| biological relevance of a stable biochemical interaction between the tombusvirus-encoded p19 and short interfering rnas. | the tomato bushy stunt virus (tbsv)-encoded p19 protein (p19) is widely used as a robust tool to suppress rna interference (rnai) in various model organisms. p19 dimers appropriate 21-nucleotide (nt) duplex short interfering rnas (sirnas) generated by dicer presumably to prevent programming of the rna-induced silencing complex (risc). in the context of virus infection, this model predicts that p19 mutants compromised for sirna binding cannot prevent risc-mediated degradation of tbsv rna and thus ... | 2006 | 16501109 |
| spontaneous short-range silencing of a gfp transgene in nicotiana benthamiana is possibly mediated by small quantities of sirna that do not trigger systemic silencing. | a green fluorescent protein (gfp) transgene under the control of the 35s cauliflower mosaic virus (camv) promoter was introduced by agrobacterium-mediated transformation into nicotiana benthamiana to generate fourteen transgenic lines. homozygous lines that contained one or two copies of the transgene showed great variation of gfp expression under ultraviolet (uv) light, which allowed classification into three types of transgenic plants. plants from more than half of the transgenic lines underwe ... | 2006 | 16507090 |
| an in vivo, luciferase-based, agrobacterium-infiltration assay system: implications for post-transcriptional gene silencing. | an in vivo assay system for analyzing transient luciferase expression in tobacco leaves infused with agrobacterium tumefaciens is described. the system makes use of a. tumefaciens harboring t-dna vectors containing either an intron-containing firefly (photinus pyralis) luciferase (ec 1.13.12.7) gene or an intron-containing sea pansy (renilla reniformis) luciferase (ec 1.13.12.5) gene. single or mixed agrobacterium lines were infiltrated into leaf tissues (nicotiana tabacum or nicotiana benthamia ... | 2006 | 16523348 |
| transient expression of human papillomavirus type 16 l1 protein in nicotiana benthamiana using an infectious tobamovirus vector. | a tobacco mosaic virus (tmv)-derived vector was used to express a native human papillomavirus type 16 (hpv-16) l1 gene in nicotiana benthamiana by means of infectious in vitro rna transcripts inoculated onto n. benthamiana plants. hpv-16 l1 protein expression was quantitated by enzyme-linked immunosorbent assays (elisa) after concentration of the plant extract. we estimated that the l1 product yield was 20-37 microg/kg of fresh leaf material. the l1 protein in the concentrated extract was antige ... | 2006 | 16530873 |
| xanthan induces plant susceptibility by suppressing callose deposition. | xanthan is the major exopolysaccharide secreted by xanthomonas spp. despite its diverse roles in bacterial pathogenesis of plants, little is known about the real implication of this molecule in xanthomonas pathogenesis. in this study we show that in contrast to xanthomonas campestris pv campestris strain 8004 (wild type), the xanthan minus mutant (strain 8397) and the mutant strain 8396, which is producing truncated xanthan, fail to cause disease in both nicotiana benthamiana and arabidopsis (ar ... | 2006 | 16531487 |
| the u-box protein cmpg1 is required for efficient activation of defense mechanisms triggered by multiple resistance genes in tobacco and tomato. | we previously identified three avr9/cf-9 rapidly elicited (acre) genes essential for cf-9- and cf-4-dependent hypersensitive response (hr) production in nicotiana benthamiana. two of them encode putative e3 ubiquitin ligase components. this led us to investigate other acre genes associated with the ubiquitination pathway. acre74 encodes a u-box e3 ligase homolog, highly related to parsley (petroselinum crispum) cmpg1 and arabidopsis thaliana plant u-box20 (pub20) and pub21 proteins, and was call ... | 2006 | 16531490 |
| exploiting the plant secretory pathway to improve the anticancer activity of a plant-derived hpv16 e7 vaccine. | the human papillomavirus 16 (hpv16) e7 oncoprotein can be considered a "tumor-specific antigen", and therefore it represents a promising target for a therapeutic vaccine against hpv-associated tumors. efficient production of e7 protein with a plant-based transient expression system has been already described and it was demonstrated that e7-containing crude plant extracts confer partial protection against tumor challenge in a mouse model system. before adopting the plant-based system as a cost-ef ... | 2006 | 16569357 |
| identification of a plum pox virus ci-interacting protein from chloroplast that has a negative effect in virus infection. | the cylindrical inclusion (ci) protein of potyviruses is involved in virus replication and cell-to-cell movement. these two processes should rely on multiple plant-virus interactions; however, little is known about the host factors that are involved in, or that may interfere with, ci functions. by using a yeast two-hybrid system, the ci protein from plum pox virus (ppv) was found to interact with the photosystem i psi-k protein, the product of the gene psak, of nicotiana benthamiana. coexpressio ... | 2006 | 16570664 |
| optimization of transient agrobacterium-mediated gene expression system in leaves of nicotiana benthamiana. | here we report on a simple and reproducible system of agrobacterium-mediated transient gene expression assay that utilizes infiltration of young nicotiana benthamiana leaves. although some of the phenomena described in this paper have been already reported by other researchers, here we have further developed them. the highest level of transient gfp gene expression was detected in the youngest leaves of n. benthamiana infiltrated with a. tumefaciens strains agl0 and eha105 precultured in the pres ... | 2006 | 16582986 |
| nitrate reductase is responsible for elicitin-induced nitric oxide production in nicotiana benthamiana. | recent works have established a key role for nitric oxide (no) in activating disease resistance in plants. nitrate reductase (nr) is one of the enzymes that are capable of producing no in plants. in a previous study, we reported that pathogen signals induce expression of nr genes in potato, suggesting the involvement of nr in no production induced by pathogen signals. in this study, we cloned nr genes from nicotiana benthamiana and investigated their involvement in no production induced by inf1, ... | 2006 | 16608868 |
| efficient transient expression of human gm-csf protein in nicotiana benthamiana using potato virus x vector. | the human granulocyte macrophage colony-stimulating factor (gm-csf) is a glycoprotein with important clinical applications for the treatment of neutropenia and aplastic anemia and reducing infections associated with bone marrow transplants. we evaluated the potential for using a potato virus x (pvx) viral vector system for efficient expression of the biologically functional gm-csf protein in nicotiana benthamiana leaves. the gm-csf gene was cloned into pvx viral expression vector, driven with th ... | 2006 | 16612640 |
| role of sgt1 in resistance protein accumulation in plant immunity. | a highly conserved eukaryotic protein sgt1 binds specifically to the molecular chaperone, hsp90. in plants, sgt1 positively regulates disease resistance conferred by many resistance (r) proteins and developmental responses to the phytohormone, auxin. we show that silencing of sgt1 in nicotiana benthamiana causes a reduction in steady-state levels of the r protein, rx. these data support a role of sgt1 in r protein accumulation, possibly at the level of complex assembly. in arabidopsis, two sgt1 ... | 2006 | 16619029 |
| prohibitin is involved in mitochondrial biogenesis in plants. | prohibitin, which consists of two subunits phb1 and phb2, plays a role in cell-cycle progression, senescence, apoptosis, and maintenance of mitochondrial function in mammals and yeast. in this study, we examined the role of prohibitins in plants by using virus-induced gene silencing (vigs) of two prohibitin subunit genes of nicotiana benthamiana, designated nbphb1 and nbphb2. nbphb1 and nbphb2 were targeted to the mitochondria, and their gene expression was suppressed during senescence. vigs of ... | 2006 | 16640602 |
| tobamovirus infection is independent of hsp101 mrna induction and protein expression. | heat shock protein 101 (hsp101) has been implicated in tobamovirus infections by virtue of its ability to enhance translation of mrnas possessing the 5'omega-leader of tobacco mosaic virus (tmv). enhanced translation is mediated by hsp101 binding to a caa-repeat motif in tmv omega leader. caa repeat sequences are present in the 5' leaders of other tobamoviruses including oilseed rape mosaic virus (ormv), which infects arabidopsis thaliana. hsp101 is one of eight hsp100 gene family members encode ... | 2006 | 16644052 |
| role of the leader sequence in tobacco pectin methylesterase secretion. | we report that unprocessed tobacco pectin methylesterase (pme) contains n-terminal pro-sequence including the transmembrane (tm) domain and spacer segment preceding the mature pme. the mature portion of pme was replaced by green fluorescent protein (gfp) gene and various deletion mutants of pro-sequence fused to gfp were cloned into binary vectors and agroinjected in nicotiana benthamiana leaves. the pme pro-sequence delivered gfp to the cell wall (cw). we showed that a transient binding of pme ... | 2006 | 16709413 |
| perception of the bacterial pamp ef-tu by the receptor efr restricts agrobacterium-mediated transformation. | higher eukaryotes sense microbes through the perception of pathogen-associated molecular patterns (pamps). arabidopsis plants detect a variety of pamps including conserved domains of bacterial flagellin and of bacterial ef-tu. here, we show that flagellin and ef-tu activate a common set of signaling events and defense responses but without clear synergistic effects. treatment with either pamp results in increased binding sites for both pamps. we used this finding in a targeted reverse-genetic ap ... | 2006 | 16713565 |
| capsid protein gene and the type of host plant differentially modulate cell-to-cell movement of cowpea chlorotic mottle virus. | a study was undertaken to measure the rate of coat protein (cp) independent cell-to-cell movement of cowpea chlorotic mottle bromovirus (ccmv) in three different host plants. a ccmv rna3 variant in which the cp gene was substituted with enhanced green fluorescent protein (c3/deltacp-egfp) was coinoculated to three different host plants with transcripts of wild type rnas 1 and 2. comparative analysis of cell-to-cell movement monitored by the egfp expression at various days post inoculation reveal ... | 2006 | 16732474 |
| atrli2 is an endogenous suppressor of rna silencing. | rna silencing is a mechanism involved in gene regulation during development and anti-viral defense in plants and animals. although many viral suppressors of this mechanism have been described up to now, this is not the case for endogenous suppressors. we have identified a novel endogenous suppressor in plants: rnase l inhibitor (rli) of arabidopsis thaliana. rli is a very conserved protein among eukaryotes and archaea. it was first known as component of the interferon-induced mammalian 2'-5' oli ... | 2006 | 16786298 |
| in planta production of two peptides of the classical swine fever virus (csfv) e2 glycoprotein fused to the coat protein of potato virus x. | classical swine fever (csfv) is one of the most important viral infectious diseases affecting wild boars and domestic pigs. the etiological agent of the disease is the csf virus, a single stranded rna virus belonging to the family flaviviridae. all preventive measures in domestic pigs have been focused in interrupting the chain of infection and in avoiding the spread of csfv within wild boars as well as interrupting transmission from wild boars to domestic pigs. the use of plant based vaccine ag ... | 2006 | 16792815 |
| a novel function for a ubiquitous plant enzyme pectin methylesterase: the enhancer of rna silencing. | co-agroinjection of nicotiana benthamiana leaves with the pectin methylesterase (propme) gene and the tmv:gfp vector resulted in a stimulation of virus-induced rna silencing (inhibition of gfp production, virus rna degradation, stimulation of sirnas production). conversely, co-expression of tmv:gfp with either antisense pme construct or with enzymatically inactive propme restored synthesis of viral rna. furthermore, expression of propme enhanced the gfp transgene-induced gene silencing accompani ... | 2006 | 16797009 |
| a simplified method for cloning of short interfering rnas from brassica juncea infected with turnip mosaic potyvirus and turnip crinkle carmovirus. | rna silencing is a plant defense mechanism in which virus infected plants produce short interfering rnas (sirnas) derived from viral rna, that attack the virus at the post-transcriptional level. in a previous study on cymbidium ringspot tombusvirus (cymrsv) infection in nicotiana benthamiana, sirnas (determined by cloning and sequencing) predominantly originated from the sense (+) strand of the viral rna, suggesting that the majority of sirnas are produced through the direct cleavage of the viru ... | 2006 | 16815561 |
| efficient virus-induced gene silencing in arabidopsis. | virus-induced gene silencing (vigs) is a plant rna-silencing technique that uses viral vectors carrying a fragment of a gene of interest to generate double-stranded rna, which initiates the silencing of the target gene. several viral vectors have been developed for vigs and they have been successfully used in reverse genetics studies of a variety of processes occurring in plants. this approach has not been widely adopted for the model dicotyledonous species arabidopsis (arabidopsis thaliana), po ... | 2006 | 16815951 |
| bovine cd14 receptor produced in plants reduces severity of intramammary bacterial infection. | cd14 is a high-affinity receptor protein for the complex of bacterial lps (lps) and lps binding protein in animals. binding of the soluble form of cd14 (scd14) to lps, found in the outer membrane of escherichia coli and other gram-negative bacteria, enhances host innate immune responses, reduces the severity of mastitis, and facilitates clearance and neutralization of lps, thus protecting against an excessive immune response to lps and development of endotoxic shock. a truncated form of scd14, c ... | 2006 | 16816109 |
| development of cucumber mosaic virus as a vector modifiable for different host species to produce therapeutic proteins. | we have developed cucumber mosaic virus (cmv) as a plant virus vector especially for production of pharmaceutical proteins. the cmv vector is a vector modifiable for different host plants and does not require further engineering steps. cmv contains three genomic rna molecules (rnas 1-3) necessary for infectivity. with this system, instead of creating different vector constructs for each plant we use, we take advantage of the formation of pseudrecombinants between two cmv isolates by simply reass ... | 2007 | 16821041 |
| molecular and enzymatic characterizations of novel bifunctional 3beta-hydroxysteroid dehydrogenases/c-4 decarboxylases from arabidopsis thaliana. | we have isolated two cdnas from arabidopsis thaliana encoding bifunctional 3beta-hydroxysteroid dehydrogenase/c-4 decarboxylases (3betahsd/d) involved in sterol synthesis, termed at3betahsd/d1 and at3betahsd/d2. transformation of the yeast ergosterol auxotroph erg26 mutant, which lacks 3betahsd/d activity, with the at3betahsd/d1 isoform or with at3betahsd/d2 isoform containing a c-terminal at3betahsd/d1 endoplasmic reticulum-retrieval sequence restored growth and ergosterol synthesis in erg26. a ... | 2006 | 16835224 |
| the arginine-rich motif of bamboo mosaic virus satellite rna-encoded p20 mediates self-interaction, intracellular targeting, and cell-to-cell movement. | satellite rna of bamboo mosaic virus (satbamv) has a single open reading frame for a nonstructural, rna-binding protein, p20, which facilitates the long-distance movement of satbamv in nicotiana benthamiana. here, we elucidate various biological properties of p20 and the involvement of a single domain in its activities. p20 displayed a strong self-interaction in vitro and in vivo, and cross-linking assays demonstrated its oligomerization. domain mapping, using the bacterial two-hybrid system, in ... | 2006 | 16838788 |
| corr regulates multiple components of virulence in pseudomonas syringae pv. tomato dc3000. | the phytotoxin coronatine (cor) is produced by various pathovars of pseudomonas syringae, including p. syringae pv. tomato dc3000, which is pathogenic on crucifers and tomato, and p. syringae pv. glycinea pg4180, a soybean pathogen. the cor molecule contains two distinct components, coronafacic acid (cfa) and coronamic acid (cma), which are intermediates in the cor biosynthetic pathway. in p. syringae pv. tomato dc3000, it is not clear whether corr, which encodes a response regulator, positively ... | 2006 | 16838789 |
| functional analysis of the five melon necrotic spot virus genome-encoded proteins. | function of the melon necrotic spot virus (mnsv) genome-encoded proteins (p29, p89, p7a, p7b and p42) has been studied. protein-expression mutants of an infectious, full-length cdna clone of a spanish mnsv-al isolate and a recombinant green fluorescent protein (gfp)-expressing virus were used in infection bioassays on melon plants. results revealed that p29 and p89 are both essential for virus replication, whereas small proteins p7a and p7b are sufficient to support viral movement between adjace ... | 2006 | 16847133 |
| detection of 6k1 as a mature protein of 6 kda in plum pox virus-infected nicotiana benthamiana. | the rna genome of plum pox virus (ppv) encodes one large polyprotein that is subsequently cleaved into mature viral proteins. one of the products of proteolytic processing, the 6k1 protein, has not yet been identified in vivo for any member of the genus potyvirus. in this study, 6k1-specific polyclonal antiserum was raised against ppv 6k1 expressed in escherichia coli as a translational fusion with the n terminus of avian troponin c and an unusual metal-binding cluster of troponin t-1. for detec ... | 2006 | 16847134 |
| barley stripe mosaic virus-encoded proteins triple-gene block 2 and gammab localize to chloroplasts in virus-infected monocot and dicot plants, revealing hitherto-unknown roles in virus replication. | replication of barley stripe mosaic virus (bsmv), genus hordeivirus, is thought to be associated with vesicles in proplastids and chloroplasts, but the molecular details of the process and identity of virus proteins involved in establishing the virus replication complexes are unknown. in addition, bsmv encodes a triple-gene block of movement proteins (tgbs) that putatively share functional roles with their counterparts in other hordei-, pomo- and pecluviruses, but detailed information on the int ... | 2006 | 16847137 |
| post-transcriptional gene silencing in controlling viruses of the tomato yellow leaf curl virus complex. | tomato yellow leaf curl disease (tylcd) is caused by a group of geminiviruses that belong to the tomato yellow leaf curl virus (tylcv) complex and are transmitted by the whitefly (bemisia tabaci genn.). the disease causes great yield losses in many countries throughout the mediterranean region and the middle east. in this study, the efficacy of post-transcriptional gene silencing (ptgs) to control the disease caused by tylcv complex was investigated. non-coding conserved regions from the genome ... | 2006 | 16862387 |
| a 38-amino-acid sequence encompassing the arm domain of the cucumber necrosis virus coat protein functions as a chloroplast transit peptide in infected plants. | experiments to determine the subcellular location of the coat protein (cp) of the tombusvirus cucumber necrosis virus (cnv) have been conducted. by confocal microscopy, it was found that an agroinfiltrated cnv cp-green fluorescent protein (gfp) fusion targets chloroplasts in nicotiana benthamiana leaves and that a 38-amino-acid (aa) region that includes the complete cp arm region plus the first 4 amino acids of the shell domain are sufficient for targeting. western blot analyses of purified and ... | 2006 | 16873252 |
| a viral resistance gene from common bean functions across plant families and is up-regulated in a non-virus-specific manner. | genes involved in a viral resistance response in common bean (phaseolus vulgaris cv. othello) were identified by inoculating a geminivirus reporter (bean dwarf mosaic virus expressing the green fluorescent protein), extracting rna from tissue undergoing the defense response, and amplifying sequences with degenerate r gene primers. one such gene (a tir-nbs-lrr gene, rt4-4) was selected for functional analysis in which transgenic nicotiana benthamiana were generated and screened for resistance to ... | 2006 | 16880399 |
| permeabilized mammalian cells as an experimental system for nuclear import of geminiviral karyophilic proteins and of synthetic peptides derived from their nuclear localization signal regions. | the plant-infecting geminiviruses deliver their genome and viral proteins into the host cell nucleus. members of the family geminiviridae possess either a bipartite genome composed of two approximately 2.6 kb dnas or a monopartite genome of approximately 3.0 kb dna. the bipartite genome of bean dwarf mosaic virus (bdmv) encodes several karyophilic proteins, among them the capsid protein (cp) and bv1 (nuclear shuttle protein). a cp is also encoded by the monopartite genome of tomato yellow leaf c ... | 2006 | 16894212 |
| propagation of plant viruses in hairy root cultures: a potential method for in vitro production of epitope vaccines and foreign proteins. | hairy roots were used as an in vitro culture system for the propagation of wild-type and transgenic plant viruses. tobacco mosaic virus (tmv) was added to the liquid culture medium at the same time as root inoculation. hairy root growth was unaffected by viral infection. maximum concentrations of tmv in nicotiana benthamiana hairy roots were 1-2 orders of magnitude greater than in suspended n. benthamiana cells and reached levels of 1-2 mg g(-1) dry weight or 20-28% total soluble protein. virus ... | 2007 | 16900508 |
| synergistic interactions of the plant cell death pathways induced by phytophthora infestans nepl-like protein pinpp1.1 and inf1 elicitin. | cell death plays a ubiquitous role in plant-microbe interactions, given that it is associated with both susceptible and resistance interactions. a class of cell death-inducing proteins, termed nepl-like proteins (nlps), has been reported in bacteria, fungi, and oomycetes. these proteins induce nonspecific necrosis in a variety of dicotyledonous plants. here, we describe three members of the nlp family from the oomycete phytophthora infestans (pinpp1.1, pinpp1.2, and pinpp1.3). using agroinfectio ... | 2006 | 16903351 |
| characterization of the recombinant forms arising from a potato virus x chimeric virus infection under rna silencing pressure. | recombination is a frequent phenomenon in rna viruses whose net result is largely influenced by selective pressures. rna silencing in plants acts as a defense mechanism against viruses and can be used to engineer virus resistance. here, we have investigated the influence of rna silencing as a selective pressure to favor recombinants of pvx-hct, a chimeric potato virus x (pvx) vector carrying the helper-component proteinase (hc-pro) gene from plum pox virus (ppv). all the plants from two lines ex ... | 2006 | 16903356 |
| tobacco wlim1 is a novel f-actin binding protein involved in actin cytoskeleton remodeling. | we used confocal microscopy and in vitro analyses to show that nicotiana tabacum wlim1, a lim domain protein related to animal cys-rich proteins, is a novel actin binding protein in plants. green fluorescent protein (gfp)-tagged wlim1 protein accumulated in the nucleus and cytoplasm of tobacco by2 cells. it associated predominantly with actin cytoskeleton, as demonstrated by colabeling and treatment with actin-depolymerizing latrunculin b. high-speed cosedimentation assays revealed the ability o ... | 2006 | 16905656 |
| down-regulation of the 26s proteasome subunit rpn9 inhibits viral systemic transport and alters plant vascular development. | plant viruses utilize the vascular system for systemic movement. the plant vascular network also transports water, photosynthates, and signaling molecules and is essential for plant growth. however, the molecular mechanisms governing vascular development and patterning are still largely unknown. from viral transport suppressor screening using virus-induced gene silencing, we identified a 26s proteasome subunit, rpn9, which is required for broad-spectrum viral systemic transport. silencing of rpn ... | 2006 | 16905670 |
| vpg of potato virus a alone does not suppress rna silencing but affects virulence of a heterologous virus. | the viral genome-linked protein (vpg) is a well-known virulence factor in potyviruses (genus potyvirus), including potato virus a (pva). its ability to suppress onset and signalling of transgene-mediated rna silencing and accumulation of small interfering rna (sirna) was studied using cross-protection and agrobacterium infiltration assays and green fluorescent protein (gfp) and pva vpg protein-expressing transgenic nicotiana benthamiana plants. n. benthamiana plants were also transformed with a ... | 2007 | 16927117 |
| protein-protein interactions and nuclear trafficking of coat protein and betac1 protein associated with bhendi yellow vein mosaic disease. | bhendi yellow vein mosaic disease (byvmd) is caused by a complex consisting of a monopartite begomovirus byvmv and a satellite dna beta component. byvmv represents a new member of the emerging group of monopartite begomoviruses requiring a satellite component for symptom induction. here we report the results of the transient expression of green fluorescent protein (gfp) fused with the betac1 and coat protein (cp) coding regions, in the epidermal cells of nicotiana benthamiana. gfpcp was found to ... | 2006 | 16934356 |
| translocation of tomato bushy stunt virus p19 protein into the nucleus by aly proteins compromises its silencing suppressor activity. | the p19 protein of tomato bushy stunt virus is a potent suppressor of rna silencing and, depending on the host species, is required for short- and long-distance virus movement and symptom production. p19 interacts with plant aly proteins and relocalizes a subset of these proteins from the nucleus to the cytoplasm. here we showed that coexpression by agroinfiltration in nicotiana benthamiana of p19 and the subset of aly proteins that are not relocalized from the nucleus interfered with the abilit ... | 2006 | 16940518 |
| the type iii effector repertoire of pseudomonas syringae pv. syringae b728a and its role in survival and disease on host and non-host plants. | the bacterial plant pathogen pseudomonas syringae injects a large repertoire of effector proteins into plant cells using a type iii secretion apparatus. effectors can trigger or suppress defences in a host-dependent fashion. host defences are often accompanied by programmed cell death, while interference with defences is sometimes associated with cell death suppression. we previously predicted the effector repertoire of the sequenced bean pathogen p. syringae pv. syringae (psy) b728a using bioin ... | 2006 | 16942603 |
| encapsidation of genomic but not subgenomic turnip yellow mosaic virus rna by coat protein provided in trans. | we have studied the encapsidation requirements of turnip yellow mosaic virus (tymv) genomic and subgenomic rna using an "agroinfiltration" procedure involving transient expression of rnas and coat protein (cp) in nicotiana benthamiana leaves. although n. benthamiana is a nonhost, expression of tymv rna in its leaves by agroinfiltration resulted in efficient local infection and production of the expected virions containing genomic and subgenomic rnas together with empty capsids. a nonreplicating ... | 2006 | 16942786 |
| robotized thermal and chlorophyll fluorescence imaging of pepper mild mottle virus infection in nicotiana benthamiana. | after infecting a susceptible host, pathogens spread throughout the plant. depending on pathogen type and strain, the severity of symptoms varies greatly. in the case of pepper mild mottle virus (pmmov) infection in nicotiana benthamiana, newly developing leaves display visual symptoms (symptomatic leaves). in this study, two pmmov strains were used, the spanish strain (pmmov-s) being more virulent than the italian strain (pmmov-i). plants infected with pmmov-i could recover from the virus-induc ... | 2006 | 16943218 |
| 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 |
| 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 |
| 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 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 |