Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| synergism of a dna and an rna virus: enhanced tissue infiltration of the begomovirus abutilon mosaic virus (abmv) mediated by cucumber mosaic virus (cmv). | replication of the begomovirus abutilon mosaic virus (abmv) is restricted to phloem nuclei, generating moderate levels of virus dna. co-infection with cucumber mosaic virus (cmv) evidently increased abmv titers in nicotiana benthamiana, tobacco, and tomato, resulting in synergistic symptom enhancement. in situ hybridization revealed that in double-infected leaves an increased number of nuclei contained elevated amounts of abmv. additionally, the begomoviral phloem-limitation was broken. whereas ... | 2007 | 16959287 |
| methods for effective real-time rt-pcr analysis of virus-induced gene silencing. | we applied real-time rt-pcr to the analysis of tobacco rattle virus (trv)-mediated virus-induced gene silencing (vigs) of the phytoene desaturase (pds) gene in nicotiana benthamiana and tomato. using a combination of direct measurement and mathematical assessment, we evaluated three plant genes, ubiquitin (ubi3), elongation factor-1 alpha (ef-1), and actin, for use as internal reference transcripts and found that ef-1 and ubi3 were least variable under our experimental conditions. primer sets de ... | 2006 | 16959330 |
| the c-terminal half of phytophthora infestans rxlr effector avr3a is sufficient to trigger r3a-mediated hypersensitivity and suppress inf1-induced cell death in nicotiana benthamiana. | the rxlr cytoplasmic effector avr3a of phytophthora infestans confers avirulence on potato plants carrying the r3a gene. two alleles of avr3a encode secreted proteins that differ in only three amino acid residues, two of which are in the mature protein. avirulent isolates carry the avr3a allele, which encodes avr3aki (containing amino acids c19, k80 and i103), whereas virulent isolates express only the virulence allele avr3a, encoding avr3aem (s19, e80 and m103). only the avr3aki protein is reco ... | 2006 | 16965554 |
| cocksfoot mottle virus p1 suppresses rna silencing in nicotiana benthamiana and nicotiana tabacum. | the sobemovirus genome consists of positive sense, single-stranded polycistronic rna. the 5'-terminal orf, encoding the protein p1, is its most variable region. sobemoviral p1 has been described as dispensable for replication but indispensable for systemic infection. the p1 of rice yellow mottle virus-nigerian isolate (rymv-n) is the only rna silencing suppressor reported for sobemoviruses until now. using an agrobacterium-mediated transient assay, we demonstrate here that p1 of cocksfoot mottle ... | 2007 | 16971015 |
| comparison of several nicotiana species as hosts for high-scale agrobacterium-mediated transient expression. | agrobacterium-mediated transient expression may be regarded as a promising method for inexpensive large-scale production of recombinant proteins. we optimized the protocol of transient expression in nicotiana benthamiana and compared six australian species of nicotiana as hosts for transient expression. the transient expression of gfp under 35s camv promoter was observed in all species tested, although the gfp content in leaves of n. benthamiana, n. exigua, and n. excelsior was significantly hig ... | 2007 | 16983697 |
| nicotiana (nicotiana tobaccum, nicotiana benthamiana). | agrobacterium-mediated transformation of nicotiana species, namely, nicotiana tobaccum and nicotiana benthamiana, using leaf disks as the target explant has provided the plant community with a valuable tool for rapid evaluation of transgenes in higher plants. this protocol has a number of desirable attributes: readily available explant material, high efficiency, and a relatively quick turnaround time. the in vitro regeneration scheme of the leaf disks is prolific and follows an indirect organoge ... | 2006 | 16988341 |
| transgenes consisting of a dsrna of an rnai suppressor plus the 3' utr provide resistance to citrus tristeza virus sequences in nicotiana benthamiana but not in citrus. | in an attempt to utilize post-transcriptional gene silencing (ptgs) as a means to impart resistance against citrus tristeza virus (ctv) into citrus plants, the p23 + 3'utr sequence (p23u) of the vt strain of ctv was engineered to fold into a double-stranded (ds) rna structure. the resulting construct (p23ui) was introduced into nicotiana benthamiana and alemow (citrus macrophylla) plants by agrobacterium-mediated transformation. transgenic p23ui- n. benthamiana were resistant to infection with a ... | 2006 | 16991003 |
| sequence analysis of a "true" chalcone synthase (chs_h1) oligofamily from hop (humulus lupulus l.) and pap1 activation of chs_h1 in heterologous systems. | screening of a cdna library of the hop cv. osvald's 72 and genomic cloning were used to isolate members of an oligofamily of chs_h1 genes that codetermine the biosynthesis of prenylated chalcones known to be valuable medicinal compounds present in hop (humulus lupulus l.). chs_h1 oligofamily members showed more than 99% and 98% identity on nucleotide and amino acid levels, respectively, and retained all conserved amino acids that form the catalytic center characteristic for "true" chalcone synth ... | 2006 | 17002429 |
| in vivo packaging of brome mosaic virus rna3, but not rnas 1 and 2, is dependent on a cis-acting 3' trna-like structure. | the four encapsidated rnas of brome mosaic virus (bmv; b1, b2, b3, and b4) contain a highly conserved 3' 200-nucleotide (nt) region encompassing the trna-like structure (tls) which is required for packaging in vitro (y. g. choi, t. w. dreher, and a. l. n. rao, proc. natl. acad. sci. usa 99:655-660, 2002). to validate these observations in vivo, we performed packaging assays using agrobacterium-mediated transient expression of rnas and coat protein (cp) (p. annamalai and a. l. n. rao, virology 33 ... | 2007 | 17005656 |
| rna silencing suppression by a second copy of the p1 serine protease of cucumber vein yellowing ipomovirus, a member of the family potyviridae that lacks the cysteine protease hcpro. | the p1 protein of viruses of the family potyviridae is a serine proteinase, which is highly variable in length and sequence, and its role in the virus infection cycle is not clear. one of the proposed activities of p1 is to assist hcpro, the product that viruses of the genus potyvirus use to counteract antiviral defense mediated by rna silencing. indeed, an hcpro-coding region is present in all the genomes of members of the genera potyvirus, rymovirus, and tritimovirus that have been sequenced. ... | 2006 | 17005683 |
| packaging of brome mosaic virus subgenomic rna is functionally coupled to replication-dependent transcription and translation of coat protein. | in brome mosaic virus (bmv), genomic rna1 (gb1) and rna2 (gb2), encoding the replication factors, are packaged into two separate virions, whereas genomic rna3 (gb3) and its subgenomic coat protein (cp) mrna (sgb4) are copackaged into a third virion. in vitro assembly assays performed between a series of deletion variants of sgb4 and wild-type (wt) cp subunits demonstrated that packaging of sgb4 is independent of sequences encoding the cp open reading frame. to confirm these observations in vivo ... | 2006 | 17005687 |
| expression of bacterial biphenyl-chlorobiphenyl dioxygenase genes in tobacco plants. | optimized plant-microbe bioremediation processes in which the plant initiates the metabolism of xenobiotics and releases the metabolites in the rhizosphere to be further degraded by the rhizobacteria is a promising alternative to restore contaminated sites in situ. however, such processes require that plants produce the metabolites that bacteria can readily oxidize. the biphenyl dioxygenase is the first enzyme of the bacterial catabolic pathway involved in the degradation of polychlorinated biph ... | 2007 | 17006888 |
| identification of plant cytoskeleton-interacting proteins by screening for actin stress fiber association in mammalian fibroblasts. | taking advantage of the high conservation of the cytoskeleton building blocks actin and tubulin between plant and animal kingdoms, we developed a functional genomic screen for the isolation of new plant cytoskeleton-binding proteins that uses a mammalian cell expression system. a yellow fluorescent protein (yfp)-fusion cdna library from arabidopsis was inserted into rat fibroblasts and screened for fluorescent chimeras localizing to cytoskeletal structures. the high-throughput screen was perform ... | 2006 | 17010111 |
| aconitase plays a role in regulating resistance to oxidative stress and cell death in arabidopsis and nicotiana benthamiana. | in animals, aconitase is a bifunctional protein. when an iron-sulfur cluster is present in its catalytic center, aconitase displays enzymatic activity; when this cluster is lost, it switches to an rna-binding protein that regulates the translatability or stability of certain transcripts. to investigate the role of aconitase in plants, we assessed its ability to bind mrna. recombinant aconitase failed to bind an iron responsive element (ire) from the human ferritin gene. however, it bound the 5' ... | 2007 | 17013749 |
| an eif4e allele confers resistance to an uncapped and non-polyadenylated rna virus in melon. | the characterization of natural recessive resistance genes and virus-resistant mutants of arabidopsis have implicated translation initiation factors of the 4e family [eif4e and eif(iso)4e] as susceptibility factors required for virus multiplication and resistance expression. to date, viruses controlled by these genes mainly belong to the family potyviridae. melon necrotic spot virus (mnsv) belongs to the family tombusviridae (genus carmovirus) and is an uncapped and non-polyadenylated rna virus. ... | 2006 | 17026540 |
| production of plum pox virus hc-pro functionally active for aphid transmission in a transient-expression system. | potyviruses are non-persistently transmitted by aphid vectors with the assistance of a viral accessory factor known as helper component (hc-pro), a multifunctional protein that is also involved in many other essential processes during the virus infection cycle. a transient agrobacterium-mediated expression system was used to produce plum pox virus (ppv) hc-pro in nicotiana benthamiana leaves from constructs that incorporated the 5' region of the genome, yielding high levels of hc-pro in agroinfi ... | 2006 | 17030878 |
| lotus japonicus nodulation requires two gras domain regulators, one of which is functionally conserved in a non-legume. | a new nodulation-defective mutant of lotus japonicus does not initiate nodule cortical cell division in response to mesorhizobium loti, but induces root hair deformation, nod factor-induced calcium spiking, and mycorrhization. this phenotype, together with mapping data, suggested that the mutation could be in the ortholog of the medicago truncatula nsp1 gene (mtnsp1). the sequence of the orthologous gene (ljnsp1) in the l. japonicus mutant (ljnsp1-1) revealed a mutation causing a premature stop ... | 2006 | 17071642 |
| functional expression of the cotton gibberellic acid oxidase homologous gene ghga20ox1 in tobacco. | to determine the physiological function of ghga20ox1, a homologous gene of ga 20-oxidase from elongating cotton fibers, we expressed this gene ectopically in nicotiana benthamiana. reverse transcription-pcr analysis showed that the ghga20ox1 gene was expressed in the transgenic plants at various levels. it was demonstrated that overexpression of ghga20ox1 enhanced preferentially the ga(4+7) biosynthesis in n. benthamiana and conferred ga-overproduction characters to transformants. the extent of ... | 2006 | 17075180 |
| visualization of the interaction between the precursors of vpg, the viral protein linked to the genome of turnip mosaic virus, and the translation eukaryotic initiation factor iso 4e in planta. | the rna genome of turnip mosaic virus is covalently linked at its 5' end to a viral protein known as vpg. this protein binds to the translation eukaryotic initiation factor iso 4e [eif(iso)4e]. this interaction has been shown to be important for virus infection, although its exact biological function(s) has not been elucidated. in this study, we investigated the subcellular site of the vpg-eif(iso)4e interaction using bimolecular fluorescence complementation (bifc). as a first step, eif(iso)4e, ... | 2007 | 17079311 |
| arabidopsis samt1 defines a plastid transporter regulating plastid biogenesis and plant development. | s-adenosylmethionine (sam) is formed exclusively in the cytosol but plays a major role in plastids; sam can either act as a methyl donor for the biogenesis of small molecules such as prenyllipids and macromolecules or as a regulator of the synthesis of aspartate-derived amino acids. because the biosynthesis of sam is restricted to the cytosol, plastids require a sam importer. however, this transporter has not yet been identified. here, we report the molecular and functional characterization of a ... | 2006 | 17098813 |
| tomato yellow spot virus, a tomato-infecting begomovirus from brazil with a closer relationship to viruses from sida sp., forms pseudorecombinants with begomoviruses from tomato but not from sida. | geminiviruses are characterized by a circular, single-stranded dna genome and twinned icosahedral particles. begomoviruses (whitefly-transmitted geminiviruses) are a major constraint to crop production worldwide. in brazil, tomato-infecting begomoviruses emerged as serious pathogens over the last 10 years, due to the introduction of a new biotype of the insect vector. tomato yellow spot virus (toysv) is a newly described begomovirus originally isolated from tomato, but phylogenetically closer to ... | 2006 | 17098986 |
| engineering and expression of the intracellular domain of insulinoma-associated tyrosine phosphatase (ia-2ic), a type 1 diabetes autoantigen, in plants. | we have produced the recombinant intracellular domain of human ia-2 (ia-2ic), a diabetes-associated autoantigen, in plants. this was achieved by transient expression using agroinfiltration of nicotiana benthamiana plants. the resulting plant-derived ia-2ic had the expected size, reacted with polyclonal and monoclonal antibodies specific to human ia-2ic and competitively inhibited radiolabeled ia-2ic in an immunoprecipitation assay. the expression level of recombinant ia-2ic was estimated to be 0 ... | 2007 | 17103024 |
| silencing of chaperonin 21, that was differentially expressed in inflorescence of seedless and seeded grapes, promoted seed abortion in tobacco and tomato fruits. | vitis vinifera l. cv. 'thompson seedless' presents a type of stenospermocarpy in grape where fertilization occurs but seeds abort and fail to develop. to unravel the molecular basis for stenospermocarpy in grapes, subtractive hybridization was carried out in order to isolate differentially regulated genes that participate in the seedlessness machinery. two 'thompson' lines, a seeded and a seedless, were screened during different flower developmental stages. one of the genes, that was differentia ... | 2007 | 17103240 |
| production of sirna targeted against tylcv coat protein transcripts leads to silencing of its expression and resistance to the virus. | the coat protein (cp) of tomato yellow leaf curl virus (tylcv), encoded by the v1 gene, is the only known component of the viral capsid. in addition, the cp plays a role in the virus transport into the host cell nucleus where viral genes are replicated and transcribed. in this study, we analyzed the effect of small interfering double-stranded rnas (sirnas), derived from an intron-hairpin rna (ihprna) construct and targeting the v1 gene product, on cp accumulation. transient assays involving agro ... | 2007 | 17103242 |
| deletion and recombination events between the dna-a and dna-b components of indian cassava-infecting geminiviruses generate defective molecules in nicotiana benthamiana. | cloned dna-b components, belonging to the bipartite begomoviruses indian cassava mosaic virus (icmv) and sri lankan cassava mosaic virus (slcmv), family geminiviridae, when co-inoculated along with previously cloned dna-a components of the respective viruses onto the experimental host nicotiana benthamiana, generated defective dnas (def-dna) ranging in size from 549 to 1555 nucleotides. all the cloned def-dnas contained the common region (cr) as well as portions of either dna-a or dna-b and, in ... | 2007 | 17109983 |
| tomato chlorotic mottle virus is a target of rna silencing but the presence of specific short interfering rnas does not guarantee resistance in transgenic plants. | tomato chlorotic mottle virus (tocmov) is a begomovirus found widespread in tomato fields in brazil. tocmov isolate ba-se1 (tocmov-[ba-se1]) was shown to trigger the plant rna silencing surveillance in different host plants and, coinciding with a decrease in viral dna levels, small interfering rnas (sirnas) specific to tocmov-[ba-se1] accumulated in infected plants. although not homogeneously distributed, the sirna population in both infected nicotiana benthamiana and tomato plants represented t ... | 2006 | 17135316 |
| in planta akt2 subunits constitute a ph- and ca2+-sensitive inward rectifying k+ channel. | heterologous expression of plant genes in yeast and animal cells represents a common approach to study plant ion channels. when expressed in xenopus oocytes and cos cells the arabidopsis shaker-like k+ channel, akt2 forms a weakly voltage-dependent channel, blocked by ca2+ and protons. channels with these characteristics, however, were not found in akt2-expressing arabidopsis cell types. to understand this phenomenon, we employed agrobacterium-mediated transient transformation to functionally ch ... | 2007 | 17146665 |
| high-yield production of authentic human growth hormone using a plant virus-based expression system. | we describe here a high-yield transient expression system for the production of human growth hormone (hgh, or somatotropin) in transfected nicotiana benthamiana leaves. the system is based on a recently described plant virus-based modular expression vector [gleba, y., marillonnet, s. and klimyuk, v. (2004) engineering viral expression vectors for plants: the 'full virus' and the 'deconstructed virus' strategies. curr. opin. plant biol. 7, 182-188; marillonnet, s., giritch, a., gils, m., kandzia, ... | 2005 | 17147632 |
| distinct viral sequence elements are necessary for expression of tomato golden mosaic virus complementary sense transcripts that direct al2 and al3 gene expression. | transient expression studies using nicotiana benthamiana protoplasts and plants have identified sequences important for transcription of complementary sense rnas derived from tomato golden mosaic virus (tgmv) dna component a that direct expression of al2 and al3. transcription of two complementary sense rnas, initiating at nucleotides 1,935 (al1935) and 1,629 (al1629), is directed by unique sequences located upstream of each transcription initiation site. one element is located between 28 and 12 ... | 2006 | 17153924 |
| analysis of transitive rna silencing after grafting in transgenic plants with the coat protein gene of sweet potato feathery mottle virus. | we have previously reported the graft transmission of target specificity for rna silencing using transgenic nicotiana benthamiana plants expressing the coat protein gene (cp, including the 3' non-translated region) of sweet potato feathery mottle virus. transgenic plants carrying the 5' 200 and 400 bp regions of cp were newly produced. from these plants, two silenced and two non-silenced lines were selected to investigate the manifestation of transitive rna silencing by graft experiments. non-si ... | 2007 | 17160454 |
| the rna2 5' leader of blackcurrant reversion virus mediates efficient in vivo translation through an internal ribosomal entry site mechanism. | the 5' and 3' non-translated regions (ntrs) of mrnas of eukaryotes and their viruses often contain translational enhancers, including internal ribosomal entry sites (iress) comprised in the 5' leaders of many uncapped viral mrnas. blackcurrant reversion virus (brv) has a genome composed of two uncapped, polyadenylated rnas with relatively short 5' ntrs, almost devoid of secondary structure. in this work, a role of the rna2 5' ntr in translation was studied by using mono- and dicistronic photinus ... | 2007 | 17170462 |
| apple chlorotic leaf spot virus 50 kda movement protein acts as a suppressor of systemic silencing without interfering with local silencing in nicotiana benthamiana. | apple chlorotic leaf spot virus (aclsv) is the type species of the genus trichovirus and its single-stranded, plus-sense rna genome encodes a 216 kda protein (p216) involved in replication, a 50 kda movement protein (p50) and a 21 kda coat protein (cp). in this study, it was investigated whether these proteins might have rna silencing-suppressor activities by agrobacterium-mediated transient assay in the green fluorescent protein-expressing nicotiana benthamiana line 16c. the results indicated t ... | 2007 | 17170464 |
| optimization of agrobacterium-mediated transient assays of gene expression in lettuce, tomato and arabidopsis. | agrobacterium-mediated transient assays for gene function are increasingly being used as alternatives to genetic complementation and stable transformation. however, such assays are variable and not equally successful in different plant species. we analysed a range of genetic and physiological factors affecting transient expression following agroinfiltration, and developed a protocol for efficient and routine transient assays in several plant species. lettuce exhibited high levels of transient ex ... | 2005 | 17173625 |
| interaction network of proteins associated with abiotic stress response and development in wheat. | wheat is the most widely adapted crop to abiotic stresses and considered an excellent system to study stress tolerance in spite of its genetic complexity. recent studies indicated that several hundred genes are either up- or down-regulated in response to stress treatment. to elucidate the function of some of these genes, an interactome of proteins associated with abiotic stress response and development in wheat was generated using the yeast two-hybrid gal4 system and specific protein interaction ... | 2007 | 17211514 |
| accumulation of viroid-specific small rnas and increase in nucleolytic activities linked to viroid-caused pathogenesis. | strong viroid-caused pathogenesis was achieved in tomato cv. rutgers by biolistic transfer of severe or lethal potato spindle tuber viroid (pstvd) strains, while other tomato genotypes (e.g., moneymaker) were tolerant. with reciprocal hybrids between sensitive and tolerant genotypes, we show that plant depression dominates over tolerance. biolistic transfer of the most pathogenic pstvd strain as1 to nicotiana benthamiana, which is considered to be a symptomless pstvd host, led to a strong pathog ... | 2007 | 17214544 |
| genetic stability of recombinant potato virus x virus vectors presenting foreign epitopes. | we investigated the genetic stability of recombinant potato virus x vectors presenting beet necrotic yellow vein virus (bnyvv) epitopes. following n-terminal pvx coat protein (cp) fusion of the bnyvv epitopes, we inoculated nicotiana benthamiana plants with recombinant (r)pvx and carried out five serial passages through systemically-infected plants. rt-pcr investigation of the bnyvv epitope sequences revealed the accumulation of several point mutations and deletions, predominantly affecting posi ... | 2007 | 17216135 |
| silencing of nbbtf3 results in developmental defects and disturbed gene expression in chloroplasts and mitochondria of higher plants. | btf3 (betanac) was originally isolated as a general transcription factor required for rna polymerase ii-dependent transcription, and later found to be a beta-subunit of nascent-polypeptide-associated complex that has been implicated in regulating protein localization during translation. in this study, virus-induced gene silencing of nbbtf3 encoding a nicotiana benthamiana homolog of human btf3 caused leaf yellowing and abnormal leaf morphology without altering the overall growth of the plant. th ... | 2007 | 17216232 |
| stability of potato virus x expression vectors is related to insert size: implications for replication models and risk assessment. | we investigated the stability of expression constructs based on potato virus x (pvx) as a function of insert length. five different inserts ranging in length from 261 to 1,758 bp (human proinsulin, murine interleukin-10, hiv-1 nef, petunia expansin-1 and human gad65) were expressed using a pvx vector in nicotiana benthamiana plants for three sequential passages. using a competitive rt-pcr approach we demonstrated that insert-deletion could occur in the first infection cycle for all inserts, but ... | 2007 | 17216546 |
| early events in the pathogenicity of pseudomonas syringae on nicotiana benthamiana. | conserved microbial molecules known as pamps (pathogen-associated molecular patterns) elicit defence responses in plants through extracellular receptor proteins. one important pamp is the flagellin protein derived from motile bacteria. we show here that the solanaceous species nicotiana benthamiana perceives the flagellin proteins of both pathogenic and non-host species of pseudomonas syringae. the response to flagellin required a gene closely related to that encoding the arabidopsis thaliana fl ... | 2007 | 17217460 |
| molecular and functional analysis of phosphomannomutase (pmm) from higher plants and genetic evidence for the involvement of pmm in ascorbic acid biosynthesis in arabidopsis and nicotiana benthamiana. | phosphomannomutase (pmm) catalyzes the interconversion of mannose-6-phosphate and mannose-1-phosphate. however, systematic molecular and functional investigations on pmm from higher plants have hitherto not been reported. in this work, pmm cdnas were isolated from arabidopsis, nicotiana benthamiana, soybean, tomato, rice and wheat. amino acid sequence comparisons indicated that plant pmm proteins exhibited significant identity to their fungal and mammalian orthologs. in line with the similarity ... | 2007 | 17217471 |
| application of phi29 dna polymerase in identification and full-length clone inoculation of tomato yellow leaf curl thailand virus and tobacco leaf curl thailand virus. | tomato plants grown in greenhouses in thailand developed typical symptoms of a tomato yellow leaf curl thailand virus (tylcthv) infection. after confirmation by elisa, a phi29 dna polymerase approach was chosen for further molecular analysis of tylcthv. total dna purified from infected tomato leaves was subjected to rolling-circle amplification (rca) of dna-a and dna-b of tylcvthv. in addition, a new monopartite geminivirus with a putative recombinant background was identified by rca and tentati ... | 2007 | 17226067 |
| rnai-associated ssrna-specific ribonucleases in tombusvirus p19 mutant-infected plants and evidence for a discrete sirna-containing effector complex. | tomato bushy stunt virus (tbsv) and other tombusviruses encode a p19 protein (p19), which is a suppressor of rnai. wild-type tbsv or p19-defective mutants initially show a similar infection course in nicotiana benthamiana, but the absence of an active p19 results in viral rna degradation followed by recovery from infection. p19 homodimers sequester 21-nt virus-derived duplex sirnas, and it is thought that this prevents the programming of an antiviral rna-induced silencing complex to avoid viral ... | 2007 | 17244709 |
| identification and characterization of plant genes involved in agrobacterium-mediated plant transformation by virus-induced gene silencing. | genetic transformation of plant cells by agrobacterium tumefaciens represents a unique case of trans-kingdom sex requiring the involvement of both bacterial virulence proteins and plant-encoded proteins. we have developed in planta and leaf-disk assays in nicotiana benthamiana for identifying plant genes involved in agrobacterium-mediated plant transformation using virus-induced gene silencing (vigs) as a genomics tool. vigs was used to validate the role of several genes that are either known or ... | 2007 | 17249421 |
| a plasmodesmata-associated beta-1,3-glucanase in arabidopsis. | plasmodesmal conductivity is regulated in part by callose turnover, which is hypothesized to be determined by beta-1,3-glucan synthase versus glucanase activities. a proteomic analysis of an arabidopsis thaliana plasmodesmata (pd)-rich fraction identified a beta-1,3-glucanase as present in this fraction. the protein encoded by the putative plasmodesmal associated protein (ppap) gene, termed atbg_ppap, had previously been found to be a post-translationally modified glycosylphosphatidylinositol (g ... | 2007 | 17270015 |
| a wheat (triticum aestivum) protein phosphatase 2a catalytic subunit gene provides enhanced drought tolerance in tobacco. | multiple copies of genes encoding the catalytic subunit (c) of protein phosphatase 2a (pp2a) are commonly found in plants. for some of these genes, expression is up-regulated under water stress. the aim of this study was to investigate expression and characterization of tapp2ac-1 from triticum aestivum, and to evaluate the effects of tapp2ac-1 on nicotiana benthamiana in response to water stress. | 2007 | 17272305 |
| indirect activation of a plant nucleotide binding site-leucine-rich repeat protein by a bacterial protease. | nucleotide binding site-leucine-rich repeat (nbs-lrr) proteins mediate pathogen recognition in both mammals and plants. the molecular mechanisms by which pathogen molecules activate nbs-lrr proteins are poorly understood. here we show that rps5, a nbs-lrr protein from arabidopsis, is activated by avrpphb, a bacterial protease, via an indirect mechanism. when transiently expressed in nicotiana benthamiana leaves, full-length rps5 protein triggered programmed cell death, but only when coexpressed ... | 2007 | 17277084 |
| geminivirus pathogenicity protein c4 interacts with arabidopsis thaliana shaggy-related protein kinase atsketa, a component of the brassinosteroid signalling pathway. | beet curly top virus (bctv) c4 interacted with two members of the shaggy-related protein kinase family (atsketa and atskzeta) and a putative leucine-rich repeat receptor-like kinase (lrr-rlk) in a yeast two-hybrid assay. tomato golden mosaic virus (tgmv) ac4 also bound with similar efficiency to atsketa and atskzeta but was unable to interact with the lrr-rlk. bctv c4 interaction with atsketa was confirmed using an in vitro binding assay. the protein kinases were capable of autophosphorylation i ... | 2007 | 17280695 |
| anti-cancer activity of plant-produced hpv16 e7 vaccine. | the e7 oncoprotein from human papilloma virus (hpv) is an attractive candidate for anti-cancer vaccine development. in this study, we engineered hpv16 e7 coding sequence (wild type or mutagenized sequence, e7ggg) as fusions to beta-1,3-1,4-glucanase (lickm) of clostridium thermocellum and produced in nicotiana benthamiana plants using a transient expression system. target antigens were purified and evaluated in mice for their potential as prophylactic and therapeutic vaccine candidates. both fus ... | 2007 | 17280752 |
| immunogenicity of a subunit vaccine against bacillus anthracis. | the current approved vaccine against anthrax is based on protective antigen (pa) of bacillus anthracis, requires six injections over an 18-month period and has a known history of side effects. therefore, there is significant effort towards developing an improved vaccine against b. anthracis. here we separately engineered and expressed domain 4 of pa (pad4) and domain 1 of lethal factor (lfd1) as fusions to lichenase (lickm), a thermostable enzyme from clostridium thermocellum, and transiently ex ... | 2007 | 17280756 |
| a plant-produced plague vaccine candidate confers protection to monkeys. | production of vaccine antigens in plants has received considerable attention over the last decade. however, despite many antigens being expressed in plant systems, and promising efficacy data with rodent models, few vaccine candidates have advanced into studies in non-human primates or human clinical trials. here, we report on the transient expression of the f1 and lcrv antigens of yersinia pestis in nicotiana benthamiana. the antigens were expressed as fusions to the thermostable enzyme of clos ... | 2007 | 17287055 |
| improved expression of recombinant gfp using a replicating vector based on beet curly top virus in leaf-disks and infiltrated nicotiana benthamiana leaves. | recombinant green fluorescent protein (gfp) with a molecular mass of 29 kda was transiently expressed in agrobacterium-inoculated leaf-disks prepared from nicotiana benthamiana plants. expression of gfp from the cauliflower mosaic virus (camv) 35 s promoter within a replicating vector based on the geminivirus beet curly top virus (bctv) was more than 3 times higher than from a control, non-replicating vector. use of the cassava vein mosaic virus (csvmv) promoter in the bctv replicating vector in ... | 2007 | 17294255 |
| a begomovirus associated with ageratum yellow vein disease in indonesia: evidence for natural recombination between tomato leaf curl java virus and ageratum yellow vein virus-[java]. | a begomovirus (2747 nucleotides) and a satellite dna beta component (1360 nucleotides) have been isolated from ageratum conyzoides l. plants with yellow vein symptoms growing in java, indonesia. the begomovirus is most closely related to tomato leaf curl java virus (tolcjv) (91 and 98% in the total nucleotide and coat protein amino acid sequences, respectively), although the products of orfs c1 and c4 are more closely related to those of ageratum yellow vein virus-[java] (91 and 95% identity, re ... | 2007 | 17294343 |
| a chemically inducible cucumber mosaic virus amplicon system for expression of heterologous proteins in plant tissues. | a novel cucumber mosaic virus inducible viral amplicon (cmviva) expression system has been developed that allows for tightly regulated chemically inducible expression of heterologous genes in plant hosts. transient production of recombinant alpha(1)-antitrypsin (raat), a human blood protein, was demonstrated in nicotiana benthamiana leaves. the highest production levels were obtained by co-infiltrating leaves with agrobacterium tumefaciens cells containing cmviva carrying the aat gene and a. tum ... | 2006 | 17309729 |
| a high-throughput screen of cell-death-inducing factors in nicotiana benthamiana identifies a novel mapkk that mediates inf1-induced cell death signaling and non-host resistance to pseudomonas cichorii. | a high-throughput overexpression screen of nicotiana benthamiana cdnas identified a gene for a mitogen-activated protein kinase kinase (mapkk) as a potent inducer of the hypersensitive response (hr)-like cell death. nbmkk1 protein is localized to the nucleus, and the n-terminal putative mapk docking site of nbmkk1 is required for its function as a cell-death inducer. nbmkk1-mediated leaf-cell death was compromised in leaves where nbsipk expression was silenced by virus-induced gene silencing. a ... | 2007 | 17319846 |
| use of pentapeptide-insertion scanning mutagenesis for functional mapping of the plum pox virus helper component proteinase suppressor of gene silencing. | helper component proteinase (hc-pro) of plum pox virus is a multifunctional potyvirus protein that has been examined intensively. in addition to its involvement in aphid transmission, genome amplification and long-distance movement, it is also one of the better-studied plant virus suppressors of rna silencing. the first systematic analysis using pentapeptide-insertion scanning mutagenesis of the silencing suppression function of a potyvirus hc-pro is presented here. sixty-three in-frame insertio ... | 2007 | 17325375 |
| synergistic pathogenicity of a phloem-limited begomovirus and tobamoviruses, despite negative interference. | in contrast to previous observations on phloem-limited geminiviruses supported in movement andaccumulation by rna viruses such as cucumo- and tobamoviruses, tissue infiltration by abutilon mosaic virus (abmv) was enhanced by neither tobacco mosaic virus nor tomato mosaic virus (tomv) in two different hosts, nicotiana benthamiana and tomato. both tobamoviruses exerted a negative effect on the dna virus, resulting in a decrease in abmv accumulation and significantly reduced infectivity in n. benth ... | 2007 | 17325378 |
| dna abrasion onto plants is an effective method for geminivirus infection and virus-induced gene silencing. | geminiviruses belong to a rapidly growing group of plant pathogens that contribute to crop losses in tropical and subtropical areas of the world. geminivirus infection is a model for plant dna replication and virus/host interactions. geminiviruses are also used as vectors to induce silencing of endogenous genes in several plant species. a method was analyzed for inoculating geminiviruses using plasmid dna rubbed onto leaves in the presence of an abrasive (dna abrasion). although the use of dna a ... | 2007 | 17337069 |
| a functional genetic assay for nuclear trafficking in plants. | the receptor importin-alpha mediates the nuclear import of functionally diverse cargo proteins that contain arginine/lysine-rich nuclear localization signals (nlss). functional homologs of importin-alpha have been characterized in a wide range of species including yeast, human and plants. however, the differential cargo selectivity of plant importin-alpha homologs has not been established. to advance nuclear import studies conducted in plant cells, we have developed a method that allows importin ... | 2007 | 17346267 |
| the mi-1-mediated pest resistance requires hsp90 and sgt1. | the tomato (solanum lycopersicum) mi-1 gene encodes a protein with putative coiled-coil nucleotide-binding site and leucine-rich repeat motifs. mi-1 confers resistance to root-knot nematodes (meloidogyne spp.), potato aphids (macrosiphum euphorbiae), and sweet potato whitefly (bemisia tabaci). to identify genes required in the mi-1-mediated resistance to nematodes and aphids, we used tobacco rattle virus (trv)-based virus-induced gene silencing (vigs) to repress candidate genes and assay for nem ... | 2007 | 17351050 |
| rna-binding proteins that inhibit rna virus infection. | arrays of >5,000 saccharomyces cerevisiae proteins were screened to identify proteins that can preferentially bind a small rna hairpin that contains a clamped adenine motif (cam). a cam is required for the replication of brome mosaic virus (bmv), a plant-infecting rna virus that can replicate in s. cerevisiae. several hits were selected for further characterization in nicotiana benthamiana. pseudouridine synthase 4 (pus4) and the actin patch protein 1 (app1) modestly reduced bmv genomic plus-str ... | 2007 | 17360619 |
| functional analysis of the naturally recombinant dna-a of the bipartite begomovirus tomato chlorotic mottle virus. | all geminiviruses found in brazil belong to the begomovirus genus with a bipartite genome that is split between two genomic components, dna-a and dna-b. the dna-a of the bipartite begomovirus tocmov-[mg-bt] (tomato chlorotic mottle virus), however, possesses as a peculiar characteristic the capacity to systemically infect nicotiana benthamiana. here we further characterize this variant dna-a and show that it also infects solanum lycopersicum and other host plants, in the absence of dna-b. the to ... | 2007 | 17367887 |
| 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 |
| genetic structure and population variability of tomato yellow leaf curl china virus. | geminiviruses have circular single-stranded dna genomes and are important pathogens in tropical and subtropical regions, but their population diversity and variability are poorly understood. here, we have investigated variations accumulating in tomato yellow leaf curl china virus (tylccnv), a geminivirus in the genus begomovirus of the family geminiviridae. the population variation was analyzed in a naturally infected tomato (solanum lycopersicom) plant and in nicotiana benthamiana and tomato pl ... | 2007 | 17376922 |
| suppressor of rna silencing encoded by the monopartite tomato leaf curl java begomovirus. | we previously isolated the monopartite begomovirus tomato leaf curl java virus (tolcjav) and satellite dnabeta02 from the same naturally infected tomato source in indonesia. tolcjav induced mild leaf curl symptoms in nicotiana benthamiana plants; dnabeta02 encoded the betac1 gene and produced severe leaf curl symptoms when co-inoculated with tolcjav in n. benthamiana. however, dnabeta02mbetac1, which contains a frame shift mutation, did not induce severe symptoms in n. benthamiana when co-inocul ... | 2007 | 17385070 |
| calcium-dependent protein kinases regulate the production of reactive oxygen species by potato nadph oxidase. | reactive oxygen species (ros) are implicated in plant innate immunity. nadph oxidase (rboh; for respiratory burst oxidase homolog) plays a central role in the oxidative burst, and ef-hand motifs in the n terminus of this protein suggest possible regulation by ca(2+). however, regulatory mechanisms are largely unknown. we identified ser-82 and ser-97 in the n terminus of potato (solanum tuberosum) st rbohb as potential phosphorylation sites. an anti-phosphopeptide antibody (pser82) indicated that ... | 2007 | 17400895 |
| microscopic and transcriptome analyses of early colonization of tomato roots by trichoderma harzianum. | the capacity of the fungus trichoderma harzianum cect 2413 to colonize roots and stimulate plant growth was analyzed. tobacco seedlings (nicotiana benthamiana) transferred to petri dishes inoculated with t. harzianum conidia showed increased plant fresh weight (140%) and foliar area (300%), as well as the proliferation of secondary roots (300%) and true leaves (140%). the interaction between strain cect 2413 and the tomato-root system was also studied during the early stages of root colonization ... | 2007 | 17407057 |
| al1-dependent repression of transcription enhances expression of tomato golden mosaic virus al2 and al3. | studies using nicotiana benthamiana protoplasts have determined that repression of upstream transcription by al1 protein enhances al2 and al3 expression in tomato golden mosaic virus (tgmv). mutations resulting in the inability of tgmv al1 protein to associate with its cognate binding site, result in a decrease in both al2 and al3 expression. reduced expression correlates with an increase in transcription from the al62 start site, and decreased transcription from downstream initiation sites (al1 ... | 2007 | 17407785 |
| rna4-encoded p31 of beet necrotic yellow vein virus is involved in efficient vector transmission, symptom severity and silencing suppression in roots. | rna3 and rna4 of beet necrotic yellow vein virus (bnyvv) are not essential for virus multiplication, but are associated with vector-mediated infection and disease development in sugar beet roots. here, a unique role for rna4 in virus transmission, virulence and rna silencing suppression was demonstrated. mutagenic analysis revealed that the rna4-encoded p31 open reading frame (orf) was involved in efficient vector transmission and slight enhancement of symptom expression in some beta species. no ... | 2007 | 17412994 |
| replication-independent long-distance trafficking by viral rnas in nicotiana benthamiana. | viruses with separately encapsidated genomes could have their genomes introduced into different leaves of a plant, thus necessitating long-distance trafficking of the viral rnas for successful infection. to examine this possibility, individual or combinations of genome segments from the tripartite brome mosaic virus (bmv) were transiently expressed in leaves of nicotiana benthamiana plants using engineered agrobacterium tumefaciens. bmv rna3 was found to traffic from the initial site of expressi ... | 2007 | 17416731 |
| the consensus n-myristoylation motif of a geminivirus ac4 protein is required for membrane binding and pathogenicity. | some geminiviruses encode a small protein, ac4, whose role in pathogenesis has only recently attracted attention. a few studies have shown that this protein is involved in pathogenesis and suppresses rna silencing. here, using nicotiana benthamiana, we show that east african cassava mosaic cameroon virus (eacmcv) ac4 is a pathogenicity determinant and that it suppresses the systemic phase of rna silencing. furthermore, confocal imaging analyses show that it binds preferentially to the plasma mem ... | 2007 | 17427808 |
| a polygalacturonase-inhibiting protein from grapevine reduces the symptoms of the endopolygalacturonase bcpg2 from botrytis cinerea in nicotiana benthamiana leaves without any evidence for in vitro interaction. | six endopolygalacturonases from botrytis cinerea (bcpg1 to bcpg6) as well as mutated forms of bcpg1 and bcpg2 were expressed transiently in leaves of nicotiana benthamiana using agroinfiltration. expression of bcpg1, bcpg2, bcpg4, bcpg5, and mutant bcpg1-d203a caused symptoms, whereas bcpg3, bcpg6, and mutant bcpg2-d192a caused no symptoms. expression of bcpg2 caused the most severe symptoms, including wilting and necrosis. bcpg2 previously has been shown to be essential for b. cinerea virulence ... | 2007 | 17427809 |
| [the c4 proteins of ageratum yellow vein china virus and stachytarpheta leaf curl virus are suppressors of rna silencing]. | rna silencing is a highly conserved mechanism in many eukaryotic organisms that involves sequence-specific rna degradation. one of the important roles of rna silencing is antiviral infection. to counter this defense mechanism, many plant viruses have evolved or acquired functional proteins (suppressors) for suppression of rna silencing. geminiviruses are a family of small circular single-stranded dna (ssdna) viruses that cause severe diseases in major crop plants worldwide. ac2 (c2) and ac4 (c4) ... | 2007 | 17436621 |
| virus-induced gene silencing of 14-3-3 genes abrogates dark repression of nitrate reductase activity in nicotiana benthamiana. | in order to study the effect of repression of 14-3-3 genes on actual activity of the nitrate reductase (nr) in nicotiana benthamiana leaves, nb14-3-3a gene was silenced by virus-induced gene silencing (vigs) method using potato virus x (pvx). expression of nb14-3-3a as well as nb14-3-3b genes was altogether repressed in the leaves of pvx-14-3a-infected plants. furthermore, two-dimensional gel electrophoresis and immunoblot analysis with anti-14-3-3 antiserum suggested that the expressions of nb1 ... | 2007 | 17443349 |
| a tom1 homologue is required for multiplication of tobacco mosaic virus in nicotiana benthamiana. | the attom1 gene of arabidopsis thaliana had been shown to be essential for the efficient multiplication of tobacco mosaic virus (tmv) in a. thaliana. in this study, we cloned an attom1-like gene from nicotiana benthamiana named as nbtom1. sequence alignment showed that nbtom1 is closely related to attom1 homologues of n. tabacum and lycopersicon esculentum with 97.2% and 92.6% nucleotide sequence identities, respectively. silencing of nbtom1 by a modified viral satellite dna-based vector resulte ... | 2007 | 17444600 |
| transgenic nicotiana benthamiana plants resistant to cucumber green mottle mosaic virus based on rna silencing. | rna silencing technology was used to confer resistance to cucumber green mottle mosaic virus (cgmmv). nicotiana benthamiana was transformed with a transgene designed to produce an inverted repeat rna containing cgmmv-coat protein gene (cp) sequences, which were separated by an intron sequence, under the control of the cauliflower mosaic virus 35s promoter. we attempted to confirm the resistance of seven independent transgenic lines; five lines showed resistance to cgmmv infection. the systemic s ... | 2007 | 17453214 |
| abutilon mosaic virus dna b component supports mechanical virus transmission, but does not counteract begomoviral phloem limitation in transgenic plants. | different nicotiana benthamiana lines stably transformed with abutilon mosaic virus (abmv) dimeric dna b were capable of systemically spreading complete bipartite abmv genomes, following agroinoculation of dna a alone. constitutively expressed viral movement protein (bc1) did not induce any persistent disease phenotype, but plants developed transient morphological abnormalities such as radially symmetric leaves after kanamycin withdrawal. systemic abmv infection produced symptoms and virus titer ... | 2007 | 17462695 |
| plant-derived human acetylcholinesterase-r provides protection from lethal organophosphate poisoning and its chronic aftermath. | therapeutically valuable proteins are often rare and/or unstable in their natural context, calling for production solutions in heterologous systems. a relevant example is that of the stress-induced, normally rare, and naturally unstable "read-through" human acetylcholinesterase variant, ache-r. ache-r shares its active site with the synaptic ache-s variant, which is the target of poisonous organophosphate anticholinesterase insecticides such as the parathion metabolite paraoxon. inherent ache-r ... | 2007 | 17475919 |
| expression of human acidic fibroblast growth factor in nicotiana benthamiana with a potato-virus-x-based binary vector. | the afgf (acidic fibroblast growth factor) plays an important role in morphogenesis, angiogenesis and wound healing and is therefore of potential medical interest. a dna fragment encoding hafgf (human afgf) has been cloned into the pvx (potato virus x)-based binary vector (pgr107) and transiently expressed in nicotiana benthamiana (a wild australian tobacco) by agroinfection. approx. 1 week after agroinfection, the recombinant hafgf accumulated in the agroinfected plants reached up to 1% of the ... | 2007 | 17484724 |
| arabidopsis vire2 interacting protein2 is required for agrobacterium t-dna integration in plants. | agrobacterium tumefaciens-mediated genetic transformation is an efficient tool for genetic engineering of plants. vire2 is a single-stranded dna binding agrobacterium protein that is transported into the plant cell and presumably protects the t-dna from degradation. using a yeast two-hybrid system, we identified arabidopsis thaliana vire2-interacting protein2 (vip2) with a not domain that is conserved in both plants and animals. furthermore, we provide evidence supporting vip2 interaction with v ... | 2007 | 17496122 |
| molecular and pathotypic characterization of new xanthomonas oryzae strains from west africa. | dna polymorphism analysis and pathogenicity assays were used to characterize strains of xanthomonas oryzae pv. oryzae and xanthomonas oryzae pv. oryzicola collected from rice leaves in west africa. restriction fragment length polymorphism (rflp), repetitive sequence-based polymerase chain reaction, fluorescent amplified fragment-length polymorphism (faflp) analyses were assessed for molecular characterization, while pathogenicity was tested by leaf clipping and leaf infiltration. dendrograms wer ... | 2007 | 17506331 |
| the senescence-induced staygreen protein regulates chlorophyll degradation. | loss of green color in leaves results from chlorophyll (chl) degradation in chloroplasts, but little is known about how chl catabolism is regulated throughout leaf development. using the staygreen (sgr) mutant in rice (oryza sativa), which maintains greenness during leaf senescence, we identified sgr, a senescence-associated gene encoding a novel chloroplast protein. transgenic rice overexpressing sgr produces yellowish-brown leaves, and arabidopsis thaliana pheophorbide a oxygenase-impaired mut ... | 2007 | 17513504 |
| cytosine methylation is associated with rna silencing in silenced plants but not with systemic and transitive rna silencing through grafting. | rna silencing is often associated with methylation of the target gene. the dna methylation level of transgenes was investigated in post-transcriptionally silenced or non-silenced nicotiana benthamiana carrying either the 5' region (200 or 400 bp) or the entire region of the coat protein gene (cp, including the 3' non-translated region) of sweet potato feathery mottle virus. higher levels of transgene cytosine methylation were observed in both symmetrical (cpg, cpnpg) and non-symmetrical (cphph) ... | 2007 | 17521830 |
| physical association of the nb-lrr resistance protein rx with a ran gtpase-activating protein is required for extreme resistance to potato virus x. | nucleotide binding leucine-rich repeat (nb-lrr) proteins play an important role in plant and mammalian innate immunity. in plants, these resistance proteins recognize specific pathogen-derived effector proteins. recognition subsequently triggers a rapid and efficient defense response often associated with the hypersensitive response and other poorly understood processes that suppress the pathogen. to investigate mechanisms associated with the activation of disease resistance responses, we invest ... | 2007 | 17526750 |
| molecular identification and characterization of the tomato flagellin receptor lefls2, an orthologue of arabidopsis fls2 exhibiting characteristically different perception specificities. | bacterial flagellin is known to stimulate host immune responses in mammals and plants. in arabidopsis thaliana, the receptor kinase fls2 mediates flagellin perception through physical interaction with a highly conserved epitope in the n-terminus of flagellin, represented by the peptide flg22 derived from pseudomonas syringae. the peptide flg22 is highly active as an elicitor in many plant species. in contrast, a shortened version of the same epitope derived from escherichia coli, flg15(e coli), ... | 2007 | 17530419 |
| the nucleoprotein of tomato spotted wilt virus as protein tag for easy purification and enhanced production of recombinant proteins in plants. | upon infection, tomato spotted wilt virus (tswv) forms ribonucleoprotein particles (rnps) that consist of nucleoprotein (n) and viral rna. these aggregates result from the homopolymerization of the n protein, and are highly stable in plant cells. these properties feature the n protein as a potentially useful protein fusion partner. to evaluate this potential, the n protein was fused to the aequorea victoria green fluorescent protein (gfp), either at the amino or carboxy terminus, and expressed i ... | 2007 | 17532227 |
| translational control of recombinant human acetylcholinesterase accumulation in plants. | codon usage differences are known to regulate the levels of gene expression in a species-specific manner, with the primary factors often cited to be mrna processing and accumulation. we have challenged this conclusion by expressing the human acetylcholinesterase coding sequence in transgenic plants in its native gc-rich sequence and compared to a matched sequence with (dicotyledonous) plant-optimized codon usage and a lower gc content. | 2007 | 17537261 |
| changes in photosynthetic metabolism induced by tobamovirus infection in nicotiana benthamiana studied in vivo by thermoluminescence. | * in thylakoids from nicotiana benthamiana infected with the pepper mild mottle virus (pmmov), a decreased amount of the psbp and psbq proteins of photosystem ii and different proteins of the calvin cycle have been previously observed. we used thermoluminescence to study the consequences in vivo. * measurements on unfrozen discs from symptomatic and asymptomatic leaves of plants infected by two tobamovirus pmmov-s and pmmov-i strains were compared with homologous samples in control plants. * the ... | 2007 | 17547672 |
| plant signalling components eds1 and sgt1 enhance disease caused by the necrotrophic pathogen botrytis cinerea. | * botrytis cinerea is a necrotrophic fungus that causes grey mould on a wide range of food plants, especially grapevine, tomato, soft fruits and vegetables. this disease brings about important economic losses in both pre- and postharvest crops. successful protection of host plants against this pathogen is severely hampered by a lack of resistance genes in the hosts and the considerable phenotypic diversity of the fungus. * the aim of this study was to test whether b. cinerea manipulates the immu ... | 2007 | 17547673 |
| genomic regions of tomato leaf curl virus dna satellite required for replication and for satellite-mediated delivery of heterologous dnas. | tomato leaf curl virus (tlcv) satellite dna (sat-dna) is a 682 nt, circular, single-stranded molecule that lacks an open reading frame (orf) or an apparent promoter. it contains binding motifs for the tlcv replication-associated protein, but these are dispensable for replication. to identify the regions of the sat-dna critical for replication, the entire sequence was scanned by deletion/replacement mutagenesis. transient assays using nicotiana benthamiana revealed that sequences within nt 296-35 ... | 2007 | 17554042 |
| quantitative analysis of efficient endogenous gene silencing in nicotiana benthamiana plants using tomato bushy stunt virus vectors that retain the capsid protein gene. | tomato bushy stunt virus (tbsv) coat protein (cp) replacement vectors have been used previously to silence transgenes (e.g., the green fluorescent protein gene) but have not been effective for silencing endogenous plant genes. new tbsv vectors which retained the cp gene were developed by engineering an xhoi restriction site in three positions (3f, ceb, and cea) of the ptbsv-100 infectious clone. magnesium chelatase (chlh) and phytoene desaturase (pds) were chosen as targets for endogenous gene s ... | 2007 | 17555269 |
| downregulation of the nbnaca1 gene encoding a movement-protein-interacting protein reduces cell-to-cell movement of brome mosaic virus in nicotiana benthamiana. | the 3a movement protein (mp) plays a central role in the movement of the rna plant virus, brome mosaic virus (bmv). to identify host factor genes involved in viral movement, a cdna library of nicotiana benthamiana, a systemic host for bmv, was screened with far-western blotting using a recombinant bmv mp as probe. one positive clone encoded a protein with sequence similarity to the alpha chain of nascent-polypeptide-associated complex from various organisms, which is proposed to contribute to th ... | 2007 | 17555275 |
| identification and characterization of a new virus in the genus potyvirus from wild populations of angelica lucida l. and a. genuflexa nutt., family apiaceae. | a novel potyvirus was discovered in angelica lucida l. (wild celery) and a. genuflexa nutt. (kneeling angelica) (family apiaceae) in the matanuska- susitna valley, alaska. the experimental plant host range of the virus included species in three families: chenopodiaceae (chenopodium amaranticolor coste et reyn and chenopodium quinoa willd.), solanaceae (nicotiana benthamiana domin, and n. clevlandii gray.), and apiaceae (anethum graveolens l., apium graveolens l. var. dulce (miller)), daucus caro ... | 2007 | 17558540 |
| a pseudomonas syringae pv. tomato dc3000 mutant lacking the type iii effector hopq1-1 is able to cause disease in the model plant nicotiana benthamiana. | the model pathogen pseudomonas syringae pv. tomato dc3000 causes bacterial speck in tomato and arabidopsis, but nicotiana benthamiana, an important model plant, is considered to be a non-host. strain dc3000 injects approximately 28 effector proteins into plant cells via the type iii secretion system (t3ss). these proteins were individually delivered into n. benthamiana leaf cells via t3ss-proficient pseudomonas fluorescens, and eight, including hopq1-1, showed some capacity to cause cell death i ... | 2007 | 17559511 |
| arabidopsis cytochrome p450 monooxygenase 71a13 catalyzes the conversion of indole-3-acetaldoxime in camalexin synthesis. | camalexin (3-thiazol-2-yl-indole) is an indole alkaloid phytoalexin produced by arabidopsis thaliana that is thought to be important for resistance to necrotrophic fungal pathogens, such as alternaria brassicicola and botrytis cinerea. it is produced from trp, which is converted to indole acetaldoxime (iaox) by the action of cytochrome p450 monooxygenases cyp79b2 and cyp79b3. the remaining biosynthetic steps are unknown except for the last step, which is conversion of dihydrocamalexic acid to ca ... | 2007 | 17573535 |
| expression of a metacaspase gene of nicotiana benthamiana after inoculation with colletotrichum destructivum or pseudomonas syringae pv. tomato, and the effect of silencing the gene on the host response. | metacaspases are cysteine proteinases that have homology to caspases, which play a central role in signaling and executing programmed cell death in animals. a type ii metacaspase cdna, nbmca1, was amplified from nicotiana benthamiana infected with colletotrichum destructivum. it showed a peak in expression at 72 h post-inoculation corresponding with the switch to necrotrophy by c. destructivum. inoculation of n. benthamiana with an incompatible bacterium, pseudomonas syringae pv. tomato, which s ... | 2007 | 17576564 |
| the syntaxin syp132 contributes to plant resistance against bacteria and secretion of pathogenesis-related protein 1. | in contrast to many mammalian pathogens, potential bacterial pathogens of plants remain outside the host cell. the plant must, therefore, promote an active resistance mechanism to combat the extracellular infection. how this resistance against bacteria is manifested and whether similar processes mediate basal, gene-for-gene, and salicylate-associated defense, however, are poorly understood. here, we identify a specific plasma membrane syntaxin, nbsyp132, as a component contributing to gene-for-g ... | 2007 | 17592123 |
| characterization of virus-induced gene silencing in tobacco plants infected with apple latent spherical virus. | apple latent spherical virus (alsv) expressing green fluorescent protein (gfp-alsv) was used for analysis of virus-induced gene silencing (vigs) in tobacco plants expressing gfp (gfp-tobacco). in gfp-tobacco inoculated with gfp-alsv, small dark spots appeared on inoculated leaves at 5 days post-inoculation (dpi), then expanded, and finally covered the whole area of the leaves after 12 dpi. most of the fluorescence of upper leaves above the 12th true leaf disappeared at 21 dpi. thus, gfp-alsv inf ... | 2007 | 17598069 |
| psite vectors for stable integration or transient expression of autofluorescent protein fusions in plants: probing nicotiana benthamiana-virus interactions. | plant functional proteomics research is increasingly dependent upon vectors that facilitate high-throughput gene cloning and expression of fusions to autofluorescent proteins. here, we describe the psite family of plasmids, a new set of agrobacterium binary vectors, suitable for the stable integration or transient expression of various autofluorescent protein fusions in plant cells. the psite vectors permit single-step gateway-mediated recombination cloning for construction of binary vectors tha ... | 2007 | 17601162 |
| bacterial cyclic beta-(1,2)-glucan acts in systemic suppression of plant immune responses. | although cyclic glucans have been shown to be important for a number of symbiotic and pathogenic bacterium-plant interactions, their precise roles are unclear. here, we examined the role of cyclic beta-(1,2)-glucan in the virulence of the black rot pathogen xanthomonas campestris pv campestris (xcc). disruption of the xcc nodule development b (ndvb) gene, which encodes a glycosyltransferase required for cyclic glucan synthesis, generated a mutant that failed to synthesize extracellular cyclic be ... | 2007 | 17601826 |
| tobacco mosaic virus defective rnas expressing c-terminal methyltransferase domain sequences are severely impaired in long-distance movement in nicotiana benthamiana. | tobamovirus replicase proteins, which function in replication and gene expression, are also implicated in viral cell-to-cell and long-distance movement. the role(s) of tobacco mosaic virus (tmv) 126-/183-kda replicase protein in the complex movement process are not understood due to lack of systems that can separate the multiple steps involved. we previously developed a bipartite tmv-defective rna (drna) system to dissect the role of the n-terminal methyltransferase (mt) domain in accumulation a ... | 2007 | 17602721 |