Publications

TitleAbstractYear(sorted descending)
Filter
PMID
Filter
geminiviral vectors based on bean yellow dwarf virus for production of vaccine antigens and monoclonal antibodies in plants.expression of recombinant vaccine antigens and monoclonal antibodies using plant viral vectors has developed extensively during the past several years. the approach benefits from high yields of recombinant protein obtained within days after transient delivery of viral vectors to leaves of nicotiana benthamiana, a tobacco relative. modified viral genomes of both rna and dna viruses have been created. geminiviruses such as bean yellow dwarf virus (beydv) have a small, single stranded dna genome th ...201121358270
virus infection suppresses nicotiana benthamiana adaptive phenotypic plasticity.competition and parasitism are two important selective forces that shape life-histories, migration rates and population dynamics. recently, it has been shown in various pathosystems that parasites can modify intraspecific competition, thus generating an indirect cost of parasitism. here, we investigated if this phenomenon was present in a plant-potyvirus system using two viruses of different virulence (tobacco etch virus and turnip mosaic virus). moreover, we asked if parasitism interacted with ...201121359142
fragment complementation and co-immunoprecipitation assays for understanding r protein structure and function.plant disease resistance (r) proteins confer protection against specific pathogens or pathogen isolates. r proteins function by recognizing pathogen-encoded avirulence (avr) proteins and translating this recognition event into an initiation of downstream signaling pathways. key to understanding this process is the study of the protein-protein interactions involving r proteins. recognition and signaling mechanisms are mediated by both intramolecular interactions that take place between different ...201121359796
purification of effector-target protein complexes via transient expression in nicotiana benthamiana.effectors of plant pathogens play important roles in not only pathogenesis but also plant immunity. plant pathogens use these effectors to manipulate host cells for colonization, and their activities likely influence the evolution of plant immune responses. analyses of genome sequences revealed that oomycete pathogens, such as phytophthora spp., possess hundreds of rxlr effectors that are thought to be delivered into the host cells and hence function inside the cells by interacting with the host ...201121359809
molecular characterization of tomato leaf curl china virus, infecting tomato plants in china, and functional analyses of its associated betasatellite.a novel tomato-infecting begomovirus from guangxi province, china, was identified and characterized, for which the name tomato leaf curl china virus (tolccnv) was proposed. phylogenetic and recombination analyses of the virus genomic sequences suggested that tolccnv may have arisen by recombination among tomato leaf curl vietnam virus (tolcvv), tomato leaf curl gujarat virus (tolcgv), and an unknown virus. a betasatellite molecule was found to be associated with tolccnv (tolccnb), and its comple ...201121378048
tomato 14-3-3 protein tft7 interacts with a map kinase kinase to regulate immunity-associated programmed cell death mediated by diverse disease resistance proteins.programmed cell death (pcd) associated with immunity is triggered when a plant disease resistance (r) protein recognizes a corresponding pathogen virulence protein. in tomato, detection by the host pto kinase of the pseudomonas syringae proteins avrpto or avrptob causes localized pcd. previously, we reported that both mapkkka (mitogen-activated protein kinase kinase kinase) and the tomato 14-3-3 protein 7 (tft7) positively regulate pto-mediated pcd in tomato and nicotiana benthamiana. in additio ...201121378171
phosphorylation of the nicotiana benthamiana wrky8 transcription factor by mapk functions in the defense response.mitogen-activated protein kinase (mapk) cascades have pivotal roles in plant innate immunity. however, downstream signaling of plant defense-related mapks is not well understood. here, we provide evidence that the nicotiana benthamiana wrky8 transcription factor is a physiological substrate of sipk, ntf4, and wipk. clustered pro-directed ser residues (sp cluster), which are conserved in group i wrky proteins, in the n-terminal region of wrky8 were phosphorylated by these mapks in vitro. antiphos ...201121386030
plant-made trastuzumab (herceptin) inhibits her2/neu+ cell proliferation and retards tumor growth.plant biotechnology provides a valuable contribution to global health, in part because it can decrease the cost of pharmaceutical products. breast cancer can now be successfully treated by a humanized monoclonal antibody (mab), trastuzumab (herceptin). a course of treatment, however, is expensive and requires repeated administrations of the mab. here we used an agrobacterium-mediated transient expression system to produce trastuzumab in plant cells.201121390232
the hrpz gene of pseudomonas syringae pv. phaseolicola enhances resistance to rhizomania disease in transgenic nicotiana benthamiana and sugar beet.to explore possible sources of transgenic resistance to the rhizomania-causing beet necrotic yellow vein virus (bnyvv), nicotiana benthamiana plants were constructed to express the harpin of pseudomonas syringae pv. phaseolicola (hrpz(psph)). the hrpz protein was expressed as an n-terminal fusion to the pr1 signal peptide (sp/hrpz) to direct harpin accumulation to the plant apoplast. transgene integration was verified by mpcr in all primary transformants (t0), while immunoblot analysis confirmed ...201121394206
watermelon chlorotic stunt virus (wmcsv): a serious disease threatening watermelon production in jordan.the incidence of watermelon chlorotic stunt disease and the molecular characterization of the jordanian isolate of watermelon chlorotic stunt virus (wmcsv-[jo]) are described in this study. symptomatic leaf samples obtained from watermelon (citrullus lanatus thunb.), melon (cucumis melo l.), squash (cucurbita pepo), cucumber (cucumis sativus l.), and bottle gourd (lagenaria siceraria) plants were tested for wmcsv-[jo] infection by pcr. the virus could be detected in 8 melon and 87 watermelon sam ...201121399920
silencing of nbxrn4 facilitates the systemic infection of tobacco mosaic virus in nicotiana benthamiana.the 5'-3' exoribonucleases (xrns) play key roles in degradation and processing pathways of several classes of rnas including mrna, rrna, mirna and other small rnas. recent work revealed that the cytoplasmic xrn (xrn1p in yeast and xrn4 in plants) affected the stability of the viral rna of tombusviruses in yeast and plants, which indicates that the cytoplasmic xrn might be involved in plant defense against virus by degrading viral rna. here, we demonstrated that silencing of nicotiana benthamiana ...201121402112
identification of pns12 as the second silencing suppressor of rice gall dwarf virus.rna silencing is a conserved mechanism found ubiquitously in eukaryotic organisms. it has been used to regulate gene expression and development. in addition, rna silencing serves as an important mechanism in plants' defense against invasive nucleic acids, such as viruses, transposons, and transgenes. as a counter-defense, most plants, and some animal viruses, encode rna silencing suppressors to interfere at one or several points of the silencing pathway. in this study, we showed that pns12 of rg ...201121416320
genetic variability of east african cassava mosaic cameroon virus under field and controlled environment conditions.cassava geminiviruses occur in all cassava growing areas of africa and are considered to be the most damaging vector-borne plant pathogens. at least seven species of these viruses have been identified. we investigated genetic variation in east african cassava mosaic cassava cameroon virus (eacmcv) from naturally infected cassava and from experimentally infected nicotiana benthamiana. results showed that the populations of eacmcv in cassava and in n. benthamiana were genetically heterogeneous. mu ...201121429548
expression of a recombinant chimeric protein of hepatitis a virus vp1-fc using a replicating vector based on beet curly top virus in tobacco leaves and its immunogenicity in mice.we describe the expression and immunogenicity of a recombinant chimeric protein (hav vp1-fc) consisting of human hepatitis a virus vp1 and an fc antibody fragment using a replicating vector based on beet curly top virus (bctv) in agrobacterium-infiltrated nicotiana benthamiana leaves. recombinant hav vp1-fc was expressed with a molecular mass of approximately 68 kda. recombinant hav vp1-fc, purified using protein a sepharose affinity chromatography, elicited production of specific igg antibodies ...201121442402
a subcellular localization compendium of hydrogen peroxide-induced proteins.the signal transduction mechanisms of the oxidative stress response in plants remain largely unexplored. previously, increased levels of cellular hydrogen peroxide (h(2) o(2) ) had been shown to drastically affect the plant transcriptome. genome-wide transcriptome analyses allowed us to build a comprehensive inventory of h(2) o(2) -induced genes in plants. here, the primary objective was to determine the subcellular localization of these genes and to assess potential trafficking during oxidative ...201121443605
a common set of developmental mirnas are upregulated in nicotiana benthamiana by diverse begomoviruses.begomoviruses are single-stranded dna viruses that cause economically important diseases of many crops throughout the world and induce symptoms in plants, including enations, leaf curling and stunting, that resemble developmental abnormalities. micrornas (mirnas) are small endogenous rnas that are involved in a variety of activities, including plant development, signal transduction and protein degradation, as well as response to environmental stress, and pathogen invasion.201121447165
cloning and characterization of a 9-lipoxygenase gene induced by pathogen attack from nicotiana benthamiana for biotechnological application.plant lipoxygenases (loxs) have been proposed to form biologically active compounds both during normal developmental stages such as germination or growth as well as during responses to environmental stress such as wounding or pathogen attack. in our previous study, we found that enzyme activity of endogenous 9-lox in nicotiana benthamiana was highly induced by agroinfiltration using a tobacco mosaic virus (tmv) based vector system.201121450085
magnetic virus-like nanoparticles in n. benthamiana plants: a new paradigm for environmental and agronomic biotechnological research.this article demonstrates the encapsulation of cubic iron oxide nanoparticles (nps) by brome mosaic virus capsid shells and the formation, for the first time, of virus-based nanoparticles (vnps) with cubic cores. cubic iron oxide nps functionalized with phospholipids containing poly(ethylene glycol) tails and terminal carboxyl groups exhibited exceptional relaxivity in magnetic resonance imaging experiments, which opens the way for in vivo mri studies of systemic virus movement in plants. prelim ...201121452886
pectobacterium carotovorum elicits plant cell death with dspe/f but the p. carotovorum dspe does not suppress callose or induce expression of plant genes early in plant-microbe interactions.the broad-host-range bacterial soft rot pathogen pectobacterium carotovorum causes a dspe/f-dependent plant cell death on nicotiana benthamiana within 24 h postinoculation (hpi) followed by leaf maceration within 48 hpi. p. carotovorum strains with mutations in type iii secretion system (t3ss) regulatory and structural genes, including the dspe/f operon, did not cause hypersensitive response (hr)-like cell death and or leaf maceration. a strain with a mutation in the type ii secretion system cau ...201121469936
phytobacterial type iii effectors hopx1, hopab1 and hopf2 enhance sense-post transcriptional gene silencing independently of plant r gene-effector recognition.plant and animal pathogenic bacteria deploy a variable arsenal of type iii effector proteins (t3eps) to manipulate host defense. specific biochemical functions and molecular/sub-cellular targets have been demonstrated or proposed for a growing number of t3eps, but remain unknown for the majority of them. here we show that transient expression of genes coding certain bacterial t3eps (hopab1, hopx1 and hopf2), which did not elicit hypersensitive response (hr) in transgenic gfp nicotiana benthamian ...201121469938
transformation of {beta}-lycopene cyclase genes from salicornia europaea and arabidopsis conferred salt tolerance in arabidopsis and tobacco.inhibition of lycopene cyclization decreased the salt tolerance of the euhalophyte salicornia europaea l. we isolated a β-lycopene cyclase gene selcy from s. europaea and transformed it into arabidopsis with stable expression. transgenic arabidopsis on post-germination exhibited enhanced tolerance to oxidative and salt stress. after 8 and 21 d recovery from 200 mm nacl treatment, transgenic lines had a higher survival ratio than wild-type (wt) plants. three-week-old transgenic plants treated wit ...201121471119
an optimized mrfp-based bimolecular fluorescence complementation system for the detection of protein-protein interactions in planta.an existing bimolecular fluorescence complementation (bifc) system, based on a monomeric red fluorescent protein (mrfp), has been optimized for the investigation of protein-protein interactions in planta. the expression plasmids, encoding the n-terminal amino acids (aa) 1-168 and the c-terminal aa 169-225 of the mrfp, allow n- or c-terminal fusion of a split mrfp, with the genes of interest. two major improvements over the original vectors have been made. firstly, the coding sequence of a gggsgg ...201121473882
the unfolded protein response is triggered by a plant viral movement protein.infection with potato virus x (pvx) in nicotiana benthamiana plants leads to increased transcript levels of several stress-related host genes, including basic-region leucine zipper 60 (bzip60), skp1, er luminal binding protein (bip), protein disulfide isomerase (pdi), calreticulin (crt), and calmodulin (cam). bzip60 is a key transcription factor that responds to endoplasmic reticulum (er) stress and induces the expression of er-resident chaperones (bip, pdi, crt, and cam). skp1 is a component of ...201121474436
hierarchy and roles of pathogen-associated molecular pattern-induced responses in nicotiana benthamiana.our current understanding of pathogen-associated molecular pattern (pamp)-triggered immunity signaling pathways in plants is limited due to the redundancy of several components or the lethality of mutants in arabidopsis (arabidopsis thaliana). to overcome this, we used a virus-induced gene silencing-based approach in combination with pharmacological studies to decipher links between early pamp-triggered immunity events and their roles in immunity following pamp perception in nicotiana benthamian ...201121478366
quantitative analysis of dynamic protein-protein interactions in planta with a floated-leaf luciferase complementation imaging assay (fluci assay) using binary gateway-vectors.dynamic protein-protein interactions are essential in all cellular and developmental processes. a range of protein-fragment complementation assays (pcas) allow investigating such protein-protein interactions in vivo. in contrast to other pcas, the split-luciferase (split-luc) complementation approach facilitates the dynamic and quantitative in vivo analysis of protein interactions since the reconstitution of luciferase activity upon protein-protein interaction of investigated proteins is reversi ...201121481030
the receptor-like kinase slserk1 is required for mi-1-mediated resistance to potato aphids in tomato.the plant receptor-like kinase somatic embryogenesis receptor kinase 3 (serk3)/brassinosteroid insensitive 1-associated kinase 1 (bak1) is required for pathogen-associated molecular pattern (pamp)-triggered immunity (pti). here we show that a distinct member of the serk family, serk1, is required for the full functioning of mi-1, a nucleotide binding leucine-rich repeat (nb-lrr) resistance protein. mi-1 confers resistance to meloidogyne spp. (root-knot nematodes, rkns) and three phloem-feeding i ...201121481032
infectious clones of tomato leaf curl palampur virus with a defective dna b and their pseudo-recombination with tomato leaf curl new delhi virus.abstract: background: tomato leaf curl palampur virus (tolcpmv) is a bipartite begomovirus which has been reported from india and iran but infectious clones have not been obtained. we have previously shown the association of zucchini yellow mosaic virus (zymv), a potyvirus, with severe leaf curl disease of muskmelon in pakistan. however, the severity of symptoms in the field and yield losses led us to believe that some other agent, such as a begomovirus, could be associated with the disease. res ...201121496256
high levels of expression of fibroblast growth factor 21 in transgenic tobacco (nicotiana benthamiana).fibroblast growth factor-21 (fgf21) is a hepatic hormone that plays a critical role in metabolism, stimulating fatty acid oxidation in the liver and glucose uptake in adipose tissue. in this study, we produced tobacco plants expressing human recombinant fgf21 (hfgf21) via agrobacterium-mediated transformation using a potato virus x (pvx)-based vector (pgr107). the vector contained the sequence encoding the human fgf21 gene fused with green florescence protein and a histidine tag. the recombinant ...201121505802
dynamics of a plant rna virus intracellular accumulation: stamping machine versus geometric replication.the tremendous evolutionary potential of rna viruses allows them thriving despite host defense mechanisms and endows them with properties as emergence, host switching and virulence. the frequency of mutant viruses after an infectious process results from the interplay between the error rate of the viral replicase, from purifying mechanisms acting after transcription on aberrant rnas, and from the amplification dynamics of virus rna positive (+) and negative (-) strands. two extreme scenarios des ...201121515574
helper component proteinase of genus potyvirus is an interaction partner of translation initiation factors eif(iso)4e and eif4e that contains a 4e binding motif.the multifunctional helper component proteinase (hcpro) of potyviruses (genus potyvirus; potyviridae) shows self-interaction and interacts with other potyviral and host plant proteins. host proteins that are pivotal to potyvirus infection include the eukaryotic translation initiation factor eif4e and the isoform eif(iso)4e, which interact with viral genome-linked protein (vpg). here we show that hcpro of potato virus a (pva) interacts with both eif4e and eif(iso)4e, with interactions with eif(is ...201121525344
pseudomonas syringae colonizes distant tissues in nicotiana benthamiana through xylem vessels.the ability to move from the primary infection site and colonize distant tissue in the leaf is an important property of bacterial plant pathogens, yet hardly investigated for model pathogens. here we show that gfp-expressing pseudomonas syringae pv. syringae dc3000 lacking the hopq1-1 effector (ptodc3000δhq) has a strong capacity to colonize distant leaf tissue from wound-inoculated sites in n. benthamiana. distant colonization occurs within one week after toothpick inoculation and is characteri ...201121554458
the early secretory pathway and an actin-myosin viii motility system are required for plasmodesmatal localization of the nsvc4 protein of rice stripe virus.plant viruses utilize movement proteins to gain access to plasmodesmata (pd) for cell-to-cell propagation. while the nsvc4 protein of rice stripe virus (rsv) is implicated in the passage of viruses from cell to cell, its role remains to be elucidated. we examined the mechanisms by which rsv nsvc4 is targeted to pd in cell walls. nsvc4 accumulated at pd when expressed as a fusion with yellow fluorescent protein in leaf cells of nicotiana benthamiana. nsvc4 was targeted to pd via the endoplasmic r ...201121565229
an unusual plant triterpene synthase with predominant α-amyrin producing activity identified by characterising oxidosqualene cyclases from malus x domestica.the pentacyclic triterpenes, in particular ursolic acid and oleanolic acid and their derivatives, exist abundantly in the plant kingdom where they are well-known for their anti-inflammatory, anti-tumour and anti-microbial properties. α-amyrin and β-amyrin are the precursors to ursolic and oleanolic acids respectively, formed by concerted cyclisation of squalene epoxide by a complex synthase reaction. we identified three full-length expressed sequence tag (est) sequences in cdna libraries constru ...201121575133
comparison of phenotypes produced in response to transient expression of genes encoded by four distinct begomoviruses in nicotiana benthamiana and their correlation with the levels of developmental mirnas.abstract: background: whitefly-transmitted geminiviruses (begomoviruses) are a major limiting factor for the production of numerous dicotyledonous crops throughout the world. begomoviruses differ in the number of components that make up their genomes and association with satellites, and yet they cause strikingly similar phenotypes, such as leaf curling, chlorosis and stunted plant growth. micrornas (mirnas) are small endogenous rnas that regulate plant growth and development. the study described ...201121592402
molecular functions of the pp2a regulatory subunit tap46 in plants.tap42/α4 is a regulatory subunit of the protein phosphatase 2a (pp2a) family of phosphatases and plays a role in the target of rapamycin (tor) pathway that regulates cell growth, ribosome biogenesis, translation and cell cycle progression in both yeast and mammals. we determined the cellular functions of tap46, the plant homolog of tap42/α4, in both arabidopsis thaliana and nicotiana benthamiana. tap46 associated with the catalytic subunits of pp2a and the pp2a-like phosphatases pp4 and pp6 in v ...201121597327
evaluation of dna fragments covering the entire genome of a monopartite begomovirus for induction of viral resistance in transgenic plants via gene silencing.tomato-infecting begomoviruses, a member of whitefly-transmitted geminivirus, cause the most devastating virus disease complex of cultivated tomato crops in the tropical and subtropical regions. numerous strategies have been used to engineer crops for their resistance to geminiviruses. however, nearly all have concentrated on engineering the replication-associated gene (rep), but not on a comprehensive evaluation of the entire virus genome. in this study, tomato leaf curl taiwan virus (tolctwv), ...201121597979
identification of an argonaute for antiviral rna silencing in nicotiana benthamiana.argonaute proteins (agos) are known to be key components of the rna silencing mechanism in eukaryotes that, among other functions, serves to protect against viral invaders. higher plants encode at least ten individual agos yet the role played by many in rna silencing-related antiviral defense is largely unknown, except for reports that ago1, ago2, and ago7 play an antiviral role in arabidopsis. in the plant virus model host nicotiana benthamiana, tomato bushy stunt virus (tbsv) p19-suppressor mu ...201121606315
diverse spontaneous silencing of a transgene among two nicotiana species.in plants, transgenes frequently become spontaneously silenced for unknown reasons. typically, transgene silencing involves the generation of small interfering rnas (sirnas) that directly or indirectly target cognate dna and mrna sequences for methylation and degradation, respectively. in this report, we compared spontaneous silencing of a transgene in nicotiana benthamiana and nicotiana tabacum. in both species, abundant sirnas were produced. in n. benthamiana, the self-silencing process involv ...201121617990
application of electrochemically produced aluminum hydroxide gel for prepurification of recombinant synthetic green fluorescent protein produced in tobacco leaves.the use of recombinant proteins has increased greatly in recent years, as also have increased the number of techniques and materials used for their production and purification. among the different types of bioreactors being studied, there is a general consensus among scientists that production in green plant tissues such as leaves is more feasible. however, the presence of chlorophyll and phenolic compounds in plant extracts, which can precipitate and denature the proteins besides damaging separ ...201121626720
endomembrane ca ( 2+) -atpases play a significant role in virus-induced adaptation to oxidative stress.although the role of ca2+ influx channels in oxidative stress signaling and cross-tolerance in plants is well established, little is known about the role of active ca2+ efflux systems in this process. in our recent paper,17 we reported potato virus x (pvx)-induced acquired resistance to oxidative stress in nicotiana benthamiana and showed the critical role of plasma membrane ca2+/h+ exchangers in this process. the current study continues this research. using biochemical and electrophysiological ...201121633195
involvement of sgt1 in cor-mediated signal transduction pathway leading to disease symptom development.pseudomonas syringae pv. tomato dc3000 (pst dc3000), that causes bacterial speck disease on tomato, produces a non-host-specific virulence effector, coronatine (cor). cor functions as a jasmonic acid (ja)-isoleucine mimic in planta and has multiple roles in the pathogenicity of pst dc3000. one of the hallmarks of bacterial speck disease on tomato is the formation of necrotic lesions surrounded by chlorosis and cor is required for disease development. however, the molecular basis of cor-mediated ...201121633196
the merging of two dynasties-identification of an african cotton leaf curl disease-associated begomovirus with cotton in pakistan.cotton leaf curl disease (clcud) is a severe disease of cotton that occurs in africa and pakistan/northwestern india. the disease is caused by begomoviruses in association with specific betasatellites that differ between africa and asia. during survey of symptomatic cotton in sindh (southern pakistan) cotton leaf curl gezira virus (clcugv), the begomovirus associated with clcud in africa, was identified. however, the cognate african betasatellite (cotton leaf curl gezira betasatellite) was not f ...201121637815
human α-mannosidase produced in transgenic tobacco plants is processed in human α-mannosidosis cell lines.deficiency in human lysosomal α-mannosidase (man2b1) results in α-mannosidosis, a lysosomal storage disorder; patients present a wide range of neurological, immunological, and skeletal symptoms caused by a multisystemic accumulation of mannose-containing oligosaccharides. here, we describe the expression of recombinant man2b1 both transiently in nicotiana benthamiana leaves and in the leaves and seeds of stably transformed n. tabacum plants. after purification from tobacco leaves, the recombinan ...201121645202
molecular cloning and functional characterization of a putative sulfite oxidase (so) ortholog from nicotiana benthamiana.sulfite oxidase (so) catalyzes the oxidation of sulfite to sulfate and thus has important roles in diverse metabolic processes. however, systematic molecular and functional investigations on the putative so from tobacco (nicotiana benthamiana) have hitherto not been reported. in this work, a full-length cdna encoding putative sulfite oxidase from n. benthamiana (nbso) was isolated. the deduced nbso protein shares high homology and typical structural features with other species sos. phylogenetic ...201121667106
male sterile 2 encodes a plastid-localized fatty acyl acp reductase required for pollen exine development in arabidopsis thaliana.male sterile 2 (ms2) is predicted to encode a fatty acid reductase required for pollen wall development in arabidopsis thaliana. transient expression of ms2 in tobacco leaves resulted in the accumulation of significant levels of c16 and c18 fatty alcohols. expression of ms2 fused with gfp revealed that an n-terminal transit peptide targets the ms2 to plastids. the plastidial localization of ms2 is biologically important because genetic complementation of ms2 in ms2 homozygous plants was dependen ...201121813653
co-expression of multiple target proteins in plants from a tobacco mosaic virus vector using a combination of homologous and heterologous subgenomic promoters.to co-express multiple target proteins, we engineered a single-component chimeric tobacco mosaic virus (tmv)-based vector containing homologous and heterologous capsid protein subgenomic rna promoters. delivery of this vector into nicotiana benthamiana plants via agroinfiltration resulted in co-expression of two reporter genes within a single cell. furthermore, co-expression of a host-specific antisense rna or a silencing suppressor protein from this vector augmented the accumulation of green fl ...201121779909
agrobacterium-mediated infection of whole plants by yellow dwarf viruses.barley yellow dwarf virus-pav (bydv-pav) and cereal yellow dwarf virus-rpv (cydv-rpv) are only transmitted between host plants by aphid vectors and not by mechanical transmission. this presents a severe limitation for the use of a reverse genetics approach to analyze the effects of mutations in these viruses on plant infection and aphid transmission. here we describe the use of agroinfection to infect plants with bydv-pav and cydv-rpv. the cdnas corresponding to the complete rna genomes of bydv- ...201121763366
physical association of arabidopsis hypersensitive induced reaction proteins (hirs) with the immune receptor rps2.arabidopsis rps2 is a typical nb-lrr resistance (r) protein, which indirectly recognizes the bacterial effector protein avrrpt2 and thereby activates effector-triggered immunity (eti). previously, we identified two hypersensitive induced reaction (athir) proteins, athir1 (at1g09840) and athir2 (at3g01290) as potential rps2 complex components. athir proteins contain the stomatin/prohibitin/flotillin/hflk/c (spfh) domain (also known as the prohibitin (phb) domain or band 7 domain). in this study, ...201121757708
suppressors of rna silencing encoded by the components of the cotton leaf curl begomovirus-betasatellite complex.begomoviruses (family geminiviridae) are single-stranded dna viruses transmitted by the whitefly bemisia tabaci. many economically important diseases in crops are caused by begomoviruses, particularly in tropical and subtropical environments. these include the betasatellite-associated begomoviruses causing cotton leaf curl disease (clcud) that causes significant losses to a mainstay of the economy of pakistan, cotton. rna interference (rnai) or gene silencing is a natural defense response of pla ...201121751853
flagellin produced in plants is a potent adjuvant for oral immunization.the aim of this study was to produce adjuvant with high biosafety, efficacy and low cost. towards this goal, the plant nicotiana benthamiana transient expression system was successfully used to express salmonella typhimurium's flagellin (fljb). the yield of the expressed fljb was 280mg per kg of fresh weight (fw) leaves. the lyophilized plant powder containing plant expressing fljb was mixed with ovalbumin (ova) and used for oral immunization of balb/c mice. the elisa analysis showed higher and ...201121745522
knockdown of ntmed8, a med8-like gene, causes abnormal development of vegetative and floral organs in tobacco (nicotiana tabacum l.).med8, a subunit of mediator complex, has proved to possess crucial functions in many organisms from yeast to human. in plant, the med8 mutant of arabidopsis thaliana displayed delayed anthesis and increased number of leaves during the vegetative period. however, the roles of med8 in other flowering plants are still unknown. to investigate the function of med8 ortholog in tobacco (nicotiana tabacum l.; named as ntmed8), we created transgenic tobacco plants with repressed ntmed8 expression mediate ...201121744120
arabidopsis thaliana alpha1,2-glucosyltransferase (alg10) is required for efficient n-glycosylation and leaf growth.assembly of the dolichol-linked oligosaccharide precursor (glc(3) man(9) glcnac(2) ) is highly conserved among eukaryotes. in contrast to yeast and mammals, little is known about the biosynthesis of dolichol-linked oligosaccharides and the transfer to asparagine residues of nascent polypeptides in plants. to understand the biological function of these processes in plants we characterized the arabidopsis thaliana homolog of yeast alg10, the +¦1,2-glucosyltransferase that transfers the terminal gl ...201121707802
plant hsp90 proteins interact with b-cells and stimulate their proliferation.the molecular chaperone heat shock protein 90 (hsp90) plays an important role in folding stabilization and activation of client proteins. besides, hsp90 of mammals and mammalian pathogens displays immunostimulatory properties. here, we investigated the role of plant-derived hsp90s as b-cell mitogens by measuring their proliferative responses in vitro.201121701588
rna viruses and their silencing suppressors boost abutilon mosaic virus, but not the old world tomato yellow leaf curl sardinia virus.mixed viral infections can induce different changes in symptom development, genome accumulation and tissue tropism. these issues were investigated for two phloem-limited begomoviruses, abutilon mosaic virus (abmv) and tomato yellow leaf curl sardinia virus (tylcsv) in nicotiana benthamiana plants doubly infected by either the potyvirus cowpea aphid-borne mosaic virus (cabmv) or the tombusvirus artichoke mottled crinkle virus (amcv). both rna viruses induced an increase of the amount of abmv, led ...201121843560
self-interaction of abutilon mosaic virus replication initiator protein (rep) in plant cell nuclei.geminiviruses replicate their circular single-stranded dna genome in nuclei of infected plant cells. their replication initiator proteins (reps) possess interaction domains for homo- and hetero-oligomerization as shown previously by in vitro studies and yeast two hybrid assays. here, homo-oligomerization and cellular localization of the abutilon mosaic virus (abmv) rep was analysed with bimolecular fluorescence complementation (bifc) in epidermal tissues of nicotiana benthamiana. bifc revealed t ...201121840354
characterization and functional analysis of ghrdr6, a novel rdr6 gene from cotton (gossypium hirsutum l).rna-dependent rna polymerase 6 (rdr6) is not only involved in viral resistance but also plays an important role in natural plant development. in the present study, a novel rdr gene named ghrdr6 was isolated from cotton (gossypium hirsutum l). alignment and evolutionary relationship analyses showed that ghrdr6 is more closely related to rdr6 than to other rdrs. expression analysis indicated that this single-copy gene is constitutively expressed in roots, stems and leaves. semi-quantitative rt-pcr ...201121679158
the sina e3 ligase osdis1 negatively regulates drought response in rice.ubiquitin-regulated protein degradation is a critical regulatory mechanism that controls a wide range of biological processes in plants. here, we report that osdis1 (for oryza sativa drought-induced sina protein 1), a c3hc4 ring finger e3 ligase, is involved in drought-stress signal transduction in rice (o. sativa). the expression of osdis1 was up-regulated by drought treatment. in vitro ubiquitination assays showed that osdis1 possessed e3 ubiquitin ligase activity and that the conserved region ...201121719639
molecular cloning of mevalonate pathway genes from taraxacum brevicorniculatum and functional characterisation of the key enzyme 3-hydroxy-3-methylglutaryl-coenzyme a reductase.taraxacum brevicorniculatum is known to produce high quality rubber. the biosynthesis of rubber is dependent on isopentenyl pyrophosphate (ipp) precursors derived from the mevalonate (mva) pathway. the cdna sequences of seven mva pathway genes from latex of t. brevicorniculatum were isolated, including three cdna sequences encoding for 3-hydroxy-3-methylglutaryl-coenzyme a (hmg-coa) reductases (tbhmgr1-3). expression analyses indicate an important role of tbhmgr1 as well as for the hmg-coa synth ...201121833516
orthologues of a plant-specific at-4/1 gene in the genus nicotiana and the structural properties of bacterially expressed 4/1 protein.arabidopsis thaliana at-4/1 is the protein of unknown function capable of polar localization in plant cells and intercellular trafficking. in this work, we cloned cdnas and chromosomal genes of at-4/1 orthologues from several nicotiana species. similarly to the 4/1 genes of a.-áthaliana and oryza sativa, nicotiana 4/1 genes have eight exons and seven introns but are considerably longer due to their larger introns. the allotetraploid genome of nicotiana tabacum, which is known to consist of the ' ...201121712068
garlic virus x 11-kda protein granules move within the cytoplasm and traffic a host protein normally found in the nucleolus.the subcellular localization of the 11-kda protein (p11) encoded by orf3 of garlic virus x (garvx; genus allexivirus, family alphaflexiviridae) was examined by confocal microscopy. granules with intense fluorescence were visible on the endoplasmic reticulum when p11 fused with green or red fluorescent protein (gfp or rfp) was expressed in epidermal cells of nicotiana benthamiana. moreover, the p11-rfp granules moved in the cytoplasm, along the cell periphery and through the cell membranes to adj ...201121726366
high-level recombinant protein expression in transgenic plants by using a double-inducible viral vector.we describe here a unique ethanol-inducible process for expression of recombinant proteins in transgenic plants. the process is based on inducible release of viral rna replicons from stably integrated dna proreplicons. a simple treatment with ethanol releases the replicon leading to rna amplification and high-level protein production. to achieve tight control of replicon activation and spread in the uninduced state, the viral vector has been deconstructed, and its two components, the replicon an ...201121825158
detection and characterization of spontaneous internal deletion mutants of beet necrotic yellow vein virus rna3 from systemic host nicotiana benthamiana.beet necrotic yellow vein virus (bnyvv) is a member of the genus benyvirus causing a worldwide sugar beet disease rhizomania. bnyvv contains four or five plus-sense single stranded rnas. in altered selective conditions, multipartite rna viruses of plant are prone to undergoing internal deletions, thus turning into defective rnas (d rnas). although several d rnas have been reported in bnyvv infection, the spontaneous internal deletion mutants responsible for severe symptom in systemic host nicoti ...201121718549
potyviral vpg enhances viral rna translation and inhibits reporter mrna translation in planta.viral protein genome-linked (vpg) plays a central role in several stages of potyvirus infection. this study sought to answer questions about the role of potato virus a (pva; genus potyvirus) vpg in viral and host rna expression. when expressed in nicotiana benthamiana leaves in trans, a dual role of vpg in translation is observed. it repressed the expression of monocistronic luciferase (luc) mrna and simultaneously induced a significant upregulation in the expression of both replicating and nonr ...201121697470
analysis by virus induced gene silencing of the expression of two proline biosynthetic pathway genes in nicotiana benthamiana under stress conditions.proline accumulation is responsible for stress adaptation in many plants. to distinguish the involvement of two proline synthetic pathways, the virus induced gene silencing (vigs) system that silenced the expression of genes encoding +ö(1)-pyrroline-5-carboxylate synthetase (p5cs; ec:1.5.1.12) and ornithine-+¦-aminotransferase (oat; ec 2.6.1.13) was performed, separately or concomitantly, in four-week-old nicotiana benthamiana. leaf discs of vigs-treated tobacco were subjected to the treatment o ...201121831656
tracking viral movement in plants by means of chlorophyll fluorescence imaging.many techniques have been applied to understand viral cell-to-cell movement in host plants, but little progress has been made in understanding viral vascular transport mechanisms. we propose the use of chlorophyll fluorescence imaging techniques, not only to diagnose the viral infection, but also to follow the movement of the virus through the vascular system and its subsequent spread into the leaves. in nicotiana benthamiana plants, imaging of chlorophyll fluorescence parameters such as ðñ(psii ...201121820756
the cytokinin receptors of arabidopsis are located mainly to the endoplasmic reticulum.the plant hormone cytokinin is perceived by membrane-located sensor histidine kinases. arabidopsis (arabidopsis thaliana) possesses three cytokinin receptors: arabidopsis histidine kinase2 (ahk2), ahk3, and cytokinin response1/ahk4. the current model predicts perception of the cytokinin signal at the plasma membrane. however, cytokinin-binding studies with membrane fractions separated by two-phase partitioning showed that in the wild type, as well as in mutants retaining only single cytokinin re ...201121709172
comparative genomics yields insights into niche adaptation of plant vascular wilt pathogens.the vascular wilt fungi verticillium dahliae and v. albo-atrum infect over 200 plant species, causing billions of dollars in annual crop losses. the characteristic wilt symptoms are a result of colonization and proliferation of the pathogens in the xylem vessels, which undergo fluctuations in osmolarity. to gain insights into the mechanisms that confer the organisms' pathogenicity and enable them to proliferate in the unique ecological niche of the plant vascular system, we sequenced the genomes ...201121829347
direct inhibition of tombusvirus plus-strand rna synthesis by a dominant negative mutant of a host metabolic enzyme, glyceraldehyde-3-phosphate dehydrogenase, in yeast and plants.the replication of plus-strand rna viruses depends on many cellular factors. glyceraldehyde-3-phosphate dehydrogenase (gapdh) is an abundant metabolic enzyme that is recruited to the replicase complex of tomato bushy stunt virus (tbsv) and affects asymmetric viral rna synthesis. to further our understanding on the role of gapdh in tbsv replication, we used an in vitro tbsv replication assay based on recombinant p33 and p92(pol) viral replication proteins and cell-free yeast extract. we found tha ...201121697488
satellite rna reduces expression of the 2b suppressor protein resulting in the attenuation of symptoms caused by cucumber mosaic virus infection.satellite rnas (satrnas) depend on cognate helper viruses for replication, encapsidation, movement and transmission. many satrnas with different symptom modulation effects have been reported. the pathogenicity of satrnas is thought to be the result of a direct interaction among the satrna, helper viruses and host factors by unknown mechanisms. to understand the effect of satrna of cucumber mosaic virus (a severe field shandong strain, sd-cmv) on pathogenicity, and the possible involvement of hos ...201121722297
the role of a putative peroxisomal-targeted epoxide hydrolase of nicotiana benthamiana in interactions with colletotrichum destructivum, c. orbiculare or pseudomonas syringae pv. tabaci.motif analysis among 30 eh1 and eh2 epoxide hydrolases from solanaceaeous plants showed differences primarily in the lid region around the catalytic site. based on in silico models of 3d structures, eh1 proteins lack a catalytic triad because of the orientation of one of the conserved lid tyrosines, while the orientation of that tyrosine in eh2 proteins fomed a catalytic triad inside a hydrophobic tunnel. two similar eh2 protein genes from nicotiana benthamiana, nbeh2.1 and nbeh2.2, have a predi ...201121683883
glyceraldehyde 3-phosphate dehydrogenase negatively regulates the replication of bamboo mosaic virus and its associated satellite rna.the identification of cellular proteins associated with virus replicase complexes is crucial to our understanding of virus-host interactions, influencing the host range, replication, and virulence of viruses. a previous in vitro study has demonstrated that partially purified bamboo mosaic virus (bamv) replicase complexes can be employed for the replication of both bamv genomic and satellite bamv (satbamv) rnas. in this study, we investigated the bamv and satbamv 3' untranslated region (utr) bind ...201121715476
p2 of Rice stripe virus (RSV) interacts with OsSGS3 and is a silencing suppressor.A rice cDNA library was screened by a galactosidase 4 (Gal4)-based yeast two-hybrid system with Rice stripe virus (RSV) p2 as bait. The results revealed that RSV p2 interacted with a rice protein exhibiting a high degree of identity with Arabidopsis thaliana suppressor of gene silencing 3 (AtSGS3). The interaction was confirmed by bimolecular fluorescence complementation assay. SGS3 has been shown to be involved in sense transgene-induced RNA silencing and in the biogenesis of trans-acting small ...201121726383
interaction of the host protein nbdnaj with potato virus x minus-strand stem-loop 1 rna and capsid protein affects viral replication and movement.plant viruses must interact with host cellular components to replicate and move from cell to cell. in the case of potato virus x (pvx), it carries stem-loop 1 (sl1) rna essential for viral replication and movement. using two-dimensional electrophoresis northwestern blot analysis, we previously identified several host proteins that bind to sl1 rna. of those, we further characterized a dnaj-like protein from nicotiana benthamiana named nbdnaj. an electrophoretic mobility shift assay confirmed that ...201122166218
satellite rna-derived small interfering rna satsir-12 targeting the 3' untranslated region of cucumber mosaic virus triggers viral rnas for degradation.rna silencing provides protection against rna viruses by targeting both the helper virus and its satellite rna (satrna). virus-derived small interfering rnas (vsirnas) bound with argonaute (ago) proteins are presumed participants in the silencing process. here, we show that a vsirna targeted to virus rnas triggers the host rna-dependent rna polymerase 6 (rdr6)-mediated degradation of viral rnas. we confirmed that satrna-derived small interfering rnas (satsirnas) could be associated with differen ...201121994448
A multifunctional protein encoded by turkey herpesvirus suppresses RNA silencing in Nicotiana benthamiana.Many plant and animal viruses counteract RNA silencing-mediated defense by encoding diverse RNA silencing suppressors. We characterized HVT063, a multifunctional protein encoded by turkey herpesvirus (HVT), as a silencing suppressor in coinfiltration assays with green fluorescent protein transgenic Nicotiana benthamiana line 16c. Our results indicated that HVT063 could strongly suppress both local and systemic RNA silencing induced by either sense RNA or double-stranded RNA (dsRNA). HVT063 could ...201121957299
Biochemical characterization of a chloroplast localized fatty acid reductase from Arabidopsis thaliana.Primary long-chain fatty alcohols are present in a variety of phyla. In eukaryotes, the production of fatty alcohols is catalyzed by fatty acyl-CoA reductase (FAR) enzymes that convert fatty acyl-CoAs or acyl-ACPs into fatty alcohols. Here, we report on the biochemical properties of a purified plant FAR, Arabidopsis FAR6 (AtFAR6). In vitro assays show that the enzyme preferentially uses 16 carbon acyl-chains as substrates and produces predominantly fatty alcohols. Free fatty acids and fatty alde ...201122166367
Detection of protein interactions in plant using a gateway compatible bimolecular fluorescence complementation (BiFC) system.We have developed a BiFC technique to test the interaction between two proteins in vivo. This is accomplished by splitting a yellow fluorescent protein (YFP) into two non-overlapping fragments. Each fragment is cloned in-frame to a gene of interest. These constructs can then be co-transformed into Nicotiana benthamiana via Agrobacterium mediated transformation, allowing the transit expression of fusion proteins. The reconstitution of YFP signal only occurs when the inquest proteins interact (1-7 ...201121947026
risk-managed production of bioactive recombinant proteins using a novel plant virus vector with a helper plant to complement viral systemic movement.a plant viral vector has the potential to efficiently produce recombinant proteins at a low cost in a short period. although recombinant proteins can be also produced by transgenic plants, a plant viral vector, if available, may be more convenient when urgent scale-up in production is needed. however, it is difficult to use a viral vector in open fields because of the risk of escape to the environment. in this study, we constructed a novel viral vector system using a movement-defective cucumber ...201120492549
reverse genetic analysis of ourmiaviruses reveals the nucleolar localization of the coat protein in nicotiana benthamiana and unusual requirements for virion formation.ourmia melon virus (oumv) is the type member of the genus ourmiavirus. these viruses have a trisegmented genome, each part of which encodes a single protein. ourmiaviruses share a distant similarity with other plant viruses only in their movement proteins (mp), whereas their rna-dependent rna polymerase (rdrp) shares features only with fungal viruses of the family narnaviridae. thus, ourmiaviruses are in a unique phylogenetic position among existing plant viruses. here, we developed an agroinocu ...201121411534
potato snakin-1 gene silencing affects cell division, primary metabolism, and cell wall composition.snakin-1 (sn1) is an antimicrobial cysteine-rich peptide isolated from potato (solanum tuberosum) that was classified as a member of the snakin/gibberellic acid stimulated in arabidopsis protein family. in this work, a transgenic approach was used to study the role of sn1 in planta. even when overexpressing sn1, potato lines did not show remarkable morphological differences from the wild type; sn1 silencing resulted in reduced height, which was accompanied by an overall reduction in leaf size an ...201122080603
rna interference-based resistance against a legume mastrevirus.rna interference (rnai) is a homology-dependant gene silencing mechanism and has been widely used to engineer resistance in plants against rna viruses. however, its usefulness in delivering resistance against plant dna viruses belonging to family geminiviridae is still being debated. although the rnai approach has been shown, using a transient assay, to be useful in countering monocotyledonous plant-infecting geminiviruses of the genus mastrevirus, it has yet to be investigated as a means of del ...201122047503
rnai-mediated resistance to diverse isolates belonging to two virus species involved in cassava brown streak disease.cassava brown streak disease (cbsd) is emerging as one of the most important viral diseases of cassava (manihot esculenta) and is considered today as the biggest threat to cassava cultivation in east africa. the disease is caused by isolates of at least two phylogenetically distinct species of single-stranded rna viruses belonging to the family potyviridae, genus ipomovirus. the two species are present predominantly in the coastal lowland [cassava brown streak virus (cbsv); tanzania and mozambiq ...201121118347
agroinoculation of nicotiana benthamiana with cloned honeysuckle yellow vein virus isolated from lonicera japonica.a new honeysuckle yellow vein geminivirus (hyvv) isolate (2,763 nucleotides) and the hyvv-β satellite (1,227 nucleotides) from korea were cloned and characterized from symptomatic leaves of lonicera japonica with a yellow net mosaic appearance. phylogenetic analysis of hyvv and 13 other begomoviruses revealed that hyvv has the highest nucleotide sequence homology to hyvv-uk2. grafting challenge of a virus-free l. japonica (scion) on an hyvv-infected l. japonica (stock) resulted in the appearance ...201121279729
molecular characterisation of the full-length genome of olive latent virus 1 isolated from tomato.olive latent virus 1 (olv-1) is a species of the necrovirus genus. so far, it has been reported to infect olive, citrus tree and tulip. here, we determined and analysed the complete genomic sequence of an isolate designated as cm1, which was collected from tomato plant in the wielkopolska region of poland and represents the prevalent isolate of olv-1. the cm1 genome consists of monopartite single-stranded positive-sense rna genome sized 3,699 nt with five open reading frames (orfs) and small int ...201121181333
the receptor-like kinase serk3/bak1 is required for basal resistance against the late blight pathogen phytophthora infestans in nicotiana benthamiana.the filamentous oomycete plant pathogen phytophthora infestans causes late blight, an economically important disease, on members of the nightshade family (solanaceae), such as the crop plants potato and tomato. the related plant nicotiana benthamiana is a model system to study plant-pathogen interactions, and the susceptibility of n. benthamiana to phytophthora species varies from susceptible to resistant. little is known about the extent to which plant basal immunity, mediated by membrane recep ...201121304602
silencing of aphid genes by dsrna feeding from plants.rna interference (rnai) is a valuable reverse genetics tool to study gene function in various organisms, including hemipteran insects such as aphids. previous work has shown that rnai-mediated knockdown of pea aphid (acyrthosiphon pisum) genes can be achieved through direct injection of double-stranded rna (dsrna) or small-interfering rnas (sirna) into the pea aphid hemolymph or by feeding these insects on artificial diets containing the small rnas.201121998682
autophosphorylation is essential for the in vivo function of the lotus japonicus nod factor receptor 1 and receptor-mediated signalling in cooperation with nod factor receptor 5.soil-living rhizobia secrete lipochitin oligosaccharides known as nod factors, which in lotus japonicus are perceived by at least two nod-factor receptors, nfr1 and nfr5. despite progress in identifying molecular components critical for initial legume host recognition of the microsymbiont and cloning of downstream components, little is known about the activation and signalling mechanisms of the nod-factor receptors themselves. here we show that both receptor proteins localize to the plasma membr ...201121265894
the two endo-β-n-acetylglucosaminidase genes from arabidopsis thaliana encode cytoplasmic enzymes controlling free n-glycan levels.endo-β-n-acetylglucosaminidases (engases) cleave n-glycans from proteins and/or peptides by hydrolyzing the o-glycosidic linkage between the two core-n-acetylglucosamine (glcnac) residues. although, two homologous genes potentially encoding engases have been identified in arabidopsis thaliana, their respective substrate specificity, their subcellular and their organ specific localization was hitherto unknown. in order to investigate the role of engases in this model plant species, we transiently ...201121796445
salicylic acid and its location in response to biotic and abiotic stress.salicylic acid (sa) is an important signal involved in the activation of plant defence responses against abiotic and biotic stress. sa may derive from the phenylpropanoid pathway or via isochorismate synthase as demonstrated in nicotiana benthamiana, tomato and arabidopsis thaliana. the phenylpropanoid pathway as well as isochorismate synthase are localized in the chloroplasts but it remains unknown if the end product sa is in the same organelle. we have studied the localization of sa in a. thal ...201121530511
cell death mediated by the n-terminal domains of a unique and highly conserved class of nb-lrr protein.plant genomes encode large numbers of nucleotide-binding, leucine-rich repeat (nb-lrr) proteins, many of which are active in pathogen detection and defense response induction. nb-lrr proteins fall into two broad classes: those with a toll and interleukin-1 receptor (tir) domain at their n-terminus and those with a coiled-coil (cc) domain at the n-terminus. within cc-nb-lrr-encoding genes, one basal clade is distinguished by having cc domains resembling the arabidopsis thaliana rpw8 protein, whic ...201121501087
a putative arabidopsis thaliana glycosyltransferase, at4g01220, which is closely related to three plant cell wall-specific xylosyltransferases, is differentially expressed spatially and temporally.plant cell wall polysaccharides are amongst the most complex, heterogeneous and abundant bio-molecules on earth. this makes the biosynthetic enzymes, namely the glycosyltransferases and polysaccharide synthases, important research targets in plant science and biotechnology. as an initial step to characterize at4g01220, a putative arabidopsis thaliana encoding glycosyltransferases in cazy gt-family-77 that is similar to three known xylosyltransferases involved in the biosynthesis of the pectic po ...201121421394
metabolic engineering in nicotiana benthamiana reveals key enzyme functions in arabidopsis indole glucosinolate modification.indole glucosinolates, derived from the amino acid trp, are plant secondary metabolites that mediate numerous biological interactions between cruciferous plants and their natural enemies, such as herbivorous insects, pathogens, and other pests. while the genes and enzymes involved in the arabidopsis thaliana core biosynthetic pathway, leading to indol-3-yl-methyl glucosinolate (i3m), have been identified and characterized, the genes and gene products responsible for modification reactions of the ...201121317374
modulation of sulfur metabolism enables efficient glucosinolate engineering.metabolic engineering in heterologous organisms is an attractive approach to achieve efficient production of valuable natural products. glucosinolates represent a good example of such compounds as they are thought to be the cancer-preventive agents in cruciferous plants. we have recently demonstrated that it is feasible to engineer benzylglucosinolate (bgls) in the non-cruciferous plant nicotiana benthamiana by transient expression of five genes from arabidopsis thaliana. in the same study, we s ...201121281472
rpk2 is an essential receptor-like kinase that transmits the clv3 signal in arabidopsis.the shoot apical meristem (sam) is the fundamental structure that is located at the growing tip and gives rise to all aerial parts of plant tissues and organs, such as leaves, stems and flowers. in arabidopsis thaliana, the clavata3 (clv3) pathway regulates the stem cell pool in the sam, in which a small peptide ligand derived from clv3 is perceived by two major receptor complexes, clv1 and clv2-coryne (crn)/suppressor of llp1 2 (sol2), to restrict wuschel (wus) expression. in this study, we use ...201020978082
multiple regulatory elements in the arabidopsis nia1 promoter act synergistically to form a nitrate enhancer.to accommodate fluctuating nutrient levels in the soil, plants modulate their metabolism and root development via signaling mechanisms that rapidly reprogram the plant transcriptome. in the case of nitrate, over 1,000 genes are induced or repressed within minutes of nitrate exposure. to identify cis-regulatory elements that mediate these responses, an enhancer screen was performed in transgenic arabidopsis (arabidopsis thaliana) plants. a 1.8-kb promoter fragment from the nitrate reductase gene ...201020668061
methods to study pamp-triggered immunity using tomato and nicotiana benthamiana.understanding the molecular basis of plant responses to pathogen-associated molecular patterns (pamps) is an active area of research in the field of plant-microbe interactions. a growing number of plant genes involved in various steps of pamp-triggered immunity (pti) pathways and microbial factors involved in the elicitation or suppression of pti have been identified. these studies have largely relied on arabidopsis thaliana and, therefore, most of the pti assays have been developed and optimize ...201020615110
plastidial thioredoxin z interacts with two fructokinase-like proteins in a thiol-dependent manner: evidence for an essential role in chloroplast development in arabidopsis and nicotiana benthamiana.here, we characterize a plastidial thioredoxin (trx) isoform from arabidopsis thaliana that defines a previously unknown branch of plastidial trxs lying between x- and y-type trxs and thus was named trx z. an arabidopsis knockout mutant of trx z had a severe albino phenotype and was inhibited in chloroplast development. quantitative real-time rt-pcr analysis of the mutant suggested that the expressions of genes that depend on a plastid-encoded rna polymerase (pep) were specifically decreased. si ...201020511297
arabidopsis thaliana pattern recognition receptors for bacterial elongation factor tu and flagellin can be combined to form functional chimeric receptors.the receptor kinase efr of arabidopsis thaliana detects the microbe-associated molecular pattern elf18, a peptide that represents the n terminus of bacterial elongation factor tu. here, we tested subdomains of efr for their importance in receptor function. transient expression of tagged versions of efr and efr lacking its cytoplasmic domain in leaves of nicotiana benthamiana resulted in functional binding sites for elf18. no binding of ligand was found with the ectodomain lacking the transmembra ...201020410299
interfamily transfer of a plant pattern-recognition receptor confers broad-spectrum bacterial resistance.plant diseases cause massive losses in agriculture. increasing the natural defenses of plants may reduce the impact of phytopathogens on agricultural productivity. pattern-recognition receptors (prrs) detect microbes by recognizing conserved pathogen-associated molecular patterns (pamps). although the overall importance of pamp-triggered immunity for plant defense is established, it has not been used to confer disease resistance in crops. we report that activity of a prr is retained after its tr ...201020231819
multiple receptor complexes assembled for transmitting clv3 signaling in arabidopsis.in arabidopsis, the feedback regulatory loop between clavata3 (clv3) signaling pathway and transcription factor, wuschel (wus) plays a significant role in shoot apical meristems (sam) maintenance. previously, clv1/clv2 heterodimers were supposed to perceive and transmit clv3 signaling. recent genetic analysis isolated a novel receptor kinase, coryne (crn), which was found to be involved in the clv3 pathway. therefore, new hypothesis was put forward that crn probably acts with clv2 to transmit cl ...201020220313
Refresh
firstprev
...11121314151617181920...
nextlast
Displaying items 1201 - 1300 of 2488