| trans replication and high copy numbers of wheat dwarf virus vectors in maize cells. | the replication of shuttle vectors derived from wheat dwarf virus, a monopartite geminivirus, was studied in cultured maize endosperm cells, and in the black mexican sweet (bms) maize cell line. using in vivo labeling and dna methylation analysis, we showed that replication was initiated within 24 hrs after transfection, and did not require cell division in both cell lines. copy numbers of 30,000 ds dna molecules per cell were observed in endosperm cells after three days. the replication protein ... | 1992 | 1508689 |
| coordinate regulation of replication and virion sense gene expression in wheat dwarf virus. | we have investigated the relationship between viral dna replication and virion sense gene expression in wheat dwarf virus (wdv), a member of the geminivirus group, by testing a series of deletion mutants in transfected triticum monococcum (einkorn) protoplasts. mutants contained a transcription fusion of the chloramphenicol acetyltransferase coding sequence to the virion sense promoter that replaced the viral coat protein coding sequence. the deletion analysis revealed that wdv replication and v ... | 1992 | 1633494 |
| wheat dwarf virus vectors replicate and express foreign genes in cells of monocotyledonous plants. | wheat dwarf virus (wdv) is a geminivirus that infects monocotyledonous plants. to exploit the potential of wdv as a replicative gene vector, we developed a transient replication and expression system based on the transfection of protoplasts derived from triticum monococcum suspension culture cells. cloned genomic copies of various wdv isolates as well as mutants constructed in vitro were introduced into the protoplasts and assayed for their ability to replicate. as a result, regions of the wdv g ... | 1991 | 1840909 |
| replication of a geminivirus derived shuttle vector in maize endosperm cells. | a maize (zea mays l.) endosperm cell culture has been shown to efficiently replicate dna sequences derived from wheat dwarf virus (wdv), a monopartite monocot geminivirus. to analyze sequences necessary for viral replication and to verify their application for a plant gene expression vector, we have developed a 3.7 kilobase pairs escherichia coli--plant cell shuttle vector, pwi-11. the p15a origin of replication, functional in e. coli, was introduced into the viral sequences. we have replaced th ... | 1991 | 1849629 |
| transcript mapping reveals different expression strategies for the bicistronic rnas of the geminivirus wheat dwarf virus. | we have characterised the major transcripts of the czech isolate of wheat dwarf virus (wdv-cji) which show that wdv uses two different mechanisms for expressing overlapping open reading frames (orfs). mapping of the virion sense rnas identified a single polyadenylated transcript of 1.1kb spanning the overlapping orfs v1 and v2 which encode cell-cell spread functions and the coat protein respectively. this finding distinguishes wdv from other monocot-infecting geminiviruses studied so far which w ... | 1991 | 1870964 |
| dna replication of wheat dwarf virus, a geminivirus, requires two cis-acting signals. | replication of the single-stranded dna genome of wheat dwarf virus (wdv) leads to the accumulation of covalently closed double-stranded dna of genome length in infected cells. by studying the replication properties of a naturally occurring deletion mutant of wdv isolated from infected plants and of deletion mutants constructed in vitro, we have defined cis-acting regions required for viral dna replication. the results show that two distinct regions are required in cis to yield the normal replica ... | 1991 | 1887595 |
| geminivirus-based shuttle vectors capable of replication in escherichia coli and monocotyledonous plant cells. | shuttle vectors have been constructed that are able to replicate in either escherichia coli or plant cells. they contain the cole1 origin of replication and parts of the wheat dwarf virus genome, a geminivirus infecting a variety of species of monocotyledonous plants. such plasmids are able to replicate in e. coli and wheat cells. the plasmids can be rescued in e. coli and show no changes during their passage through plant cells. such an e. coli/plant cell shuttle vector system could be used for ... | 1991 | 1916295 |
| characterization of the sugarcane streak agent as a distinct geminivirus. | the relationship between maize streak virus and the geminivirus causing streak in sugarcane was investigated. the dna of sugarcane streak virus does not cross-hybridize detectably with that of maize streak virus and vice versa. restriction mapping of native replicative form viral dna (genome size 2.7 kb) and of cloned viral dna, combined with limited sequencing and estimated dna sequence divergence, showed that sugarcane streak virus is as unrelated to maize streak virus and digitaria streak vir ... | 1991 | 2016148 |
| wheat dwarf virus ac/ds vectors: expression and excision of transposable elements introduced into various cereals by a viral replicon. | the maize transposon activator (ac) and in vitro-generated nonautonomous derivatives thereof [ac delta or dissociation (ds) elements] were inserted into the genome of a geminivirus of graminaceous plants, wheat dwarf virus, at a site that does not interfere with viral replication. these recombinant viral genomes were introduced into wheat, maize, and rice protoplasts, where rapid and efficient excision of ac was observed. excision was detected only in vectors in which, after transfection, the vi ... | 1990 | 2170986 |
| replication of wheat dwarf virus dna in protoplasts and analysis of coat protein mutants in protoplasts and plants. | the replication of wheat dwarf virus (wdv) in protoplasts derived from a triticum monococcum suspension cell system was investigated. the production of circular viral double-stranded dna (dsdna) forms consistent with the replication of the viral genome was observed. in comparison to whole plants, the production of viral single-stranded dna (ssdna) was reduced, possibly due to only low levels of viral coat protein being produced in the protoplasts. mutations introduced into the viral coat protein ... | 1989 | 2549505 |
| uptake and transient expression of chimeric genes in seed-derived embryos. | uptake of dna in dry and viable embryos of wheat by imbibition in dna solution was detected by monitoring the transient expression of chimeric genes. gene expression vectors used in this study contained a neomycin phosphotransferase (npt) ii reporter gene fused to various promoters. some of the chimeric "neo" genes were shown to yield reproducibly npt ii activity in germinating embryos. this npt ii activity was increased markedly when the neo genes were carried by a vector capable of autonomous ... | 1989 | 2562504 |
| computer analysis between nucleotide and amino acid sequences of bean golden mosaic virus and those of maize streak, wheat dwarf, chloris striate mosaic, and beet curly top viruses. | bean golden mosaic virus (bgmv) dna 1 and 2 have little sequence homology with maize streak virus (msv), wheat dwarf virus (wdv), and chloris striate mosaic virus (csmv) dnas. bgmv dna 1 and beet curly top virus (bctv) dna are closely related, whereas bgmv dna 2 and bctv dna are not related. direct amino acid homologies of predicted proteins between bgmv orfs and msv orfs, wdv orfs or csmv orfs were 40-50%. bgmv 1l1 and bctv l1, and bgmv il3 and bctv l4 were highly conserved. the sequence taatat ... | 1989 | 2615677 |
| wheat dwarf virus, a geminivirus of graminaceous plants needs splicing for replication. | by analysing mrnas with the polymerase chain reaction (pcr) and by studying in vitro generated mutants we have identified an intron in the genome of wheat dwarf virus (wdv), a geminivirus of cereals. polypeptides whose expression is essential for the replication of the viral dna have been defined. they are encoded by two distinct overlapping open reading frames (orfs). the joining of these two orfs by deletion of the intron as well as the introduction of a frameshift mutation within the intron d ... | 1989 | 2721484 |
| infectivity and complete nucleotide sequence of the genome of a south african isolate of maize streak virus. | the complete infectious genome of a south african isolate of the geminivirus maize streak (msv-s) has been cloned, characterized, and sequenced. using an a. tumefaciens ti plasmid delivery system, the cloned -2.7 kb single circular msv component was shown to be necessary and sufficient for infection of maize. based on sequence analysis of the infectious clone, msv-s is highly homologous to the previously characterized kenyan and nigerian isolates. while the genomic organization of msv-s has elem ... | 1988 | 2829117 |
| nucleotide sequence of the geminivirus chloris striate mosaic virus. | the genome of chloris striate mosaic virus (csmv) comprises a single circular dna as determined by analyses on virion single-stranded (ss) dna and virus-specific covalently closed circular (ccc) dna isolated from infected plants. the nucleotide sequence of csmv dna was determined from cccdna and the data were accommodated into one dna circle of 2750 nucleotides. comparison of the nucleotide sequence with those of maize streak virus (msv), wheat dwarf virus (wdv), and digitaria streak virus (dsv) ... | 1988 | 3369088 |
| the nucleotide sequence of a geminivirus from digitaria sanguinalis. | the encapsidated single-stranded circular dna of a geminivirus isolated from digitaria sanguinalis has been sequenced. the data obtained are consistent with there being one dna circle of 2701 nucleotides. comparison of the nucleotide sequence with those of maize streak virus (msv) and wheat dwarf virus showed 64 and 47% dna homology, respectively. the sequence has four potential coding regions for proteins of greater than 10 kda, two in the viral (+) sense and two in the complementary (-) sense. ... | 1987 | 3672928 |
| sequence homology between the coat proteins of dna and rna plant viruses. | the coat proteins of the leafhopper transmitted gemini viruses, viz., maize streak virus and wheat dwarf virus that contain a single circle of dna in their genomes are shown to bear good amino acid sequence homology with the coat protein of an rna plant virus, the satellite tobacco necrosis virus. it is suggested that for icosahedral assemblage, the coat protein architecture transcends genomic preferences. | 1986 | 3947330 |
| identification and analysis of a retinoblastoma binding motif in the replication protein of a plant dna virus: requirement for efficient viral dna replication. | geminiviruses are plant dna viruses with small genomes whose replication, except for the viral replication protein (rep), depends on host proteins and, in this respect, are analogous to animal dna tumor viruses, e.g. sv40. the mechanism by which these animal viruses create a cellular environment permissive for viral dna replication involves the binding of a virally encoded oncoprotein, through its lxcxe motif, to the retinoblastoma protein (rb). we have identified such a lxcxe motif in the rep p ... | 1995 | 7664747 |
| determination of the origin cleavage and joining domain of geminivirus rep proteins. | replication of the single-stranded dna genome of plant geminiviruses follows a rolling circle mechanism. it strictly depends on a 'rolling circle replication initiator protein', the m(r) 41 kda viral rep protein, encoded by the c1 or ac1 genes. using wheat dwarf virus (wdv) and tomato yellow leaf curl virus (tylcv) as examples, we show that not only the full-size rep proteins, but also a putative 30 kda translation product of wdv open reading frame c1-n as well as an artificially shortened 24 kd ... | 1995 | 7731803 |
| an approach towards genetically engineered cell fate mapping in maize using the lc gene as a visible marker: transactivation capacity of lc vectors in differentiated maize cells and microinjection of lc vectors into somatic embryos and shoot apical meristems. | to establish a system for genetically engineered cell fate mapping, different vectors carrying the lc gene, a member of the r gene family, were delivered into embryonic and meristematic cells of maize by the microinjection technique. vectors in which the lc cdna is driven either by a constitutive promoter (camv 35s), with or without the adh1 intron 1 of maize, or a tissue-specific promoter (phosphoenolpyruvate carboxylase, pepc) as well as self-replicating wheat dwarf virus (wdv) vectors carryin ... | 1994 | 8012407 |
| identification of the initiation sequence for viral-strand dna synthesis of wheat dwarf virus. | the intergenic region of the circular single-stranded dna genome of geminiviruses contains a sequence potentially able to fold into a stem-loop structure. this sequence has been reported to be involved in viral replication by serving as the origin for rolling-circle replication. however, in wheat dwarf virus (wdv) a deletion of 128 bp, removing this sequence, surprisingly does not prevent de novo viral dna synthesis, but instead abrogates the processing of replicative intermediates into monomeri ... | 1993 | 8223454 |
| the conserved nonanucleotide motif of the geminivirus stem-loop sequence promotes replicational release of virus molecules from redundant copies. | recombinant plasmids containing head-to-tail copies of different coat-protein replacement genomes of wheat dwarf virus (wdv) were used to study the mechanism leading to the release of replicating unit-length molecules in suspension culture cells of triticum monococcum. for plasmids bearing two complete genomes, the viral unit bracketed by the two large intergenic regions (lir) becomes preferentially released. addition of a third copy of the lir on the inoculum plasmid is necessary for release of ... | 1993 | 8268260 |
| replication of the dna a component of african cassava mosaic virus in a heterologous system. | the capacity for autonomous replication of the dna a of african cassava mosaic virus (acmv), a member of the bipartite geminiviruses infecting dicotyledonous plants, has been compared in host and non-host cells. a derivative of the acmv dna a was transfected into tobacco and maize protoplasts. although acmv is not able to infect maize, replication of the dna a in maize protoplasts was observed to occur. the efficiency of replication was 10 to 20% of that seen in tobacco protoplasts. in both plan ... | 1993 | 8277277 |
| the two nonstructural proteins from wheat dwarf virus involved in viral gene expression and replication are retinoblastoma-binding proteins. | tumor-inducing viruses like simian virus 40 or the human adenovirus produce oncoproteins which interfere with the cellular retinoblastoma (rb) tumor-suppressor protein to create an appropriate molecular environment in the nucleus for viral transcription and replication. such a strategy has been considered to be restricted to animal viruses. here we demonstrate that plant viruses may use similar mechanisms for recruiting host factors. wheat dwarf virus (wdv) encodes two potential nonstructural pr ... | 1996 | 8623550 |
| a maize cdna encoding a member of the retinoblastoma protein family: involvement in endoreduplication. | retinoblastoma (rb-1) is a tumor suppressor gene that encodes a 105-kda nuclear phosphoprotein. to date, rb genes have been isolated only from metazoans. we have isolated a cdna from maize endosperm whose predicted protein product (zmrb) shows homology to the "pocket" a and b domains of the rb protein family. we found zmrb behaves as a pocket protein based on its ability to specifically interact with oncoproteins encoded by dna tumor viruses (e7, t-ag, e1a). zmrb can interact in vitro and in viv ... | 1996 | 8799136 |
| dna replication of wheat dwarf geminivirus vectors: effects of origin structure and size. | wheat dwarf virus (wdv) is a representative member of subgroup i of the geminiviridae, a unique plant dna virus family. since geminivirus dna replication occurs in the host cell nucleus exclusively via double-stranded dna intermediates, a considerable interest has arisen to use them as expression vectors. we have used particle bombardment to introduce wdv vectors into cultured wheat cells and to analyze the fate of input dna and the accumulation of newly replicated dna. under our conditions, we ... | 1997 | 9018138 |
| ds excision from extrachromosomal geminivirus vector dna is coupled to vector dna replication in maize. | analysis of transposition products generated after activator (ac) excision from the p locus in maize suggest that ac excises either during or after replication of the p locus. the frequency of excision of the non-autonomous ac derivative, dissociation (ds), from extrachromosomal replicating and nonreplicating vector dnas in transfected black mexican sweet maize protoplasts was compared to assess directly a role of extrachromosomal vector dna replication in ds excision. replicating (rep+) and non ... | 1997 | 9025307 |
| splicing features in maize streak virus virion- and complementary-sense gene expression. | the single-stranded dna geminiviruses produce transcripts from both strands (virion- and complementary-sense) of a nuclear double-stranded dna molecule. in maize streak virus (msv)-infected maize plants, approximately 80% of the complementary-sense transcripts produce the c1 protein, whilst the remaining 20% are spliced to remove a 92 nt intron and produce a c1:c2 fusion protein (rep). disruption of the complementary-sense 3' splice site abolished virus replication. the majority of the virion-se ... | 1997 | 9450342 |
| organization of the cis-acting element required for wheat dwarf geminivirus dna replication and visualization of a rep protein-dna complex. | initiation of geminivirus dna replication depends on the activity of the initiator protein (rep) upon interaction with dna sequences present in the intergenic region of the viral dna. in this study, we have analyzed the dna sequences present in the large intergenic region (lir) of wheat dwarf virus (wdv), a subgroup i member of the geminivirus family, which are required for viral dna replication. we have (i) defined the boundaries of the viral cis-acting dna replication element, (ii) determined ... | 1998 | 9527921 |
| plant cell-directed control of virion sense gene expression in wheat dwarf virus. | we have used particle bombardment (biolistics) to deliver replication-competent wheat dwarf virus (wdv)-based constructs, carrying reporter gene sequences fused to the virion sense promoter (pv) or the camv 35s promoter, to suspension culture cells and immature zygotic embryos of wheat. while the replication of wdv double-stranded dna forms (replicons) was equivalent between wheat suspension culture cells and embryos, gus reporter gene activity was 20-40 times higher in the embryo cultures. maxi ... | 1999 | 10076003 |
| bean yellow dwarf virus repa, but not rep, binds to maize retinoblastoma protein, and the virus tolerates mutations in the consensus binding motif. | it has previously been reported that complementary-sense gene products of wheat dwarf virus (wdv), a geminivirus of the genus mastrevirus that infects monocotyledonous plants, bind to human and maize retinoblastoma (rb) protein. rb proteins control cell-cycle progression by sequestering transcription factors required for entry into s-phase, suggesting that the virus modifies the cellular environment to produce conditions suitable for viral dna replication. using a yeast two-hybrid assay, we have ... | 1999 | 10191192 |
| relationship of oligomerization to dna binding of wheat dwarf virus repa and rep proteins. | members of the genus mastrevirus (family geminiviridae) produce a complementary-sense (c-sense) transcription unit with the potential to encode two proteins, repa and rep. in the present work, we have studied the dna-protein complexes formed by the wheat dwarf virus (wdv) repa protein within the wdv large intergenic region. wdv repa forms large nucleoprotein complexes near the tata boxes of the viral complementary-sense and virion-sense (v-sense) promoters (the repa c- and v-complexes, respectiv ... | 2000 | 10891420 |
| bent dna in the large intergenic region of wheat dwarf geminivirus. | wheat dwarf virus (wdv) is a member of the geminivirus group, unique plant dna viruses which replicate exclusively via dsdna replication intermediates. the large intergenic region (lir), a nontranscribed regulatory region, contains an inverted repeat with the potential to form a stem-loop structure in which the initiation site for wdv (+)strand (virion-sense) dna replication has been mapped. in this work, we have studied by two-dimensional electrophoresis and by electron microscopy the dna struc ... | 1995 | 11831712 |
| genetic diversity of wheat dwarf virus. | the complete sequence of a new wheat-infecting isolate of wheat dwarf virus from sweden (wdv-[enk1]) was determined, as well as a 726-nt region covering part of rep and the long intergenic region (lir) of six other wheat-infecting swedish isolates and a barley-infecting isolate from hungary (wdv-bar[hu]). analyses including these and previously published sequences showed that the wheat-infecting isolates of wdv displayed less than 3% of divergence. most of the nucleotide changes were silent and ... | 2002 | 11858231 |
| interaction of geminivirus rep protein with replication factor c and its potential role during geminivirus dna replication. | geminivirus dna replication during the rolling-circle stage depends on the use of a dna primer, a strategy poorly understood as compared with other eukaryotic viral systems that rely on rna or protein as primers. here we have used wheat dwarf virus (wdv) with the aim of elucidating the events leading to recruitment of cell factors at the replication origin. we have identified a novel interaction of wdv rep, the replication initiation protein, with the large subunit of the wheat replication facto ... | 2002 | 12429518 |
| regulation of msv and wdv virion-sense promoters by wdv nonstructural proteins: a role for their retinoblastoma protein-binding motifs. | in this work we demonstrate that wheat dwarf virus (wdv) repa can activate wdv and maize streak virus (msv) virion (v)-sense expression in plant tissues. rep alone does not have any effect on the silent wdv promoter and it represses the basal msv promoter activity. msv promoter activation by repa depends on an intact repa retinoblastoma protein (rb)-binding domain. promoter repression by rep also depends on this domain to some extent. mutation of the repa rb-binding domain has no effect on wdv p ... | 2003 | 12642104 |
| t-dna recombination and replication in maize cells. | t-dna recombination and replication was analyzed in 'black mexican sweet' (bms) cells transformed with t-dnas containing the replication system from wheat dwarf virus (wdv). upon recombination between the t-dna ends, a promoterless marker gene (gusa) was activated. activation of the recombination marker gene was delayed and increased exponentially over time, suggesting that recombination and amplification of the t-dna occurred in maize cells. mutant versions of the viral initiator gene (rep), kn ... | 2003 | 12943549 |
| geminivirus dna replication and cell cycle interactions. | the geminiviridae family includes a large number of viruses that infect plants and have a unique geminate virion particle, a single-stranded genome of approximately 2.6-3.0 kb, and replicate through a rolling-circle mechanism. since they encode for just a few proteins (4-6 depending on the members that belong to four different genera), a rich variety of interactions has evolved between viral proteins and host factors to develop the virus replicative cycle. among them, we have been particularly i ... | 2004 | 14741123 |
| the epidemiology of wheat dwarf virus in relation to occurrence of the leafhopper psammotettix alienus in middle-germany. | occurrence of the leafhopper psammotettix alienus dahlb. and its infectivity with wheat dwarf virus (wdv) were studied in cereal crops in saxony-anhalt (middle-germany) in 2000 and 2001. the leafhoppers were collected with a sweep net and/or a cage trap and their wdv infectivity was determined by transmission to test plants. in 2000, adult leafhoppers were caught from the second week of may to the third week of december, whereas in 2001 they were trapped from the fourth week of may to the second ... | 2004 | 15036841 |
| phloem specific expression driven by wheat dwarf geminivirus v-sense promoter in transgenic dicotyledonous species. | wheat dwarf geminivirus (wdv) is a single-stranded dna mastrevirus. the large intergenic region (lir) of wdv contains cis-acting elements essential for the replication of the genome as well as for the bidirectional transcription of virus genes. the lir was fused to the gus (uida) reporter gene and the wdv viral sense (v-sense) promoter activity derived from the stable integration of that promoter was analysed in transgenic dicot plants. various dicot species were tested, including nicotiana taba ... | 2004 | 15086824 |
| asf/sf2-like maize pre-mrna splicing factors affect splice site utilization and their transcripts are alternatively spliced. | three asf/sf2-like alternative splicing genes from maize were identified, cloned, and analyzed. each of these genes (zmsrp30, zmsrp31, and zmsrp32) contains two rna binding domains, a signature sequence swqdlkd, and a characteristic serine/ariginine-rich domain. there is a strong structural similarity to the human asf/sf2 splicing factor and to the arabidopsis atsrp34/p30 proteins. similar to asf/sf2-like genes in other organisms, the maize pre-mrna messages are alternatively spliced. they are d ... | 2004 | 15363843 |
| the nucleotide sequence of cloned wheat dwarf virus dna. | restriction analysis and cloning of virus-specific double-stranded dna isolated from plants infected with wheat dwarf virus (wdv) indicated that the virus genome, like that of maize streak virus (msv), consists of a single dna circle. the complete nucleotide sequence of cloned wdv dna (2749 nucleotides) has been determined. comparison of the potential coding regions in wdv dna with those in the dna of two strains of msv suggests that these viruses encode at least two functional proteins, the coa ... | 1985 | 15938050 |
| cyclin-dependent kinase inhibitors in maize endosperm and their potential role in endoreduplication. | two maize (zea mays) cyclin-dependent kinase (cdk) inhibitors, zeama;krp;1 and zeama;krp;2, were characterized and shown to be expressed in developing endosperm. similar to the cdk inhibitors in arabidopsis (arabidopsis thaliana) and tobacco (nicotiana tabacum), the maize proteins contain a carboxy-terminal region related to the inhibitory domain of the mammalian cip/kip inhibitors. zeama;krp;1 is present in the endosperm between 7 and 21 d after pollination, a period that encompasses the onset ... | 2005 | 16055680 |
| rbr3, a member of the retinoblastoma-related family from maize, is regulated by the rbr1/e2f pathway. | retinoblastoma-related (rbr) proteins regulate cell division in higher eukaryotes by controlling the adenovirus e2 promoter binding factor (e2f)/dimerization partner (dp) family of transcription factors that regulate expression of many genes involved in cell-cycle progression. we identified a previously undescribed member of the maize rbr family, rbr3, which has the characteristic structure and binding activities of pocket proteins, where interaction depends on a lxcxe motif in the partner prote ... | 2005 | 16141340 |
| grasses like mammals? redundancy and compensatory regulation within the retinoblastoma protein family. | the retinoblastoma (rb) protein family plays a conserved and inhibitory role in cell cycle progression in higher eukaryotes. in mammals, this family includes, in addition to rb, the related (rbr) proteins p107 and p130, which appear to have both specific and redundant functions compared to those of the prototypical rb protein. whereas most plant species seem to possess only one rbr gene, a recent study has shown that in maize there are two types of distinctly regulated rbr proteins, rbr1 and rbr ... | 2006 | 16479170 |
| the complete genome sequence for a turkish isolate of wheat dwarf virus (wdv) from barley confirms the presence of two distinct wdv strains. | the complete genome for a barley isolate of wheat dwarf virus (wdv) from tekirdağ, turkey, wdv-bar[tr], was isolated and sequenced. the genome was found to be 2739 nucleotides long, which is shorter than wheat-infecting wdv isolates, and with a genome organization typical for mastreviruses. the complete genome of wdv-bar[tr] showed 83-84% nucleotide identity to wheat isolates of wdv, with the non-coding regions sir and lir least conserved (72-74% identity). the deduced amino acid sequences for r ... | 2007 | 16927119 |
| identification of long intergenic region sequences involved in maize streak virus replication. | the main cis-acting control regions for replication of the single-stranded dna genome of maize streak virus (msv) are believed to reside within an approximately 310 nt long intergenic region (lir). however, neither the minimum lir sequence required nor the sequence determinants of replication specificity have been determined experimentally. there are iterated sequences, or iterons, both within the conserved inverted-repeat sequences with the potential to form a stem-loop structure at the origin ... | 2007 | 17485545 |
| assessment of codivergence of mastreviruses with their plant hosts. | viruses that have spent most of their evolutionary time associated with a single host lineage should have sequences that reflect codivergence of virus and host. several examples for rna viruses of host-virus tree congruence are being challenged. dna viruses, such as mastreviruses, are more likely than rna viruses to have maintained a record of host lineage association. | 2008 | 19094195 |
| discrimination and genetic diversity of wheat dwarf virus in the czech republic. | cereal-infecting mastreviruses are one of the most ubiquitous of viruses, having caused huge yield losses during the last decade in the czech republic. the presence of two strains of wheat dwarf virus (wdv), one of which is wheat adapted and one barley adapted, have been confirmed from among field samples of wheat and barley plants. the virus typing was conducted by both pcr-rflp and sequencing-based methods. the czech wdv isolates of the barley strain are more variable than the isolates of the ... | 2009 | 19326201 |
| activation of geminivirus v-sense promoters in roots is restricted to nematode feeding sites. | obligate sedentary endoparasitic nematodes, such as the root-knot and cyst nematodes, elicit the differentiation of specialized nematode nurse or feeding cells [nematode feeding sites (nfs), giant cells and syncytia, respectively]. during nfs differentiation, marked changes in cell cycle progression occur, partly similar to those induced by some geminiviruses. in this work, we describe the activation of v-sense promoters from the maize streak virus (msv) and wheat dwarf virus (wdv) in nfs formed ... | 2010 | 20447288 |
| detection of wheat dwarf virus (wdv) in wheat and vector leafhopper (psammotettix alienus dahlb.) by real-time pcr. | wheat dwarf virus (wdv) is a newly emerging pathogen affecting wheat production in china. a real-time pcr method using the taqman probe is described for quantitative detection of wdv in wheat tissues and in leafhopper (psammotettix alienus dahlb.). primers and probes for specific detection of wdv were designed within the conserved region of the coat protein (cp) gene sequence. a sensitivity assay showed the detection limit of the assay was 30 copies, and the standard curve was linear over range ... | 2010 | 20691208 |
| Comparison of the nucleotide sequences of wheat dwarf virus (WDV) isolates from Hungary and Ukraine. | Wheat dwarf virus (WDV) is the most ubiquitous virus in cereals causing huge losses in both Hungary and Ukraine. The presence of barley-and wheat-adapted strains has been confirmed, suggesting that the barley strain is restricted to barley, while the wheat strain is present in both wheat and barley plants. Five WDV isolates from wheat plants sampled in Hungary and Ukraine were sequenced and compared with known WDV isolates from GenBank. Four WDV isolates belonged to the wheat strain. Our results ... | 2011 | 21905629 |
| Real-time PCR assay for the discrimination and quantification of wheat and barley strains of Wheat dwarf virus. | A rapid method for detection, discrimination and quantification of wheat and barley strains of wheat dwarf virus (WDV) was successfully developed. The sensitivity of quantification of the wheat and barley strains of WDV ranged from an average of 1.2 × 10(7)-1.2 × 10(2) and from an average of 1.4 × 10(7)-1.4 × 10(4) copies of viral genome, respectively. These standard serial dilutions were applied to plant and vector tissues for virus titer calculations. Both strains of WDV were clearly discrimin ... | 2011 | 22173982 |
| detection of a non-structural protein of m r 11 000 encoded by the virion dna of maize streak virus. | a polypeptide of approximately 11 000 daltons (11 kda protein) encoded by an open reading frame (10.9 orf) from the virion sense of maize streak virus (msv) dna has been detected among the products of in vitro translation reactions programmed with rna from infected maize plants and also in total protein extracts from infected leaves. the 11 kda protein has not been detected in virions and is therefore proposed to have a nonstructural role.viral dna with an additional in-frame translation stop co ... | 1988 | 24272158 |
| agroinfection and nucleotide sequence of cloned wheat dwarf virus dna. | cloned dna of the geminivirus wheat dwarf virus (wdv) was successfully used to infect seedling wheat plants. the clone was derived from circular double-stranded viral dna isolated from naturally infected tissue. the initiation of infection was mediated by agrobacterium tumefaciens using cloned dimeric wdv genomes in a binary agrobacterium vector. the wdv dna which comprised the infectious clone was sequenced and is compared with the published sequence of a swedish isolate of the same virus. the ... | 1988 | 24272156 |
| development of a multiplex polymerase chain reaction for simultaneous detection of wheat viruses and a phytoplasma in china. | barley yellow dwarf viruses (bydvs, mainly consisting of three strains, gav, gpv and pav, in china), barley stripe mosaic virus (bsmv), wheat yellow mosaic virus (wymv), wheat dwarf virus (wdv) and wheat blue dwarf phytoplasma (wbd) constitute a group of major wheat pathogens that have caused huge yield losses but are scarcely distinguished by their phenotype alone. for the simultaneous detection and discrimination of these seven pathogens in wheat, a multiplex polymerase chain reaction (m-pcr) ... | 2012 | 22456911 |
| genome sequences of beet curly top iran virus, oat dwarf virus, turnip curly top virus, and wheat dwarf virus identified in leafhoppers. | implementation of a vector-enabled metagenomics approach resulted in the identification of various geminiviruses. we identified the genome sequences of beet curly top iran virus, turnip curly top viruses, oat dwarf viruses, the first from iran, and wheat dwarf virus from leafhoppers feeding on beet, parsley, pumpkin, and turnip plants. | 2017 | 28232449 |
| integrative and self-replicating lc vectors and their transactivation capacity in maize callus protoplasts. | the regulatory lc gene is a member of the r gene family of maize which amongst other transcriptional activators controls anthocyanin biosynthetic genes. the availability of r locus mutants which lack anthocyanin production in all tissues offers the possibility of studying cell lineage by introducing a chimeric lc gene into defined cells and following cell autonomous anthocyanin production. for this purpose integrative and self-replicating lc vectors were constructed. integrative expression vecto ... | 1994 | 24196222 |
| detection and characterization of viral species/subspecies using isothermal recombinase polymerase amplification (rpa) assays. | numerous molecular-based detection protocols include an amplification step of the targeted nucleic acids. this step is important to reach the expected sensitive detection of pathogens in diagnostic procedures. amplifications of nucleic acid sequences are generally performed, in the presence of appropriate primers, using thermocyclers. however, the time requested to amplify molecular targets and the cost of the thermocycler machines could impair the use of these methods in routine diagnostics. re ... | 2015 | 25981257 |
| replication-associated proteins encoded by wheat dwarf virus act as rna silencing suppressors. | wheat dwarf virus (wdv) is an economically important and widespread single-stranded dna virus in the genus mastrevirus, family geminiviridae. so far, an rna silencing suppressor in the genus mastrevirus has not been reported. in this study, the viral replication-associated proteins of wdv, rep and repa proteins, were demonstrated to have rna silencing suppressor activities when expressed in agro-infiltrated leaves of nicotiana benthamiana line 16c, by their ability to inhibit posttranscriptional ... | 2014 | 25016035 |
| high-efficiency gene targeting in hexaploid wheat using dna replicons and crispr/cas9. | the ability to edit plant genomes through gene targeting (gt) requires efficient methods to deliver both sequence-specific nucleases (ssns) and repair templates to plant cells. this is typically achieved using agrobacterium t-dna, biolistics or by stably integrating nuclease-encoding cassettes and repair templates into the plant genome. in dicotyledonous plants, such as nicotinana tabacum (tobacco) and solanum lycopersicum (tomato), greater than 10-fold enhancements in gt frequencies have been a ... | 2017 | 27943461 |
| phylogenetic analysis of wheat dwarf virus isolates from iran. | wheat dwarf virus (wdv) adversely affects cereal production in asia, europe, and north africa. in this study, sequences of several wdv isolates from iran which is located in the fertile crescent were analyzed. analysis revealed a new geographic cluster for wdv-wheat from iran. recombination analysis demonstrated the existence of several breakpoints in different regions of the viral genome. data analysis demonstrated that wdv-barley has an older history and lower diversity than wdv-wheat. sequenc ... | 2017 | 27900587 |
| mating behavior of psammotettix alienus (hemiptera: cicadellidae). | the wheat dwarf virus, the causal agent of the wheat dwarf disease, is transmitted by leafhoppers from the genus psammotettix and currently the main protection strategy is based on the use of insecticide treatments. sustainable management strategies for insect vectors should include methods that are targeted to disrupt reproductive behavior and here we investigated the mating behavior of psammotettix alineus (dahlbom 1850) in order to determine the role of vibrational signals in intra-specific c ... | 2016 | 27450152 |
| identification and characterization of a maize-associated mastrevirus in china by deep sequencing small rna populations. | maize streak reunion virus (msrv) is a member of the mastrevirus genus in the family geminiviridae. of the diverse and increasing number of mastrevirus species found so far, only wheat dwarf virus and sweetpotato symptomless virus 1 have been discovered in china. recently, a novel, unbiased approach based on deep sequencing of small interfering rnas followed by de novo assembly of sirna, has greatly offered opportunities for plant virus identification. | 2015 | 26437663 |
| polycistronic artificial mirna-mediated resistance to wheat dwarf virus in barley is highly efficient at low temperature. | infection of wheat dwarf virus (wdv) strains on barley results in dwarf disease, imposing severe economic losses on crop production. as the natural resistance resources against this virus are limited, it is imperative to elaborate a biotechnological approach that will provide effective and safe immunity to a wide range of wdv strains. because vector insect-mediated wdv infection occurs during cool periods in nature, it is important to identify a technology which is effective at lower temperature ... | 2016 | 26136043 |
| variation in susceptibility to wheat dwarf virus among wild and domesticated wheat. | we investigated the variation in plant response in host-pathogen interactions between wild (aegilops spp., triticum spp.) and domesticated wheat (triticum spp.) and wheat dwarf virus (wdv). the distribution of wdv and its wild host species overlaps in western asia in the fertile crescent, suggesting a coevolutionary relationship. bread wheat originates from a natural hybridization between wild emmer wheat (carrying the a and b genomes) and the wild d genome donor aegilops tauschii, followed by p ... | 2015 | 25837893 |
| global-scale computational analysis of genomic sequences reveals the recombination pattern and coevolution dynamics of cereal-infecting geminiviruses. | genetic diversity and recombination patterns were evaluated for 229 isolates of wheat dwarf virus (wdv), which are important cereal-infecting geminiviruses. recombination hot spots were concentrated at the boundary of the genes encoding for the replication protein (rep), the coat protein (cp) and the movement protein (mp), as well as inside rep and cp and in the short intergenic regions (sir). phylogenomic analyses confirmed that the global population of wdv clustered into two groups according t ... | 2015 | 25633348 |
| identification of an rna silencing suppressor encoded by a mastrevirus. | wheat dwarf virus (wdv) is a dna virus belonging to the genus mastrevirus of the family geminiviridae. in this study, we report that the rep protein encoded by wdv is a rna silencing supressor as determined by co-infiltration assays using transgenic nicotiana benthamiana line 16c carrying the gfp reporter gene. the rep protein was shown to inhibit both local and systemic rna silencing of the gfp gene as well as the spread of systemic gfp rna silencing signals. gel mobility shift assays showed th ... | 2014 | 24866851 |
| localization and distribution of wheat dwarf virus in its vector leafhopper, psammotettix alienus. | numerous virus pathogens are transmitted by specific arthropod vectors. understanding the mechanism of transmission is a critical step in the epidemiology of plant viruses and is crucial for the development of effective disease control strategies. in this study, we describe the localization and distribution of wheat dwarf virus (wdv), an economically important and widespread single-stranded dna virus, in its leafhopper vector, psammotettix alienus. the results suggest that wdv not only can move ... | 2014 | 24502202 |
| analysis of complete genomes of isolates of the wheat dwarf virus from new geographical locations and descriptions of their defective forms. | recently, the importance of the geminiviruses infecting cereal crops has been appreciated, and they are now being studied in detail. barley and wheat strains of wheat dwarf virus are recorded in most european countries. information on complete sequences of isolates from the united kingdom, spain, and austria are reported here for the first time. analysis revealed that their sequences are very stable. recombination between strains was recorded only for the barley strain. we identified several def ... | 2014 | 24122067 |
| modification of non-vector aphid feeding behavior on virus-infected host plant. | virus-infected host plants can have positive, neutral or negative effects on vector aphids. even though the proportion of non-vector aphids associated with a plant far exceeds that of vector species, little is known about the effect of virus-infected plants on non-vector aphids. in the present study, the english grain aphid sitobion avenae (fabricius) (hemiptera: aphididae), a non-vector of wheat dwarf virus (wdv) and cereal yellow dwarf virus-rpv (cydv-rpv), was monitored on, virus-infected, vi ... | 2013 | 23902296 |
| agrobacterium - and microprojectile - mediated viral dna delivery into barley microspore-derived cultures. | anther cultures of barley (hordeum vulgare l. var. "igri") were used as targets for agrobacterium-mediated dna transfer and direct dna uptake by particle bombardment. a wheat dwarf virus construct which can replicate to a high copy number in cereal cells provided a sensitive marker for successful dna delivery. although dna delivery was achieved using both procedures, particle bombardment gave more reproducible and higher levels of infection. the ability to deliver dna into cereal cells which hav ... | 1990 | 24232785 |
| viral vectors for plant genome engineering. | recent advances in genome engineering (ge) has made it possible to precisely alter dna sequences in plant cells, providing specifically engineered plants with traits of interest. gene targeting efficiency depends on the delivery-method of both sequence-specific nucleases and repair templates, to plant cells. typically, this is achieved using agrobacterium mediated transformation or particle bombardment, both of which transform only a subset of cells in treated tissues. the alternate in planta ap ... | 2017 | 28443125 |
| integrating multiple criteria for the characterization of psammotettix populations in european cereal fields. | the wheat dwarf disease is among the most damaging diseases in cereals. its aetiological agent is the wheat dwarf virus (wdv), which is exclusively transmitted from plant to plant by leafhoppers from the genus psammotettix (hemiptera, cicadellidae). the parameters linked to the wdv/psammotettix pathosystem are still poorly understood. we studied psammotettix individuals collected in wheat and barley fields in france and, as a comparison, from grassland at agroecological interface in west sloveni ... | 2017 | 28747234 |