Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| potyvirus-induced gene silencing: the dynamic process of systemic silencing and silencing suppression. | potato virus a (pva; genus potyvirus) was used for virus-induced gene silencing in a model system that included transgenic nicotiana benthamiana (line 16c) expressing the gfp transgene for green fluorescent protein (gfp) and chimeric pva (pva-gfp) carrying gfp in the p1-encoding region. infection of the 16c plants with pva-gfp in five experiments resulted in a reproducible pattern of systemic gfp transgene silencing, despite the presence of the strong silencing-suppressor protein, hc-pro, produc ... | 2007 | 17622640 |
| the receptor-like kinase serk3/bak1 is a central regulator of innate immunity in plants. | in pathogen-associated molecular pattern (pamp)-triggered immunity (pti), plant cell surface receptors sense potential microbial pathogens by recognizing elicitors called pamps. although diverse pamps trigger pti through distinct receptors, the resulting intracellular responses overlap extensively. despite this, a common component(s) linking signal perception with transduction remains unknown. in this study, we identify somatic embryogenesis receptor kinase (serk)3/brassinosteroid-associated kin ... | 2007 | 17626179 |
| the arabidopsis bap1 and bap2 genes are general inhibitors of programmed cell death. | here we identify the bap1 and bap2 genes of arabidopsis (arabidopsis thaliana) as general inhibitors of programmed cell death (pcd) across the kingdoms. these two homologous genes encode small proteins containing a calcium-dependent phospholipid-binding c2 domain. bap1 and its functional partner bon1 have been shown to negatively regulate defense responses and a disease resistance gene snc1. genetic studies here reveal an overlapping function of the bap1 and bap2 genes in cell death control. the ... | 2007 | 17631528 |
| modification of small rnas associated with suppression of rna silencing by tobamovirus replicase protein. | plant viruses act as triggers and targets of rna silencing and have evolved proteins to suppress this plant defense response during infection. although tobacco mosaic tobamovirus (tmv) triggers the production of virus-specific small interfering rnas (sirnas), this does not lead to efficient silencing of tmv nor is a tmv-green fluorescent protein (gfp) hybrid able to induce silencing of a gfp-transgene in nicotiana benthamiana, indicating that a tmv silencing suppressor is active and acts downstr ... | 2007 | 17634237 |
| geminivirus-induced gene silencing of the tobacco retinoblastoma-related gene results in cell death and altered development. | the retinoblastoma-related protein (rbr) is required for cell cycle control and differentiation and is expressed throughout the life of plants and animals. in this study, the tomato golden mosaic virus (tgmv) geminivirus vector was used to silence nbrbr1 in nicotiana benthamiana by microprojectile bombardment into fully developed leaves. similar to previous results using agroinoculation of a tobacco rattle virus silencing vector [park et al. (plant j 42:153, 2005)], developmental defects caused ... | 2007 | 17634748 |
| controlled synthesis of the dsf cell-cell signal is required for biofilm formation and virulence in xanthomonas campestris. | virulence of the black rot pathogen xanthomonas campestris pv. campestris (xcc) is regulated by cell-cell signalling involving the diffusible signal factor dsf. synthesis and perception of dsf require products of genes within the rpf cluster (for regulation of pathogenicity factors). rpff directs dsf synthesis whereas rpfc and rpfg are involved in dsf perception. here we have examined the role of the rpf/dsf system in biofilm formation in minimal medium using confocal laser-scanning microscopy o ... | 2007 | 17635553 |
| genetic and molecular requirements for function of the pto/prf effector recognition complex in tomato and nicotiana benthamiana. | the pto gene of tomato (solanum lycopersicum) confers specific recognition of the unrelated bacterial effector proteins avrpto and avrptob. pto resides in a constitutive molecular complex with the nucleotide binding site-leucine rich repeats protein prf. prf is absolutely required for specific recognition of both effectors. here, using stable transgenic lines, we show that expression of pto from its genomic promoter in susceptible tomatoes was sufficient to complement recognition of pseudomonas ... | 2007 | 17635766 |
| enzymatic properties and subcellular localization of arabidopsis beta-n-acetylhexosaminidases. | plant glycoproteins contain substantial amounts of paucimannosidic n-glycans lacking terminal glcnac residues at their nonreducing ends. it has been proposed that this is due to the action of beta-hexosaminidases during late stages of n-glycan processing or in the course of n-glycan turnover. we have now cloned the three putative beta-hexosaminidase sequences present in the arabidopsis (arabidopsis thaliana) genome. when heterologously expressed as soluble forms in spodoptera frugiperda cells, t ... | 2007 | 17644627 |
| a rangap protein physically interacts with the nb-lrr protein rx, and is required for rx-mediated viral resistance. | race-specific disease resistance in plants is mediated by the products of host disease resistance (r) genes. plant genomes possess hundreds of r gene homologs encoding nucleotide-binding and leucine-rich repeat (nb-lrr) proteins. nb-lrr proteins induce a disease resistance response following recognition of pathogen-encoded avirulence (avr) proteins. however, little is known about the general mechanisms by which nb-lrr proteins recognize avr proteins or how they subsequently induce defense respon ... | 2007 | 17655649 |
| high-frequency reversion of geminivirus replication protein mutants during infection. | the geminivirus replication protein al1 interacts with retinoblastoma-related protein (rbr), a key regulator of the plant division cell cycle, to induce conditions permissive for viral dna replication. previous studies of tomato golden mosaic virus (tgmv) al1 showed that amino acid l148 in the conserved helix 4 motif is critical for rbr binding. in this work, we examined the effect of an l148v mutation on tgmv replication in tobacco cells and during infection of nicotiana benthamiana plants. the ... | 2007 | 17670823 |
| expression of the arabidopsis xrn4p 5'-3' exoribonuclease facilitates degradation of tombusvirus rna and promotes rapid emergence of viral variants in plants. | rapid rna virus evolution is a major problem due to the devastating diseases caused by human, animal and plant-pathogenic rna viruses. a previous genome-wide screen for host factors affecting recombination in tomato bushy stunt tombusvirus (tbsv), a small monopartite plant virus, identified xrn1p 5'-3' exoribonuclease of yeast, a model host, whose absence led to increased appearance of recombinants [serviene, e., shapka, n., cheng, c.p., panavas, t., phuangrat, b., baker, j., nagy, p.d., (2005). ... | 2007 | 17688902 |
| effectiveness and stability of heterologous proteins expressed in plants by turnip mosaic virus vector at five different insertion sites. | the n-terminal (nt) regions of particular protein-coding sequences are generally used for in-frame insertion of heterologous open reading frames (orfs) in potyviral vectors for protein expression in plants. an infectious cdna clone of turnip mosaic virus (tumv) isolate yc5 was engineered at the generally used nt regions of hc-pro and cp, and other possibly permissive sites to investigate their effectiveness to express the gfp (jellyfish green fluorescent protein) and der p 5 (allergen from the d ... | 2007 | 17689817 |
| assessing the expression of chicken anemia virus proteins in plants. | chicken anemia virus (cav) is an important pathogen of chicken worldwide, causing severe anemia and immunodeficiency. its small single-stranded dna genome (2.3kb) encodes three proteins: vp1, the only structural protein, vp2, a protein phosphatase, and vp3, also known as apoptin, which induces apoptosis. in this study, cav proteins were expressed in plants as an alternative for recombinant protein production in animal cells. additionally, the effect of vp3 expression was tested to evaluate possi ... | 2007 | 17698236 |
| hlmyb3, a putative regulatory factor in hop (humulus lupulus l.), shows diverse biological effects in heterologous transgenotes. | a hop-specific cdna library from glandular tissue-enriched hop cones was screened for myb transcription factors. cdna encoding for r2r3 myb, designated hlmyb3, was cloned and characterized. according to the amino acid (aa) sequence, hlmyb3 shows the highest homology to ghmyb5 from cotton and is unrelated to the previously characterized hlmyb1 from the hop. southern blot analyses indicated that hlmyb3 is a unique gene, which was detected in various humulus lupulus cultivars, but not in humulus ja ... | 2007 | 17708645 |
| mature monomeric forms of hop stunt viroid resist rna silencing in transgenic plants. | viroids, small non-coding pathogenic rnas, are able to induce rna silencing, a phenomenon that has been associated with the pathogenesis and evolution of these small rnas. it has been recently suggested that viroids may resist this plant defense mechanism. however, the simultaneous degradation of non-replicating full-length viroid rna, and the resistance of mature forms of viroids to rna silencing, have not been experimentally demonstrated. transgenic nicotiana benthamiana plants expressing a di ... | 2007 | 17711417 |
| pseudomonas syringae type iii effector avrptob is phosphorylated in plant cells on serine 258, promoting its virulence activity. | the pseudomonas syringae pv. tomato protein avrptob is translocated into plant cells via the bacterial type iii secretion system. in resistant tomato leaves, avrptob acts as an avirulence protein by interacting with the host pto kinase and eliciting the host immune response. pto-mediated immunity requires prf, a pto-interacting protein with a putative nucleotide-binding site and a region of leucine-rich repeats. in susceptible tomato plants, which lack either pto or prf, avrptob acts as a virule ... | 2007 | 17711844 |
| expression of animal ced-9 anti-apoptotic gene in tobacco modifies plasma membrane ion fluxes in response to salinity and oxidative stress. | apoptosis, one form of programmed cell death (pcd), plays an important role in mediating plant adaptive responses to the environment. recent studies suggest that expression of animal anti-apoptotic genes in transgenic plants may significantly improve a plant's ability to tolerate a variety of biotic and abiotic stresses. the underlying cellular mechanisms of this process remain unexplored. in this study, we investigated specific ion flux "signatures" in nicotiana benthamiana plants transiently e ... | 2007 | 17712568 |
| a novel nuclear protein interacts with the symbiotic dmi3 calcium- and calmodulin-dependent protein kinase of medicago truncatula. | many higher plants establish symbiotic relationships with arbuscular mycorrhizal (am) fungi that improve their ability to acquire nutrients from the soil. in addition to establishing am symbiosis, legumes also enter into a nitrogen-fixing symbiosis with bacteria known as rhizobia that results in the formation of root nodules. several genes involved in the perception and transduction of bacterial symbiotic signals named "nod factors" have been cloned recently in model legumes through forward gene ... | 2007 | 17722695 |
| comparative expression profiling of nicotiana benthamiana leaves systemically infected with three fruit tree viruses. | plant viruses cause a wide array of disease symptoms and cytopathic effects. although some of these changes are virus specific, many appear to be common even among diverse viruses. currently, little is known about the underlying molecular determinants. to identify gene expression changes that are concomitant with virus symptoms, we performed comparative expression profiling experiments on nicotiana benthamiana leaves infected with one of three different fruit tree viruses that produce distinct s ... | 2007 | 17722703 |
| recovery of nicotiana benthamiana plants from a necrotic response induced by a nepovirus is associated with rna silencing but not with reduced virus titer. | recovery of plants from virus-induced symptoms is often described as a consequence of rna silencing, an antiviral defense mechanism. for example, recovery of nicotiana clevelandii from a nepovirus (tomato black ring virus) is associated with a decreased viral rna concentration and sequence-specific resistance to further virus infection. in this study, we have characterized the interaction of another nepovirus, tomato ringspot virus (torsv), with host defense responses during symptom induction an ... | 2007 | 17728227 |
| infection, propagation, distribution and stability of plant virus in hairy root cultures. | nicotiana benthamiana hairy root cultures were infected with tobacco mosaic virus (tmv) and used for in vitro plant virus propagation. the roots were infected with tmv by addition of virus to the medium at the same time as root inoculation. viral accumulation in the biomass was 7-11-fold greater when the initial infection was carried out in b5 medium rather than sodium phosphate buffer; virus accumulation also increased with increasing viral inoculum concentration. the amount of tmv accumulated ... | 2007 | 17767969 |
| ap2-erf transcription factors mediate nod factor dependent mt enod11 activation in root hairs via a novel cis-regulatory motif. | rhizobium nod factors (nfs) are specific lipochitooligosaccharides that activate host legume signaling pathways essential for initiating the nitrogen-fixing symbiotic association. this study describes the characterization of cis-regulatory elements and trans-interacting factors that regulate nf-dependent and epidermis-specific gene transcription in medicago truncatula. detailed analysis of the mt enod11 promoter using deletion, mutation, and gain-of-function constructs has led to the identificat ... | 2007 | 17827349 |
| a chimeric plum pox virus shows reduced spread and cannot compete with its parental wild-type viruses in a mixed infection. | the effect of a recombination event in the genomic 3' end on the biological properties and competitiveness of plum pox virus (ppv) was investigated. therefore, a fragment spanning the coat protein (cp) coding region and a part of the 3' non-translated region of a non-aphid-transmissible strain of ppv (ppv-nat) was replaced by the corresponding region of a ppv sour cherry isolate (ppv-soc). the resulting chimera (ppv-nat/soc) caused severe symptoms in nicotiana benthamiana, resembling those of pp ... | 2007 | 17872539 |
| a cucumber mosaic virus mutant lacking the 2b counter-defence protein gene provides protection against wild-type strains. | several plant virus mutants, in which genes encoding silencing suppressor proteins have been deleted, are known to induce systemic or localized rna silencing against themselves and other rna molecules containing homologous sequences. thus, it is thought that many cases of cross-protection, in which infection with a mild or asymptomatic virus mutant protects plants against challenge infection with closely related virulent viruses, can be explained by rna silencing. we found that a cucumber mosaic ... | 2007 | 17872541 |
| the chimeric cyclic nucleotide-gated ion channel atcngc11/12 constitutively induces programmed cell death in a ca2+ dependent manner. | the hypersensitive response (hr) involves programmed cell death (pcd) in response to pathogen infection. to investigate the pathogen resistance signaling pathway, we previously identified the arabidopsis mutant cpr22, which displays constitutive activation of multiple defense responses including hr like cell death. the cpr22 mutation has been identified as a 3 kb deletion that fuses two cyclic nucleotide-gated ion channel (cngc)-encoding genes, atcngc11 and atcngc12, to generate a novel chimeric ... | 2007 | 17885810 |
| virp1 is a host protein with a major role in potato spindle tuber viroid infection in nicotiana plants. | viroids are small, circular, single-stranded rna molecules that, while not coding for any protein, cause several plant diseases. viroids rely for their infectious cycle on host proteins, most of which are likely to be involved in endogenous rna-mediated phenomena. therefore, characterization of host factors interacting with the viroid may contribute to the elucidation of rna-related pathways of the hosts. potato spindle tuber viroid (pstvd) infects several members of the solanaceae family. in an ... | 2007 | 17898061 |
| resistance to grapevine leafroll associated virus-2 is conferred by post-transcriptional gene silencing in transgenic nicotiana benthamiana. | grapevine leafroll-associated virus-2 (glrav-2) is an important component of the leafroll disease complex in grapevine. we have previously sequenced the glrav-2 genome and identified the coat protein (cp) gene. the objective of this study is to test the concept of pathogen-derived resistance against a closterovirus associated with grapevine leafroll disease. because glrav-2 is capable of infecting nicotiana benthamiana, we decided to test the concept on this herbaceous host. thirty-seven t(0) tr ... | 2008 | 17912600 |
| antagonistic control of powdery mildew host cell entry by barley calcium-dependent protein kinases (cdpks). | calcium-dependent protein kinases (cdpks) are known to play pivotal roles in intracellular signaling during abiotic and biotic stress responses. to unravel potential functions of cdpks in the course of barley (hordeum vulgare)-powdery mildew (blumeria graminis) interactions, we systematically analyzed the hvcdpk gene family. we found that, according to the existence of respective expressed sequence tags, at least nine paralogs are expressed in the barley leaf epidermis, the sole target tissue of ... | 2007 | 17918623 |
| new type iii effectors from xanthomonas campestris pv. vesicatoria trigger plant reactions dependent on a conserved n-myristoylation motif. | pathogenicity of the gram-negative plant pathogen xanthomonas campestris pv. vesicatoria depends on a type iii secretion system, which translocates bacterial effector proteins into the plant cell. in this study, we identified two novel type iii effectors, xope1 and xope2 (xanthomonas outer proteins), using the avrbs3 effector domain as reporter. xope1 and xope2 belong to the hopx family and possess a conserved putative n-myristoylation motif that is also present in the effector xopj from x. camp ... | 2007 | 17918627 |
| oligonucleotide microarray-based detection and genotyping of plum pox virus. | plum pox virus (ppv) is the most damaging viral pathogen of stone fruits. the detection and identification of its strains are therefore of critical importance to plant quarantine and certification programs. existing methods to screen strains of ppv suffer from significant limitations such as the simultaneous detection and genotyping of several strains of ppv in samples infected with different isolates of the virus. a genomic strategy for ppv screening based on the viral nucleotide sequence was d ... | 2008 | 17920703 |
| the pclean dual binary vector system for agrobacterium-mediated plant transformation. | the development of novel transformation vectors is essential to the improvement of plant transformation technologies. here, we report the construction and testing of a new multifunctional dual binary vector system, pclean, for agrobacterium-mediated plant transformation. the pclean vectors are based on the widely used pgreen/psoup system and the pclean-g/pclean-s plasmids are fully compatible with the existing pgreen/psoup vectors. a single agrobacterium can harbor (1) pclean-g and psoup, (2) pg ... | 2007 | 17932303 |
| a ligation-independent cloning tobacco rattle virus vector for high-throughput virus-induced gene silencing identifies roles for nbmads4-1 and -2 in floral development. | virus-induced gene silencing (vigs) is a widely used, powerful technique for reverse genetics. vigs vectors derived from the tobacco rattle virus (trv) are among the most popular for vigs. we have developed a trv rna2 vector that allows the insertion of gene silencing fragments by ligation-independent cloning (lic). this new vector has several advantages over previous vectors, particularly for applications involving the analysis of large numbers of sequences, since trv-lic vectors containing the ... | 2007 | 17932306 |
| solanum lycopersicon mill. and nicotiana benthamiana l. under high light show distinct responses to anti-oxidative stress. | two experimentally important species, solanum lycopersicon mill. and nicotiana benthamiana l., were propagated in vitro under low light (50 micromol m(-2) s(-1)) and transferred to hl (200 micromol m(-2) s(-1)) under a protocol previously developed for grapevine and chestnut. compared with photooxidative stress parameters already tested in those species, imaging of hydrogen peroxide and superoxide revealed an accumulation on d2-3 and d6 in s. lycopersicon and d1-2 and d5-7 in n. benthamiana. sod ... | 2008 | 17945381 |
| size reversion of a truncated dnabeta associated with tobacco curly shoot virus. | our previous results demonstrated that dnabeta associated with tobacco curly shoot virus (tbcsv) is not necessary for infection but intensifies symptoms in some hosts. to better understand the function of dnabeta in virus infection, a betac1 deleted infectious clone of the tbcsv dnabeta was constructed. agroinoculation showed that the truncated dnabeta (dnadeltac1beta) was trans-replicated by tbcsv in tobacco and petunia hybrida plants. however, pcr and southern blot analysis demonstrated that t ... | 2008 | 17950948 |
| alternative splicing and mrna levels of the disease resistance gene rps4 are induced during defense responses. | the arabidopsis (arabidopsis thaliana) disease resistance protein resistance to pseudomonas syringae4 (rps4) activates defenses in response to bacterial pathogens expressing avrrps4 in a gene-for-gene specific manner. the rps4 gene produces multiple transcripts via alternative splicing of two regular introns flanking exon 3 and a cryptic intron within exon 3. we showed previously that rps4-mediated resistance requires the combined presence of transcripts encoding both full-length and truncated o ... | 2007 | 17951452 |
| point mutations in helper component protease of clover yellow vein virus are associated with the attenuation of rna-silencing suppression activity and symptom expression in broad bean. | helper component protease (hc-pro) is a potyvirus-encoded multifunctional protein and a major determinant of symptom expression in a susceptible plant. here, we show the involvement of clover yellow vein virus (clyvv) hc-pro in necrotic symptom expression in broad bean (vicia faba cv. wase). in this host, lethal necrosis was induced by clyvv no. 30, from which a spontaneous, mosaic-inducing mutant (mm) was obtained. mapping with chimeric viruses between clyvv no. 30 and mm attributed the symptom ... | 2008 | 17955160 |
| induction of a small heat shock protein and its functional roles in nicotiana plants in the defense response against ralstonia solanacearum. | in tobacco (nicotiana tabacum), ralstonia solanacearum oe1-1 (rsoe1-1) is pathogenic, whereas r. solanacearum 8107 (rs8107) is nonpathogenic and induces the hypersensitive response (hr). to elucidate the molecular mechanisms of plant-r. solanacearum interactions, we used differential display to isolate a cdna fragment, a6, regulated in tobacco by inoculation with rsoe1-1. the deduced amino acid sequence predicted from full-length a6-cdna showed similarity to small heat shock proteins from arabid ... | 2007 | 17965181 |
| transient expression of hpv16 e7 peptide (aa 44-60) and hpv16 l2 peptide (aa 108-120) on chimeric potyvirus-like particles using potato virus x-based vector. | the optimized expression of recombinant potato virus a coat protein (acp) carrying two different epitopes from human papillomavirus type 16 (hpv16) was developed. epitope derived from minor capsid protein l2 was expressed as n-terminal fusion with acp while an epitope derived from e7 oncoprotein was fused to its c-terminus. the construct was cloned into potato x potexvirus (pvx) based vector and transiently expressed in plants using agrobacterium tumefaciens mediated inoculation. to increase the ... | 2008 | 17980618 |
| high-level transient production of a heterologous protein in plants by optimizing induction of a chemically inducible viral amplicon expression system. | we have demonstrated that the method of chemical induction using a chemically inducible viral amplicon expression system can be optimized to increase expression of a heterologous protein in plants. a cucumber mosaic virus inducible viral amplicon (cmviva) expression system was used to transiently produce a recombinant human blood protein, alpha-1-antitrypsin (aat), by co-infiltrating intact and detached nicotiana benthamiana leaves with two agrobacterium tumefaciens strains, one containing the c ... | 2007 | 17994759 |
| a systematic study to determine the extent of gene silencing in nicotiana benthamiana and other solanaceae species when heterologous gene sequences are used for virus-induced gene silencing. | virus-induced gene silencing (vigs) is a rapid and robust method for determining and studying the function of plant genes or expressed sequence tags (ests). however, only a few plant species are amenable to vigs. there is a need for a systematic study to identify vigs-efficient plant species and to determine the extent of homology required between the heterologous genes and their endogenous orthologs for silencing. two approaches were used. first, the extent of phytoene desaturase (pds) gene sil ... | 2007 | 17997764 |
| the arabidopsis vacuolar malate channel is a member of the almt family. | in plants, malate is a central metabolite and fulfills a large number of functions. vacuolar malate may reach very high concentrations and fluctuate rapidly, whereas cytosolic malate is kept at a constant level allowing optimal metabolism. recently, a vacuolar malate transporter (arabidopsis thaliana tonoplast dicarboxylate transporter, attdt) was identified that did not correspond to the well-characterized vacuolar malate channel. we therefore hypothesized that a member of the aluminum-activate ... | 2007 | 18005230 |
| genomic resources for myzus persicae: est sequencing, snp identification, and microarray design. | the green peach aphid, myzus persicae (sulzer), is a world-wide insect pest capable of infesting more than 40 plant families, including many crop species. however, despite the significant damage inflicted by m. persicae in agricultural systems through direct feeding damage and by its ability to transmit plant viruses, limited genomic information is available for this species. | 2007 | 18021414 |
| one-step cloning approach for construction of agroinfectious begomovirus clones. | most begomoviruses have a bipartite genome containing two circular ssdna segments (dna-a and dna-b). routine infectious clone construction relies upon cloning of the whole genome, which is then subcloned as a tandem one-and-half or two genome- (containing two replication origins) cassette into a vector prior to agro-inoculation. the construction of cassettes containing two replication origins is, however, a time-consuming process. here an improved method for rapid construction of agroinfectious ... | 2008 | 18022703 |
| intracellular targeting of a hordeiviral membrane-spanning movement protein: sequence requirements and involvement of an unconventional mechanism. | the membrane-spanning protein tgbp3 is one of the three movement proteins (mps) of poa semilatent virus. tgbp3 is thought to direct other viral mps and genomic rna to peripheral bodies located in close proximity to plasmodesmata. we used the ectopic expression of green fluorescent protein-fused tgbp3 in epidermal cells of nicotiana benthamiana leaves to study the tgbp3 intracellular trafficking pathway. treatment with inhibitors was used to reveal that the targeting of tgbp3 to plasmodesmata doe ... | 2008 | 18032484 |
| replication-coupled packaging mechanism in positive-strand rna viruses: synchronized coexpression of functional multigenome rna components of an animal and a plant virus in nicotiana benthamiana cells by agroinfiltration. | flock house virus (fhv), a bipartite rna virus of insects and a member of the nodaviridae family, shares viral replication features with the tripartite brome mosaic virus (bmv), an rna virus that infects plants and is a member of the bromoviridae family. in bmv and fhv, genome packaging is coupled to replication, a widely conserved mechanism among positive-strand rna viruses of diverse origin. to unravel the events that modulate the mechanism of replication-coupled packaging, in this study, we h ... | 2008 | 18032497 |
| role of a gdsl lipase-like protein as sinapine esterase in brassicaceae. | the seeds of most members of the brassicaceae accumulate high amounts of sinapine (sinapoylcholine) that is rapidly hydrolyzed during early stages of seed germination. one of three isoforms of sinapine esterase activity (bnsce3) has been isolated from brassica napus seedlings and subjected to trypsin digestion and spectrometric sequencing. the peptide sequences were used to isolate bnsce3 cdna, which was shown to contain an open reading frame of 1170 bp encoding a protein of 389 amino acids, inc ... | 2008 | 18036206 |
| adaptation of the "in-gel release method" to n-glycome analysis of low-milligram amounts of material. | protein n-glycosylation is a post-translational modification which plays numerous crucial physiological roles. the n-glycan pattern varies depending on the species organs, tissues and even cell types and their respective physiological states. obtaining enough starting material from a particular cell type or tissue for n-glycan purification by conventional methods can, in certain cases, be very difficult. previously, a sensitive technique, the "in-gel release method" that allows the determination ... | 2007 | 18041037 |
| calcium efflux as a component of the hypersensitive response of nicotiana benthamiana to pseudomonas syringae. | using a model plant nicotiana benthamiana, we have demonstrated that initial calcium uptake in response to the hr (hypersensitive response)-causing pathogen pseudomonas syringae pv syringae 61 is followed by net calcium efflux initiated at about 12 h after the bacterial challenge and sustained for at least 48 h. our data suggest that calcium not only acts as an important second messenger in the activation of resistance responses but may also be a downstream mediator of later cell death accelerat ... | 2008 | 18048411 |
| interaction between sgt1 and cytosolic/nuclear hsc70 chaperones regulates arabidopsis immune responses. | the conserved eukaryotic protein sgt1 (for suppressor of g2 allele of skp1) has characteristics of an hsp90 (for heat shock protein 90 kd) cochaperone and in plants regulates hormone responses and resistance gene-triggered immunity. we affinity-purified sgt1-interacting proteins from arabidopsis thaliana leaf extracts and identified by mass spectrometry cytosolic heat shock cognate 70 (hsc70) chaperones as the major stable sgt1 interactors. arabidopsis sgt1a and sgt1b proteins associate with hsc ... | 2007 | 18065690 |
| biosynthesis of circular proteins in plants. | plant cyclotides are a large family of naturally occurring circular proteins that are produced from linear precursors containing one, two or three cyclotide domains. the mechanism of excision of the cyclotide domains and ligation of the free n- and c-termini to produce the circular peptides has not been elucidated. here, we investigate production of the prototypic cyclotide kalata b1 from the precursor oak1 from the african plant oldenlandia affinis. immunoprecipitation experiments and maldi-tof ... | 2008 | 18086282 |
| partial demethylation of oligogalacturonides by pectin methyl esterase 1 is required for eliciting defence responses in wild strawberry (fragaria vesca). | in addition to the role of the cell wall as a physical barrier against pathogens, some of its constituents, such as pectin-derived oligogalacturonides (oga), are essential components for elicitation of defence responses. to investigate how modifications of pectin alter defence responses, we expressed the fruit-specific fragaria x ananassa pectin methyl esterase fape1 in the wild strawberry fragaria vesca. pectin from transgenic ripe fruits differed from the wild-type with regard to the degree an ... | 2008 | 18088306 |
| pathogenicity of a naturally occurring recombinant dna satellite associated with tomato yellow leaf curl china virus. | recombinant dna beta molecules (recdna-abeta) comprising parts of dna a and dna beta associated with tomato yellow leaf curl china virus (tylccnv) have been identified in naturally infected tobacco plants. several examples of the recombinant dna have been cloned and characterized by sequence analysis. all are approximately half the size of tylccnv genomic dna, and all contain the betac1 gene and the a-rich region from tylccnv dna beta as well as intergenic region sequences and the 5' terminus of ... | 2008 | 18089755 |
| regulation of rice nadph oxidase by binding of rac gtpase to its n-terminal extension. | reactive oxygen species (ros) produced by nadph oxidase play critical roles in various cellular activities, including plant innate immunity response. in contrast with the large multiprotein nadph oxidase complex of phagocytes, in plants, only the homologs of the catalytic subunit gp91phox and the cytosolic regulator small gtpase rac are found. plant homologs of the gp91phox subunit are known as rboh (for respiratory burst oxidase homolog). although numerous rboh have been isolated in plants, the ... | 2007 | 18156215 |
| salicylic acid and systemic acquired resistance play a role in attenuating crown gall disease caused by agrobacterium tumefaciens. | we investigated the effects of salicylic acid (sa) and systemic acquired resistance (sar) on crown gall disease caused by agrobacterium tumefaciens. nicotiana benthamiana plants treated with sa showed decreased susceptibility to agrobacterium infection. exogenous application of sa to agrobacterium cultures decreased its growth, virulence, and attachment to plant cells. using agrobacterium whole-genome microarrays, we characterized the direct effects of sa on bacterial gene expression and showed ... | 2008 | 18156296 |
| cis- and trans-acting functions of brome mosaic virus protein 1a in genomic rna1 replication. | rna viruses employ a combination of mechanisms to regulate their gene expression and replication. brome mosaic virus (bmv) is a tripartite positive-strand rna virus used to study the requirements for virus infection. bmv genomic rna1 encodes protein 1a, which contains a methyltransferase (mt) domain and a helicase domain that are required for replication. 1a forms a complex with the 2a rna-dependent rna polymerase for the replication and transcription of all bmv rnas. rna1 expressed with 2a from ... | 2008 | 18160434 |
| characterization of a defective rna derived from rna 3 of the y strain of cucumber mosaic virus. | a defective (d) rna 3 naturally generated from the y strain of cucumber mosaic virus (cmv-y) was characterized using a biologically active cdna clone. sequencing of the clone revealed that the d rna 3, named d rna 3yalpha, was derived from cmv-y rna 3 and contained a 10 nt deletion in the 5' untranslated region and a 162 nt deletion within the 3a open reading frame. co-inoculation of d rna 3yalpha with cmv-y derived from in vitro transcripts facilitated propagation of cmv-y containing d rna 3yal ... | 2008 | 18175038 |
| infectivity of the cloned components of a begomovirus: dna beta complex causing chilli leaf curl disease in india. | the full-length genome of a begomovirus and its cognate dna-beta satellite component associated with chilli leaf curl disease (chlcd), originating from varanasi, india, were cloned. sequence analysis revealed that the viral genome (ef190217) is 2,750 bp and the dna-beta satellite (ef190215) is 1,361 bp in length. agroinoculation with partial tandem repeats of the viral genome along with the satellite induced symptoms typical of chlcd in chilli and nicotiana benthamiana. however, symptom expressi ... | 2008 | 18175042 |
| myosin xi-k is required for rapid trafficking of golgi stacks, peroxisomes, and mitochondria in leaf cells of nicotiana benthamiana. | a prominent feature of plant cells is the rapid, incessant movement of the organelles traditionally defined as cytoplasmic streaming and attributed to actomyosin motility. we sequenced six complete nicotiana benthamiana cdnas that encode class xi and class viii myosins. phylogenetic analysis indicates that these two classes of myosins diverged prior to the radiation of green algae and land plants from a common ancestor and that the common ancestor of land plants likely possessed at least seven m ... | 2008 | 18178670 |
| a genomic map of viroid rna motifs critical for replication and systemic trafficking. | rna replication and systemic trafficking play significant roles in developmental regulation and host-pathogen interactions. viroids are the simplest noncoding eukaryotic rna pathogens and genetic units that are capable of autonomous replication and systemic trafficking and offer excellent models to investigate the role of rna structures in these processes. like other rnas, the predicted secondary structure of a viroid rna contains many loops and bulges flanked by double-stranded helices, the bio ... | 2008 | 18178767 |
| different subcellular localizations and functions of arabidopsis myosin viii. | myosins are actin-activated atpases that use energy to generate force and move along actin filaments, dragging with their tails different cargos. plant myosins belong to the group of unconventional myosins and arabidopsis myosin viii gene family contains four members: atm1, atm2, myosin viiia and myosin viiib. | 2008 | 18179725 |
| physiological function of ispe, a plastid mep pathway gene for isoprenoid biosynthesis, in organelle biogenesis and cell morphogenesis in nicotiana benthamiana. | isoprenoid biosynthesis in plants occurs by two independent pathways: the cytosolic mevalonate (mva) pathway and the plastidic methylerythritol phosphate (mep) pathway. in this study, we investigated the cellular effects of depletion of ispe, a protein involved in the mep pathway, using virus-induced gene silencing (vigs). the ispe gene is preferentially expressed in young tissues, and induced by light and methyl jasmonate. the gfp fusion protein of ispe was targeted to chloroplasts. reduction o ... | 2008 | 18180879 |
| phenotypes and functional effects caused by various viral rna silencing suppressors in transgenic nicotiana benthamiana and n. tabacum. | rna silencing suppressor genes derived from six virus genera were transformed into nicotiana benthamiana and n. tabacum plants. these suppressors were p1 of rice yellow mottle virus (rymv), p1 of cocksfoot mottle virus, p19 of tomato bushy stunt virus, p25 of potato virus x, hcpro of potato virus y (strain n), 2b of cucumber mosaic virus (strain kin), and ac2 of african cassava mosaic virus (acmv). hcpro caused the most severe phenotypes in both nicotiana spp. ac2 also produced severe effects in ... | 2008 | 18184062 |
| biological activity of transcripts from cdna of pelargonium line pattern virus. | a set of cdnas of pelargonium line pattern virus (plpv) was assembled under the control of t7 rna polymerase promoter and ligated into the plasmid puc18. transcripts synthesized in vitro from cdna were infectious on chenopodium quinoa according to locally induced lesions and hybridization assay. the biological activity of the viral transcripts was particularly sensitive to the short 3' terminus extensions, whereas inclusion of the 3 extra bases at the 5' terminus did not substantially affect the ... | 2007 | 18197735 |
| recognition of the hyaloperonospora parasitica effector atr13 triggers resistance against oomycete, bacterial, and viral pathogens. | phytopathogenic oomycetes cause some of the most devastating diseases affecting agricultural crops. hyaloperonospora parasitica is a native oomycete pathogen of arabidopsis and is related to other oomycete phytopathogens that include several species of phytophthora, including the causal agent of potato late blight. recently, four oomycete effector genes have been isolated, and several oomycete genomes have been sequenced. we have developed an efficient and genetically amenable system to test put ... | 2008 | 18198274 |
| class viii myosins are required for plasmodesmatal localization of a closterovirus hsp70 homolog. | the hsp70 homolog (hsp70h) of beet yellows virus (byv) functions in virion assembly and cell-to-cell movement and is autonomously targeted to plasmodesmata in association with the actomyosin motility system (a. i. prokhnevsky, v. v. peremyslov, and v. v. dolja, j. virol. 79:14421-14428, 2005). myosins are a diverse category of molecular motors that possess a motor domain and a tail domain involved in cargo binding. plants have two classes of myosins, viii and xi, whose specific functions are poo ... | 2008 | 18199648 |
| salicylic acid production in response to biotic and abiotic stress depends on isochorismate in nicotiana benthamiana. | salicylic acid (sa) is an important signal involved in the activation of defence responses against abiotic and biotic stress. in tobacco, benzoic acid or glucosyl benzoate were proposed to be precursors of sa. this is in sharp contrast with studies in arabidopsis thaliana, where sa derives from isochorismate. we have determined the importance of isochorismate for sa biosynthesis in nicotiana benthamiana using virus-induced gene silencing of the isochorismate synthase (ics) gene. plants with sile ... | 2008 | 18201575 |
| overexpression of osisap8, a member of stress associated protein (sap) gene family of rice confers tolerance to salt, drought and cold stress in transgenic tobacco and rice. | we describe here the isolation and characterization of osisap8, a member of stress associated protein (sap) gene family from rice characterized by the presence of a20 and an1 type zinc finger domains. osisap8 is a multiple stress inducible gene, induced by various stresses, namely heat, cold, salt, desiccation, submergence, wounding, heavy metals as well as stress hormone abscisic acid. osisap8 protein fused to gfp was localized towards the periphery of the cells in the epidermal cells of infilt ... | 2008 | 18205020 |
| optimized cdna libraries for virus-induced gene silencing (vigs) using tobacco rattle virus. | abstract: | 2008 | 18211705 |
| nuclear targeting by fragmentation of the potato spindle tuber viroid genome. | transient expression of engineered reporter rnas encoding an intron-containing green fluorescent protein (gfp) from a potato virus x-based expression vector previously demonstrated the nuclear targeting capability of the 359 nucleotide potato spindle tuber viroid (pstvd) rna genome. to further delimit the putative nuclear-targeting signal, pstvd subgenomic fragments were embedded within the intron, and recombinant reporter rnas were inoculated onto nicotiana benthamiana plants. appearance of gre ... | 2008 | 18211806 |
| heat shock 70 protein interaction with turnip mosaic virus rna-dependent rna polymerase within virus-induced membrane vesicles. | tandem affinity purification was used in arabidopsis thaliana to identify cellular interactors of turnip mosaic virus (tumv) rna-dependent rna polymerase (rdrp). the heat shock cognate 70-3 (hsc70-3) and poly(a)-binding (pabp) host proteins were recovered and shown to interact with the rdrp in vitro. as previously shown for pabp, hsc70-3 was redistributed to nuclear and membranous fractions in infected plants and both rdrp interactors were co-immunoprecipitated from a membrane-enriched extract u ... | 2008 | 18222516 |
| molecular variation of satellite dna beta molecules associated with malvastrum yellow vein virus and their role in pathogenicity. | previous studies have found that the diversity of begomovirus-associated dna beta satellites is related to host and geographical origin. in this study, we have cloned and sequenced 20 different isolates of dna beta molecules associated with malvastrum yellow vein virus (myvv) isolated from malvastrum coromandelianum plants in different geographical locations of yunnan province, china. analyses of their molecular variation indicate that the satellites are clustered together according to their geo ... | 2008 | 18245261 |
| tobacco mosaic virus (tmv) replicase and movement protein function synergistically in facilitating tmv spread by lateral diffusion in the plasmodesmal desmotubule of nicotiana benthamiana. | virus spread through plasmodesmata (pd) is mediated by virus-encoded movement proteins (mps) that modify pd structure and function. the mp of tobacco mosaic virus ((tmv)mp) is an endoplasmic reticulum (er) integral membrane protein that binds viral rna (vrna), forming a vrna:mp:er complex. it has been hypothesized that (tmv)mp causes pd to dilate, thus potentiating a cytoskeletal mediated sliding of the vrna:mp:er complex through pd; in the absence of mp, by contrast, the er cannot move through ... | 2008 | 18257683 |
| the expression of a mountain cedar allergen comparing plant-viral apoplastic and yeast expression systems. | jun a 3, a major allergenic protein in mountain cedar pollen, causes seasonal allergic rhinitis in hypersensitive individuals. recombinant jun a 3 was expressed in nicotiana benthamiana interstitial fluid (300 microg/g leaf material) and pichia pastoris (100 microg/ml media). polyclonal anti-jun a 3 and ige antibodies from the sera of allergic patients both reacted with the recombinant protein. of the two systems, recombinant protein from the plant apoplast contained fewer contaminating proteins ... | 2008 | 18270658 |
| expression of the rabies virus nucleoprotein in plants at high-levels and evaluation of immune responses in mice. | transgenic plants have been employed successfully as a low-cost system for the production of therapeutically valuable proteins including antibodies, antigens and hormones. here, we report expression of a full-length nucleoprotein gene of rabies virus in transgenic tomato plants. the nucleoprotein was also transiently expressed in nicotiana benthamiana plants by agroinfiltration. in both cases, the nucleoprotein was expressed at high levels, 1-5% of total soluble protein in tomato and 45% in n. b ... | 2008 | 18270708 |
| supervirulent pseudorecombination and asymmetric synergism between genomic components of two distinct species of begomovirus associated with severe tomato leaf curl disease in india. | isolates of two distinct begomovirus species, the severe strain of the species tomato leaf curl new delhi virus (tomato leaf curl new delhi virus-[india:new delhi:severe:1992]; tolcndv-[in:nd:svr:92], bipartite) and the varanasi strain of the species tomato leaf curl gujarat virus (tomato leaf curl gujarat virus-[india:varanasi:2001]; tolcgv-[in:var:01], mono/bipartite) infect tomato (lycopersicon esculentum) and cause severe yield losses in northern india. this study investigated the infectivit ... | 2008 | 18272774 |
| the activity and isoforms of nadp-malic enzyme in nicotiana benthamiana plants under biotic stress. | the activity and presence of isoforms of nadp-dependent malic enzyme (nadp-me, ec 1.1.1.40) were studied in non-transgenic and transgenic nicotiana benthamiana plants containing potyviral gene for helper component protease (hc-pro) and in plants infected by potato virus y strain ntn (pvy(ntn)). no significant changes in enzyme activities and isoenzyme pattern were observed due to foreign gene introduction and pvy(ntn) infection. however, the activity and isoenzyme composition of nadp-me measured ... | 2007 | 18281746 |
| assessment of camv-mediated gene silencing and integration of camv into gm plants with a 35s rna promoter. | four gm plant species (arabidopsis thaliana, brassica napus, nicotiana benthamiana and n. tabacum), each expressing the gene encoding the jellyfish green fluorescent protein (gfp) regulated by the cauliflower mosaic virus (camv) 35s rna promoter, were assessed for the extent of transgene silencing and viral genome integration following infection by camv. the first three species are systemic hosts of camv, while n. tabacum is only a local host for a few strains of camv. a generalized systemic sil ... | 2008 | 18289501 |
| complete sequencing of potato virus x new strain genome and construction of viral vector for production of target proteins in plants. | the complete nucleotide sequence of the genome of a new potato virus x (pvx) strain tula isolated by us has been determined. based on comparison of the pvx tula nucleotide sequence with the sequences of 12 other pvx strains, this strain was assigned to the european cluster of pvx strains. phylogenetic analysis revealed the same phylogeny for both full genome sequences and nucleotide sequences of polymerase and coat protein genes, suggesting that the pvx evolution did not involve recombination be ... | 2008 | 18294128 |
| production of recombinant proteins in clonal root cultures using episomal expression vectors. | we have developed a fully contained system for expressing recombinant proteins that is based on clonal root cultures and episomal expression vectors. clonal root lines expressing green fluorescent protein (gfp) or human growth hormone were generated from nicotiana benthamiana leaves infected with the tobacco mosaic virus-based vector 30b after exposure to agrobacterium rhizogenes. these lines accumulated gfp at over 50 mg per kg fresh tissue, a level that is comparable with other plant productio ... | 2008 | 18306425 |
| an efficient plant viral expression system generating orally immunogenic norwalk virus-like particles. | virus-like particles (vlps) derived from enteric pathogens like norwalk virus (nv) are well suited to study oral immunization. we previously described stable transgenic plants that accumulate recombinant nv-like particles (rnvs) that were orally immunogenic in mice and humans. the transgenic approach suffers from long generation time and modest level of antigen accumulation. we now overcome these constraints with an efficient tobacco mosaic virus (tmv)-derived transient expression system using l ... | 2008 | 18325641 |
| generation of glyco-engineered nicotiana benthamiana for the production of monoclonal antibodies with a homogeneous human-like n-glycan structure. | a common argument against using plants as a production system for therapeutic proteins is their inability to perform authentic human n-glycosylation (i.e. the presence of beta1,2-xylosylation and core alpha1,3-fucosylation). in this study, rna interference (rnai) technology was used to obtain a targeted down-regulation of the endogenous beta1,2-xylosyltransferase (xylt) and alpha1,3-fucosyltransferase (fuct) genes in nicotiana benthamiana, a tobacco-related plant species widely used for recombin ... | 2008 | 18346095 |
| molecular cloning and characterization of wheat calreticulin (crt) gene involved in drought-stressed responses. | calreticulin (crt) is a highly conserved and ubiquitously expressed ca(2+)-binding protein in multicellular eukaryotes. crt plays a crucial role in many cellular processes including ca(2+) storage and release, protein synthesis, and molecular chaperone activity. to elucidate the function of crts in plant responses against drought, a main abiotic stress limiting cereal crop production worldwide, a full-length cdna encoding calreticulin protein namely tacrt was isolated from wheat (triticum aestiv ... | 2008 | 18349049 |
| the f-box protein acre189/acif1 regulates cell death and defense responses activated during pathogen recognition in tobacco and tomato. | virus-induced gene silencing identified the avr9/cf-9 rapidly elicited gene acre189 as essential for the cf-9- and cf-4-mediated hypersensitive response (hr) in nicotiana benthamiana. we report a role for acre189 in disease resistance in tomato (solanum lycopersicum) and tobacco (nicotiana tabacum). acre189 (herein renamed avr9/cf-9-induced f-box1 [acif1]) encodes an f-box protein with a leu-rich-repeat domain. acif1 is widely conserved and is closely related to f-box proteins regulating plant h ... | 2008 | 18375657 |
| conserved c-terminal motifs required for avirulence and suppression of cell death by phytophthora sojae effector avr1b. | the sequenced genomes of oomycete plant pathogens contain large superfamilies of effector proteins containing the protein translocation motif rxlr-deer. however, the contributions of these effectors to pathogenicity remain poorly understood. here, we show that the phytophthora sojae effector protein avr1b can contribute positively to virulence and can suppress programmed cell death (pcd) triggered by the mouse bax protein in yeast, soybean (glycine max), and nicotiana benthamiana cells. we ident ... | 2008 | 18390593 |
| regulatory network of microrna399 and pho2 by systemic signaling. | recently, we showed that microrna399s (mir399s) control inorganic phosphate (pi) homeostasis by regulating the expression of pho2 encoding a ubiquitin-conjugating e2 enzyme 24. arabidopsis (arabidopsis thaliana) plants overexpressing mir399 or the pho2 mutant overaccumulate pi in shoots. the association of pi translocation and coexpression of mir399s and pho2 in vascular tissues suggests their involvement in long-distance signaling. in this study, we used reciprocal grafting between wild-type an ... | 2008 | 18390805 |
| the arabidopsis class viii myosin atm2 is involved in endocytosis. | members of the class xi of the myosin superfamily comprising higher plant, actin-based molecular motors have been shown to be involved in peroxisome and golgi vesicle trafficking comparable to yeast and animal class v myosins. the tasks of the second class of myosins of higher plants, class viii, are unclear. in this study the class viii myosin atm2 from the model plant arabidopsis thaliana was selected for the examination of cargo specificity in vivo. fluorescent protein-fusion plasmid construc ... | 2008 | 18393384 |
| role of a geminivirus av2 protein putative protein kinase c motif on subcellular localization and pathogenicity. | virus-derived genes or genome fragments are increasingly being used to generate transgenic plants with resistance to plant viruses. there is need to rapidly investigate these genes in plants using transient expression prior to using them as transgenes since they may be pathogenic to plants. in this study, we investigated the av2 protein encoded by east african cassava mosaic cameroon virus, a virus associated with a cassava disease epidemic in western africa. for subcellular localization, av2 wa ... | 2008 | 18405995 |
| wolman disease/cholesteryl ester storage disease: efficacy of plant-produced human lysosomal acid lipase in mice. | lysosomal acid lipase (lal) is an essential enzyme that hydrolyzes triglycerides (tgs) and cholesteryl esters (ces) in lysosomes. genetic lal mutations lead to wolman disease (wd) and cholesteryl ester storage disease (cesd). an lal-null (lal(-/-)) mouse model resembles human wd/cesd with storage of ces and tgs in multiple organs. human lal (hlal) was expressed in nicotiana benthamiana using the geneware expression system (g-hlal). purified g-hlal showed mannose receptor-dependent uptake into ma ... | 2008 | 18413899 |
| functional analysis of bipartite begomovirus coat protein promoter sequences. | we demonstrate that the al2 gene of cabbage leaf curl virus (calcuv) activates the cp promoter in mesophyll and acts to derepress the promoter in vascular tissue, similar to that observed for tomato golden mosaic virus (tgmv). binding studies indicate that sequences mediating repression and activation of the tgmv and calcuv cp promoter specifically bind different nuclear factors common to nicotiana benthamiana, spinach and tomato. however, chromatin immunoprecipitation demonstrates that tgmv al2 ... | 2008 | 18430450 |
| multicolor fluorescence imaging of leaves--a useful tool for visualizing systemic viral infections in plants. | multicolor fluorescence induced by uv light is a sensitive and specific tool that may be used to provide information about the primary and secondary metabolism of plants by monitoring signals of the chlorophyll fluorescence (chl-f) and blue-green fluorescence (bgf), respectively. we have followed the systemic infection of nicotiana benthamiana plants with the pepper mild mottle virus (pmmov) by means of a multicolor fluorescence-imaging system, to detect differences between two strains of pmmov ... | 2008 | 18435702 |
| identification of a xylogalacturonan xylosyltransferase involved in pectin biosynthesis in arabidopsis. | xylogalacturonan (xga) is a class of pectic polysaccharide found in plant cell walls. the arabidopsis thaliana locus at5g33290 encodes a predicted type ii membrane protein, and insertion mutants of the at5g33290 locus had decreased cell wall xylose. immunological studies, enzymatic extraction of polysaccharides, monosaccharide linkage analysis, and oligosaccharide mass profiling were employed to identify the affected cell wall polymer. pectic xga was reduced to much lower levels in mutant than i ... | 2008 | 18460606 |
| quantifying fungal infection of plant leaves by digital image analysis using scion image software. | a digital image analysis method previously used to evaluate leaf color changes due to nutritional changes was modified to measure the severity of several foliar fungal diseases. images captured with a flatbed scanner or digital camera were analyzed with a freely available software package, scion image, to measure changes in leaf color caused by fungal sporulation or tissue damage. high correlations were observed between the percent diseased leaf area estimated by scion image analysis and the per ... | 2008 | 18466990 |
| effects of viral silencing suppressors on tobacco ringspot virus infection in two nicotiana species. | this study investigated the effects of silencing suppressors derived from six different viruses (p1, p19, p25, hcpro, ac2 and 2b), expressed in transgenic nicotiana tabacum and nicotiana benthamiana plants, on the infection pattern of tobacco ringspot virus (trsv) potato calico strain. in n. benthamiana, this virus produced an initial infection with severe systemic symptoms, but the infection was strongly reduced within a few weeks as the plant recovered from the infection. p25 and hcpro silenci ... | 2008 | 18474567 |
| generation and characterization of a recombinant antibody fragment that binds to the coat protein of grapevine leafroll-associated virus 3. | pathogen-specific recombinant antibodies have been used to characterize pathogen infections and to engineer resistance in crops. we selected a single-chain antibody fragment (scfvlr3cp-1) specific for the coat protein of grapevine leafroll-associated virus 3 (glrav-3), one of the agents of grapevine leafroll (glr) disease, from a phage display library. the antibody binds specifically to the entire length of glrav-3 particles and has a high binding affinity value (k(d)) of 42 nm. the amino acid m ... | 2008 | 18478181 |
| rna-directed rna polymerase3 from nicotiana attenuata is required for competitive growth in natural environments. | sde1/sgs2/rdr6, a putative rna-directed rna polymerase, maintains plant defenses against viruses in arabidopsis (arabidopsis thaliana) and nicotiana benthamiana, but its function has not been examined in natural habitats or with respect to other ecological stresses. we evaluated the organismic-level function of this gene (nardr3) in an ecological model species, nicotiana attenuata, by transforming plants to stably silence rdr3 (irrdr3). minor morphological changes (elongated leaves and reduced l ... | 2008 | 18480375 |
| symptomless infectious cdna clone of a norwegian isolate of poinsettia mosaic virus. | an infectious cdna clone of a norwegian isolate of poinsettia mosaic virus (pnmv) was generated. it consisted of 6,098 nucleotides and encoded a polyprotein of 219.5 kda. sequence comparisons indicated that this isolate shared 98.6% (nucleotide) and 97.1% (amino acid) identity with the previously sequenced isolate from germany. rna transcripts derived from this cdna were infectious in nicotiana benthamiana. however, plants did not present typical pnmv symptoms. furthermore, rna transcripts from ... | 2008 | 18504521 |
| three heterologous proteins simultaneously expressed from a chimeric potyvirus: infectivity, stability and the correlation of genome and virion lengths. | three heterologous proteins were simultaneously expressed from a chimeric potyvirus potato virus a (pva) in nicotiana benthamiana. the genes for green fluorescent protein of aequoria victoriae ("g"; 714 nucleotides, nt), luciferase of renilla reniformis ("l", 933 nt) and beta-glucuronidase of escherichia coli ("u", 1806 nt) were inserted into the engineered cloning sites at the n-terminus of the p1 domain, the junction of p1 and helper component protein (hc-pro), and the junction of the viral re ... | 2008 | 18511144 |
| physiological function of nbranbp1 in nicotiana benthamiana. | this study addresses the physiological functions of the ran-binding protein homolog nbranbp1 in nicotiana benthamiana. virus-induced gene silencing (vigs) of nbranbp1 caused stunted growth, leaf yellowing, and abnormal leaf morphology. the nbranbp1 gene was constitutively expressed in diverse tissues and an nbranbp1:gfp fusion protein was primarily localized to the nuclear rim and the cytosol. bifc analysis revealed in vivo interaction between nbranbp1 and nbran1 in the nuclear envelope and the ... | 2008 | 18511878 |
| increased organophosphate scavenging in a butyrylcholinesterase mutant. | nicotiana benthamiana plant lines expressing a reengineered human butyrylcholinesterase (bche) with enhanced cocaine hydrolase activity were created. subsequent purification and biochemical analysis revealed that compared to wild-type butyrylcholinesterase, the cocaine hydrolase displayed increased affinity to the organophosphate (op) pesticides paraoxon (6.8 4x 10(-10)m vs. 1.11 x 10(-8)m) and malaoxon (9.81 x 10(-8)m vs. 5.99 x 10(-7)m). furthermore, the cocaine hydrolase retained identical an ... | 2008 | 18514178 |
| mapk signaling regulates nitric oxide and nadph oxidase-dependent oxidative bursts in nicotiana benthamiana. | nitric oxide (no) and reactive oxygen species (ros) act as signals in innate immunity in plants. the radical burst is induced by inf1 elicitin, produced by the oomycete pathogen phytophthora infestans. no associated1 (noa1) and nadph oxidase participate in the radical burst. here, we show that mitogen-activated protein kinase (mapk) cascades mek2-sipk/ntf4 and mek1-ntf6 participate in the regulation of the radical burst. no generation was induced by conditional activation of sipk/ntf4, but not b ... | 2008 | 18515503 |