Publications

a unique virulence factor for proliferation and dwarfism in plants identified from a phytopathogenic bacterium.	one of the most important themes in agricultural science is the identification of virulence factors involved in plant disease. here, we show that a single virulence factor, tengu-su inducer (tengu), induces witches' broom and dwarfism and is a small secreted protein of the plant-pathogenic bacterium, phytoplasma. when tengu was expressed in nicotiana benthamiana plants, these plants showed symptoms of witches' broom and dwarfism, which are typical of phytoplasma infection. transgenic arabidopsis ...	2009	19329488
scaleable manufacture of hiv-1 entry inhibitor griffithsin and validation of its safety and efficacy as a topical microbicide component.	to prevent sexually transmitted hiv, the most desirable active ingredients of microbicides are antiretrovirals (arvs) that directly target viral entry and avert infection at mucosal surfaces. however, most promising arv entry inhibitors are biologicals, which are costly to manufacture and deliver to resource-poor areas where effective microbicides are urgently needed. here, we report a manufacturing breakthrough for griffithsin (grft), one of the most potent hiv entry inhibitors. this red algal ...	2009	19332801
cymbidium mosaic potexvirus isolate-dependent host movement systems reveal two movement control determinants and the coat protein is the dominant.	little is known about how plant viruses of a single species exhibit different movement behavior in different host species. two cymbidium mosaic potexvirus (cymmv) isolates, m1 and m2, were studied. both can infect phalaenopsis orchids, but only m1 can systemically infect nicotiana benthamiana plants. protoplast inoculation and whole-mount in situ hybridization revealed that both isolates can replicate in n. benthamiana; however, m2 was restricted to the initially infected cells. genome shuffling ...	2009	19345971
analysis of temperature modulation of plant defense against biotrophic microbes.	plant-pathogen interactions are known to be affected by environmental factors including temperature; however, the temperature effects have not been systematically studied in plant disease resistance. here, we characterized the effects of a moderate increase in temperature on resistance to bacterial pathogen pseudomonas syringae and two viral elicitors in arabidopsis thaliana and nicotiana benthamiana. both the basal and the resistance (r) gene-mediated defense responses to pseudomonas syringae a ...	2009	19348568
a comparative study of the involvement of 17 arabidopsis myosin family members on the motility of golgi and other organelles.	gene families with multiple members are predicted to have individuals with overlapping functions. we examined all of the arabidopsis (arabidopsis thaliana) myosin family members for their involvement in golgi and other organelle motility. truncated fragments of all 17 annotated arabidopsis myosins containing either the iq tail or tail domains only were fused to fluorescent markers and coexpressed with a golgi marker in two different plants. we tracked and calculated golgi body displacement rate ...	2009	19369591
studies of the role and function of barley stripe mosaic virus encoded proteins in replication and movement using gfp fusions.	this chapter describes techniques to investigate the localisation and function of virus-encoded proteins in plants using green fluorescent protein (gfp) transiently expressed from plasmids or infectious cdna reporter clones of barley stripe mosaic virus. virus movement and the localisation of gfp-tagged proteins in living cells were monitored by confocal laser scanning microscopy (clsm). in addition, gfp expression was imaged in transgenic plants where specific organelles or subcellular structur ...	2009	19378124
deletions in the repertoire of pseudomonas syringae pv. tomato dc3000 type iii secretion effector genes reveal functional overlap among effectors.	the gamma-proteobacterial plant pathogen pseudomonas syringae pv. tomato dc3000 uses the type iii secretion system to inject ca. 28 avr/hop effector proteins into plants, which enables the bacterium to grow from low inoculum levels to produce bacterial speck symptoms in tomato, arabidopsis thaliana, and (when lacking hopq1-1) nicotiana benthamiana. the effectors are collectively essential but individually dispensable for the ability of the bacteria to defeat defenses, grow, and produce symptoms ...	2009	19381254
a severe symptom phenotype in tomato in mali is caused by a reassortant between a novel recombinant begomovirus (tomato yellow leaf curl mali virus) and a betasatellite.	tomato production in west africa has been severely affected by begomovirus diseases, including yellow leaf curl and a severe symptom phenotype, characterized by extremely stunted and distorted growth and small deformed leaves. here, a novel recombinant begomovirus from mali, tomato yellow leaf curl mali virus (tylcmlv), is described that, alone, causes tomato yellow leaf curl disease or, in combination with a betasatellite, causes the severe symptom phenotype. tylcmlv is an old world monopartite ...	2009	19400843
synergistic interaction between the potyvirus, turnip mosaic virus and the crinivirus, lettuce infectious yellows virus in plants and protoplasts.	lettuce infectious yellows virus (liyv), the type member of the genus crinivirus in the family closteroviridae, is specifically transmitted by the sweet potato whitefly (bemisia tabaci) in a semipersistent manner. liyv infections result in a low virus titer in plants and protoplasts, impeding reverse genetic efforts to analyze liyv gene/protein functions. we found that synergistic interactions occurred in mixed infections of liyv and turnip mosaic virus (tumv) in nicotiana benthamiana plants, an ...	2009	19409943
gene silencing and virus resistance based on defective interfering constructs in transgenic nicotiana benthamiana is not linked to accumulation of sirna.	rna interference (rnai) was established in nicotiana benthamiana plants by introducing constructs containing a defective interfering (di) sequence from tomato bushy stunt virus (tbsv) in combination with a conserved sense-sequence from the target grapevine fanleaf virus (gflv). silencing in plants was confirmed by agrobacterium-mediated infiltration of a gfp-sensor containing the gflv-derived target sequence. the transgene-induced rnai led to silencing of the gfp-sensor and gfp fluorescence was ...	2009	19419883
transient co-expression for fast and high-yield production of antibodies with human-like n-glycans in plants.	plant-based transient expression is potentially the most rapid and cost-efficient system for the production of recombinant pharmaceutical proteins, but safety concerns associated with plant-specific n-glycosylation have hampered its adoption as a commercial production system. in this article, we describe an approach based on the simultaneous transient co-expression of an antibody, a suppressor of silencing and a chimaeric human beta1,4-galactosyltransferase targeted for optimal activity to the e ...	2009	19422604
impact of a defective rna 3 from cucumber mosaic virus on helper virus infection dynamics.	d rna 3yalpha (d3yalpha), a defective (d) rna 3 derived from the y strain of cucumber mosaic virus (cmv-y), was further characterized in combination with different helper viruses in the genus cucumovirus. interestingly, nicotiana benthamiana plants inoculated with cmv-d8 and d3yalpha developed systemic symptoms which were different from those induced by cmv-d8. to elucidate the potential effects of d rna 3 on virus infection on the basis of the original combination of cmv-y and d3yalpha, a point ...	2009	19427011
characterization of vitis vinifera npr1 homologs involved in the regulation of pathogenesis-related gene expression.	grapevine protection against diseases needs alternative strategies to the use of phytochemicals, implying a thorough knowledge of innate defense mechanisms. however, signalling pathways and regulatory elements leading to induction of defense responses have yet to be characterized in this species. in order to study defense response signalling to pathogens in vitis vinifera, we took advantage of its recently completed genome sequence to characterize two putative orthologs of npr1, a key player in ...	2009	19432948
evidence that the linker between the methyltransferase and helicase domains of potato virus x replicase is involved in homologous rna recombination.	recombination in rna viruses, one of the main factors contributing to their genetic variability and evolution, is a widespread phenomenon. in this study, an in vivo assay to characterize rna recombination in potato virus x (pvx), under high selection pressure, was established. agrobacterium tumefaciens was used to express in nicotiana benthamiana leaf tissue both a pvx isolate labeled with green fluorescent protein (gfp) containing a coat protein deletion mutation (deltacp) and a transcript enco ...	2009	19439477
identification and functional characterization of regions that can be crosslinked to rna in the helicase-like domain of bamv replicase.	the helicase-like domain of the bamboo mosaic virus replicase catalyzes the release of 5'-gamma-phosphate from both atp and 5'-triphosphated rna by an identical set of catalytic residues with a presumably larger binding pocket for rna. in this study, the peptidyl regions involved in rna binding were mapped by reversible formaldehyde crosslinking and mass spectrometry. eleven residues within these regions were examined by mutational analysis. h636a, y704a, and k706a greatly diminished the enzymat ...	2009	19443005
nitric oxide as a partner of reactive oxygen species participates in disease resistance to nectrotophic pathogen botryis cinerea in nicotiana benthamiana.	nitric oxide (no) is an essential regulatory molecule in plant immunity in synergy with reactive oxygen species (ros). however, little is known about the role of no in disease resistance to necrotrophic pathogens. no and oxidative bursts were induced during necrotrophic fungal pathogen botrytis cinerea and nicotiana benthamiana compatible interaction. histochemical analyses showed that both no and ros were produced in adjacent cells of invaded areas in n. benthamiana leaves. activation of salicy ...	2009	19445587
the xanthomonas campestris pv. vesicatoria type iii effector protein xopj inhibits protein secretion: evidence for interference with cell wall-associated defense responses.	the phytopathogenic bacterium xanthomonas campestris pv. vesicatoria uses the type iii secretion system (t3ss) to inject effector proteins into cells of its solanaceous host plants. it is generally assumed that these effectors manipulate host pathways to favor bacterial replication and survival. however, the molecular mechanisms by which type iii effectors suppress host defense responses are far from being understood. based on sequence similarity, xanthomonas outer protein j (xopj) is a member o ...	2009	19445590
trans-replication of, and competition between, dna beta satellites in plants inoculated with tomato yellow leaf curl china virus and tobacco curly shoot virus.	tomato yellow leaf curl china virus (tylccnv) y10 isolate (y10) and tobacco curly shoot virus (tbcsv) y35 isolate (y35), both obtained from yunnan province, were each found to be associated with a distinct species of satellite dna (dna beta). here, we demonstrate that both y10 dna beta (y10beta) and y35 dna beta (y35beta) were stably trans-replicated by the noncognate begomovirus, although the noncognate dna beta accumulated in plants at a lower level than did the cognate dna beta. in nicotiana ...	2009	19453231
functional redundancy in the arabidopsis cathepsin b gene family contributes to basal defence, the hypersensitive response and senescence.	cysteine proteases are required for programmed cell death (pcd) in animals. recent work in nicotiana benthamiana has implicated cathepsin b-like cysteine proteases in the hypersensitive response (hr) in plants, a form of pcd involved in disease resistance. here, we investigate the function and regulation of cathepsin b (cathb) genes in plant defence, and in both pathogen-inducible and developmental forms of pcd. single, double and triple knockout mutants were isolated for the three arabidopsis t ...	2009	19453434
the role of respiratory burst oxidase homologues in elicitor-induced stomatal closure and hypersensitive response in nicotiana benthamiana.	active oxygen species (aos) are central components of the defence reactions of plants against pathogens. plant respiratory burst oxidase homologues (rboh) of gp91(phox), a plasma membrane protein of the neutrophil nicotinamide adenine dinucleotide phosphate (nadph) oxidase, play a prominent role in aos production. the role of two rboh from nicotiana benthamiana, nbrboha and nbrbohb that encode plant nadph oxidase in the process of elicitor-induced stomatal closure and hypersensitive cell death i ...	2009	19454596
fluorometric quantification of green fluorescent protein in tobacco leaf extracts.	the main use of green fluorescent protein (gfp) is as a reporter system, where the existence of the protein is usually determined visually using fluorescent microscopy. although fluorescence-based quantification of gfp is possible, background fluorescence in plants and in plant extracts was observed by our group. another phenomenon we observed that makes quantification difficult is the increased level of gfp fluorescence in nicotiana benthamiana leaf extracts, probably the result of dimerization ...	2009	19457429
three c-terminal phosphorylation sites in the abutilon mosaic virus movement protein affect symptom development and viral dna accumulation.	the abutilon mosaic virus (abmv, geminiviridae) dna b component encodes a movement protein (mp), which facilitates viral transport within plants and affects pathogenicity. the presence of phosphorylated serine and threonine residues was confirmed for mp expressed in yeast and nicotiana benthamiana by comparative western blot analysis using phospho-amino acid- and mp-specific immunodetection. mass spectrometry of yeast-derived mp identified three phosphorylation sites located in the c-terminal do ...	2009	19464722
overexpression of citrus junos mitochondrial citrate synthase gene in nicotiana benthamiana confers aluminum tolerance.	aluminum (al) toxicity is one of the major factors that limit plant growth in acid soils. al-induced release of organic acids into rhizosphere from the root apex has been identified as a major al-tolerance mechanism in many plant species. in this study, al tolerance of yuzu (citrus junos sieb. ex tanaka) was tested on the basis of root elongation and the results demonstrated that yuzu was al tolerant compared with other plant species. exposure to al triggered the exudation of citrate from the yu ...	2009	19466450
the multiplicity of infection of a plant virus varies during colonization of its eukaryotic host.	the multiplicity of infection (moi), i.e., the number of virus genomes that infect a cell, is a key parameter in virus evolution, as it determines processes such as genetic exchange among genomes, selection intensity on viral genes, epistatic interactions, and the evolution of multipartite viruses. in fact, the moi level is equivalent to the virus ploidy during genome expression. nevertheless, there are few experimental estimates of moi, particularly for viruses with eukaryotic hosts. here we es ...	2009	19474097
effects of dicer-like endoribonucleases 2 and 4 on infection of arabidopsis thaliana by cucumber mosaic virus and a mutant virus lacking the 2b counter-defence protein gene.	in tobacco and nicotiana benthamiana, limited cross-protection against cucumber mosaic virus strain fny (fny-cmv) was provided by prior inoculation with a deletion mutant lacking the 2b silencing-suppressor protein gene (fny-cmvdelta2b). cross-protection by fny-cmvdelta2b did not result from induction of systemic rna silencing. we investigated whether protection occurs through induction of localized rna silencing by using arabidopsis thaliana plants harbouring mutations in genes encoding the dic ...	2009	19474248
rna binding by the brome mosaic virus capsid protein and the regulation of viral rna accumulation.	viral capsid proteins (cps) can regulate gene expression and encapsulate viral rnas. low-level expression of the brome mosaic virus (bmv) cp was found to stimulate viral rna accumulation, while higher levels inhibited translation and bmv rna replication. regulation of translation acts through an rna element named the b box, which is also critical for the replicase assembly. the bmv cp has also been shown to preferentially bind to an rna element named slc that contains the core promoter for genom ...	2009	19481091
identification of domains of the tomato spotted wilt virus nsm protein involved in tubule formation, movement and symptomatology.	deletion and alanine-substitution mutants of the tomato spotted wilt virus nsm protein were generated to identify domains involved in tubule formation, movement and symptomatology using a heterologous tobacco mosaic virus expression system. two regions of nsm, g(19)-s(159) and g(209)-v(283), were required for both tubule formation in protoplasts and cell-to-cell movement in plants, indicating a correlation between these activities. three amino acid groups, d(154), eykk(205-208) and eeeee(284-288 ...	2009	19481775
optimization of the bioprocessing conditions for scale-up of transient production of a heterologous protein in plants using a chemically inducible viral amplicon expression system.	use of transient expression for the rapid, large-scale production of recombinant proteins in plants requires optimization of existing methods to facilitate scale-up of the process. we have demonstrated that the techniques used for agroinfiltration and induction greatly impact transient production levels of heterologous protein. a cucumber mosaic virus inducible viral amplicon (cmviva) expression system was used to transiently produce recombinant alpha-1-antitrypsin (raat) by co-infiltrating harv ...	2009	19504593
virus-induced gene silencing (vigs) in nicotiana benthamiana and tomato.	rna interference (rnai) is a highly specific gene-silencing phenomenon triggered by dsrna. this silencing mechanism uses two major classes of rna regulators: micrornas, which are produced from non-protein coding genes and short interfering rnas (sirnas). plants use rnai to control transposons and to exert tight control over developmental processes such as flower organ formation and leaf development. plants also use rnai to defend themselves against infection by viruses. consequently, many viruse ...	2009	19516240
selective binding of glutathione conjugates of fatty acid derivatives by plant glutathione transferases.	proteomic studies with arabidopsis thaliana have revealed that the plant-specific tau (u) class glutathione transferases (gsts) are selectively retained by s-hexylglutathione affinity supports. overexpression of members of the arabidopsis gst superfamily in escherichia coli showed that 25 of the complement of 28 gstus caused the aberrant accumulation of acylated glutathione thioesters in vivo, a perturbation that was not observed with other gst classes. each gstu caused a specific group of fatty ...	2009	19520850
boosted expression of the sars-cov nucleocapsid protein in tobacco and its immunogenicity in mice.	vaccines produced in plant systems are safe and economical; however, the extensive application of plant-based vaccines is mainly hindered by low expression levels of heterologous proteins in plant systems. here, we demonstrated that the post-transcriptional gene silencing suppressor p19 protein from tomato bushy stunt virus substantially enhanced the transient expression of recombinant sars-cov nucleocapsid (rn) protein in nicotiana benthamiana. the rn protein in the agrobacteria-infiltrated pla ...	2009	19523911
differential requirement of ribosomal protein s6 by plant rna viruses with different translation initiation strategies.	potyvirus infection has been reported to cause an increase in the mrna transcripts of many plant ribosomal proteins (r-proteins). in this study, increased expression of r-protein mrna transcripts was determined to occur in nicotiana benthamiana during infection by potyviruses as well as a tobamovirus demonstrating that this response is not unique to potyviruses. five r-protein genes, rps6, rpl19, rpl13, rpl7, and rps2, were silenced in n. benthamiana to test their roles in viral infection. the a ...	2009	19524993
a novel cation-dependent o-methyltransferase involved in anthocyanin methylation in grapevine.	anthocyanins are major pigments in colored grape (vitis vinifera) berries, and most of them are monomethoxylated or dimethoxylated. we report here the functional characterization of an anthocyanin o-methyltransferase (aomt) from grapevine. the expression pattern in two cultivars with different anthocyanin methylation profiles (syrah and nebbiolo) showed a peak at start ripening (véraison), when the concentrations of all methylated anthocyanins begin to increase. the purified recombinant aomt pro ...	2009	19525322
cucurbit yellow stunting disorder virus p25 is a suppressor of post-transcriptional gene silencing.	post-transcriptional gene silencing (ptgs) degrades rna in a sequence-specific manner and is utilised by plants as a natural defence mechanism against virus invaders. two members of the genus crinivirus have been reported to encode suppressors and counter ptgs: sweet potato chlorotic stunt virus p22 and tomato chlorosis virus (tocv) p22, coat protein and coat protein minor. using an agrobacterium-mediated transient assay on nicotiana benthamiana wildtype and 16c plants, we screened four cucurbit ...	2009	19540278
suppression of local rna silencing is not sufficient to promote cell-to-cell movement of turnip crinkle virus in nicotiana benthamiana.	the biological relationship between suppression of rna silencing and virus movement poses an intriguing question in virus-plant interactions. here, we have used a local rna silencing assay, based on a movement-deficient turnip crinkle virus tcv/gfpdeltacp, to investigate the influence of silencing suppression by three different viral suppressors: the tcv 38k coat protein (cp), the 126k protein of tobacco mosaic virus (tmv), and p19 of tomato bushy stunt virus (tbsv) on cell-to-cell movement and ...	2009	19568335
a branched-chain aminotransferase may regulate hormone levels by affecting knox genes in plants.	branched-chain amino acid transaminases (bcats) play a crucial role in the metabolic pathway of leucine, isoleucine and valine by catalyzing the last step of synthesis and/or the initial step of degradation of these amino acids. in this study, we characterized a new bcat from nicotiana benthamiana (nbbcat, genebank accession no. eu194916), the deduced amino acid sequence of which exhibits a very high percentage of identity to the homologous enzymes from solanum tuberosum (stbcat-2, 91.5%) and ar ...	2009	19568767
maintenance of an old world betasatellite by a new world helper begomovirus and possible rapid adaptation of the betasatellite.	begomoviruses (family geminiviridae) cause major losses to crops throughout the tropical regions of the world. begomoviruses originating from the new world (nw) and the old world (ow) are genetically distinct. whereas the majority of ow begomoviruses have monopartite genomes and whereas most of these associate with a class of symptom-modulating satellites (known as betasatellites), the genomes of nw begomoviruses are exclusively bipartite and do not associate with satellites. here, we show for t ...	2009	19570867
subcellular localization of the barley stripe mosaic virus triple gene block proteins.	barley stripe mosaic virus (bsmv) spreads from cell to cell through the coordinated actions of three triple gene block (tgb) proteins (tgb1, tgb2, and tgb3) arranged in overlapping open reading frames (orfs). our previous studies (d. m. lawrence and a. o. jackson, j. virol. 75:8712-8723, 2001; d. m. lawrence and a. o. jackson, mol. plant pathol. 2:65-75, 2001) have shown that each of these proteins is required for cell-to-cell movement in monocot and dicot hosts. we recently found (h.-s. lim, j. ...	2009	19570874
interaction of tomato yellow leaf curl virus with diverse betasatellites enhances symptom severity.	the complete nucleotide sequence was determined for a begomovirus isolated from tomato exhibiting leaf curling and yellowing symptoms in tochigi prefecture in japan. the genome organization of this virus was similar to those of other old world monopartite begomoviruses. neither a dna betasatellite nor a dna-b component was detected. it had the highest total nucleotide sequence identity (99%) with tomato yellow leaf curl virus-israel[japan:tosa:2005] (tylcv-il[jr:tos:05]) and tylcv-israel[japan:h ...	2009	19575277
identification of beet necrotic yellow vein virus p25 pathogenicity factor-interacting sugar beet proteins that represent putative virus targets or components of plant resistance.	beet necrotic yellow vein virus (bnyvv) induces the most important disease threatening sugar beet. the growth of partially resistant hybrids carrying monogenic dominant resistance genes stabilize yield but are unable to entirely prevent virus infection and replication. p25 is responsible for symptom development and previous studies have shown that recently occurring resistance-breaking isolates possess increased p25 variability. to better understand the viral pathogenicity factor's interplay wit ...	2009	19589075
molecular characterization and pathogenicity of tomato yellow leaf curl virus in china.	several tomato production regions in china were surveyed for tomato yellow leaf curl disease (tylcd), and 31 tomato leaf samples showing tylcd-like symptoms were collected. the partial or full-length genomes of these isolates were sequenced and tomato yellow leaf curl virus (tylcv) was detected in shanghai, zhejiang, jiangsu shandong and hebei provinces of china. the tylcv isolates found in china share high sequence identity ([98%) and have more than 97% sequence identity with tylcvil[ il:reo] ( ...	2009	19590945
in vitro propagation of plant virus using different forms of plant tissue culture and modes of culture operation.	plant virus accumulation was investigated in vitro using three different forms of plant tissue culture. suspended cells, hairy roots and shooty teratomas of nicotiana benthamiana were infected with tobacco mosaic virus (tmv) using the same initial virus:biomass ratio. viral infection did not affect tissue growth or morphology in any of the three culture systems. average maximum virus concentrations in hairy roots and shooty teratomas were similar and about an order of magnitude higher than in su ...	2009	19616595
expression dynamics and ultrastructural localization of epitope-tagged abutilon mosaic virus nuclear shuttle and movement proteins in nicotiana benthamiana cells.	the geminivirus abutilon mosaic virus (abmv) encodes two proteins which are essential for viral spread within plants. the nuclear shuttle protein (nsp) transfers viral dna between the nucleus and cytoplasm, whereas the movement protein (mp) facilitates transport between cells through plasmodesmata and long-distance via phloem. an inducible overexpression system for epitope-tagged nsp and mp in plants yielded unprecedented amounts of both proteins. western blots revealed extensive posttranslation ...	2009	19628237
tomato bushy stunt virus recombination guided by introduced microrna target sequences.	previously we described tomato bushy stunt virus (tbsv) vectors, which retained their capsid protein gene and were engineered with magnesium chelatase (chlh) and phytoene desaturase (pds) gene sequences from nicotiana benthamiana. upon plant infection, these vectors eventually lost the inserted sequences, presumably as a result of recombination. here, we modified the same vectors to also contain the plant mir171 or mir159 target sequences immediately 3' of the silencing inserts. we inoculated n. ...	2009	19640975
nbhb1, nicotiana benthamiana homeobox 1, is a jasmonic acid-dependent positive regulator of pathogen-induced plant cell death.	induction of cell death is an important component of plant defense against pathogens. there have been many reports on the role of phytohormones in pathogen-induced cell death, but jasmonic acid (ja) has not been implicated as a regulator of the response. here, we report the function of nbhb1, nicotiana benthamiana homeobox1, in pathogen-induced cell death in connection with ja signaling. involvement of nbhb1 in cell death was analysed by gain- and loss-of-function studies using agrobacterium-med ...	2009	19645736
regulation of defense gene expression by arabidopsis srfr1.	reduced growth and viability is a common phenotype of plants with constitutively activated pathogen defenses. one branch of the plant innate immunity system, effector-triggered immunity, is especially potent and requires tight control to enable normal plant development. while some facets of this control that directly regulate resistance protein abundance or activity have been documented, general control of effector-triggered signaling sensitivity is poorly understood. we recently identified supp ...	2009	19649196
turnip mosaic virus rna replication complex vesicles are mobile, align with microfilaments, and are each derived from a single viral genome.	nicotiana benthamiana plants were agroinoculated with an infectious cdna clone of turnip mosaic virus (tumv) that was engineered to express a fluorescent protein (green fluorescent protein [gfp] or mcherry) fused to the viral 6k2 protein known to induce vesicle formation. cytoplasmic fluorescent discrete protein structures were observed in infected cells, corresponding to the vesicles containing the viral rna replication complex. the vesicles were motile and aligned with microfilaments. intracel ...	2009	19656892
molecular characterisation and infectivity of a "legumovirus" (genus begomovirus: family geminiviridae) infecting the leguminous weed rhynchosia minima in pakistan.	the legume yellow mosaic viruses (lymvs) that cause extensive losses to grain legumes across southern asia are an evolutionarily unusual group of begomoviruses (genus begomovirus; family geminiviridae) with bipartite genomes. all previously identified lymvs were isolated from leguminous crop species. here we have identified a virus related to the lymvs in a common weed, the legume rhynchosia minima originating from pakistan. analysis of the sequence of the virus shows it to be a typical bipartit ...	2009	19664665
characterization of the cassava geminivirus transcription activation protein putative nuclear localization signal.	the geminivirus transcription activation protein (trap) localizes to the nucleus and contains a putative nuclear localization signal (nls) ((28)prrrr(32)) on the n-terminus. the role of individual residues of this putative nls on nuclear localization and symptom induction was investigated using trap of east african cassava mosaic cameroon virus (eacmcv). subcellular localization was conducted using the green fluorescent protein (gfp). results showed that the proline residue at position 28 (pro-2 ...	2009	19665038
proteolysis of a negative regulator of innate immunity is dependent on resistance genes in tomato and nicotiana benthamiana and induced by multiple bacterial effectors.	rpm1-interacting protein 4 (rin4), a negative regulator of the basal defense response in plants, is targeted by multiple bacterial virulence effectors. we show that rin4 degradation is induced by the effector avrpto from pseudomonas syringae and that this degradation in solanaceous plants is dependent on the resistance protein, pto, a protein kinase, and prf, a nucleotide binding site-leucine-rich repeat protein. our data demonstrate overlap between two of the best-characterized pathways for rec ...	2009	19671880
protein mislocalization in plant cells using a gfp-binding chromobody.	a key challenge in cell biology is to directly link protein localization to function. the green fluorescent protein (gfp)-binding protein, gbp, is a 13-kda soluble protein derived from a llama heavy chain antibody that binds with high affinity to gfp as well as to some gfp variants such as yellow fluorescent protein (yfp). a gbp fusion to the red fluorescent protein (rfp), a molecule termed a chromobody, was previously used to trace in vivo the localization of various animal antigens. in this st ...	2009	19686537
characterization of a member of a new potyvirus species infecting arracacha in brazil.	an arracacha (arracacia xanthorrhiza) plant collected in brazil was found to be infected by a new virus. this viral isolate (named c17) systemically infected nicotiana benthamiana and apium graveolens. a polyclonal antibody was raised, and analysis of our arracacha germplasm collection showed a high infection rate of c17-like viruses (93% infection). sequencing of the ca. 1.7 kb 3'-terminal genomic region revealed a typical potyvirus genome organization. it shared less than 70% nucleotide identi ...	2009	19109690
functional characterization of a stilbene synthase gene using a transient expression system in planta.	the expression and functionality of a resveratrol synthase (rs) gene from peanut (arachis hypogaea) was studied using an agrobacterium tumefaciens-mediated transient expression system in nicotiana benthamiana leaves. functional analysis of rs was demonstrated by tracking its expression during 96 h. to measure the transcripts levels of rs transgene, real-time qrt-pcr was used and revealed that the highest level of transcripts was at 48 h post-transfection. western blot analyses showed that rs pro ...	2009	19116720
forca, a promoter element that responds to crosstalk between defense and light signaling.	recognition of pathogenic microorganisms triggers in plants comprehensive transcriptional reprogramming. in order to identify transcriptome-level control elements required for plant immune responses we are examining several sets of genes found by microarray experiments to be co-activated in arabidopsis thaliana (arabidopsis) seedlings infected with the oomycete hyaloperonospora parasitica. promoter motifs conserved in clusters of co-expressed genes may be involved in mediating coordinated gene a ...	2009	19128484
compromised virus-induced gene silencing in rdr6-deficient plants.	rna silencing in plants serves as a potent antiviral defense mechanism through the action of small interfering rnas (sirnas), which direct rna degradation. sirnas can be derived directly from the viral genome or via the action of host-encoded rna-dependent rna polymerases (rdrs). plant genomes encode multiple rdrs, and it has been demonstrated that plants defective for rdr6 hyperaccumulate several classes of virus. in this study, we compared the effectiveness of virus-induced gene silencing (vig ...	2009	19129420
allelic variants of the pseudomonas syringae type iii effector hopz1 are differentially recognized by plant resistance systems.	the bacterial plant pathogen pseudomonas syringae depends on the type iii secretion system and type iii-secreted effectors to cause disease in plants. hopz is a diverse family of type iii effectors widely distributed in p. syringae isolates. among the hopz homologs, hopz1 is ancient to p. syringae and has been shown to be under strong positive selection driven by plant resistance-imposed selective pressure. here, we characterized the virulence and avirulence functions of the three hopz1 alleles ...	2009	19132870
subcellular localization and expression of bamboo mosaic virus satellite rna-encoded protein.	the satellite rna of bamboo mosaic virus (satbamv) has a single open reading frame encoding a non-structural protein, p20, which facilitates long-distance movement of satbamv in bamv and satbamv co-infected plants. immunohistochemistry and immunoelectron microscopy revealed that the p20 protein accumulated in the cytoplasm and nuclei in co-infected cells. p20 and the helper virus coat protein (cp) were highly similar in their subcellular localization, except that aggregates of bamv virions were ...	2009	19141462
transient protein expression in three pisum sativum (green pea) varieties.	the expression of proteins in plants both transiently and via permanently transformed lines has been demonstrated by a number of groups. transient plant expression systems, due to high expression levels and speed of production, show greater promise for the manufacturing of biopharmaceuticals when compared to permanent transformants. expression vectors based on a tobacco mosaic virus (tmv) are the most commonly utilized and the primary plant used, nicotiana benthamiana, has demonstrated the abili ...	2009	19156736
grapevine fanleaf virus (gflv)-specific antibodies confer gflv and arabis mosaic virus (armv) resistance in nicotiana benthamiana.	grapevine fanleaf virus (gflv) is one of the most destructive pathogens of grapevine. in this study, we generated monoclonal antibodies binding specifically to the coat protein of gflv. antibody fl(3), which bound most strongly to gflv and showed cross-reactivity to arabis mosaic virus (armv), was used to construct the single-chain antibody fragment scfvgflvcp-55. to evaluate the potential of this single-chain variable fragment (scfv) to confer antibody-mediated virus resistance, transgenic nico ...	2009	19161351
chimeras between oilseed rape mosaic virus and tobacco mosaic virus highlight the relevant role of the tobamoviral rdrp as pathogenicity determinant in several hosts.	oilseed rape mosaic virus (ormv) is a tobamovirus taxonomically distinct from the type member of the genus, tobacco mosaic virus (tmv). both viruses display a specific host range, although they share certain hosts, such as arabidopsis thaliana, nicotiana benthamiana and n. tabacum, on which they induce different symptoms. using a gain-of-symptom approach, we generated chimeric viruses, starting from a tmv infectious clone, over which different regions of ormv were exchanged with their correspond ...	2009	19161353
tomato yellow leaf curl thailand virus-[y72] from yunnan is a monopartite begomovirus associated with dnabeta.	previous studies have shown that isolates of tomato yellow leaf curl thailand virus (tylcthv) originated from thailand are bipartite begomoviruses, while all the seven tylcthv isolates found in china are associated with dnabeta molecules. in this study, infectious clones of tylcthv isolate y72 (tylcthv-[y72]) and its dnabeta were constructed to verify the bipartite or monopartite nature of tylcthv. agroinoculation showed that tylcthv-[y72] alone was able to induce significant symptoms in nicotia ...	2009	19165588
efficient virus-induced gene silencing in plants using a modified geminivirus dna1 component.	virus-induced gene silencing (vigs) is currently recognized as a powerful reverse genetics tool for application in functional genomics. dna1, a satellite-like and single-stranded dna molecule associated with begomoviruses (family geminiviridae), has been shown to replicate autonomously but requires the helper virus for its dissemination. we developed a vigs vector based on the dna1 component of tobacco curly shoot virus (tbcsv), a monopartite begomovirus, by inserting a multiple cloning site bet ...	2009	19175519
rapid system for evaluating bioproduction capacity of complex pharmaceutical proteins in plants.	transgene product yield remains a key limitation in commercializing plant-derived pharmaceutical proteins. although significant progress has been made in understanding the roles of promoters, enhancers, integration sites, codon usage, cryptic rna sites, silencing, and product compartmentalization on product yield and quality, researchers still cannot reliably predict which proteins will be produced at high levels or what manipulations will guarantee enhanced productivity. we have optimized a sim ...	2009	19183893
expressing a whitefly groel protein in nicotiana benthamiana plants confers tolerance to tomato yellow leaf curl virus and cucumber mosaic virus, but not to grapevine virus a or tobacco mosaic virus.	transgenesis offers many ways to obtain virus-resistant plants. however, in most cases resistance is against a single virus or viral strain. we have taken a novel approach based on the ability of a whitefly endosymbiotic groel to bind viruses belonging to several genera, in vivo and in vitro. we have expressed the groel gene in nicotiana benthamiana plants, postulating that upon virus inoculation, groel will bind to virions, thereby interfering with pathogenesis. the transgenic plants were inocu ...	2009	19184338
a cis element within flowering locus t mrna determines its mobility and facilitates trafficking of heterologous viral rna.	the arabidopsis flowering locus t (ft) gene encodes the mobile florigen essential for floral induction. while movement of the ft protein has been shown to occur within plants, systemic spread of ft mrna remains to be unequivocally demonstrated. utilizing novel rna mobility assay vectors based on two distinct movement-defective viruses, potato virus x and turnip crinkle virus, and an agroinfiltration assay, we demonstrate that nontranslatable ft mrna, independent of the ft protein, moves througho ...	2009	19193810
immunogenicity of hemagglutinin from a/bar-headed goose/qinghai/1a/05 and a/anhui/1/05 strains of h5n1 influenza viruses produced in nicotiana benthamiana plants.	highly pathogenic avian influenza (hpai) viruses of the h5n1 subtype have been identified as a potential pandemic threat by the world health organization (who). since 1997, these viruses have been spreading from asia to europe and africa with increasing genetic and antigenic diversities. vaccination is the preferred strategy for the prevention and control of influenza infections and the availability of a system for the rapid engineering and production of vaccines is required in the event of an i ...	2009	19200814
a single component two-valent lcrv-f1 vaccine protects non-human primates against pneumonic plague.	yersinia pestis continues to pose a threat as a potential biological weapon and is recognized by public health experts as a re-emerging infectious disease. therefore there is great interest in developing a safe and effective vaccine. vaccines against plague containing both the fraction 1 (f1) and v antigens of y. pestis have shown promise in protecting animal models against pneumonic plague, the deadliest form of the disease. here we report on a plague vaccine consisting of the f1 and lcrv antig ...	2009	19200825
an e7-based therapeutic vaccine protects mice against hpv16 associated cancer.	plant-derived vaccines represent an attractive strategy for cancer immunotherapy due to their relative safety and cost-effectiveness. we evaluated the anti-tumour activity of a nicotiana benthamiana produced vaccine candidate based on the non-transforming e7 protein of hpv-16 fused to beta-1,3-1,4-glucanase of clostridium thermocellum. two doses of vaccine at two week intervals were administered to groups of c57bl/6 mice starting 3 or 6 days after challenge with tumourigenic e7-expressing tc-1* ...	2009	19200826
differential expression of eight defensin genes of n. benthamiana following biotic stress, wounding, ethylene, and benzothiadiazole treatments.	eight nicotiana benthamiana defensin genes were identified that could be divided into two classes with class ii defensins being longer than class i defensins due to an additional acidic c-terminal domain. class i defensins were nbdef1.1, nbdef1.2, nbdef1.3, nbdef1.4, nbdef1.5, and nbdef1.6, and class ii were nbdef2.1 and nbdef2.2. relative rt-pcr showed that nbdef1.1, nbdef1.2, and nbdef1.4 had relatively similar expression levels in healthy leaves, stems, roots, flowers, and seeds. however, nbd ...	2009	19214516
nicotiana benthamiana protein, nbpcip1, interacting with potato virus x coat protein plays a role as susceptible factor for viral infection.	the interactions of viral coat protein (cp) and host factors play an important role in viral replication and/or host defense mechanism. in this study, we constructed nicotiana benthamiana cdna library to find host factors interacting with potato virus x (pvx) cp. using yeast two-hybrid assay, we screened 3.3 x 10(6) independent yeast transformants from n. benthamiana cdna library and identified six positive clones. one positive clone, named pvx cp-interacting protein 1 (nbpcip1), is a plant-spec ...	2009	19215953
inhibition of tobacco mosaic virus movement by expression of an actin-binding protein.	the tobacco mosaic virus (tmv) movement protein (mp) required for the cell-to-cell spread of viral rna interacts with the endoplasmic reticulum (er) as well as with the cytoskeleton during infection. whereas associations of mp with er and microtubules have been intensely investigated, research on the role of actin has been rather scarce. we demonstrate that nicotiana benthamiana plants transgenic for the actin-binding domain 2 of arabidopsis (arabidopsis thaliana) fimbrin (atfim1) fused to green ...	2009	19218363
the effector protein avr2 of the xylem-colonizing fungus fusarium oxysporum activates the tomato resistance protein i-2 intracellularly.	to promote host colonization, many plant pathogens secrete effector proteins that either suppress or counteract host defences. however, when these effectors are recognized by the host's innate immune system, they trigger resistance rather than promoting virulence. effectors are therefore key molecules in determining disease susceptibility or resistance. we show here that avr2, secreted by the vascular wilt fungus fusarium oxysporum f. sp. lycopersici (fol), shows both activities: it is required ...	2009	19228334
silencing of nicotiana benthamiana xrn4p exoribonuclease promotes tombusvirus rna accumulation and recombination.	the cytosolic 5'-to-3' exoribonuclease xrn1p plays a major role in recombination and degradation of tomato bushy stunt tombusvirus (tbsv) replicon (rep)rna in yeast, a model host (serviene, e., shapka, n., cheng, c.p., panavas, t., phuangrat, b., baker, j., and nagy, p.d., 2005. genome-wide screen identifies host genes affecting viral rna recombination. proc. natl. acad. sci. u. s. a. 102(30), 10545-10550.). to test if the plant cytosolic 5'-to-3' exoribonuclease xrn4p, similar to the yeast xrn1 ...	2009	19232421
recombinant-antibody-mediated resistance against tomato yellow leaf curl virus in nicotiana benthamiana.	tomato yellow leaf curl virus (tylcv) is a geminivirus species whose members cause severe crop losses in the tropics and subtropics. we report the expression of a single-chain variable fragment (scfv) antibody that protected nicotiana benthamiana plants from a prevalent iranian isolate of the virus (tylcv-ir). two recombinant antibodies (scfv-screp1 and scfv-screp2) interacting with the multifunctional replication initiator protein (rep) were obtained from phage display libraries and expressed i ...	2009	19234665
over-expression of putative transcriptional coactivator kelp interferes with tomato mosaic virus cell-to-cell movement.	tomato mosaic virus (tomv) encodes a movement protein (mp) that is necessary for virus cell-to-cell movement. we have demonstrated previously that kelp, a putative transcriptional coactivator of arabidopsis thaliana, and its orthologue from brassica campestris can bind to tomv mp in vitro. in this study, we examined the effects of the transient over-expression of kelp on tomv infection and the intracellular localization of mp in nicotiana benthamiana, an experimental host of the virus. in co-bom ...	2009	19236566
visualization of novel virulence activities of the xanthomonas type iii effectors avrbs1, avrbs3 and avrbs4.	xanthomonas campestris pv. vesicatoria secretes at least 20 effector proteins through the type iii secretion system directly into plant cells. in this study, we uncovered virulence activities of the effector proteins avrbs1, avrbs3 and avrbs4 using agrobacterium-mediated transient expression of the corresponding genes in nicotiana benthamiana, followed by microscopic analyses. we showed that, in addition to the nuclear-localized avrbs3, the effector avrbs1, which localizes to the plant cell cyto ...	2009	19236567
characterization and subcellular localization of an rna silencing suppressor encoded by rice stripe tenuivirus.	rice stripe virus (rsv) is a single-stranded (ss) rna virus belonging to the genus tenuivirus. rsv is present in many east asian countries and causes severe diseases in rice fields, especially in china. in this study, we analyzed six proteins encoded by the virus for their abilities to suppress rna silencing in plant using a green fluorescent protein (gfp)-based transient expression assay. our results indicate that ns3 encoded by rsv rna3, but not other five rsv encoded proteins, can strongly su ...	2009	19251298
roles and interactions of begomoviruses and satellite dnas associated with okra leaf curl disease in mali, west africa.	okra leaf curl disease (olcd) is a major constraint on okra (abelmoschus esculentus) production in west africa. two monopartite begomoviruses (okra virus-1 and okra virus-2), a betasatellite and a dna1 satellite are associated with olcd in mali. okra virus-1 is an isolate of okra yellow crinkle virus (oycrv), okra virus-2 is a recombinant isolate of cotton leaf curl gezira virus (clcugv) and the betasatellite is a variant of cotton leaf curl gezira betasatellite (clcugb). cloned dna of oycrv and ...	2009	19264648
variability in the level of rna silencing suppression caused by triple gene block protein 1 (tgbp1) from various potexviruses during infection.	rna silencing is an important defence mechanism against virus infection, and many plant viruses encode rna silencing suppressors as a counter defence. in this study, we analysed the rna silencing suppression ability of multiple virus species of the genus potexvirus. nicotiana benthamiana plants exhibiting rna silencing of a green fluorescent protein (gfp) transgene showed reversal of gfp fluorescence when systemically infected with potexviruses. however, the degree of gfp fluorescence varied amo ...	2009	19264652
pseudomonas syringae hrpp is a type iii secretion substrate specificity switch domain protein that is translocated into plant cells but functions atypically for a substrate-switching protein.	pseudomonas syringae delivers virulence effector proteins into plant cells via an hrp1 type iii secretion system (t3ss). p. syringae pv. tomato dc3000 hrpp has a c-terminal, putative t3ss substrate specificity switch domain, like yersinia yscp. a deltahrpp dc3000 mutant could not cause disease in tomato or elicit a hypersensitive response (hr) in tobacco, but the hr could be restored by expression of hrpp in trans. though hrpp is a relatively divergent protein in the t3ss of different p. syringa ...	2009	19270091
unusual long-distance movement strategies of potato mop-top virus rnas in nicotiana benthamiana.	the potato mop-top virus (pmtv) genome encodes replicase, movement, and capsid proteins on three different rna species that are encapsidated within tubular rod-shaped particles. previously, we showed that the protein produced on translational readthrough (rt) of the coat protein (cp) gene, cp-rt, is associated with one extremity of the virus particles, and that the two rnas encoding replicase and movement proteins can move long distance in the absence of the third rna (rna-cp) that encodes the c ...	2009	19271953
the magnaporthe oryzae avirulence gene avrpiz-t encodes a predicted secreted protein that triggers the immunity in rice mediated by the blast resistance gene piz-t.	the magnaporthe oryzae avirulence gene avrpiz-t activates immunity in a gene-for-gene fashion to rice mediated by the blast resistance gene piz-t. to dissect the molecular mechanism underlying their recognition, we initiated the cloning of avrpiz-t using a map-based cloning strategy. the avrpiz-t gene was delimited to an approximately 21-kb genomic fragment, in which six genes were predicted. complementation tests of each of these six candidate genes led to the final identification of avrpiz-t, ...	2009	19271956
geminivirus al2 and l2 proteins suppress transcriptional gene silencing and cause genome-wide reductions in cytosine methylation.	geminiviruses replicate single-stranded dna genomes through double-stranded intermediates that associate with cellular histone proteins. unlike rna viruses, they are subject to rna-directed methylation pathways that target viral chromatin and likely lead to transcriptional gene silencing (tgs). here we present evidence that the related geminivirus proteins al2 and l2 are able to suppress this aspect of host defense. al2 and l2 interact with and inactivate adenosine kinase (adk), which is require ...	2009	19279102
post-transcriptional gene silencing and virus resistance in nicotiana benthamiana expressing a grapevine virus a minireplicon.	grapevine virus a (gva) is closely associated with the economically important rugose-wood disease of grapevine. in an attempt to develop gva resistance, we made a gfp-tagged gva-minireplicon and utilized it as a tool to consistently activate rna silencing. launching the gva-minireplicon by agroinfiltration delivery resulted in a strong rna silencing response. in light of this finding, we produced transgenic nicotiana benthamiana plants expressing the gva-minireplicon, which displayed phenotypes ...	2009	18821075
a temperature-controlled amplicon system derived from plum pox potyvirus.	the control of replication can facilitate a viral amplicon to reach high expression levels by enabling the virus to escape host defence mechanisms and reducing the deleterious effects of viral infection. we have developed a novel system to regulate amplicon expression by controlling the temperature of plant growth. nicotiana benthamiana plants were transformed at two different temperatures with a cdna copy of the plum pox potyvirus genome harbouring the open reading frame 2 of porcine circovirus ...	2009	18801011
srfr1, a suppressor of effector-triggered immunity, encodes a conserved tetratricopeptide repeat protein with similarity to transcriptional repressors.	effector-triggered immunity provides plants with strong protection from pathogens. however, this response has the potential to be highly deleterious to the host and needs to be tightly controlled. the molecular mechanisms in the plant that regulate the balance between activation and suppression of resistance are not fully understood. previously, we identified arabidopsis suppressor of rps4-rld 1 (srfr1) mutants with enhanced resistance to the bacterial effector avrrps4. these mutants were recess ...	2009	18774967
plant pharming of a full-sized, tumour-targeting antibody using different expression strategies.	the aims of this work were to obtain a human antibody against the tumour-associated antigen tenascin-c (tnc) and to compare the yield and quality of plant-produced antibody in either stable transgenics or using a transient expression system. to this end, the characterization of a full-sized human immunoglobulin g (igg) [monoclonal antibody h10 (mab h10)], derived from a selected single-chain variable fragment (scfv) and produced in plants, is presented. the human mab gene was engineered for plan ...	2009	18793269
molecular mechanisms of generation for nitric oxide and reactive oxygen species, and role of the radical burst in plant immunity.	rapid production of nitric oxide (no) and reactive oxygen species (ros) has been implicated in the regulation of innate immunity in plants. a potato calcium-dependent protein kinase (stcdpk5) activates an nadph oxidase strboha to d by direct phosphorylation of n-terminal regions, and heterologous expression of stcdpk5 and strbohs in nicotiana benthamiana results in oxidative burst. the transgenic potato plants that carry a constitutively active stcdpk5 driven by a pathogen-inducible promoter of ...	2009	19830396
a leaf-based assay using interchangeable design principles to rapidly assemble multistep recombinant pathways.	the assembly of multistep recombinant pathways in stably transformed plants is a cornerstone of crops producing new products yet can be a laborious and time-consuming process. any heterologous expression platform capable of providing a rapid estimation of the functional assembly of an entire pathway would guide the design of such transgenic traits. in this study, we use a nicotiana benthamiana transient leaf expression system to simultaneously express five genes, from five independent t(dna) bin ...	2009	19843252
differing requirements for actin and myosin by plant viruses for sustained intercellular movement.	the actin cytoskeleton has been implicated in the intra- and intercellular movement of a growing number of plant and animal viruses. however, the range of viruses influenced by actin for movement and the mechanism of this transport are poorly understood. here we determine the importance of microfilaments and myosins for the sustained intercellular movement of a group of rna-based plant viruses. we demonstrate that the intercellular movement of viruses from different genera [tobacco mosaic virus ...	2009	19805075
differential resistance to citrus psorosis virus in transgenic nicotiana benthamiana plants expressing hairpin rna derived from the coat protein and 54k protein genes.	citrus psorosis virus (cpsv), genus ophiovirus, family ophioviridae, is the causal agent of a serious disease affecting citrus trees in many countries. the viral genome consists of three ssrnas of negative polarity. post-transcriptional gene silencing (ptgs), a mechanism of plant defence against viruses, can be induced by transgenic expression of virus-derived sequences encoding hairpin rnas. since the production of transgenic citrus lines and their evaluation would take years, a herbaceous mode ...	2009	19820946
production of biologically active human myelocytokines in plants.	an effective system for expression of human granulocyte and granulocyte macrophage colony-stimulating factors (hg-csf and hgm-csf) in nicotiana benthamiana plants was developed using viral vector based on tobacco mosaic virus infecting cruciferous plants. the genes of target proteins were cloned into the viral vector driven by actin promoter of arabidopsis thaliana. the expression vectors were delivered into plant cells by agroinjection. maximal synthesis rate was detected 5 days after injection ...	2009	19916932
isolation and characterization of aawrky1, an artemisia annua transcription factor that regulates the amorpha-4,11-diene synthase gene, a key gene of artemisinin biosynthesis.	amorpha-4,11-diene synthase (ads) of artemisia annua catalyzes the conversion of farnesyl diphosphate into amorpha-4,11-diene, the first committed step in the biosynthesis of the antimalarial drug artemisinin. the promoters of ads contain two reverse-oriented ttgacc w-box cis-acting elements, which are the proposed binding sites of wrky transcription factors. a full-length cdna (aawrky1) was isolated from a cdna library of the glandular secretory trichomes (gsts) in which artemisinin is synthesi ...	2009	19880398
plastocyanin transit peptide interacts with potato virus x coat protein, while silencing of plastocyanin reduces coat protein accumulation in chloroplasts and symptom severity in host plants.	potato virus x coat protein (pvxcp) is, through communication with host proteins, involved in processes such as virus movement and symptom development. here, we report that pvxcp also interacts with the precursor of plastocyanin, a protein involved in photosynthesis, both in vitro and in vivo. yeast two-hybrid analysis indicated that pvxcp interacted with only the plastocyanin transit peptide. in subsequent bimolecular fluorescence complementation assays, both proteins were collocated within chl ...	2009	19888818
myosin xi is required for actin-associated movement of plastid stromules.	stromules are highly dynamic stroma-filled tubules extending from the surface of plastids and occasionally interconnecting individual plastids, allowing the movement of complex biological molecules between the interconnected plastids. experiments with inhibitors of cytoskeleton assembly have indicated the involvement of an actin-based system in stromule movement. however, the motor protein associated with the system had not been identified. here, we present direct evidence that myosin xi is invo ...	2009	19995729
a myosin xi tail domain homologous to the yeast myosin vacuole-binding domain interacts with plastids and stromules in nicotiana benthamiana.	the actin cytoskeleton plays a role in mobility of many different organelles in plant cells, including chloroplasts, mitochondria, golgi, and peroxisomes. while progress has been made in identifying the myosin motors involved in trafficking of various plant organelles, not all of the cargoes mobilized by different members of the myosin xi family have yet been identified. the involvement of myosins in chloroplast positioning and mitochondrial movement was demonstrated by expression of a virus-ind ...	2009	19995734
identification of two rna silencing suppressors from banana bunchy top virus.	in order to suppress rna silencing, many plant and some animal viruses encode rna silencing suppressors to achieve infection. in this study, we report that b3 and b4, encoded by dna3 and dna4 of banana bunchy top virus (bbtv), exhibit rna silencing suppression activity. b3 and b4 were able to increase the transient expression of green fluorescent protein (gfp) and dramatically enhanced the pathogenicity of potato virus x (pvx) in nicotiana benthamiana. b4 was able to reverse established gene sil ...	2009	19816653
transcriptional changes and oxidative stress associated with the synergistic interaction between potato virus x and potato virus y and their relationship with symptom expression.	many virus diseases of economic importance to agriculture result from mixtures of different pathogens invading the host at a given time. this contrasts with the relatively scarce studies available on the molecular events associated with virus-host interactions in mixed infections. compared with single infections, co-infection of nicotiana benthamiana with potato virus x (pvx) and potato virus y (pvy) resulted in increased systemic symptoms (synergism) that led to necrosis of the newly emerging l ...	2009	19810812
loss of the plant dead-box protein ise1 leads to defective mitochondria and increased cell-to-cell transport via plasmodesmata.	plants have intercellular channels, plasmodesmata (pd), that span the cell wall to enable cell-to-cell transport of micro- and macromolecules. we identified an arabidopsis thaliana embryo lethal mutant increased size exclusion limit 1 (ise1) that results in increased pd-mediated transport of fluorescent tracers. the ise1 mutants have a higher frequency of branched and twinned pd than wild-type embryos. silencing of ise1 in mature nicotiana benthamiana leaves also leads to increased pd transport, ...	2009	19805190
evidence for alternate states of cucumber mosaic virus replicase assembly in positive- and negative-strand rna synthesis.	cucumber mosaic virus (cmv) encodes two viral replication proteins, 1a and 2a. accumulating evidence implies that different aspects of 1a-2a interaction in replication complex assembly are involved in the regulation of virus replication. to further investigate cmv replicase assembly and to dissect the involvement of replicase activities in negative- and positive-strand synthesis, we transiently expressed cmv rnas and/or proteins in nicotiana benthamiana leaves using a dna or rna-mediated express ...	2009	19022467