| heterochromatin diversity in cymbidium, and its relationship to differential dna replication. | | 1976 | 56279 |
| effects of phytohormones on thermal denaturation profiles of cymbidium dna: indication of differential dna replication. | protocorm pieces of the orchid cymbidium were aseptically cultured either without phytohormones, or with one of the growth promoting substances, auxin cytokinin, and gibberellin. the derivative melting profiles of the extracted dna's differ from each other with respect to the size of various at- and gc- rich fractions. evidence has been obtained for the increase of the more at--rich fractions in auxin-treated cultures, while gibberellin stimulated the expansion of the gc-rich fractions. these re ... | 1976 | 967687 |
| isolation and characterization of native at-rich satellite dna from nuclei of the orchid cymbidium. | | 1976 | 976478 |
| an a + t-rich satelitte dna in a monocotyledonous plant, cymbidium. | the dna of aseptically grown protocorms of a cymbidium hybrid and in vitro developed leaves, as well as dna of leaves and flower buds of cymbidium ceres from the greenhouse, was analysed by analytical ultracentrifugation and thermal denaturation. upon ultracentrifugation a satellite dna with a buoyant density of 1.682 g/cm-3 appears as a shoulder on the main band (density 1.694 g/cm-3). thermal denaturation reveals an inhomogeneous main peak with the major component melting at 84 degrees c and a ... | 1975 | 1138934 |
| the mannose-specific plant lectins from cymbidium hybrid and epipactis helleborine and the (n-acetylglucosamine)n-specific plant lectin from urtica dioica are potent and selective inhibitors of human immunodeficiency virus and cytomegalovirus replication in vitro. | a series of four mannose(man)-, three n-acetylglucosamine (glcnac)n-, ten n-acetylgalactosamine/galactose(galnac/gal)-, one 5-acetylneuraminic acid (alpha-2,3-gal/galnac)- and one 5-acetylneuroaminic acid(alpha-2,6-gal/gal-nac)-specific plant agglutinins were evaluated for their antiviral activity in vitro. the mannose-specific lectins from the orchid species cymbidium hybrid (ca), epipactis helleborine (eha) and listera ovata (loa) were highly inhibitory to human immunodeficiency virus type 1 ( ... | 1992 | 1329650 |
| biologically active cymbidium ringspot virus satellite rna in transgenic plants suppresses accumulation of di rna. | a full-length dna copy of cymbidium ringspot virus (cyrsv) satellite rna was cloned downstream of the bacteriophage t7 rna polymerase promoter. in vitro transcripts were biologically active in plants when coinoculated with the helper virus or its rna. although the transcripts contained 7 or 29 extra nucleotides at the 3' end, the proper 3' terminus was restored in the satrna progeny. full-length cdna clones of cyrsv satrna under the control of the cauliflower mosaic virus 35s promoter and termin ... | 1992 | 1374981 |
| the replication of cymbidium ringspot tombusvirus defective interfering-satellite rna hybrid molecules. | a dna copy of di rna of cymbidium ringspot tombusvirus was cloned downstream of a phage t7 promoter. in vitro-transcribed rna replicated in nicotiana clevelandii when co-inoculated with full-length viral genomic rna transcripts and protected plants from apical necrosis. artificial deletion mutants derived from the di rna clone showed that most of the central sequence block is necessary for replication. hybrid di rna-satrna clones were prepared and in vitro-synthesized rna was inoculated to plant ... | 1992 | 1381535 |
| replication and movement of a coat protein mutant of cymbidium ringspot tombusvirus. | the spread of cymbidium ringspot tombusvirus (cyrsv) in host tissue was studied by using a coat protein gene mutant with a six-nucleotide deletion; the deletion removes two amino acids from the shell domain (s) of the capsid protein. mutated protein subunits were synthesized in infected cells but could not assemble into virus particles. virions were formed, however, with inoculation of mutated rna in transgenic plants expressing normal cyrsv coat protein. the mutant is restricted in long-distanc ... | 1992 | 1472715 |
| nucleotide sequences of the two orfs upstream to the coat protein gene of cymbidium mosaic virus. | | 1992 | 1581564 |
| tombusvirus genome may encode the sixth small protein near its 3' terminus. | a short open reading frame (orf), orf6, potentially encoding a polypeptide (px) of 32-69 amino acids, was revealed upon computer translation of the 3' terminal regions of tomato bushy stunt, cymbidium ringspot, cucumber necrosis and artichoke mottled crinkle tombusviruses. orf6 has an initiating aug codon in a favorable context and is evaluated as expressible, judging the distribution of guanosine residues within the codons. inspection of the alignment of the four putative products encoded by or ... | 1992 | 1589962 |
| characterization of cymbidium mosaic virus coat protein gene and its expression in transgenic tobacco plants. | cymbidium mosaic virus (cymv) is the most prevalent virus infecting orchids. here, we report the isolation of partial cdna clones encoding the genomic rna of cymv. like most of the polyadenylated monopartite positive-strand rna viruses, the open reading frame (orf) coding for the viral coat protein (cp) is located at the 3' end. the orf predicts a polypeptide chain of 220 amino acids with a molecular weight of 23,600. sequence comparison of this orf to the cp sequences of potato virus x(pvx) and ... | 1992 | 1600145 |
| ubiquitinated conjugates are found in preparations of several plant viruses. | recently d.d. dunigan, r.g. dietzgen, j.e. schoelz, and m. zaitlin (virology 165, 310-312, 1988) demonstrated that a small proportion of the subunits of tobacco mosaic virus particles were conjugated with the small protein ubiquitin. we have now detected ubiquitinated conjugates in immunoblots of virion preparations of several other plant viruses, using anti-human ubiquitin antiserum. based on their polyacrylamide gel migrations, plant virus-associated ubiquitin-immunoreactive proteins were cons ... | 1990 | 2162109 |
| cdna cloning of artichoke mottled crinkle virus rna and localization and sequencing of the coat protein gene. | we report the cdna cloning of the genomic rna of artichoke mottled crinkle virus (amcv), which is a member of tombusvirus group. amcv has a monopartite positive sense rna genome, which is not polyadenylated at the 3' end. the genome size is 4.8 kb. we have localized and sequenced the open reading frame (orf) encoding the coat protein. unlike most monopartite positive-strand rna plant viruses, the orf is not located near the 3' end, but like other members of the tombusvirus group, cyrsv (cymbidiu ... | 1989 | 2491684 |
| orchid allergy. | a female office worker acquired contact allergy by handling cymbidium cultivars for several years. the sensitizing properties of this ornamental orchid were demonstrated by experimental sensitization of guinea pigs. chemical analysis of the ether extracts disclosed the presence of two quinones. the structure of the main quinone was elucidated as 2,6-dimethoxy-1,4-benzoquinone by x-ray crystallographic analysis. in the patient and in the sensitized animals, only this quinone elicited strong react ... | 1984 | 6476858 |
| the fine structure of cymbidium ringspot virus infections in host tissues. iii. role of peroxisomes in the genesis of multivesicular bodies. | ultrastructural studies of nicotiana clevelandii plants systemically infected with cymbidium ringspot virus, a member of the tombusvirus group, have shown that a clear-cut relationship exists between perioxisomes and multivesicular bodies (mvb). in infected cells, peroxisomes undergo a progressive vesiculation of the bounding membrane through the possible addition of membranous material by the endoplasmic reticulum and become very plastic. portions of the ground cytoplasm are engulfed either thr ... | 1983 | 6848773 |
| determination of 5-methylcytosine from plant dna by high-performance liquid chromatography. | the relative amounts of the five nucleosides (deoxycytidine, 5-methyldeoxycytidine, deoxyadenosine, deoxyguanosine and thymidine) in the dna of nine plant species, one plant satellite dna, and one animal species were determined by high performance liquid chromatography. the method allows the clean separation of the nucleosides from 10 microgram samples with 15 min. the following values for the proportion of methylated cytosines among all cytosines were obtained: lobularia maritima 18.5%, nicotia ... | 1981 | 7272310 |
| the fine structure of cymbidium ringspot virus in host tissues. ii. light and electron microscopy of localized infections. | | 1981 | 7299907 |
| the fine structure of cymbidium ringspot virus in host tissues. i. electron microscopy of systemic infections. | | 1981 | 7299912 |
| the nature of multimeric forms of cymbidium ringspot tombusvirus satellite rna. | the multimeric forms of cymbidium ringspot tombusvirus (cyrsv) satellite (sat) rna were analysed. attempts to amplify the putative junction region of oligomers using the polymerase chain reaction (pcr) failed, indicating the absence of such structures. satrna-related species having the size double than the unit length were shown to be double-stranded monomers and not single-stranded dimers. similarly, satrna species of a size four times the unit length were shown to be constituted by aggregates ... | 1994 | 7526827 |
| replication of cymbidium ringspot virus satellite rna mutants. | cymbidium ringspot tombusvirus (cyrsv) supports the replication of an rna molecule known to be a satellite (sat-rna). sequence analysis of wild-type sat-rna showed that the 3' terminus is heterogeneous and terminates with one, two, or three c residues. transcripts from mutant clones which lacked up to eight nucleotides at the 3' end were biologically active and yielded progeny rna that had the 3' end restored as in wild-type rna. deletions or substitutions at the 5' end produced nonviable molecu ... | 1995 | 7531914 |
| localization of cis-acting sequences essential for cymbidium ringspot tombusvirus defective interfering rna replication. | the smallest defective interfering rna (di-2) of cymbidium ringspot tombusvirus (cyrsv) was used to identify the cis-acting sequences necessary for its replication by making a series of deletions throughout the 404 nt long molecule and testing the biological activity of mutants. deletion or substitution of the conserved sequence blocks (a, b and c) always yielded inactive molecules. the deletion of only a few nucleotides could be tolerated beyond the natural deletion sites in blocks a and b. how ... | 1995 | 7561770 |
| characterization of resistance to cymbidium ringspot virus in transgenic plants expressing a full-length viral replicase gene. | transgenic nicotiana benthamiana plants expressing the replicase gene of cymbidium ringspot tombusvirus (cymrsv) were tested for the biological activity of the transgene. protoplasts from one resistant and three susceptible transgenic lines were transfected with in vitro synthesized defective interfering (di) rna, a small subviral molecule which requires only the virus replicase for replication. only protoplasts of susceptible transgenic lines were able to sustain the replication of di rna, wher ... | 1995 | 7676638 |
| consequences of gene transfer between distantly related tombusviruses. | hybrid cdna clones were constructed by fusing the coat protein-encoding gene and/or the 3'-terminal region (including the 22- and 19-kda protein-encoding genes) derived from a clone of artichoke mottled crinkle tombusvirus to the 5'-terminal region of a full-length clone of cymbidium ringspot tombusvirus. in vitro transcripts from recombinant clones were infectious when inoculated into nicotiana clevelandii plants. inoculated plants showed symptoms different from those induced by parent viruses. ... | 1993 | 7686869 |
| cloning and sequencing of a cdna encoding the coat protein of a korean isolate of cymbidium mosaic virus. | the 3'-terminal nucleotide (nt) sequence of the coat protein (cp)-encoding gene of the korean isolate of cymbidium mosaic potexvirus (cymv-k) has been determined. the sequence contained a full-length orf coding for the viral cp. it comprises 663 nt and a polypeptide chain of 220 amino acids with a m(r) of 23,718. the stop codon (tga) is followed by a 3'-untranslated region (3'-utr) of 79 nt and a poly(a) tract. the putative polyadenylation signal, aataaa motif, is found in the terminus of the 3' ... | 1995 | 7758973 |
| generation of defective interfering rna dimers of cymbidium ringspot tombusvirus. | inoculation of nicotiana clevelandii and n. benthamiana plants with in vitro transcripts of both genomic and defective interfering (di) rnas of cymbidium ringspot tombusvirus resulted in a rapid accumulation of new di-like rna species which were demonstrated by cloning and sequencing to be head-to-tail dimers of unit length di rnas. the junction regions of dimers were represented by sequences derived precisely from the 5' and 3' termini of di rnas. only infection with di rnas of smaller size (di ... | 1995 | 7886955 |
| immunodetection of the 33 k/92 k polymerase proteins in cymbidium ringspot virus-infected and in transgenic plant tissue extracts. | an antiserum was raised against the 33 k protein encoded by the 5' proximal gene of cymbidium ringspot tombusvirus rna. this antiserum reacts specifically with the 33 k and 92 k proteins, which constitute the viral replicase, in cyrsv-infected nicotiana benthamiana plants and in transgenic plants transformed with the full-length replicase gene. in inoculated leaves of infected plants, synthesis of the 33 k/92 k proteins stops ten days after inoculation, whereas in newly produced systemically inf ... | 1994 | 7980003 |
| nucleotide sequence analysis of a cdna clone encoding the 34k movement protein gene of odontoglossum ringspot virus, orsv-cy, the korean isolate. | the partial nucleotide sequence of the 3'-terminal region of the korean isolate of odontoglossum ringspot tobamovirus (orsv-cy) from cool-growing cymbidium was determined. the sequence contained a full length open reading frame (orf) coding for the viral cell-to-cell movement protein (mp). the orf was located upstream of the coat protein gene and 105 nucleotides longer than that of tobacco mosaic virus (tmv). the orf predicts a polypeptide chain of 303 amino acids with a molecular weight of 3357 ... | 1994 | 8000012 |
| nucleotide sequence and in vitro translation of the coat protein gene of cymbidium mosaic virus. | the nucleotide sequence of the coat protein gene of cymbidium mosaic virus (cymv) has been determined from a cdna clone that encompassed the 3'-region of the virus genome. the 0.75 kb coat protein open reading frame (orf) codes for a 24kd polypeptide. the coat protein coding region was separated from the 3'-poly(a) terminal of the viral genome by an 80 base noncoding region. the derived amino acid sequence of this orf showed considerable homology with other potexvirus coat protein sequences, not ... | 1993 | 8103614 |
| 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 |
| evidence that orf 1 and 2 are the only virus-encoded replicase genes of cymbidium ringspot tombusvirus. | the 33-kda and its 92-kda readthrough protein genes (open reading frames (orfs) 1 and 2) of cymbidium ringspot tombusvirus (cyrsv) were introduced into nicotiana benthamiana plants. protoplasts derived from transgenic plants expressing the first two orfs were inoculated with in vitro transcripts of defective interfering (di) rna. the efficient replication of input di rna, which is incapable of autonomous replication, confirmed the biological activity of the expressed viral replicase. in addition ... | 1994 | 8178483 |
| repair in vivo of altered 3' terminus of cymbidium ringspot tombusvirus rna. | progeny rna of cyrsv rna transcripts ending with -ggg, instead of -ccc as in wild-type rna, was analyzed and shown to revert to wild-type. a new full-length cdna clone of cyrsv was prepared, bearing the correct 3' terminus, from which transcripts could be synthesized having very high infectivity. mutants were prepared which lacked the three terminal cs; transcripts were infectious and most cdna clones recovered from progeny rna had regained the wild-type sequence. transcripts ending in -ggccan w ... | 1993 | 8421899 |
| rapid detection of cymbidium mosaic virus by the polymerase chain reaction (pcr). | a direct, simple and sensitive method was developed for the detection of cymbidium mosaic virus (cymv), based on the polymerase chain reaction (pcr). two oligonucleotide primers were selected from regions that are homologous to potexviruses and cymv, and used to hybridize with purified viral rna and particles. this resulted in the amplification of a 313 bp fragment after 30 cycles of pcr in all samples. a less prominent fragment of 227 bp was also obtained due to mispriming of the second primer. ... | 1993 | 8432762 |
| defective interfering rna-mediated resistance against cymbidium ringspot tombusvirus in transgenic plants. | defective interfering (di) rna of cymbidium ringspot tombusvirus was cloned downstream from the bacteriophage t7 rna polymerase promoter. in vitro synthesized rna was biologically active when coinoculated with parental genomic rna onto nicotiana benthamiana plants and prevented the occurrence of apical necrosis. n. benthamiana plants were transformed with the di rna sequences in both the positive and negative orientations relative to the cauliflower mosaic virus 35s promoter. integration of di r ... | 1993 | 8438573 |
| resistance to cymbidium ringspot tombusvirus infection in transgenic nicotiana benthamiana plants expressing the virus coat protein gene. | transgenic nicotiana benthamiana plants expressing the coat protein gene of cymbidium ringspot virus (cyrsv) were tested for resistance against infection with cyrsv. transgenic plants showed resistance to infection only when the purified virions concentration in the inoculum was as low as 0.05 micrograms/ml. no protection was observed in transgenic plants inoculated with virion concentrations of 0.5 and 5.0 micrograms/ml or when the inoculum was in vitro synthesized genomic rna. | 1993 | 8448365 |
| functional analysis of cymbidium ringspot virus genome. | genomic rna of cymbidium ringspot tombusvirus (cyrsv) contains five large open reading frames (orfs). the two 5' proximal orfs encode proteins of 33 and 92 kda and the three 3' proximal orfs encode proteins of 41, 22, and 19 kda. in addition, a small reading frame encoding a protein of 4 kda was recently observed by computer analysis of the 3' nontranslated region of cyrsv and other tombusvirus rnas (orf 6). the function of putative gene products was investigated with the use of several mutants. ... | 1993 | 8503183 |
| rapid detection and identification of odontoglossum ringspot virus by polymerase chain reaction amplification. | the odontoglossum ringspot tobamovirus (orsv) movement and coat proteins genes were selected for the design of oligonucleotide primers for amplification of a 1,085 bp fragment. a combined assay of reverse transcription and the polymerase chain reaction (rt-pcr) was performed with 20-mer orsv-specific primers and crude nucleic acid extracts from virus-infected orchids for rapid detection of the virus. the lowest concentration of template viral rna required for detection was 10 fg. the rt-pcr is a ... | 1995 | 8522141 |
| the 5'-terminal region of a tombusvirus genome determines the origin of multivesicular bodies. | multivesicular bodies (mvb) are membranous cytoplasmic inclusions that are invariably associated with tombusvirus infections regardless of the virus species, the host, or the tissue examined. mvb are virus-induced structures since they are absent from tissues of healthy plants and are always present both in infected plants and protoplasts. mvb derive from peroxisomes in cells infected by a number of tombusviruses including cymbidium ringspot virus (cymrsv) and from mitochondria in cells infected ... | 1996 | 8760449 |
| coat protein gene and 3'-noncoding region of a new korean isolate of cymbidium mosaic virus. | a new korean isolate of cymbidium mosaic virus (denoted as cymmv-k2), a member of potexviruses, was identified and isolated from a korean cultivar of cymbidium species when the nucleotide sequence of the 3'-terminal region of the viral rna was compared with those of the corresponding regions of two singaporean isolates (denoted as cymmv-s1 and cymmv-s2) and a korean isolate (denoted as cymmv-k1), the nucleotide sequence of the coat protein gene of cymmv-k2 was highly homologous to other cymbidiu ... | 1997 | 9085262 |
| cymbidium mosaic potexvirus rna: complete nucleotide sequence and phylogenetic analysis. | the complete nucleotide sequence of the genomic rna of cymbidium mosaic potexvirus (cymmv) was determined to be 6227 nucleotides in length, excluding the poly (a) tail at the 3' terminus. similar to other potexviruses, its genome organisation is comprised of five major open reading frames (orfs 1 to 5), encoding a mr 160 kda putative rna-dependent rna polymerase (rdrp); a mr 26kda/13kda/10kda triple-gene-block (tgb) and a mr 24 kda coat protein. the cymmv encoded proteins shared a high degree of ... | 1997 | 9125051 |
| molecular analysis of the pothos latent virus genome. | pothos latent virus (polv) is an isometric virus with a positive-sense, single-stranded rna genome of 4415 nt. the genome contains five open reading frames (orf), coding for five proteins with approximate molecular masses of 25, 84, 40, 27 and 14 kda, respectively. in vitro synthesized polv rna was infectious to nicotiana benthamiana plants and protoplasts, but could not support replication of the defective interfering (di) and satellite rnas associated with cymbidium ringspot tombusvirus. no di ... | 1997 | 9191911 |
| secondary structure-dependent evolution of cymbidium ringspot virus defective interfering rna. | mutational analysis of defective interfering (di) rnas of cymbidium ringspot virus (cymrsv) was used to study the mechanism of di rna evolution. it was shown that a highly base-paired structure in the 3' region of the longer di rna directed the formation of smaller di rna molecules. mutations which increased the stability of the computer-predicted, highly structured 3' region of the longest di rna of cymrsv significantly enhanced the generation and accumulation of the smaller derivatives. sequen ... | 1997 | 9191912 |
| the use of dig-labelled crna probes for the detection of cymbidium mosaic potexvirus (cymmv) and odontoglossum ringspot tobamovirus (orsv) in orchids. | dig-labelled sense and antisense crna probes were synthesized from cdna clones of cymmv and orsv for virus detection in infected plants. a slot-blot hybridization assay was developed using either crude leaf extracts or total rna from infected leaves. the assay could detect 50 and 250 pg of purified cymmv and orsv rna, respectively. as little as 30 mg of nicotiana benthamiana infected leaves was sufficient to provide positive detection. cymmv and orsv were detected at 3125 and 625 times dilution ... | 1998 | 9562413 |
| phylogenetic analysis of triple gene block viruses based on the tgb 1 homolog gene indicates a convergent evolution. | the complete nucleotide sequence of the triple gene block one (tgb 1) of cymbidium mosaic potexvirus (cymmv) was compared to those from other potex-, carla-, furo- and hordeiviruses. seven conserved motifs in the tgb 1, including the atp-gtp binding domain (p-loop) consensus gxxgktsts, were found in all four virus genera. we propose that all tgbv can be classified into phylogenetic clusters based on their tgb 1 homolog genes. these clusters can be further delineated to form subgroups. the first ... | 1998 | 9654683 |
| simultaneous td/rt-pcr detection of cymbidium mosaic potexvirus and odontoglossum ringspot tobamovirus with a single pair of primers. | cymbidium mosaic potexvirus (cymmv) and odontoglossum ringspot tobamovirus (orsv) are the two most prevalent and economically important orchid viruses which have attained a world-wide distribution. we have designed one pair of common primers, which were able to detect, simultaneously, both viruses by a single polymerase chain reaction (pcr). sequence alignment and primer analyses were employed in primer design. the effect of touch-down pcr, primer annealing temperature, number of thermal cycles, ... | 1998 | 9694327 |
| membrane targeting sequences in tombusvirus infections. | infection of nicotiana benthamiana cells with cymbidium ringspot (cymrsv) and carnation italian ringspot (cirv) viruses results in the formation of conspicuous membranous bodies [multivesicular bodies (mvbs)], which develop from modified peroxisomes or mitochondria, respectively. the organelle targeting signal is located in the proteins of 33 kda (cymrsv) or 36 kda (cirv) encoded by orf 1, which contain an n-terminal hydrophilic portion followed by two predicted hydrophobic transmembrane segment ... | 1998 | 9878622 |
| cymbidium hybrida dihydroflavonol 4-reductase does not efficiently reduce dihydrokaempferol to produce orange pelargonidin-type anthocyanins. | some angiosperms are limited to a range of possible flower colors. this limitation can be due to the lack of an anthocyanin biosynthetic gene or to the substrate specificity of a key anthocyanin biosynthetic enzyme, dihydroflavonol 4-reductase (dfr). cymbidium hybrida orchid flowers primarily produce cyanidin-type (pink to red) anthocyanins and lack the pelargonidin-type (orange to brick-red) anthocyanins. to investigate the underlying molecular mechanism of this flower color range, we cloned a ... | 1999 | 10417729 |
| cymbidium mosaic virus coat protein gene in antisense confers resistance to transgenic nicotiana occidentalis. | the nucleotide sequence of the 3'-terminal region of the korean isolate of cymbidium mosaic virus (cymv-ca) from a naturally infected cattleya was determined. the sequence contains an open reading frame (orf) coding for the viral coat protein (cp) at the 3'-end and three other orfs (triple gene block or movement protein) of cymv. the cp gene encodes a polypeptide chain of 220 amino acids with a molecular mass of 23,760 da. the deduced cp sequence showed a strong homology with those of two cymvs ... | 1999 | 10672926 |
| conservation of the basic pattern of cellular amino acid composition during biological evolution in plants. | the cellular amino acid composition of plant cells was analyzed. the callus of carrot (daucus carota), leaves of torenia fournieri and protocomb-like body of cymbidium, s.p. were examined as examples of plant cells. the cellular amino acid compositions differed in the plant cells, but their basic patterns were quite similar. it is concluded that the basic pattern of the cellular amino acid composition is conserved in all terrestrial organisms, including plants. | 2000 | 10817410 |
| simultaneous quantitation of two orchid viruses by the taqman real-time rt-pcr. | simultaneous quantitation of two orchid viruses, cymbidium mosaic potexvirus (cymmv) and odontoglossum ringspot tobamovirus (orsv), were carried out using the taqman((r)) real-time rt-pcr, a novel detection technique that combines rt-pcr with the power of fluorescent detection. four taqman((r)) probes were synthesized, targeting at the rna-dependent rna polymerase (rdrp) and coat protein (cp) genes of both viruses. the reporter dye fam (6-carboxyfluorescein) was used to label the 5' terminus of ... | 2000 | 10856762 |
| restriction primers as short as 6-mers for pcr amplification of bacterial and plant genomic dna and plant viral rna. | amplification of dna or rna sequences using the polymerase chain reaction (pcr) or reverse transcriptase pcr (rt-pcr) requires primers of an appropriate length to be designed. two hexamer restriction primers, denoted as e101 and h301, which correspond to sequences of ecori and hindiii recognition sites, respectively, were selected and used as primers in pcr and rt-pcr. we first applied the restriction primers to the plasmid dna and bacterial (pseudomonas) and plant (cymbidium) genomic dnas. we o ... | 2000 | 10911610 |
| the orf1 products of tombusviruses play a crucial role in lethal necrosis of virus-infected plants. | hybrids of cymbidium ringspot (cymrsv) and carnation italian ringspot (cirv) tombusviruses were used to identify viral symptom determinants responsible for the generalized necrosis in tombusvirus-infected plants. surprisingly, symptoms of nicotiana benthamiana infected with cymrsv/cirv hybrids were distinctly different. it was demonstrated that not all chimeras expressing wild-type (wt) levels of p19 protein caused systemic necrosis as both parents cymrsv and cirv did. we showed here that hybrid ... | 2000 | 11069981 |
| detection of two orchid viruses using quartz crystal microbalance (qcm) immunosensors. | quartz crystal microbalance (qcm) immunosensors are based on the principle that adsorption of substances on the surface of a quartz crystal changes its resonance oscillation frequency. a qcm immunosensor was developed for the detection of both cymbidium mosaic potexvirus (cymmv) and odontoglossum ringspot tobamovirus (orsv) by pre-coating the qcms with virus-specific antibodies. upon binding of virions in either purified form or crude sap of infected orchids with the immobilised virus antibodies ... | 2002 | 11684305 |
| heterologous movement protein strongly modifies the infection phenotype of cucumber mosaic virus. | a hybrid virus (cmvcymmp) constructed by replacing the movement protein (mp) of cucumber mosaic cucumovirus (cmv) with that of cymbidium ringspot tombusvirus (cymrsv) was viable and could efficiently spread both cell to cell and long distance in host plants. the hybrid virus was able to move cell to cell in the absence of functional cp, whereas cp-deficient cmv was restricted to single inoculated cells. in several chenopodium and nicotiana species, the symptom phenotype of the hybrid virus infec ... | 2002 | 11884579 |
| short defective interfering rnas of tombusviruses are not targeted but trigger post-transcriptional gene silencing against their helper virus. | post-transcriptional gene silencing (ptgs) is a sequence-specific degradation mechanism that operates in almost all eukaryotic cells. in plants, double-stranded rna triggers ptgs, generating 21- to 25-nucleotide guide rnas responsible for specific degradation of cognate mrna. the double stranded rna intermediates of replicating plant viruses often induce ptgs, leading to symptom attenuation. here we demonstrate the role of ptgs in defective interfering (di) rna-mediated symptom attenuation in pl ... | 2002 | 11884680 |
| size-dependent cell-to-cell movement of defective interfering rnas of cymbidium ringspot virus. | co-inoculation of nicotiana benthamiana plants with in vitro transcripts of both genomic and short defective interfering (di) rnas of cymbidium ringspot virus results in an accumulation of de novo generated di rna dimers. time-course analysis of di rna accumulation in the inoculated leaves showed early accumulation of di rna dimers followed by increased levels of di rna monomers. in contrast, di rna dimers were barely detectable in systems where cell-to-cell movement does not take place (protopl ... | 2002 | 12029166 |
| effect of ethylene on flower abscission: a survey. | the effect of ethylene on flower abscission was investigated in monocotyledons and eudicotyledons, in about 300 species from 50 families. in all species studied except cymbidium, flower abscission was highly sensitive to ethylene. flower fall was not consistent among the species in any family studied. it also showed no relationship with petal senescence or abscission, nor with petal colour changes or flower closure. results suggest that flower abscission is generally mediated by endogenous ethyl ... | 2002 | 12102524 |
| the role of ethylene in interorgan signaling during flower senescence. | the roles of 1-aminocyclopropane-1-carboxylic acid (acc) and ethylene in interorgan signaling during senescence in orchid (cymbidium) flowers were investigated. following application of radiolabeled acc to the stigma or the rostellum (modified lobe of the stigma), radiolabeled ethylene is produced by all flower parts. in intact flowers as well as in excised central columns, stigma- or rostellum-applied acc or [alpha]-aminoisobutyric acid were largely immobile. local treatment of the central colu ... | 1995 | 12228663 |
| complete nucleotide sequence of the genomic rna of a french isolate of pepino mosaic virus (pepmv). brief report. | the complete nucleotide sequence of the genomic rna of a french isolate of pepino mosaic virus (pepmv) was determined. with a length of 6,425 nucleotides excluding the poly(a) tail at the 3' terminus, the pepmv genome contains five major open reading frames encoding a 164 kda replicase, triple gene block proteins of 26 kda, 14 kda and 9 kda, and a 25 kda coat protein. this genome organization, as well as characteristic consensus motifs and high degrees of similarity of pepmv proteins with those ... | 2002 | 12417957 |
| in situ characterization of cymbidium ringspot tombusvirus infection-induced posttranscriptional gene silencing in nicotiana benthamiana. | in plants, posttranscriptional gene silencing (ptgs) is an ancient and effective defense mechanism against viral infection. a number of viruses encode proteins that suppress virus-activated ptgs. the p19 protein of tombusviruses is a potent ptgs suppressor which interferes with the onset of ptgs-generated systemic signaling and is not required for viral replication or for viral movement in nicotiana benthamiana. this unique feature of p19 suppressor allowed us to analyze the mechanism of ptgs-ba ... | 2003 | 12719602 |
| molecular mechanism of rna silencing suppression mediated by p19 protein of tombusviruses. | rna silencing is an evolutionarily conserved surveillance system that occurs in a broad range of eukaryotic organisms. in plants, rna silencing acts as an antiviral system; thus, successful virus infection requires suppression of gene silencing. a number of viral suppressors have been identified so far; however, the molecular bases of silencing suppression are still poorly understood. here we show that p19 of cymbidium ringspot virus (cymrsv) inhibits rna silencing via its small rna-binding acti ... | 2004 | 14976549 |
| expression of tombusvirus open reading frames 1 and 2 is sufficient for the replication of defective interfering, but not satellite, rna. | yeast cells co-expressing the replication proteins p36 and p95 of carnation italian ringspot virus (cirv) support the rna-dependent replication of several defective interfering (di) rnas derived from either the genome of cirv or the related cymbidium ringspot virus (cymrsv), but not the replication of a satellite rna (sat rna) originally associated with cymrsv. di, but not sat rna, was replicated in yeast cells co-expressing both di and sat rna. using transgenic nicotiana benthamiana plants cons ... | 2004 | 15448375 |
| the complete sequence of the genomic rna of an isolate of lily virus x (genus potexvirus). | the complete sequence of the genomic rna of an isolate of lily virus x (lvx) has been determined for the first time. the isolate from the netherlands was 5823 nucleotide (nt) long excluding the 3'-poly(a) tail, making it the shortest reported potexvirus sequence. the 5'-non-coding region begins with ggaaaa like that of scallion virus x (scavx) and some isolates of cymbidium mosaic virus (cymmv), whereas those of other sequenced potexviruses probably all begin with gaaaa. the genome organisation ... | 2004 | 15578239 |
| reciprocal function of movement proteins and complementation of long-distance movement of cymbidium mosaic virus rna by odontoglossum ringspot virus coat protein. | complementation of movement and coat proteins of the orchid-infecting potexvirus cymbidium mosaic virus (cymmv) and tobamovirus odontoglossum ringspot virus (orsv) was investigated. nicotiana benthamiana, which is susceptible to both cymmv and orsv, was used as a model system. four transgenic lines, each harbouring one of the movement protein (mp) or coat protein (cp) genes of cymmv or orsv, were constructed. the mp of cymmv consists of three overlapping open reading frames, together called the ... | 2005 | 15831968 |
| transcription analysis of peloric mutants of phalaenopsis orchids derived from tissue culture. | tissue culture has been widely used for mass propagation of phalaenopsis. however, somaclonal variation occurred during micropropagation process posed a severe problem by affecting product quality. in this study, wild type and peloric flower buds of phalaenopsis hybrids derived from flower stalk nodal culture were used for cdna-rapd and cdna suppression subtractive hybridization analyses in order to study their genetic difference in terms of expressed sequence tags. a total of 209 ests from norm ... | 2005 | 16117854 |
| gene stacking in phalaenopsis orchid enhances dual tolerance to pathogen attack. | cymbidium mosaic virus (cymmv) and erwinia carotovora have been reported to cause severe damage to orchid plants. to enhance the resistance of orchids to both viral and bacterial phytopathogens, gene stacking was applied on phalaenopsis orchid by double transformation. plbs originally transformed with cymmv coat protein cdna (cp) were then re-transformed with sweet pepper ferredoxin-like protein cdna (pflp) by agrobacterium tumefaciens, to enable expression of dual (viral and bacterial) disease ... | 2005 | 16145836 |
| sugar-binding proteins potently inhibit dendritic cell human immunodeficiency virus type 1 (hiv-1) infection and dendritic-cell-directed hiv-1 transfer. | both endocytic uptake and viral fusion can lead to human immunodeficiency virus type 1 (hiv-1) transfer to cd4+ lymphocytes, either through directional regurgitation (infectious transfer in trans [i-it]) or through de novo viral production in dendritic cells (dcs) resulting in a second-phase transfer to cd4+ lymphocytes (infectious second-phase transfer [i-spt]). we have evaluated in immature monocyte-derived dcs both pathways of transfer with regard to their susceptibilities to being blocked by ... | 2005 | 16227272 |
| detection and serological relationships of cymbidium mosaic potexvirus isolates. | twenty-two isolates of cymbidium mosaic virus (cymv) were isolated from 35 orchid plants suspected of being infected with cymv. among the three methods used for detecting cymv, immunoelectron microscopy (iem-1) was shown to be the most sensitive method, being able to detect the virus in 71.43% of suspected cymv-infected plants while the electron microscopic method and the indexing plant method could detect 51.43 and 42.86%, respectively. out of 12 symptomless plants investigated, 25% were found ... | 1999 | 16232444 |
| plant virus-derived small interfering rnas originate predominantly from highly structured single-stranded viral rnas. | rna silencing is conserved in a broad range of eukaryotes and includes the phenomena of rna interference in animals and posttranscriptional gene silencing (ptgs) in plants. in plants, ptgs acts as an antiviral system; a successful virus infection requires suppression or evasion of the induced silencing response. small interfering rnas (sirnas) accumulate in plants infected with positive-strand rna viruses and provide specificity to this rna-mediated defense. we present here the results of a surv ... | 2005 | 15919934 |
| spontaneous short-range silencing of a gfp transgene in nicotiana benthamiana is possibly mediated by small quantities of sirna that do not trigger systemic silencing. | a green fluorescent protein (gfp) transgene under the control of the 35s cauliflower mosaic virus (camv) promoter was introduced by agrobacterium-mediated transformation into nicotiana benthamiana to generate fourteen transgenic lines. homozygous lines that contained one or two copies of the transgene showed great variation of gfp expression under ultraviolet (uv) light, which allowed classification into three types of transgenic plants. plants from more than half of the transgenic lines underwe ... | 2006 | 16507090 |
| contact dermatitis due to orchids (cymbidium and oncidium). | a 64-year-old male who cultivated orchids as a hobby, had noticed itchy erythematous lesions on both hands since 6 months earlier. his eruptions had gradually worsened and scales and fissures had appeared. although he was treated with topical corticosteroids by a doctor, his erythema showed no improvement. patch tests with the orchids he cultivated, fertilizers, antiseptics and insecticides showed positive reactions to the stems of cymbidium and oncidium orchids. a diagnosis of contact dermatiti ... | 2006 | 16556279 |
| a rudimentary labellar speculum in cymbidium lowianum (rchb.f.) rchb.f. and cymbidium devonianum paxton (orchidaceae). | the labellar 'hairs' of some cymbidium spp. are said to be thin-walled and to contain 'plasma', oil and sugars and it has long been speculated that they may function as food-hairs. however, the present authors' preliminary studies showed that certain atypical papillae may have a different role and, by reflecting light, function as a speculum. the purpose of the paper is to test this hypothesis. | 2006 | 16574692 |
| transgenic resistance to cymbidium mosaic virus in dendrobium expressing the viral capsid protein gene. | a taiwan isolate of cymbidium mosaic virus (cymmv-cs) was isolated from infected cymbidium sinesis willd. the cdna of the capsid protein (cp) gene was synthesized and sequenced. alignment of this cp gene with other reported cps revealed homologies of 92-98% at the nucleotide level and 98-99% at the amino acid level. to generate virus-resistant varieties, the cymmv-cs cp gene was transformed into dendrobium protocorms through particle bombardment. transformants were selected on medium supplemente ... | 2005 | 15865047 |
| [analysis of genetic diversity of 14 species of cymbidium based on rapds and aflps]. | rapds and aflps were used to investigate the genetic variation of 14 species of cymbidium. a great diversity was shown by 12 random primers and three primer combinations. upgma cluster analysis showed that the results from the rapd and aflp analysis were similar and the genetic distances were closest between c. ensifolium and c. sinense, c. kanran and c. faberi var. omeiense, c. mastersii and c. eburneum respectively. | 2004 | 15789768 |
| [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 |
| [in vitro flowering of cultures from a hybrid of cymbidium goeringii and c. hybridium]. | wild-type female spring orchid (cymbidium goeringii) was crossed with male cymbidium hybridium. over eight hundred protocorm clones were obtained from hybrid offsprings. among them, one protocorm clone was identified to differentiate visible floral buds two months after subculture in vitro (plate i). the protocorms and shoots derived from this clone were further used in studying the effects of abscisic acid (aba) and paclobutrazol (pp333) pretreatment as well as different concentrations of 6-ben ... | 2006 | 16775400 |
| expression of the cymbidium ringspot virus 33-kilodalton protein in saccharomyces cerevisiae and molecular dissection of the peroxisomal targeting signal. | open reading frame 1 in the viral genome of cymbidium ringspot virus encodes a 33-kda protein (p33), which was previously shown to localize to the peroxisomal membrane in infected and transgenic plant cells. to determine the sequence requirements for the organelle targeting and membrane insertion, the protein was expressed in the yeast saccharomyces cerevisiae in native form (33k) or fused to the green fluorescent protein (33kgfp). cell organelles were identified by immunolabeling of marker prot ... | 2004 | 15078956 |
| a simplified method for cloning of short interfering rnas from brassica juncea infected with turnip mosaic potyvirus and turnip crinkle carmovirus. | rna silencing is a plant defense mechanism in which virus infected plants produce short interfering rnas (sirnas) derived from viral rna, that attack the virus at the post-transcriptional level. in a previous study on cymbidium ringspot tombusvirus (cymrsv) infection in nicotiana benthamiana, sirnas (determined by cloning and sequencing) predominantly originated from the sense (+) strand of the viral rna, suggesting that the majority of sirnas are produced through the direct cleavage of the viru ... | 2006 | 16815561 |
| genetic variability in the coat protein genes of two orchid viruses: cymbidium mosaic virus and odontoglossum ringspot virus. | the variability in coat protein gene sequences of cymbidium mosaic virus (cymmv) and odontoglossum ringspot virus (orsv) that naturally infect orchids worldwide was investigated. samples were collected from korea, singapore and taiwan. the sequence data were compared with available published coat protein gene sequences of cymmv and orsv, including those from japan and thailand. among cymmv isolates, the homology was 89.1%-99.7% and 93.2%-100% at the nucleotide and amino acid levels, respectively ... | 2002 | 12376755 |
| orchids (cymbidium spp., oncidium, and phalaenopsis). | recent advances in genetic engineering have made the transformation and regeneration of plants into a powerful tool for orchid improvement. this chapter presents a simple and reproducible agrobacterium tumefaciens-mediated transformation protocol and molecular screening technique of transgenics for two orchid species, oncidium and phalaenopsis. the target tissues for gene transfer were protocorm-like bodies (plbs) derived from protocorms, into which constructed foreign genes were successfully in ... | 2006 | 17033075 |
| 137cs concentration in the environment of kaiga of south west coast of india. | this paper presents the results of 137cs activity in soil and vegetation obtained through a carefully planned pre-operational survey for the establishment of baseline data on background radiation level and distribution of radionuclides in the environment of kaiga, in the south west coast of india, where two nuclear power reactors of 235 mwe each are under construction. the vertical profile in soil and the seasonal variation in the activity have been studied. nine commonly available vegetation sp ... | 2001 | 11480873 |
| strategies for functional validation of genes involved in reproductive stages of orchids. | plants in the largest family of angiosperms, orchidaceae, are diverse in both specialized pollination and ecological strategies and provide a rich source for investigating evolutionary relationships and developmental biology. however, studies in orchids have been hindered by several challenges that include low transformation efficiency and long regeneration time. to overcome such obstacles, we selected a symptomless cymbidium mosaic virus (cymmv) isolate for constructing virus-induced gene-silen ... | 2007 | 17189336 |
| agrobacterium-mediated transformation of protocorm-like bodies in cymbidium. | genetically transformed plants of cymbidium were regenerated after cocultivating protocorm-like bodies (plb) with agrobacterium tumefaciens strain eha101 (pig121hm) that harbored genes for beta-glucuronidase (gus), hygromycin phosphotransferase (hpt) and neomycin phosphotransferase ii (nptii). plb of three genotypes maintained in liquid new dogashima medium (ndm), were subjected to transformation experiments. the plb inoculated with agrobacterium produced secondary plb, 4 weeks after transfer on ... | 2007 | 17205333 |
| evidence that cymbidium mosaic virus (cymmv) isolates divide into two subgroups based on nucleotide diversity of coat protein and replicase genes. | the genetic diversity of cymbidium mosaic virus (cymmv, family flexiviridae) was assessed by analysing the nucleotide sequences of coat protein (cp) and partial rna-dependent rna polymerase (rdrp) genes. thirty cymmv sequences from vanilla isolates, obtained in this work by direct sequencing of rt-pcr products, were compared to the sequences from ornamental orchid isolates available in genbank. the cymmv population exhibited overall low genetic diversity (pi=0.054 and pi=0.053 for cp and rdrp ge ... | 2007 | 17216134 |
| cymbidium ringspot tombusvirus coat protein coding sequence acts as an avirulent rna. | avirulent genes either directly or indirectly produce elicitors that are recognized by specific receptors of plant resistance genes, leading to the induction of host defense responses such as hypersensitive reaction (hr). hr is characterized by the development of a necrotic lesion at the site of infection which results in confinement of the invader to this area. artificial chimeras and mutants of cymbidium ringspot (cymrsv) and the pepper isolate of tomato bushy stunt (tbsv-p) tombusviruses were ... | 2001 | 11160744 |
| rapid simultaneous detection of two orchid viruses using lc- and/or maldi-mass spectrometry. | liquid chromatography/mass spectrometry (lc/ms) and matrix-assisted laser desorption-ionization (maldi) mass spectrometry are capable of providing molecular mass information on biological samples with high speed, accuracy and sensitivity. with mass spectrometry, identifying a virus based on the molecular weight of its coat protein is relatively simple and accurate. the technique can be applied to all viruses with known coat protein molecular weights. using the lc/ms and/or maldi, this paper desc ... | 2000 | 10716342 |
| antiviral activity of carbohydrate-binding agents against nidovirales in cell culture. | coronaviruses are important human and animal pathogens, the relevance of which increased due to the emergence of new human coronaviruses like sars-cov, hku1 and nl63. together with toroviruses, arteriviruses, and roniviruses the coronaviruses belong to the order nidovirales. so far antivirals are hardly available to combat infections with viruses of this order. therefore, various antiviral strategies to counter nidoviral infections are under evaluation. lectins, which bind to n-linked oligosacch ... | 2007 | 17560666 |
| the gprime package: computer programs for identifying the best regions of aligned genes to target in nucleic acid hybridisation-based diagnostic tests, and their use with plant viruses. | the gprime (group primer design) programs examine aligned sets of gene sequences to discover homologous regions to be targeted in diagnostic tests. the core program moves a 'window' over the aligned sequences and calculates, at each window position, a 'redundancy value', namely the number of sequences that would represent all permutations of the variable sequence positions within that window. regions with minimal redundancy values may then be targeted in diagnostic tests based on oligonucleotide ... | 1998 | 9763130 |
| synthesis of biologically active cdna clones of cymbidium mosaic potexvirus using a population cloning strategy. | biologically active cdna clones of cymbidium mosaic potexvirus (cymmv) were synthesized using a population cloning strategy. three populations of overlapping rt-pcr products encompassing the entire viral rna of cymmv were ligated into pbluescriptks+ with t7 rna polymerase promoter fused to the 5' extreme of the viral cdna. capped-rna in vitro transcripts were infectious. this is the first report of successful synthesis of biologically active cymmv clones. unlike the conventional methods, populat ... | 1998 | 9739338 |
| silencing of the n family of resistance genes in nicotiana edwardsonii compromises the hypersensitive response to tombusviruses. | the nontarget effects associated with silencing of the n gene in nicotiana edwardsonii, an amphidiploid species derived from n. glutinosa and n. clevelandii, have been characterized in this study. the n protein confers resistance to tobacco mosaic virus (tmv), and is representative of a family of nucleotide-binding site leucine-rich repeat proteins present in n. glutinosa. previous studies have shown that silencing of the n gene or of other plant genes associated with n-mediated defenses abolish ... | 2007 | 17918628 |
| [production of monoclonal antibodies to cymbidium mosaic virus and application in orchids virus detection]. | three hybridoma cell lines, 2c6, 5b7 and 12g9, secreting monoclonal antibodies (mcabs) against cymbidium mosaic virus (cymmv) were produced by fusing mouse myeloma cells (sp2/0) with spleen cells from balb/ c immunized by the cymmv particles. the three mcabs could specifically react with cymmv. the titres of ascitic fluids of two mcabs are up to 10(-6) in i-elisa. isotypes and subclasses of the the three mcabs belong to igg1. isotypes of light strains of the three mcabs all belong to kappa. they ... | 2007 | 18062276 |
| synergism in replication of cymbidium mosaic potexvirus (cymmv) and odontoglossum ringspot tobamovirus (orsv) rna in orchid protoplasts. | an in vitro orchid protoplast isolation method to study replication kinetics of cymmv and orsv was developed. this method allows the isolation of viable and raphid-free petal protoplasts from an orchid hybrid, dendrobium sonia (dendrobium caesar x dendrobium tomie drake). the optimum field strength for both viral rna to achieve good efficiency of electroporation was 750 v/cm and the optimum viral rna concentration required was 1 microgram and 4 micrograms per 2 x 10(6) protoplasts for cymmv and ... | 1998 | 9722873 |
| genome characterization of a korean isolate of cymbidium mosaic virus. | the complete nucleotide sequence of the genomic rna of a korean isolate of cymbidium mosaic virus (cymmv-k2) was determined. the genomic rna is 6227 nucleotides in length, excluding the poly(a) tail. it contains a 5'-noncoding region (ncr) of 73 nucleotides, five open reading frames (orfs 1 to 5) which encode proteins with m(r) 160 kda rna-dependent rna polymerase (orf1), 26 kda movement protein 1 (orf2), 13 kda movement protein 2 (orf3), 10 kda movement protein 3 (orf4), 24 kda coat protein (of ... | 1998 | 9638650 |
| characterization of hawaiian isolates of cymbidium mosaic virus (cymmv) co-infecting dendrobium orchid. | we report here the isolation and characterization of three distinct isolates of cymbidium mosaic virus (cymmv) co-infecting dendrobium orchid in hawaii. isolates 1 and 2 were phylogenetically distinct from previously reported cymmv isolates. however, isolate 3 was highly similar to previously reported cymmv sequences and could be localised to cymmv subgroup a. isolate 2 localised to cymmv subgroup b. thus, we report here the first full-length cymmv subgroup b isolate. isolate 1 represents a reco ... | 2008 | 18458814 |
| [the genetic diversity of cymbidium by issr]. | issr was applied to detect the relationship between 16 cymbidium species, and 836 bands were amplified with 15 primers, including 227 polymorphic bands. the polymorphic percentage is 27.2%. upgma results showed that the genetic distance were closest between c.goeringii (rchb.f.) rchb.f. and c. goeringii var. longibracteatum, and c.lancifolium hook. was far away from the other 15 species. this result is quite similar to the traditional classification, indicating that the technique could supplemen ... | 2008 | 18487154 |
| use of reverse transcription-polymerase chain reaction for cloning of coat protein-encoding genes of cymbidium mosaic virus. | a reverse transcription-polymerase chain reaction (rt-pcr) has been developed for the cloning of coat protein-encoding genes (cp) of cymbidium mosaic virus (cymv) isolated from three different infected species of thai orchid: cattleya, mokara and oncidium. the analysis of the compiled sequences of the cdna clones shows a single open reading frame which encoded a cymv cp gene. the gene is 669 nucleotides (nt) long and codes for a 23 761-da protein. the nt sequences of cymv cp from the thai isolat ... | 1996 | 8955635 |
| an appraisal of the banded and paracrystalline cytoplasmic inclusions induced in cymbidium mosaic potexvirus- and odontoglossum ringspot tobamovirus infected orchid cells using confocal laser scanning microscropy. | the cymbidium mosaic potexvirus (cymv) banded inclusions and the odontoglossum ringspot tobamovirus (orsv) paracrystalline inclusions were studied in flowers and leaves of nine orchid cultivars using the confocal laser scanning microscope. the inclusions varied in length and width and were mostly located adjacent to the cell walls. some orsv inclusions fully extended across entire infected cells. we propose that the cymv banded inclusion was formed from virus aggregates which aligned as periodic ... | 1996 | 8634017 |
| the rx gene confers resistance to a range of potexviruses in transgenic nicotiana plants. | rx-mediated resistance was analyzed in rx-expressing transgenic nicotiana plants. the infection outcome of nine potato virus x isolates mutated at amino acid positions 121 and 127 of the coat protein (cp) confirmed the key role of these amino acids but provided a more complex picture than previously reported. in particular, in rx-expressing nicotiana spp., eliciting activity modulated by amino acid 121 was conditioned by the nature of amino acid 127. these results suggest that the specificity of ... | 2008 | 18700820 |
| cymbidium ringspot virus harnesses rna silencing to control the accumulation of virus parasite satellite rna. | cymbidium ringspot virus (cymrsv) satellite rna (satrna) is a parasitic subviral rna replicon that replicates and accumulates at the cost of its helper virus. this 621-nucleotide (nt) satrna species has no sequence similarity to the helper virus, except for a 51-nt-long region termed the helper-satellite homology (hsh) region, which is essential for satrna replication. we show that the accumulation of satrna strongly depends on temperature and on the presence of the helper virus p19 silencing su ... | 2008 | 18815304 |
| 3' terminal putative stem-loop structure required for the accumulation of cymbidium ringspot viral rna. | defective interfering (di) rna of cymbidium ringspot tombusvirus (cymrsv) was used to identify the cis-acting nature of the last 77-nt sequence of the viral genome which is required for di rna accumulation. the 3'-terminal cis-essential domain of both genomic and di rnas can be folded into a stable stem-loop structure composed of three hairpins and two short non-base-paired regions. none of the three conserved stem-loops can be deleted without abolishing the infectivity of di rna. similarly, tho ... | 1995 | 8525627 |
| cymbidium mosaic virus rna synthesis in isolated orchid protoplasts. | an in vitro protoplast host system has been developed to facilitate the study of cymbidium mosaic virus (cymv) replication mechanisms. cymv, a member of the potexvirus group of plant viruses, is among the most significant pathogens of cultivated orchid plants, but a convenient system for studying its molecular genetics has not been available previously. a cdna probe representing a segment of the cymv genome was used to detect viral rna following inoculation of vanda floral protoplasts with virus ... | 1993 | 8249447 |