatomy of tupaia (tree shrew) adenovirus genome; evolution of viral genes and viral phylogeny. | adenoviruses are globally spread and infect species in all five taxons of vertebrates. outstanding attention is focused on adenoviruses because of their transformation potential, their possible usability as vectors in gene therapy and their applicability in studies dealing with, e.g. cell cycle control, dna replication, transcription, splicing, virus-host interactions, apoptosis, and viral evolution. the accumulation of genetic data provides the basis for the increase of our knowledge about aden ... | 2003 | 12913356 |
| cucumoviruses. | research on the molecular biology of cucumoviruses and their plant-virus interactions has been very extensive in the last decade. cucumovirus genome structures have been analyzed, giving new insights into their genetic variability, evolution, and taxonomy. a new viral gene has been discovered, and its role in promoting virus infection has been delineated. the localization and various functions of each viral-encoded gene product have been established. the particle structures of cucumber mosaic vi ... | 2003 | 14719367 |
| eucaryotic initiation factor 4b controls eif3-mediated ribosomal entry of viral reinitiation factor. | the cauliflower mosaic virus reinitiation factor tav interacts with host translation initiation factor 3 (eif3) and the 60s ribosomal subunit to accomplish translation of polycistronic mrnas. interaction between tav and eif3g is critical for the reinitiation process. here, we show that eif4b can preclude formation of the tav/eif3 complex via competition with tav for eif3g binding; indeed, the eif4b- and tav-binding sites on eif3g overlap. our data indicate that eif4b interferes with tav/eif3/40s ... | 2004 | 14988734 |
| compatibility of the movement protein and the coat protein of cucumoviruses is required for cell-to-cell movement. | for the cell-to-cell movement of cucumoviruses both the movement protein (mp) and the coat protein (cp) are required. these are not reversibly exchangeable between cucumber mosaic virus (cmv) and tomato aspermy virus (tav). the mp of cmv is able to function with the tav cp (chimera rt), but tav mp is unable to promote the cell-to-cell movement in the presence of cmv cp (chimera tr). to gain further insight into the non-infectious nature of the tr recombinant, rna 3 chimeras were constructed with ... | 2004 | 15039546 |
| the avirulence domain of cauliflower mosaic virus transactivator/viroplasmin is a determinant of viral virulence in susceptible hosts. | cauliflower mosaic virus (camv) transactivator/viroplasmin (tav) is a multifunctional protein essential for basic replication of camv. it also plays a role in viral pathogenesis in crucifer and solanaceous host plants. deletion mutagenesis revealed that n- and c-terminal parts of tav are not essential for camv replication in transfected protoplasts. two deletion mutants having only minimal defects in basic replication were infectious in turnips but only with highly attenuated virulence. this was ... | 2004 | 15141951 |
| [viruses of orchids of the natural flora in ukraine]. | orchids from biogeocenosis of natural landscapes of ukraine (the crimea, carpathians) were analyzed for presence of viral pathogens. it is demonstrated that tobacco rattle virus (trv), tomato aspermy virus (tav), cymbidium mosaic virus (cymmv) and arabis mosaic virus (armv) are the most spreaded pathogens of orchid plants. there are orchid species distinguished in natural flora of ukraine with characteristic high frequency of viral infection. | 2004 | 15208857 |
| stable and unstable mutations in the 5' non-translated regions of tomato aspermy virus rnas 1 and 2 generated de novo from infectious cdna clones containing a cauliflower mosaic virus 35s promoter. | tomato aspermy virus rnas derived from infectious cdna clones exhibited a number of sequence alterations in the 5' non-translated region (ntr). these included a deletion of the first four residues in both rnas 1 and 2, transversion of residue 5 from a g to a u in rna 1, and transversion of a to c at position of 50 of rna 1. these alterations were not stable in the infected plants while the insertion of a u residue between nucleotides 1 and 5 of rna 1 was stable in the infected plants. generation ... | 2004 | 15266109 |
| control of translation reinitiation on the cauliflower mosaic virus (camv) polycistronic rna. | translation of the polycistronic 35s rna of camv (cauliflower mosaic virus) occurs via a reinitiation mechanism, which requires tav (transactivator/viroplasmin). to allow translation reinitiation of the major open reading frames on the polycistronic rna, tav interacts with the host translational machinery via eif3 (eukaryotic initiation factor 3) and the 60s ribosome. accumulation of tav and eif3 in the polysomal fraction isolated from camv-infected cells suggested that tav prevents loss of eif3 ... | 2004 | 15270684 |
| a novel strategy for creating recombinant infectious rna virus genomes. | reverse transcriptases with rnase h activity are particularly apt to switch templates and generate recombinant molecules in vitro. this property has been exploited for the first time to create a library of recombinant rnas 3 between two strains of cucumber mosaic virus (cmv) or between cmv and tomato aspermy virus (tav), which share 75 and 63% sequence identity, respectively. the recombination events were almost entirely of the precise homologous type, and occurred at the same sites as those pre ... | 2004 | 15381363 |
| a map of the diversity of rna3 recombinants appearing in plants infected with cucumber mosaic virus and tomato aspermy virus. | in order to better understand the role of recombination in creating the diversity of viral genomes that is acted on by selection, we have studied in detail the population of recombinant rna3 molecules occurring in tobacco plants coinfected with wild-type strains of cucumber mosaic virus (cmv) and tomato aspermy virus (tav) under conditions of minimal selection pressure. recombinant rna3s were observed in 9.6% of the samples. precise homologous recombination predominated since it was observed at ... | 2005 | 15582658 |
| the conserved, 5' termini of rnas 1 and 2 of tomato aspermy virus are dispensable for infection but affect virulence. | the 5' terminus of each of the three genomic rnas (rnas 1, 2 and 3) of tomato aspermy virus (tav) begins with the sequence 5'-guuu, which is also shared by a number of other viruses. mutagenic analyses showed that the 5'-guuu sequence of rnas 1 and 2 of tav was dispensable for viral infection and did not prevent symptom induction. on the other hand, substitution of u at position 5 for g in rna 1, but not rna 2, induced veinal necrosis symptoms in nicotiana glutinosa. the mutants constructed incl ... | 2005 | 15744575 |
| homology modelling and protein structure based functional analysis of five cucumovirus coat proteins. | coat proteins (cp) of five cucumovirus isolates, cucumber mosaic virus (cmv) strains r, m and trk7, tomato aspermy virus (tav) strain p and peanut stunt virus (psv) strain er, were constructed by homology modelling. the x-ray structure of the fny-cmv cp subunit b was used as a template. models of cucumovirus cps were built by the modeller program. model refinements were carried out using the kollman molecular mechanical force field. models were analyzed by the procheck programs. electrostatic po ... | 2006 | 16257549 |
| comparison of properties of particles of cucumber mosaic virus and tomato aspermy virus based on the analysis of molecular surfaces of capsids. | the plant rna viruses cucumber mosaic virus (cmv) and tomato aspermy virus (tav) (genus cucumovirus) have similar icosahedral particles, the crystal structures of which have been reported recently. similarity in particle structure agrees with reports of stable capsids assembled from their capsid proteins and of viable recombinant viruses with chimeric capsid proteins derived from cmv and tav. however, differences between the cucumoviruses have been reported for physicochemical properties. here, ... | 2006 | 16760411 |
| analysis of the viability of coat-protein hybrids between cucumber mosaic virus and tomato aspermy virus. | coat-protein (cp) hybrids between cucumber mosaic virus (cmv) and tomato aspermy virus (tav) were engineered to analyse reported cp-associated differences between these viruses. cp portions delimited by aa 1-59, 60-148 and 149-219 were exchanged in all possible combinations within tav rna3. the seven possible chimeras were able to replicate in tobacco protoplasts to similar levels, but only those having residues 1-59 or 60-148 from cmv were infectious to tobacco plants, a common host for cmv and ... | 2006 | 16760412 |
| echo-doppler measurements of portal vein and hepatic artery in asymptomatic patients with hepatitis b virus and healthy adults. | the aim of this prospective study was to determine the range of various hemodynamic parameters of portal vein and hepatic artery with echo-doppler imaging in asymptomatic carriers of hepatitis b virus (hbv) and healthy adults. | 2006 | 17205145 |
| the cucumovirus 2b gene drives selection of inter-viral recombinants affecting the crossover site, the acceptor rna and the rate of selection. | rna-rna recombination is an important pathway in virus evolution and has been described for many viruses. however, the factors driving recombination or promoting the selection of recombinants are still unclear. here, we show that the small movement protein (2b) was able to promote selection of rna 1/2-rna 3 recombinants within a chimeric virus having rnas 1 and 2 from cucumber mosaic virus, and rna 3 from the related tomato aspermy virus, along with heterologous 2b genes. the source of the 2b al ... | 2008 | 18086712 |
| evaluation of potential risks associated with recombination in transgenic plants expressing viral sequences. | virus-resistant transgenic plants have been created primarily through the expression of viral sequences. it has been hypothesized that recombination between the viral transgene mrna and the rna of an infecting virus could generate novel viruses. as mrna/viral rna recombination can occur in virus-resistant transgenic plants, the key to testing this risk hypothesis is to compare the populations of recombinant viruses generated in transgenic and non-transgenic plants. this has been done with two cu ... | 2008 | 18089757 |
| contrasting effects of hc-pro and 2b viral suppressors from sugarcane mosaic virus and tomato aspermy cucumovirus on the accumulation of sirnas. | rna silencing and suppression of silencing are host and virus interactions for defense and counter-defense. here, we explored the function effect of hc-pro encoded by sugarcane mosaic virus (scmv) on the suppression of rna silencing. sirna northern blotting assay indicated that the replication of scmv was regulated by host rna silencing machinery. co-expression assay demonstrated that the hc-pro encoded by scmv suppressed the rna silencing induced by sense rna and dsrna. transitive rna silencing ... | 2008 | 18280529 |
| structural basis for rna-silencing suppression by tomato aspermy virus protein 2b. | the 2b proteins encoded by cucumovirus act as post-transcriptional gene silencing suppressors to counter host defence during infection. here we report the crystal structure of tomato aspermy virus 2b (tav2b) protein bound to a 19 bp small interfering rna (sirna) duplex. tav2b adopts an all alpha-helix structure and forms a homodimer to measure sirna duplex in a length-preference mode. tav2b has a pair of hook-like structures to recognize simultaneously two alpha-helical turns of a-form rna duple ... | 2008 | 18600235 |
| comparative studies on two satellite rnas of cucumber mosaic virus. | cucumber mosaic virus (cmv) satellite rna (sat-rna, d. w. mossop and r. i. b. francki, 1978, virology86, 562-566) is similar in many of its physical and biological properties to cmv associated rna 5 (carna 5) described by kaper and tousignant (1977, virology85, 323-327). however, carna 5, unlike sat-rna, causes a serious necrotic disease of tomato. sat-rna when inoculated together with various cmv or tomato aspermy virus strains not only failed to increase the severity of symptoms in infected to ... | 1979 | 18627899 |
| the rnas of cucumoviruses: 3'-terminal sequence analysis of two strains of tomato aspermy virus. | the sequences of 189 residues from the 3' terminus of three rnas of one strain and two rnas of another strain of tomato aspermy virus have been determined; there was almost complete sequence homology between the rnas. a base-paired transfer rna-like structure is proposed for tomato aspermy virus rnas which is similar in many aspects to the structure proposed for the 3'-terminal 172 residues of rna 4 of the q-strain of cucumber mosaic virus (r. h. symons, nucleic acids res.7, 825-837, 1979). thes ... | 1981 | 18635070 |
| comparative studies on tomato aspermy and cucumber mosaic viruses. vi. partial compatibility of genome segments from the two viruses. | isolated rna genomic segments (rnas 1, 2, and 3) of tomato aspermy virus and of three strains of cucumber mosaic virus (cmv) were inoculated to leaves of chenopodium amaranticolor costs and reyn in all combinations. the data presented demonstrate that whereas rna 3 is readily interchangeable between the two viruses to produce infections resulting in lesion development, rnas 1 and 2 are not, although they are interchangeable between the three cmv strains. the possible significance of these observ ... | 1981 | 18635103 |
| comparative studies on tomato aspermy and cucumber mosaic viruses. vii. serological relationships reinvestigated. | distant antigenic relationships between australian strains of tomato aspermy virus (tav) and cucumber mosaic virus (cmv) were investigated by three serological methods: radial double immunodiffusion in agar, enzyme-linked immunosorbent assays (elisa), and immune-electron microscopy (iem) using the antibody decoration technique. based on the work with tav and cmv presented in this paper, it appears that the elisa method is especially suitable for studying antigenic relationships among viruses. fo ... | 1982 | 18635114 |
| stability and structural transitions of tomato aspermy virus and cucumber mosaic virus. | the properties of the s-strain of cucumber mosaic virus (s-cmv) and the b-strain of tomato aspermy virus (b-tav) have been studied with respect to their (i) size and sedimentation behavior, (ii) requirement of divalent metal ions for stability, (iii) sensitivity towards chloride salts and the anionic detergent sodium dodecyl sulfate, (iv) solubility in ammonium sulfate-containing buffers, and (v) ph-dependent structural transitions. the results indicate that the coat protein of b-tav is more hyd ... | 1984 | 18639813 |
| nucleotide sequence analysis of six satellite rnas of cucumber mosaic virus: primary sequence and secondary structure alterations do not correlate with differences in pathogenicity. | the nucleotide sequences of six satellite rnas of cucumber mosaic virus (cmv) differing in their pathological properties have been determined. although these rnas varied in length from 333 to 342 nucleotides, the extent of nucleotide sequence homology to each other and to four other satellite rnas ranged from 84 to 97%, allowing satellite rna subgrouping on the basis of nucleotide sequence. this subgrouping was further extended by an analysis of the nature of the differences in nucleotide sequen ... | 1987 | 18644565 |
| the camv transactivator/viroplasmin interferes with rdr6-dependent trans-acting and secondary sirna pathways in arabidopsis. | several rna silencing pathways in plants restrict viral infections and are suppressed by distinct viral proteins. here we show that the endogenous trans-acting (ta)sirna pathway, which depends on dicer-like (dcl) 4 and rna-dependent rna polymerase (rdr) 6, is suppressed by infection of arabidopsis with cauliflower mosaic virus (camv). this effect was associated with overaccumulation of unprocessed, rdr6-dependent precursors of tasirnas and is due solely to expression of the camv transactivator/v ... | 2008 | 18801846 |
| multiple targets for suppression of rna interference by tomato aspermy virus protein 2b. | viral suppressors of rna interference (rnai) appear to have evolved as a response to this innate genomic defense. we report the nucleic acid binding properties of the cucumovirus rnai suppressor tomato aspermy virus protein 2b (tav 2b). using total internal reflection fluorescence spectroscopy (tirfs), we show that tav 2b binds double-stranded rna corresponding to sirnas and mirnas, as well as single-stranded rna oligonucleotides. a number of positively charged residues between amino acids 20 an ... | 2008 | 18986165 |
| stability and competitiveness of interviral recombinant rnas derived from a chimeric cucumovirus. | we previously described interviral recombinant rnas derived from a chimeric virus having rnas 1 and 2 of cucumber mosaic virus (cmv) with rna 3 from the related tomato aspermy virus (tav) and the 2b gene from either tav or another strain of cmv. here, we show that these interviral recombinant rnas 3 were stable in the infected plants and could co-exist with their wild-type parental viral rnas in the same plants, but their de novo generations were inhibited in the presence of the wild-type parent ... | 2009 | 19063925 |
| the quantification of tomato micrornas response to viral infection by stem-loop real-time rt-pcr. | micrornas (mirnas) are rna molecules consisting of 20-24 nucleotides that play important roles in regulating plant's gene expression for growth and development, cell viability and stress responses. viral infection often has a noticeable influence on host gene expression, which may result in a range of developmental abnormalities. to investigate the molecular mechanisms underlying viral infection, mirna pathway and host gene expression, we report herein the application of the novel mirnas quantif ... | 2009 | 19374024 |
| the 3' untranslated region of cucumber mosaic virus (cmv) subgroup ii rna3 arose by interspecific recombination between cmv and tomato aspermy virus. | recombination in single-stranded rna viruses is one of the principal mechanisms responsible for their evolution. here we show, using a variety of different methods, that the 3' untranslated region (3'utr) of subgroup ii strains of cucumber mosaic virus [cmv(ii)] is related more closely to that of tomato aspermy virus (tav) than to those of cmv(i) strains. these results suggest that the cmv(ii) 3'utr arose by interspecific cmv/tav recombination. the putative crossover is close to the 5' end of th ... | 2009 | 19474245 |
| a new plant protein interacts with eif3 and 60s to enhance virus-activated translation re-initiation. | the plant viral re-initiation factor transactivator viroplasmin (tav) activates translation of polycistronic mrna by a re-initiation mechanism involving translation initiation factor 3 (eif3) and the 60s ribosomal subunit (60s). qj;here, we report a new plant factor-re-initiation supporting protein (risp)-that enhances tav function in re-initiation. risp interacts physically with tav in vitro and in vivo. mutants defective in interaction are less active, or inactive, in transactivation and viral ... | 2009 | 19745810 |
| euprosterna elaeasa virus genome sequence and evolution of the tetraviridae family: emergence of bipartite genomes and conservation of the vpg signal with the dsrna birnaviridae family. | the tetraviridae is a family of non-enveloped positive-stranded rna insect viruses that is defined by the t=4 symmetry of virions. we report the complete euprosterna elaeasa virus (eev) genome sequence of 5698 nt with no poly(a) tail and two overlapping open reading frames, encoding the replicase and capsid precursor, with approximately 67% amino acid identity to thosea asigna virus (tav). the n-terminally positioned 17 kda protein is released from the capsid precursor by a npgp motif. eev has 4 ... | 2010 | 19954807 |
| the solution structures of the cucumber mosaic virus and tomato aspermy virus coat proteins explored with molecular dynamics simulations. | the three-dimensional structures of two cucumovirus coat proteins (cp), namely cucumber mosaic virus (cmv) and tomato aspermy virus (tav), were explored by molecular dynamics (md) simulations. the n-terminal domain and the c-terminal tail of the cps proved to be intrinsically unstructured protein regions in aqueous solution. the n-terminal alpha-helix had a partially unrolled conformation. the thermal factor analysis of the cp loop regions demonstrated that the cmv cp had more flexible loop regi ... | 2010 | 20056465 |
| cucumber mosaic virus 2b protein subcellular targets and interactions: their significance to rna silencing suppressor activity. | the rna silencing suppressor activity of the 2b protein of cucumber mosaic virus (cmv) has been variously attributed to its nuclear targeting, its interaction with and inhibition of argonaute 1 (ago1), or its ability to bind small rnas in vitro. in addition, the 2b ortholog of tomato aspermy virus forms aggregates and binds rnas in vitro. we have further studied the relationships between cmv 2b protein silencing suppressor activity and its subcellular distribution, protein-protein interactions i ... | 2010 | 20121451 |
| a progeny virus from a cucumovirus pseudorecombinant evolved to gain the ability to accumulate its rna-silencing suppressor leading to systemic infection in tobacco. | two isolates of tomato aspermy virus (tav), v-tav and c-tav, can systemically infect nicotiana benthamiana but only c-tav can move systemically in n. tabacum. any pseudorecombinants between the two strains could not move systemically in tobacco as efficiently as c-tav. however, a pseudorecombinant consisting of rnas 1 and 3 of v-tav and rna 2 of c-tav (v1c2v3), which cannot infect tobacco systemically, generated progeny with a mutation in v1 and a recombination in c2 (v1(m)c2(r)v3), enabling the ... | 2010 | 20121454 |
| symptom induction and rna silencing suppression by the cucumber mosaic virus 2b protein. | the 2b protein encoded by cucumber mosaic virus (cmv) and other cucumoviruses is multifunctional, having roles in local and systemic virus movement, symptom determination, evasion of defense mediated by salicylic acid, and in suppression of antiviral rna silencing. it also perturbs silencing-mediated regulation of host transcripts, suggesting that another function of 2b protein is to manipulate host gene expression and physiology in a way that may aid the virus. the 2b proteins encoded by the va ... | 2010 | 20404501 |
| cucumber mosaic virus, a model for rna virus evolution. | summary taxonomic relationships: cucumber mosaic virus (cmv) is the type member of the cucumovirus genus, in the family bromoviridae. additional members of the genus are peanut stunt virus (psv) and tomato aspermy virus (tav). the rnas 3 of all members of the genus can be exchanged and still yield a viable virus, while the rnas 1 and 2 can only be exchanged within a species. physical properties: the virus particles are about 29 nm in diameter, and are composed of 180 subunits (t = 3 icosahedral ... | 2001 | 20572992 |
| spatio-temporal expression of mirnas in tomato tissues upon cucumber mosaic virus and tomato aspermy virus infections. | micrornas (mirnas) play vital roles in regulating plant growth and development. recent work has shown that mirna-mediated regulation of cellular mrna expression is involved in pathogen-host interactions. however, knowledge about the timing and spatial regulation of plant mirna expression is still limited. here, we use stem-loop real-time reverse transcription-polymerase chain reaction to quantify the expression changes of seven mirnas and their target mrnas in different tomato tissues during the ... | 2011 | 21335334 |
| differential effects of cucumber mosaic virus satellite rnas in the perturbation of microrna-regulated gene expression in tomato. | viral infections generally cause disease symptoms by interfering with the microrna (mirna)-mediated regulation of gene expression of host plants. in tomato leaves, the accumulation levels of eleven mirnas and ten target mrnas were enhanced by different degrees upon cucumber mosaic virus (cmv)-fny and tomato aspermy virus (tav)-bj infections. the ability of cmv-fny to interfere with mirna pathway was dramatically suppressed in the addition of the benign satellite (sat) rna variant (satyn12), but ... | 2011 | 21590278 |
| identification a coat protein region of cucumber mosaic virus (cmv) essential for long-distance movement in cucumber. | to characterise the long-distance movement determinant of cucumoviral coat proteins (cps), five mutants were engineered into the cmv cp bearing the corresponding tomato aspermy virus (tav) loops exposed on the surface of the virion. both viruses can move long-distance in nicotiana clevelandii, but only cmv can move long-distance in cucumber. investigation of the cmv chimeras identified three amino acids of the βb-βc loop that were essential for the cmv long-distance movement in cucumber. introdu ... | 2011 | 21927896 |
| the n-terminal 12 amino acids of tomato aspermy virus 2b protein function in infection and recombination. | the roles for various regions of the 2b protein in infection, hypervirulence and recombination were examined by introducing stop codons in a chimeric virus containing rna 1 from the cucumber mosaic virus (cmv strain q), rna 3 from the tomato aspermy virus (tav) and rna 2 of cmv with a 2b gene from tav. chimeric virus expressing the intact 2b protein induced severe symptoms in inoculated nicotiana clevelandii and nicotiana glutinosa and facilitated cmv-tav recombination, while chimeric viruses no ... | 2011 | 21880843 |
| Cucumber mosaic virus: viral genes as virulence determinants. | Taxonomic relationships: Cucumber mosaic virus (CMV) is the type species of the genus Cucumovirus in the family Bromoviridae, which also encompasses the Peanut stunt virus (PSV) and the Tomato aspermy virus (TAV). Nucleotide sequence similarity among these three cucumoviruses is 60%-65%. CMV strains are divided into three subgroups, IA, IB and II, based on the sequence of the 5' untranslated region of the genomic RNA 3. Overall nucleotide sequence similarity among CMV strains is approximately 70 ... | 2011 | 21980997 |
| a novel set of polyvalent primers that detect members of the genera bromovirus and cucumovirus. | rapid detection and diagnosis of plant virus infection is one of the most important steps in preventing damages caused by viral diseases. bromoviruses and cucumoviruses belong to the family bromoviridae, which is one of the most important families of plant viruses, and infect a broad range of host plants including various economically important crops. in this study, an rt-pcr assay was developed for the universal detection of bromoviruses and cucumoviruses using a set of primers designed to targ ... | 2014 | 24717165 |
| a multiplex rt-pcr for simultaneous detection and identification of five viruses and two viroids infecting chrysanthemum. | pathogens causing significant economic losses in chrysanthemum include tomato aspermy virus (tav), chrysanthemum virus b (cvb), cucumber mosaic virus (cmv), tobacco mosaic virus (tmv), potato virus y (pvy), chrysanthemum stunt viroid (csvd) and chrysanthemum chlorotic mottle viroid (cchmvd). a multiplex reverse transcription polymerase chain reaction (rt-pcr) method, using specific primer sets for each virus or viroid, was developed for simultaneous detection and differentiation of tav, cvb, cmv ... | 2015 | 25698104 |
| a multiplex rt-pcr for rapid and simultaneous detection of viruses and viroids in chrysanthemum. | chrysanthemum plants are subject to serious virus diseases, so detection and identification of virus pathogens is important to prevent the virus spread. a reliable one-step multiplex rt-pcr was developed to simultaneously detect two viruses and two viriods: chrysanthemum virus b, tomato aspermy virus, chrysanthemum stunt viroid and chrysanthemum chlorotic mottle viroid. in addition, we investigated the detection limit and the efficiency of single and multiplex rt-pcr assays. the results showed t ... | 2013 | 23020260 |
| heterologous replicase driven 3' end repair of cucumber mosaic virus satellite rna. | to investigate the extent of the 3' end repair in a satellite rna of cucumber mosaic virus (cmv) strain q (q(sat)) by a heterologous tomato aspermy virus (tav), a set of biologically active agrotransformants corresponding to the three genomic rnas of tav was developed. analysis of nicotiana benthamiana plants agroinfiltrated with tav and either wild type or each of the six 3' deletion mutants of q(sat) revealed that (i) heterologous replicase failed to generate q(sat) multimers, a hallmark featu ... | 2015 | 25705791 |