| genomic sequence of wild potato mosaic virus as compared to the genomes of other potyviruses. | the complete nucleotide sequence of wild potato mosaic virus (wpmv) was determined, showing that it is a distinct member of the genus potyvirus (family potyviridae). the genome consists of 9853 nucleotides and encodes a single polyprotein of 3065 amino acids. the 5'- and 3'-non translated regions (ntr) were 182 and 472 nucleotides, respectively. alignment of the predicted wpmv polyprotein sequence with other members of the genus potyvirus revealed nine putative cleavage sites resulting in ten ma ... | 2003 | 12556999 |
| variation in efficiency of aphid transmission of southern cucumber mosaic virus and potato virus y in pepper. | | 1959 | 14446984 |
| a new gene, ny (tbr), for hypersensitivity to potato virus y from solanum tuberosummaps to chromosome iv. | a diploid backcross population derived from a cross between solanum tuberosum and solanum berthaultiisegregated for monogenic dominant hypersensitivity to potato virus y(pvy). we propose the symbol ny (tbr) for this locus because plants carrying this gene develop necrosis after inoculation with pvy and the allele originated in s. tuberosum. the gene mapped to chromosome iv between tg316 and tg208 at lod=2.72. this location does not correspond to any other mapped resistance genes in potato. | 2002 | 12582672 |
| recessive resistance genes against potyviruses are localized in colinear genomic regions of the tomato ( lycopersicon spp.) and pepper ( capsicum spp.) genomes. | resistance against both potato virus y (pvy) and tobacco etch virus (tev) was identified in the wild tomato relative lycopersicon hirsutum pi247087. analysis of the segregation ratio in f(2)/f(3) and bc(1) interspecific progenies indicated that a single recessive gene, or two very tightly linked recessive loci, are involved in resistance to both potyviruses. this locus was named pot-1. using amplified fragment length polymorphism markers and a set of l. hirsutum introgression lines, pot-1 was ma ... | 2002 | 12582910 |
| dna microarray: parallel detection of potato viruses. | dna microarray assay has become a useful tool for gene expression studies. less frequent is its application to detection of viruses or diagnostics of virus diseases. here we show design of a microscope slide-based microarray assay for simultaneous identification of several potato viruses. different primer pairs were designed or adopted to obtain specific amplicons from six potato viruses: potato virus a (pva), potato virus s (pvs), potato virus x (pvx), potato virus y (pvy), potato mop-top virus ... | 2003 | 12828343 |
| probable geographical grouping of pvy(n) and pvy(ntn) based on sequence variation in p1 and 5'-utr of pvy genome and methods for differentiating north american pvy(ntn). | an increasing number of countries in recent years have reported the occurrence of potato tuber necrotic ringspot disease (ptnrd), caused by tobacco veinal necrosis strain of potato virus y (pvy(n)), belonging to the sub-group tuber necrosis (pvy(ntn)). methods for the differentiation of pvy(ntn), based on primer sequences often detect isolates of european (eu) type but not the north american (na) type. to resolve this problem, the nucleotide sequence of 5'-untranslated region (5'-utr) and the p1 ... | 2002 | 12008009 |
| a new approach for the simultaneous differentiation of biological and geographical strains of potato virus y by uniplex and multiplex rt-pcr. | two strains of potato virus y (pvy), the common (pvy(o)) and the tobacco veinal necrosis (pvy(n)) have been known for decades. more recently, a tuber ringspot necrosis (pvy(ntn)), and several recombinants of pvy(o) and pvy(n) (designated here as pvy(n:o)) have been described. further, the pvy(n) group of strains have been assigned to two geographical subgroups of european (eu) pvy(n/ntn) and the north american (na) pvy(n/ntn). the evolution of new pvy(n) strains, has complicated the diagnosis, w ... | 2002 | 12020791 |
| interaction between potyvirus helper component-proteinase and capsid protein in infected plants. | monoclonal antibodies were raised against helper component-proteinase (hcpro) purified from plants infected with the potyvirus lettuce mosaic virus (lmv). these antibodies were used in a two-site triple antibody sandwich elisa assay together with polyclonal antibodies directed against purified virions. an interaction between hcpro and the viral coat protein (cp) was demonstrated in extracts of lmv-infected leaves, as well as for two other potyviruses, plum pox virus and potato virus y. the cp-hc ... | 2002 | 12075097 |
| potato gene y-1 is an n gene homolog that confers cell death upon infection with potato virus y. | adg2 is a dna sequence mapped to a resistance (r) gene-rich region at the distal end of chromosome xi in potato (solanum tuberosum subsp. andigena). the gene, in which adg2 represents the predicted nucleotide-binding domain (nbs), was cloned and characterized. the coding region of the gene (designated as y-1) is 6,187 bp long and structurally similar to gene n that confers hypersensitive resistance to tobacco mosaic virus in nicotiana spp. both belong to the tir-nbs-lrr class of genes and show 5 ... | 2002 | 12118888 |
| development of rapd and scar markers linked to the pvr4 locus for resistance to pvy in pepper ( capsicum annuum l.). | potato virus y (pvy) is the only potyvirus infecting pepper ( capsicum annuum l.) in europe. currently, the development of pepper varieties resistant to pvy seems to be the most-efficient method to control pvy damage. among the sources of resistance, a monogenic dominant gene pvr4 confers resistance against all known pvy pathotypes. in this work, bulked segregant analysis (bsa) was used to search for randomly amplified polymorphic dna (rapd) markers linked to the pvr4 gene, using segregating pro ... | 2002 | 12582935 |
| transgenic plants expressing hc-pro show enhanced virus sensitivity while silencing of the transgene results in resistance. | nicotiana benthamiana plants were engineered to express sequences of the helper component-proteinase (hc-pro) of cowpea aphid-borne mosaic potyvirus (cabmv). the sensitivity of the transgenic plants to infection with parental and heterologous viruses was studied. the lines expressing hc-pro showed enhanced symptoms after infection with the parental cabmv isolate and also after infection with a heterologous potyvirus, potato virus y (pvy) and a comovirus, cowpea mosaic virus (cpmv). on the other ... | 2002 | 12206307 |
| in situ immunocytochemical detection of potyviral proteins in plant cells. | a method for in situ protein immunodetection using a peroxidase labeling system is described for detecting functional and structural proteins encoded by potato virus y (tunisian isolate) in plant tissues. such potyviruses are characterized by the accumulation of inclusion bodies containing viral encoded proteins other than coat protein. these proteins are functional at early stages of infection, making them easy to detect. data are compared to those obtained by immunofluorescence techniques. our ... | 2002 | 12229930 |
| [a detection method for recombinant dna from genetically modified potato (newleaf y potato)]. | a detection method using the polymerase chain reaction (pcr) was developed to detect genetically modified (gm) potato (newleaf y potato; nl-y), of which the mandatory assessment has not yet been completed in japan. the potato sucrose synthase gene was used as an internal control. we designed a primer pair to specifically detect nl-y without false-positive results in processed potato foods infected with the potato virus y (pvy). the dna introduced into nl-y using the primer pair could be detected ... | 2002 | 12607929 |
| evaluation of glycoalkaloids in tubers of genetically modified virus y-resistant potato plants (var. désirée) by non-aqueous capillary electrophoresis coupled with electrospray ionization mass spectrometry (nace-esi-ms). | the glycoalkaloid content of transgenic potatoes was evaluated by an optimised method based on non-aqueous capillary electrophoresis coupled on-line with electrospray ionization-mass spectrometry (nace-esi-ms). the potato material consisted of tubers from a conventional cv. désirée and from three lines of modified plants resistant, intermediate and susceptible to infection by potato virus y (pvy). the main glycoalkaloids were confirmed to be alpha-solanine and alpha-chaconine with parent ion mas ... | 2003 | 12664181 |
| phylogenetic analysis of 5'-utr and p1 protein of indian common strain of potato virus y reveals its possible introduction in india. | the 5' untranslated region (utr) and p1 region of the indian strain of potato virus y ordinary strain (pvyo) was cloned and sequenced for the first time. database searches and multiple sequence alignment showed the highest sequence similarity with the pvyo strains of european origin. based on the phylogenetic analysis and multiple sequence alignment, the possible evolution of pvyn from pvyo is predicted. pvyo strains from china and india were perhaps introduced into these countries from a simila ... | 2004 | 15284483 |
| the detection of recombinant, tuber necrosing isolates of potato virus y (pvy(ntn)) using a three-primer pcr based in the coat protein gene. | a simple and reliable procedure for reverse transcription-polymerase chain reaction (rt-pcr) detection and strain differentiation of potato virus y (pvy) was developed. three primers were designed within the coat protein (cp) and nuclear inclusion protein b (nib) region, exploiting a single base polymorphism identified as being present in all the recombinant pvy(ntn) isolates published. samples infected with pvy produce a single band of 569 bp, while isolates belonging to pvy(ntn) strain give an ... | 2003 | 12668269 |
| evolution of north american pvy(ntn) strain tu 660 from local pvy(n) by mutation rather than recombination. | a north american (na) isolate of tobacco veinal necrotic strain of potato virus y (pvy(n)) (n-jg) and a na isolate of potato tuber necrotic strain of potato virus y (pvy(ntn) (tu 660) were tested for their phenotypes by inoculation to potato plants of three potato cultivars. upon inoculation with tu 660, tubers of the cultivars 'norchip' and 'ranger russet' developed potato tuber necrotic ringspot disease (ptnrd) but not the tubers of 'russet burbank'. n-jg failed to induce ptnrd in the tested c ... | 2003 | 12680692 |
| tagging of viral rna transcripts with strain-specific oligonucleotides: characterization and application. | binding('tagging') of a virus-specific oligonucleotide 'sticker' to rna transcripts copied from pcr products caused retardation of transcript mobility in gel. this enables detection of specific sequences within the rna transcripts, and a virus strain (pvy(ntn)) could thus be positively identified. we have demonstrated further that oligonucleotides that contained virus sequences originated from different genomic locations varied in their inhibitory effect on the rate of transcript migration in ge ... | 2003 | 12757927 |
| molecular resolution of a complex of potyviruses infecting solanaceous crops at the centre of origin in peru. | peru is a centre of origin and domestication of the potato, pepper and tomato (family solanaceae). many potyviruses (genus potyvirus) that infect these crops were described 20-30 years ago. however, definitive classification of these viruses as distinct species remains unresolved for several reasons, including their close serological relationships, similar symptomatology in test plants and lack of genomic sequence data. using samples collected from peru, we have determined the complete genomic s ... | 2003 | 12917478 |
| [the viral resistance of transgenic tobacco plants containing untranslatable pvyn coat protein gene]. | in previous study, we have proved that the resistance of the transgenic tobacco plants containing untranslatable pvyn cp gene was mediated by pvyn cp transgene rnas, and the resistance mechanism was similar to ptgs. in this paper, t0 progeny transgenic lines with different resistant levels were selected to further study the transgene inheritance and resistant stability of transgenic plants. results showed that t0 progeny susceptible lines, which contained 1-2 transgene copies, displayed a 3:1 se ... | 2003 | 12966726 |
| ultra-violet irradiation of tobacco infected with potato virus y and the availability of virus to aphids. | | 1954 | 13144758 |
| titration of potato virus y by aphid transmission as affected by leaf development and supply of manganese. | | 1958 | 13593189 |
| effect of tobacco mosaic virus and potato virus y on infection by potato virus x. | | 1961 | 13776640 |
| aphid transmission of potato virus y diminished by electrostatic charge. | | 1961 | 13872331 |
| different areas of tobacco leaves as sources of potato virus y for aphids. | | 1962 | 13872333 |
| topical susceptibility of tobacco leaves to potato virus y inoculated by aphids. | | 1962 | 13872335 |
| chromatographic studies on plant viruses. 3. the purification of potato virus x, potato virus y, tobacco mosaic virus and potato stem mottle virus by chromatography on cellulose columns with polyethylene glycol-containing solutions as solvents. | | 1964 | 14194134 |
| [genetic transformation of nicotiana africana merxm. with plasmids containing lox recombination]. | an efficient genetic transformation method for african tobacco nicotiana africana merxm. has been established. african tobacco is a valuable source for cytoplasmic male sterility (cms) and nuclear encoded resistance to potato virus y (pvy). n. africana transgenic plants have been obtained using both agrobacterium-mediated and direct transformation of leaf explants with gold particle bombardment using particle inflow gun. plasmid vectors containing phosphinothricin resistance gene (bar gene) codi ... | 2004 | 15715158 |
| specific differentiation of recombinant pvy(n:o) and pvy(ntn) isolates by multiplex rt-pcr. | the recombinant isolates of tobacco veinal necrotic strain of potato virus y (pvyn) and potato tuber necrotic group (pvy(ntn)) contain segments of the pvyo and the pvy(n) genome. three major recombinant junctions (rj) are present in the genome of the recombinant pvy(ntn) at sites hc/pro-p3, 6k2-nia, and the c-terminal region of cp gene and one rj at hc/pro-p3 site in some recombinant pvyn isolates (termed pvy(n:o)). protocols for specific differentiation of the recombinant pvy(ntn) and pvy(n:o) ... | 2003 | 14553892 |
| a single nucleotide polymorphism-based technique for specific characterization of yo and yn isolates of potato virus y (pvy). | one of the most important properties used to classify potato virus y (pvy) isolates is their ability to induce (pvy(n)) or not (pvy(o)) veinal necrosis symptoms on the indicator host plant nicotiana tabacum cv. xanthi. as an alternative to biological assays, several serological and molecular detection tools have been developed for pvy detection and characterization and these have evolved as our knowledge of pvy has improved. however, the assays that have been previously published are all based o ... | 2005 | 15737420 |
| cucumber mosaic virus infection transiently breaks dsrna-induced transgenic immunity to potato virus y in tobacco. | post-transcriptional gene silencing (ptgs), an intrinsic plant defense mechanism, can be efficiently triggered by double stranded (ds)rna-producing transgenes and can provide high level virus resistance by specific targeting of cognate viral rna. the discovery of virus-encoded suppressors of ptgs led to concerns about the stability of such resistance. here, we show that cucumber mosaic virus (cmv) is able to suppress dsrna-induced ptgs and the associated potato virus y (pvy) immunity in tobacco. ... | 2003 | 14558695 |
| potato virus y nia protease activity is not sufficient for elicitation of ry-mediated disease resistance in potato. | ry confers extreme resistance (er) to all strains of potato virus y (pvy). in previous work, we have shown that the protease domain of the nuclear inclusion a protease (niapro) from pvy is the elicitor of the ry-mediated resistance and that integrity of the protease active site is required for the elicitation of the resistance response. two possibilities arise from these results: first, the structure of the active protease has elicitor activity; second, nia-mediated proteolysis is required to el ... | 2003 | 14675441 |
| arc-1, a sequence element complementary to an internal 18s rrna segment, enhances translation efficiency in plants when present in the leader or intercistronic region of mrnas. | the sequences of different plant viral leaders with known translation enhancer ability show partial complementarity to the central region of 18s rrna. such complementarity might serve as a means to attract 40s ribosomal subunits and explain in part the translation-enhancing property of these sequences. to verify this notion, we designed beta-glucuronidase (gus) mrnas differing only in the nature of 10 nt inserts in the center of their 41 base leaders. these were complementary to consecutive doma ... | 2004 | 14718549 |
| further characterization of 'sweet potato virus 2': a distinct species of the genus potyvirus. | an incompletely described potyvirus isolate from sweet potato in taiwan, referred to as 'sweet potato virus 2' (spv2), was further characterised. electron microscopy revealed that spv2 has filamentous particles of 850 nm in length and induces cytoplasmic cylindrical inclusions consisting of pinwheels and scrolls. the virus was mechanically transmitted to several species of the genera chenopodium, datura, nicotiana, and ipomoea. two biotypes of myzus persicae transmitted spv2 in a non-persistent ... | 2004 | 14745592 |
| nopl, an effector protein of rhizobium sp. ngr234, thwarts activation of plant defense reactions. | bacterial effector proteins delivered into eukaryotic cells via bacterial type iii secretion systems are important virulence factors in plant-pathogen interactions. type iii secretion systems have been found in rhizobium species that form symbiotic, nitrogen-fixing associations with legumes. one such bacterium, rhizobium sp. ngr234, secretes a number of type iii effectors, including nodulation outer protein l (nopl, formerly y4xl). here, we show that expression of nopl in tobacco (nicotiana taba ... | 2004 | 14966249 |
| mutations in potato virus y genome-linked protein determine virulence toward recessive resistances in capsicum annuum and lycopersicon hirsutum. | the recessive resistance genes pot-1 and pvr2 in lycopersicon hirsutum and capsicum annuum, respectively, control potato virus y (pvy) accumulation in the inoculated leaves. infectious cdna molecules from two pvy isolates differing in their virulence toward these resistances were obtained using two different strategies. chimeras constructed with these cdna clones showed that a single nucleotide change corresponding to an amino acid substitution (arg119his) in the central part of the viral protei ... | 2004 | 15000399 |
| pathogen-derived resistance in potato to potato virus y-aspects of stability and biosafety under field conditions. | plants of three different potato cultivars/lines were transformed via agrobacterium tumefaciens with a truncated nib gene of a necrotic strain of potato virus y (pvy(n)) which had been c-terminally fused to enhanced blue-fluorescing protein. resistance of the resulting transgenic clones was evaluated under glass house conditions using an ntn-strain of pvy. four clones with the highest levels of resistance were chosen for further experiments. their type of resistance was either recovery or extrem ... | 2004 | 15036834 |
| interaction between nutrient supplies and aphid numbers on potato (2001-2002). | we set up our experiment on 11 potato varieties with 4 treatments and 4 replications in hungary in 2001 and 2002. the aim of the experiment was to investigate the interaction between the nutrient supplies of potato and the change in the numbers of aphids feeding on the potato plant. in our experiment we sorted 4 nutrient levels according to the recommendations of soil analyses and variety holders. during the growing period we counted the numbers of aphids feeding on the potato leaves every week ... | 2003 | 15149116 |
| occurrence of colombian datura virus in brugmansia hybrids, physalis peruviana l. and solanum muricatum ait. in hungary. | colombian datura virus (cdv) has been found to infect angel trumpets (brugmansia spp.) frequently and cape gooseberry (physalis peruviana) and pepino (solanum muricatum) sporadically in hungary. a cdv brg/h isolate was characterized. it had flexuous thread-like virions of about 750 x 12 nm in size. host range and symptomathological studies revealed its great similarity to authentic cdv isolates. nicotiana tabacum cultivars and lines resistant to potato virus y (pvyn) either genically or transgen ... | 2005 | 16047739 |
| susceptibility of capsicum breeding lines to ntn strain of potato virus y (pvy(ntn)) and obuda pepper virus (obpv). | the objective of this study was to examine the reaction of 12 capsicum breeding lines to ntn strain of potato virus y (pvy(ntn)) and 16 lines to obuda pepper virus (obpv). inoculated plants were symptomatologically and serologically checked for virus infection. back inoculation was also carried out to nicotiana tabacum 'xanthi-nc' and n. tabacum 'samsun' as indicator plants. out of the 12 lines tested four (32.bogyiszlói, 4/99 f2, 17/99 f2 and vi-61 in.) proved to be resistant (immune) to pvy(nt ... | 2003 | 15151290 |
| reaction of lycopersicon species and varieties to potato virus y (pvy(ntn)) and tomato mosaic virus (tomv). | virus susceptibility of 33 lycopersicon species and varieties to ntn strain of potato virus y (pvy(ntn)) and tomato mosaic virus (tomv) were studied. inoculated plants were tested for infection symptomatologically, serologically and by back inoculation as well. new incompatible and compatible host-virus relations have been determined. all tested plants were susceptible to tomv. however, lycopersicon esculentum mill. convar. parviboccatum lehm. var. cerasiforme (dun.) alef. s.l., l. peruvianum (l ... | 2003 | 15151291 |
| qualitative and quantitative pcr methods for detection of three lines of genetically modified potatoes. | qualitative and quantitative polymerase chain reaction (pcr) methods have been developed for the detection of genetically modified (gm) potatoes. the combination of specific primers for amplification of the promoter region of cry3a gene, potato leafroll virus replicase gene, and potato virus y coat protein gene allows to identify each line of newleaf, newleaf y, and newleaf plus gm potatoes. multiplex pcr method was also established for the simple and rapid detection of the three lines of gm pot ... | 2004 | 15161181 |
| influence of cooking and microwave heating on microstructure and mechanical properties of transgenic potatoes. | the transgenic potato clones of cultivar irga with improved resistance to a necrotic strain of potato virus y (pvy(n)) were subjected to heat treatment in order to determine their technological quality. the technological quality was determined on the basis of differences between mechanical properties of unmodified potato and transgenic clones during cooking and microwave heating. the compression test was applied in order to evaluate the mechanical resistance of raw, cooked and microwave-treated ... | 2004 | 15285106 |
| strains of peru tomato virus infecting cocona (solanum sessiliflorum), tomato and pepper in peru with reference to genome evolution in genus potyvirus. | two isolates (sl1 and sl6) of peru tomato virus (ptv, genus potyvirus) were obtained from cocona plants (solanum sessiliflorum) growing in tingo maría, the jungle of the amazon basin in peru. one ptv isolate (tm) was isolated from a tomato plant (lycopersicon esculentum) growing in huaral at the peruvian coast. the three ptv isolates were readily transmissible by myzus persicae. isolate sl1, but not sl6, caused chlorotic lesions in inoculated leaves of chenopodium amaranticolor and c. quinoa. is ... | 2004 | 15290372 |
| transfer of phloem-mobile substances from the host plants to the holoparasite cuscuta sp. | during the development of the haustorium, searching hyphae of the parasite and the host parenchyma cells are connected by plasmodesmata. using transgenic tobacco plants expressing a gfp-labelled movement protein of the tobacco mosaic virus, it was demonstrated that the interspecific plasmodesmata are open. the transfer of substances in the phloem from host to the parasite is not selective. after simultaneous application of (3)h-sucrose and (14)c-labelled phloem-mobile amino acids, phytohormones, ... | 2006 | 16467411 |
| use of oils combined with low doses of insecticide for the control of myzus persicae and pvy epidemics. | experiments were carried out in the laboratory to assess the insecticidal effect on myzus persicae sulzer of different oils applied alone or combined with imidacloprid or pirimicarb. the oils tested were a horticultural mineral oil, a refined rapeseed oil, a refined soya oil and a raw fish oil. when the oils were sprayed alone on pepper plants infested with m. persicae, mineral oil caused the highest mortality of aphids (over 80%). applied before aphid infestation of pepper leaves and in mixture ... | 2006 | 16470683 |
| structural analysis of the eukaryotic initiation factor 4e gene controlling potyvirus resistance in pepper: exploitation of a bac library. | the pvr2 locus in pepper codes for a eukaryotic translation initiation factor 4e (eif4e) gene that confers resistance to viruses belonging to the potyvirus genus. in this work, we describe the isolation and characterisation of the genomic sequence carrying the pvr2 locus. a bacterial artificial chromosome (bac) library that consisted of 239,232 clones with an average insert size of 123 kilobases (kb) was constructed from a capsicum annuum line with the pvr2(+) allele for susceptibility to potato ... | 2004 | 15315824 |
| evaluation of a simple membrane-based nucleic acid preparation protocol for rt-pcr detection of potato viruses from aphid and plant tissues. | a rapid and simple protocol for preparing viral rna from aphids (myzus persicae) and potato (solanum tuberosum l.) tissue (leaves, sprouts, and tubers) for reverse transcription-polymerase chain reaction (rt-pcr) was developed. the four-step method involves: (1) preparing plant crude sap or aphid macerates in a buffered detergent (triton xl-80n) solution; (2) immobilizing clarified sap on a nitrocellulose membrane; (3) performing reverse transcription using eluted water extract from cut-out spot ... | 2004 | 15381353 |
| cucumber mosaic virus 2b protein compensates for restricted systemic spread of potato virus y in doubly infected tobacco. | tobacco plants (nicotiana tabacum cv. xanthi-nc) inoculated with a necrotic strain of potato virus y (pvy, t01 isolate) developed necrotic symptoms in some systemically infected leaves, but not in younger leaves. however, pvy expressed distinct symptoms not only in the older leaves, but also in the younger leaves, of plants that had been doubly inoculated with pvy and with cucumber mosaic virus (cmv, strain pepo). a tissue blot immunoassay of tissues from various positions of the stem detected p ... | 2004 | 15483258 |
| identification of pvy-n on potato and tobacco in tehran and mazandaran provinces. | during two growing seasons in years of 2003 and 2004 potato and tobacco of virus infected plants were collected from fields in tehran (damavand) and mazandaran (behshahr) provinces. serological methods of tas-elisa and diba were performed by using pvy antiserum (dsmz - plant virus collection; germany) but only pvy was detected. the strain of samples was determined by using mab of potato virus y (as-0403/1; dsmz; germany). the molecular weight of the virus coat protein was approximately 34 kda in ... | 2005 | 16637208 |
| effect of cdna fragments in different length derived from potato virus y coat protein gene on the induction of rna-mediated virus resistance. | we have reported that cdna derived from entire coat protein (cp) gene of potato virus y (pvy) could induce resistance to pvy infection in transgenic tobacco plants, and the resistance was further demonstrated to be rna-mediated rather than coat protein-mediated. in this study, we cloned cdna fragments of 202 bp, 417 bp, and 603 bp in length derived from the 3' end of the pvy cp gene, and the cdna fragments were introduced into tobacco (var. nc89) plants via agrobacterium-mediated transformation ... | 2004 | 15493480 |
| ectopic expression of a udp-glucose:phenylpropanoid glucosyltransferase leads to increased resistance of transgenic tobacco plants against infection with potato virus y. | transgenic tobacco plants over-expressing a salicylate- and pathogen-inducible glucosyltransferase (togt) acting on various phenylpropanoids show enhanced resistance against infection with potato virus y (pvy). the transgenic plants are characterized by a several-fold increased glucosyltransferase activity in leaves as well as in roots. under non-infectious conditions profiles of phenylpropanoids in leaves of transgenic lines were similar to that of controls. feeding experiments with leaf-discs ... | 2004 | 15509841 |
| characterisation of potato virus y nnp strain inducing veinal necrosis in pepper: a naturally occurring recombinant strain of pvy. | the full-length genome of potato virus y (pvy) nnp strain, recovered from pepper showing veinal necrosis of leaves, was cloned and sequenced, finding an organisation typical for pvy species. it consists of 9699 nucleotides (nt) excluding the 3' terminal poly(a) tail and contains an open reading frame of 9186 nt, encoding the putative polyprotein of 3061 amino acids. in elisa, the isolate reacted with a monoclonal antibody specific for pvy(c) but not with antibodies against pvy(n) or pvy(o). sequ ... | 2004 | 15592887 |
| nucleotide sequence of the coat protein genes of alstroemeria mosaic virus and amazon lily mosaic virus, a tentative species of genus potyvirus. | the nucleotide sequences of the 3' terminal region of the genomes of alstroemeria mosaic virus (alsmv) and the amazon lily mosaic virus (alimv) have been determined. these sequences contain the complete coding region of the viral coat protein (cp) gene followed by a 3'-untranslated region (3'-utr). alsmv and alimv share 74.9% identity in the amino acid sequence of the cp, and 55.6% identity in the nucleotide sequence of the 3'-utr. phylogenetic analysis of these cp genes and 3'-utrs in relation ... | 2004 | 15593424 |
| bidens mosaic virus is a member of the potato virus y species. | the nucleotide sequence of the genomic 3' terminal region (1,702 bases) of two brazilian bidens mosaic virus isolates (bimv: bimv-p and bimv-b) was determined. bimv-p and bimv-b share 98% nucleotide sequence identity, and are most closely related to members of the potyvirus species: sunflower chlorotic mottle virus (an isolate of potato virus y) and potato virus y. bimv-p shares 88% capsid protein amino acid identity and 77% 3'utr nucleotide sequence identity with sucmov an isolate of sunflower ... | 2006 | 16791418 |
| occurrence of a dna sequence of a non-retro rna virus in a host plant genome and its expression: evidence for recombination between viral and host rnas. | this study demonstrates that sequences homologous to those of the non-retro rna virus (potato virus y; pvy) are integrated into the genome of several grapevine varieties. the integrated pvy-coat-protein-like cistron is expressed in the grapevine as indicated by southern and western blot analyses as well as by rnase protection assay. in addition, genome-walking studies showed that one pvy-like sequence is flanked by 41-bp direct repeats and is embedded in authentic grapevine sequences, flanked by ... | 2005 | 15680426 |
| transfer of resistance to potato virus y (pvy) from nicotiana africana to nicotiana tabacum: possible influence of tissue culture on the rate of introgression. | a disomic chromosome addition line of tobacco, nicotiana tabacum l., was established previously that possesses a single chromosome pair from n. africana [merxm. and buttler]. this addition chromosome carries a gene that confers increased resistance to severe strains of potato virus y (pvy). methods to increase the probability of gene transfer from alien chromosomes to tobacco (2n=48) are desired. in the research described here, the pvy resistance gene was transferred to a tobacco chromosome from ... | 2005 | 15723274 |
| severe outbreaks of tomato yellow leaf curl sardinia virus in calabria, southern italy. | during the winter 2003--2004 a serious disease was observed in protected tomato crops in castrovillari, reggio calabria province, southern italy. symptoms consisted in marginal leaf yellowing, leaf curling, plant stunting, flower abortion. the disease was detected in a group of greenhouses (about 10ha) where several tomato cultivars were grown hydroponically. the highest incidence of infection (60-100%) was observed in tomatoes grafted on beaufort drs tomato rootstock. since the symptoms were si ... | 2004 | 15756842 |
| experimental and natural weed host-virus relations. | weeds, as alternative hosts of plant viruses and nutrient plants of virus vectors play important role in virus ecology and epidemiology. the aim of our study was to discover new weed-virus relations. therefore some weed species were mechanically inoculated with 28 viruses (strains or isolates) maintained in our glasshouse. different weed species with and without visible symptoms were collected from agro-, water ecosystems and wastelands of hungary between 1997 and 2003. virus infections were eva ... | 2004 | 15759395 |
| specific detection of the pvy(n)-w variant of potato virus y. | pvy(n)-w is one of the variant populations of potato virus y (pvy). this variant is of concern in seed potato production and requires a specific diagnosis since it induces more or less symptomless infections and is not detectable easily in field inspections. moreover, this variant is serologically indistinguishable from the common strain pvy(o). this study describes a simple and specific molecular detection test for the pvy(n)-w variant using a pcr protocol based on the recombinant point within ... | 2005 | 15794982 |
| changes in soil microbial community structure associated with two types of genetically engineered plants analyzing by plfa. | with the rapid expansion of geps(genetically engineered plants), people are more and more concerned about the ecological risks brought by their release. assessing the effect of geps on soil microbial ecology is indispensable to study their ecological risks. in our study, the phospholipids fatty acid ( plfa) method was used to analyze the microbial community of soil samples collected from fields with two types of geps-bt transgenic corn and pvy ( potato virus y) cell protein gene transgenic potat ... | 2005 | 15900775 |
| oligonucleotide-based microarray: a new improvement in microarray detection of plant viruses. | microarrays are one of the new emerging methods in plant virology currently being developed by various laboratories. in this study, a new approach is described on the detection of plant viruses using short synthetic single-stranded oligomers (40 nt) instead of pcr products as capture probes. a microchip detecting potato viruses, pva, pvs, pvm, pvx, pvy and plrv, in both single and mixed infections was developed and tested. the chip was also designed to distinguish between the main strains of pvy ... | 2005 | 15927276 |
| characterization of potato virus y (pvy) molecular determinants involved in the vein necrosis symptom induced by pvyn isolates in infected nicotiana tabacum cv. xanthi. | viral molecular determinant(s) involved in the tobacco vein necrosis (tvn) symptom induced by necrotic isolates of potato virus y (pvy) on nicotiana tabacum cv. xanthi leaves remain undetermined. reference isolates belonging to pvy(n) (infectious pvy(n)-605 clone) and pvy(o) (pvy(o)-139) were used to produce pvy chimeric genomes by using reverse-genetic techniques. these chimeric clones were inoculated biolistically onto nicotiana clevelandii plants to establish the clone, prior to being tested ... | 2005 | 15958688 |
| the recessive potyvirus resistance gene pot-1 is the tomato orthologue of the pepper pvr2-eif4e gene. | the translation initiation factor 4e (eif4e) has been implicated in naturally occurring resistance to potato virus y (pvy) determined by the pvr2 locus in pepper (capsicum annuum). here, the molecular basis of the recessive resistance to pvy and tobacco etch virus (tev) controlled by the pot-1 locus in tomato (lycopersicon esculentum; now solanum lycopersicum) was investigated. on the basis of genetic mapping data that indicated that pot-1 and pvr2 are located in syntenic regions of the tomato a ... | 2005 | 15971038 |
| mapping of extreme resistance to pvy (ry (sto)) on chromosome xii using anther-culture-derived primary dihaploid potato lines. | the inheritance of extreme resistance to pvy (ry (sto)) by a single dominant locus was confirmed by obtaining a 1:1 segregation ratio in a virus inoculation test with 28 resistant (ryry) to 29 susceptible (ryry) anther culture-derived dihaploid lines (2n=2x=24) from cv. "assia" (2n=4x=48) having extreme resistance derived from solanum stoloniferum in simplex constitution (ryryryry). twelve ry (sto) markers selected in aflp assays using bulked segregant analysis were applied to 106 tested potato ... | 2005 | 16044270 |
| nutritional properties of tubers of conventionally bred and transgenic lines of potato resistant to necrotic strain of potato virus y (pvyn). | the potential effect of genetic modification on nutritional properties of potatoes transformed to improve resistance to a necrotic strain of potato virus y was determined in a rat experiment. autoclaved tubers from four transgenic lines were included to a diet in the amount of 40% and compared with the conventional cv. irga. the experiment lasted 3 weeks and special attention was paid to nutritional properties of diets, caecal metabolism and serum indices. genetic modification of potato had no n ... | 2005 | 16175247 |
| differentiation of potato virus y strains using improved sets of diagnostic pcr-primers. | potato virus y (pvy) is one of the most important viruses of potato world-wide, several strain groups are recognized. in the past two decades, novel pvy variants have appeared causing necrotic symptoms on potato tubers. implicated are two groups of recombinant strains: pvy(n)w and pvy(ntn), and na-pvy(ntn). while the first two are recombinants between pvy-n- and o-strains the latter is a recombinant between an n-strain and an unknown pvy strain or other potyvirus. available biological and molecu ... | 2007 | 17182113 |
| [site-specific expression of single-stranded antibody fragments in nicotiana tabacum]. | antibody expression and immunomodulation are modern molecular techniques to produce pharmaceuticals and to interfere with cellular metabolism or pathogen infectivity in plants. nonetheless, there is still no generally applicable strategy to express correctly folded active antibodies or antibody fragments in different cell compartments. to facilitate expression, single-chain antibody fragments (scfvs) were made of mouse monoclonal antibodies, j2 and p6 that specifically recognize double-stranded ... | 2005 | 16250245 |
| development of scar markers linked to three disease resistances based on aflp within nicotiana tabacum l. | amplified fragment length polymorphism (aflp) was conducted on a set of 92 nicotiana tabacum l. accessions from diverse types (flue-cured, dark air-cured, burley, oriental, and cigar wrapper) and breeding origins to identify markers associated with disease resistances. eleven primer combinations were required to identify 33 polymorphic fragments. this allowed the identification of 92% of these accessions, and yielded sufficient information for building a neighbor joining tree. clusters of access ... | 2006 | 16283232 |
| an unusual structure at one end of potato potyvirus particles. | the particles of potato virus y (pvy) and potato virus a (pva) potyviruses are helically constructed filaments that are thought to contain a single type of coat protein subunit. examination of negatively stained virions by electron microscopy reveals flexuous rod-shaped particles with no obvious terminal structures. it is known that some helically constructed rod-shaped virus particles incorporate additional minor protein components, which form stable complexes that mediate particle disassembly, ... | 2006 | 16414068 |
| whole genome characterization of potato virus y isolates collected in the western usa and their comparison to isolates from europe and canada. | potato virus y (pvy) is a serious potato pathogen that affects potato seed and commercial production crops. in recent decades, novel pvy strains have been described that cause necrotic symptoms on tobacco foliage and/or potato tubers. the major pvy strains that affect potato include pvy(o) and pvy(n), which have distinct serotypes that can be differentiated by immunoassay. other economically important strain variants are derived from recombination events, including variants that cause tuber necr ... | 2006 | 16463126 |
| trapping of tomato yellow leaf curl virus (tylcv) and other plant viruses with a groel homologue from the whitefly bemisia tabaci. | to avoid destruction in the haemolymph of their vector, many plant circulative viruses interact with groel homologues produced by insect endosymbiotic bacteria. we have exploited this phenomenon to devise tools allowing trapping of plant viruses by either groel purified from the whitefly bemisia tabaci or by whitefly groel over-expressed in e. coli. pcr tubes or 96-well plates coated with a groel preparation were incubated with cleared sap of virus infected plant leaves or insect vectors. groel- ... | 2004 | 15290375 |
| tobacco mosaic virus regulates the expression of its own resistance gene n. | the n gene of tobacco (nicotiana tabacum) is a typical resistance (r) gene engendering localization of tobacco mosaic virus (tmv) infection and the elicitation of a hypersensitive necrotic response. the consensus model for r gene-derived resistance is at the level of protein:protein interactions, in which proteins of the pathogen interact with already present receptor-like proteins produced by the plant's r genes. this article demonstrates, by quantitative real-time reverse transcription-pcr ana ... | 2004 | 15299123 |
| marker-assisted combination of major genes for pathogen resistance in potato. | closely linked pcr-based markers facilitate the tracing and combining of resistance factors that have been introgressed previously into cultivated potato from different sources. crosses were performed to combine the ry ( adg ) gene for extreme resistance to potato virus y (pvy) with the gro1 gene for resistance to the root cyst nematode globodera rostochiensis and the rx1 gene for extreme resistance to potato virus x (pvx), or with resistance to potato wart (synchytrium endobioticum). marker-ass ... | 2006 | 16538512 |
| potyvirus terminal protein vpg, effector of host eukaryotic initiation factor eif4e. | potyvirus rna contains at the 5' end a covalently linked virus-encoded protein vpg, which is required for virus infectivity. this role has been attributed to vpg interaction with the eukaryotic translation initiation factor eif4e, a cap-binding protein. we characterized the dissociation constants for the interaction of the potato virus y vpg with different plant eif4es and its isoforms and mapped the eif(iso)4e attachment region on vpg. vpg/eif4e interaction results in the inhibition of cell-fre ... | 2006 | 16626853 |
| different mutations in the genome-linked protein vpg of potato virus y confer virulence on the pvr2(3) resistance in pepper. | five different amino acid substitutions in the vpg of potato virus y were shown to be independently responsible for virulence toward pvr2(3) resistance gene of pepper. a consequence of these multiple mutations toward virulence involving single nucleotide substitutions is a particularly high frequency of resistance breaking (37% of inoculated plants from the first inoculation) and suggests a potentially low durability of pvr2(3) resistance. these five mutants were observed with significantly diff ... | 2006 | 16673943 |
| fate of hairpin transcript components during rna silencing and its suppression in transgenic virus-resistant tobacco. | transgenic tobacco plants, carrying a potato virus y (pvy)-nia hairpin sequence separated by a unique unrelated spacer sequence were specifically silenced and highly resistant to pvy infection. in such plants neither pvy-nia nor spacer transgene transcripts were detectable by specific quantitative real time reverse transcriptase pcr (rt-qpcr) assays of similar relative efficiencies developed for direct comparative analysis. however, small interfering rnas (sirnas) specific for the pvy sequence o ... | 2006 | 16697483 |
| the complete genome sequence of pepper severe mosaic virus and comparison with other potyviruses. | the complete nucleotide sequence of pepper severe mosaic virus (pepsmv) was determined. the viral genome consisted of 9890 nucleotides, excluding a poly (a) tract at the 3' end of the genome. the pepsmv rna genome encoded a single polyprotein of 3085 amino acid residues, resulting in ten functionally distinct potyviral proteins. the lengths of the 5' nontranslated region (ntr) and the 3' ntr were 164 and 468 nucleotides, respectively. the genome organization of the virus was typical for members ... | 2006 | 16699829 |
| effect of mixed viral infections (potato virus y-potato leafroll virus) on biology and preference of vectors myzus persicae and macrosiphum euphorbiae (hemiptera: aphididae). | mixed viral infections of heterologous viruses such as potato virus y (family potyviridae, genus potyvirus, pvy) and potato leafroll virus (family luteoviridae, genus polerovirus, plrv) are a regular occurrence in idaho's potato, solanum tuberosum (l.), cropping systems. an increased number of plant samples from idaho's potato fields over the past 2 yr has serologically tested positive for both pvy and plrv via double antibody sandwich enzyme-linked immunosorbent assay (das-elisa) and exhibited ... | 2007 | 17598521 |
| pvy-resistant transgenic potato plants expressing an anti-nia protein scfv antibody. | a synthetic gene encoding a single chain fv fragment of an antibody directed against the nuclear inclusion a (nia) protein of potato virus y (pvy) was used to transform two commercial potato cultivars (claustar and bf15). the nia protease forms the nuclear inclusion body a and acts as the major protease in the cleavage of the viral polyprotein into functional proteins. immunoblot analysis showed that most of the resulting transgenic plants accumulate high levels of the transgenic protein. furthe ... | 2006 | 16757800 |
| molecular variability of the coat protein gene of potato virus y from tobacco in china. | thirty-three tobacco samples showing typical symptoms of potato virus y (pvy) infection were obtained from tobacco fields in various regions of china. the results of indirect elisa confirmed the infection with pvy. all the isolates had a capacity to infect tobacco systemically in greenhouse, causing either of two main symptoms: veinal necrosis and mosaic. the nucleotide and amino acid sequences of the coat protein (cp) gene and protein, respectively, of the isolates were determined. comparison o ... | 2006 | 16808328 |
| development and evaluation of a multiplex rt-pcr for detecting main viruses and a viroid of potato. | a multiplex rt-pcr (mrt-pcr) for detecting four potato viruses (potato virus s (pvs), potato virus x (pvx), potato virus y (pvy), and potato leaf roll virus (plrv)) and one potato viroid (potato spindle tuber viroid (pstvd)) was developed. the mrt-pcr consisted of one reaction with specific primers designed according to the sequences of coat protein (cp) genes of respective viruses and the sequence of the viroid. the entire procedure from tissue grinding to rt-pcr results takes about 4 hrs. the ... | 2006 | 16808331 |
| hc-pro protein of potato virus y can interact with three arabidopsis 20s proteasome subunits in planta. | the multifunctional protein helper component proteinase (hc-pro) is thought to interfere with the activity of the 20s proteasome; however, no sites of interaction have been identified for either protein. here, we first show that the potato virus y (pvy) hc-pro protein can interact with three arabidopsis 20s proteasome subunits (paa, pbb, and pbe), using a yeast two-hybrid system and the bimolecular fluorescence complement assay. in addition, yeast two-hybrid analysis of the interaction between s ... | 2007 | 17898064 |
| targeting dsrna-specific single-chain fv antibody fragments to different cellular locations in nicotiana tabacum l. | expression of antibodies or antibody fragments in plants is a useful tool for producing active antibody derivatives for diagnostic or pharmaceutical purposes as well as for immunomodulation. we investigated the effect of cellular expression site on the stability and yield of double-stranded rna (dsrna)-specific single-chain fv-fragments (scfv) in transgenic tobacco. two antibodies (j2 and p6) belonging to the v23(j558) heavy chain variable gene family but differing in the light chain variable do ... | 2006 | 16841475 |
| use of dried high-phenolic laden host leaves for virus and viroid preservation and detection by pcr methods. | the efficiency of rna extraction for apricot latent virus (aplv), plum bark necrosis stem pitting associated virus (pbnspav), prunus necrotic ring spot virus (pnrsv), potato virus y (pvy), and apple scar skin viroid (assvd) from infected hosts is of great importance for molecular diagnosis by the polymerase chain reaction (pcr). a method is described for drying tissue to overcome phenolic inhibitors of viral rna. this study showed that the infected host leaves, dried at 65 degrees c for 2 days a ... | 2006 | 16879877 |
| cloning and expression of functional single-chain fv antibodies directed against nia and coat proteins of potato virus y. | three single-chain variable fragment (scfv) antibodies recognizing the nuclear inclusion a (nia) and capsid proteins of potato virus y were obtained from two mouse derived hybridoma clones secreting, respectively, an anti-nia (22-1) and an anti-coat protein (136-13) monoclonal antibodies. the first monoclonal antibody was able to inhibit in vitro the pvy polyprotein cleavage by blocking the nia protease activity. the amplified scfv cdnas were first inserted into the topo vector and then sequence ... | 2006 | 16884787 |
| production of potato intraspecific somatic hybrids with improved tolerance to pvy and pythium aphanidermatum. | somatic hybridization can be an interesting alternative for the selection of heterozygous and vigorous potato plants through combination of dihaploid genomes. the resulting hybrids can harbour interesting characters and thus can be used in agriculture if they are in agreement with agronomic criteria. in this report, we used an intraspecific somatic hybridization technique for the production of tetraploid potato lines. two parental combinations were used in protoplast electrofusion procedure: ami ... | 2006 | 16904234 |
| estimation of the number of virus particles transmitted by an insect vector. | plant viruses are submitted to narrow population bottlenecks both during infection of their hosts and during horizontal transmission between host individuals. the size of bottlenecks exerted on virus populations during plant invasion has been estimated in a few pathosystems but is not addressed yet for horizontal transmission. using competition for aphid transmission between two potato virus y variants, one of them being noninfectious but equally transmissible, we obtained estimates of the size ... | 2007 | 17971440 |
| cytochrome c oxidase mrna as an internal control for detection of potato virus y and potato leafroll virus from single aphids by a co-amplification rt-pcr assay. | using cytochrome c oxidase subunit 1 (cox1) mrna as the internal control, a triplex reverse transcription-polymerase chain reaction (rt-pcr) for detection of potato virus y (pvy) and potato leafroll virus (plrv) with co-amplification of cox1 from single specimens of various aphid species has been developed. partial length cdna of cox1 from green peach aphid, myzus persicae (sulzer), potato aphid, macrosiphum euphorbiae (thomas), buckthorn aphid, aphis nasturtii (kaltenbach), and pea aphid, acyrt ... | 2006 | 17010449 |
| growth at elevated co2 concentrations leads to modified profiles of secondary metabolites in tobacco cv. samsunnn and to increased resistance against infection with potato virus y. | the effect of elevated co2 concentrations on the levels of secondary metabolites was investigated in tobacco plants grown under two nitrogen supply (5 and 8 mm nh4no3) and co2 conditions (350 and 1000 p.p.m.) each. high co2 resulted in a dramatic increase of phenylpropanoids in the leaves, including the major carbon-rich compound chlorogenic acid (cga) and the coumarins scopolin and scopoletin at both nitrogen fertilizations. this was accompanied by increased pal activity in leaves and roots, wh ... | 2006 | 17086759 |
| engineering resistance to pvy in different potato cultivars in a marker-free transformation system using a 'shooter mutant' a. tumefaciens. | in this work, potato virus y (pvy) resistant potatoes were generated using an environmentally safe construct. for this purpose, a 'shooter' mutant agrobacterium-based transformation system was used. the isopentenyl transferase gene (ipt) present on the ti plasmid of 'shooter' strains enhances shoot regeneration and can be used as a phenotypic selection marker. the introduced marker-free binary vector carried a hairpin construct derived from the coat protein gene of pvy-ntn strain in order to ind ... | 2007 | 17103215 |
| rapid identification of potato virus y strains by one-step triplex rt-pcr. | a one-step triplex rt-pcr method was characterised that allows rapid, strain-specific detection of potato virus y (pvy) occurring on potato: pvy(n), pvy(o), pvy(ntn) (recombinant isolates), pvy(n)wi and pvy(c). three specific primer pairs were designed on aligned pvy sequences available from genomic data banks. the specificity of the selected primers was first examined by simplex rt-pcr with a large number of pvy reference isolates. two fragments of 0.44 and 1.11kb were amplified for pvy(n) and ... | 2007 | 17157929 |
| a bipartite system for the constitutive and inducible expression of high levels of foreign proteins in plants. | we have developed combined transgene/virus vector systems for the expression of heterologous proteins in plants. the systems are based on the bipartite rna plant virus, cowpea mosaic virus (cpmv), and involve the amplification of integrated copies of either full-length or deleted versions of rna-2 carrying a foreign gene. in the case of plants transgenic for full-length versions of rna-2 carrying the green fluorescent protein (gfp), amplification can be achieved by supplying rna-1 either exogeno ... | 2006 | 17177795 |
| simultaneous detection of potato viruses, plrv, pva, pvx and pvy from dormant potato tubers by taqman real-time rt-pcr. | the requirements of sprouting dormant potato tubers for biological or serological assays or rna extraction for nucleic acid and pcr assays add to the cost of virus screening. recently, cheaper, reliable and more rapid methods for the screening of potato tuber-seed pieces for viruses have been developed that do not require sprouted tubers for indexing, including taqman real-time rt-pcr. although the assays are often designed for minimal time and reagent use, they still require a time-consuming an ... | 2007 | 17276522 |
| characterization of the expression and inheritance of potato leafroll virus (plrv) and potato virus y (pvy) resistance in three generations of germplasm derived from solanum etuberosum. | potato virus y (pvy) and potato leafroll virus (plrv) are two of the most important viral pathogens of potato. infection of potato by these viruses results in losses of yield and quality in commercial production and in the rejection of seed in certification programs. host plant resistance to these two viruses was identified in the backcross progeny of a solanum etuberosum lindl. somatic hybrid. multiple years of field evaluations with high-virus inoculum and aphid populations have shown the pvy ... | 2007 | 17318495 |
| stability of recombinant plant viruses containing genes of unrelated plant viruses. | the stability of hybrid plant viruses that might arise by recombination in transgenic plants was examined using hybrid viruses derived from the viral expression vectors potato virus x (pvx) and tobacco rattle virus (trv). the potato virus y (pvy) nib and hcpro open reading frames (orfs) were introduced into pvx to generate pvx-nib and pvx-hcpro, while the pvy nib orf was introduced into a vector derived from trv rna2 to generate trv-nib. all three viruses were unstable and most of the progeny vi ... | 2007 | 17374781 |
| high incidence of tobacco streak virus in the tobacco fields of iran. | currently the northern provinces of iran (mazandaran, golestan and gilan) are the main tobacco growing regions in the country and this crop has an special importance in the national economy. three tobacco types including flue-cured (mainly coker 347 and some virginia e1), burley (burley 21) and oriental (basma 178-2) are presently grown in these regions. epidemics of viral diseases have occurred during the recent years in many tobacco fields in these areas. the quality of tobacco products which ... | 2006 | 17390881 |
| evaluating the efficiency of a tpia method for the detection of two tobacco viruses. | field experiments are usually necessary for analyzing the efficiency of control methods, the resistance of varieties and many other virological studies. such experiments generally include a large number of samples to be tested serologically. das-elisa is a very accurate technique that has been widely used for identifying viral infections. for large numbers of plant samples, it takes a long time for the sample preparation, plate washing and other procedures. in this study, the efficiency of a sim ... | 2006 | 17390882 |
| improvement of potato virus y (pvy) detection and quantitation using pvy(n)- and pvy(o)-specific real-time rt-pcr assays. | a potato virus y (pvy) single nucleotide polymorphism (a/g(2213)), recently identified as a molecular determinant of the tobacco leaf necrosis symptom induced by pvy(n) isolates, has been used as a target to develop two pvy group-specific (pvy(n) and pvy(o)) fluorescent (taqman-based) real-time rt-pcr assays. these procedures allow detection, characterisation, and quantitation of a wide range of pvy isolates in samples containing 10(3)-10(8) viral transcripts. moreover, the high specificity of t ... | 2006 | 16513184 |
| molecular dissection of the potato virus y vpg virulence factor reveals complex adaptations to the pvr2 resistance allelic series in pepper. | the virulence properties of potato virus y (pvy) towards an allelic series at the pvr2 locus in pepper genotypes are related to variations in the genome-linked viral protein (vpg). eleven amino acid substitutions in the central part of the vpg were identified in strains differing by their virulence properties and were introduced, either singly or in combination, in an infectious pvy clone to get an in-depth genetic analysis of the virulence determinant. the virulence spectrum of these mutants wa ... | 2007 | 17412992 |