Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| gene targeting in gram-negative bacteria by use of a mobile group ii intron ("targetron") expressed from a broad-host-range vector. | mobile group ii introns ("targetrons") can be programmed for insertion into virtually any desired dna target with high frequency and specificity. here, we show that targetrons expressed via an m-toluic acid-inducible promoter from a broad-host-range vector containing an rk2 minireplicon can be used for efficient gene targeting in a variety of gram-negative bacteria, including escherichia coli, pseudomonas aeruginosa, and agrobacterium tumefaciens. targetrons expressed from donor plasmids introdu ... | 2007 | 17322321 |
| crystal structure of agr_c_4470p from agrobacterium tumefaciens. | we report here the crystal structure at 2.0 a resolution of the agr_c_4470p protein from the gram-negative bacterium agrobacterium tumefaciens. the protein is a tightly associated dimer, each subunit of which bears strong structural homology with the two domains of the heme utilization protein chus from escherichia coli and hems from yersinia enterocolitica. remarkably, the organization of the agr_c_4470p dimer is the same as that of the two domains in chus and hems, providing structural evidenc ... | 2007 | 17322535 |
| characterization of vascular-specific rss1 and rolc promoters for their utilization in engineering plants to develop resistance against hemipteran insect pests. | rice sucrose synthase1, rss1 (isolated from rice) and rolc (isolated from agrobacterium rhizogenes) promoters were evaluated by binding analyses of their respective cis-elements with host nuclear transcription factors. the expression profile of an insecticidal protein driven by these promoters in transgenic plants was monitored. motif-search analysis with available phloem-specific promoter sequences revealed the presence of two boxii elements in rss1. an octopine synthase element, a stem-specifi ... | 2007 | 17323077 |
| chemolithoautotrophic oxidation of thiosulfate, tetrathionate and thiocyanate by a novel rhizobacterium belonging to the genus paracoccus. | two tropical leguminous-rhizospheric strains, sst and jt 001, phylogenetically closest to paracoccus thiocyanatus and paracoccus pantotrophus, respectively, were isolated on reduced sulfur compounds as sole energy and electron sources. while sst had versatile chemolithotrophic abilities to oxidize thiosulfate, tetrathionate, thiocyanate, sulfide and elemental sulfur, jt 001 could oxidize thiosulfate, soluble sulfide, elemental sulfur and a relatively lesser amount of tetrathionate. positive hybr ... | 2007 | 17326754 |
| salidroside production by hairy roots of rhodiola sachalinensis obtained after transformation with agrobacterium rhizogenes. | hairy roots induced by agrobacterium rhizogenes grow faster, and are considered as genetically stable. these hairy roots can be used as an interesting material for the production of secondary metabolites of pharmaceutical value. salidroside has been identified as the major compounds from the roots of rhodiola sachalinensis a. bor. here, we provide an update that adds new perspectives on the prospects and challenges of producing salidroside from hairy roots induced by agrobacterium rhizogene in r ... | 2007 | 17329834 |
| microbial enzymes involved in lactone compound metabolism and their biotechnological applications. | lactone compounds are widely distributed in nature and play important roles in organisms. these compounds are synthesized and metabolized enzymatically in vivo; however, detailed investigation of these enzymes lags behind that of other common enzymes. in this paper, recent work on the enzymes involved in the metabolism of lactone compounds will be reviewed. in particular, fundamental and application studies on lactonases and baeyer-villiger monooxgenases of microbial origin are described. | 2007 | 17333168 |
| [t-dna-induced mutations in transgenic plants]. | the review surveys experimental data on changes of individual traits in genetically modified (transgenic) plants. the attention is focused on mutations induced by t-dna insertions upon agrobacterium-induced transformation of dicotyledonous plants. the character of mutation appearance in transgenic plants is examined. the prospects of mutations induced by t-dna insertions are considered. | 2007 | 17333933 |
| verification and rapid identification of soybean rhizobia in indian soils. | sixty root nodule isolates of soybean rhizobia indigenous to eight field sites in india were characterized using pcr-rflp for repeated sequence rsalpha a 1195-bp dna fragment, indole acetic acid production, and nitrogenase activity. site-dependent variations were observed in terms of iaa production and nitrogenase activities. rsalpha was conserved in slow-growing soybean rhizobia across locations and sites and was absent in other rhizobiaceae members and other bacterial genera. the results sugge ... | 2007 | 17334844 |
| making a friend from a foe: expressing a groel gene from the whitefly bemisia tabaci in the phloem of tomato plants confers resistance to tomato yellow leaf curl virus. | some (perhaps all) plant viruses transmitted in a circulative manner by their insect vectors avoid destruction in the haemolymph by interacting with groel homologues, ensuring transmission. we have previously shown that the phloem-limited begomovirus tomato yellow leaf curl virus (tylcv) interacts in vivo and in vitro with groel produced by the whitefly vector bemisia tabaci. in this study, we have exploited this phenomenon to generate transgenic tomato plants expressing the whitefly groel in th ... | 2007 | 17334947 |
| protein conformational changes of agrobacterium phytochrome agp1 during chromophore assembly and photoconversion. | phytochromes are widely distributed photochromic biliprotein photoreceptors. typical bacterial phytochromes such as agrobacterium agp1 have a c-terminal histidine kinase module; the n-terminal chromophore module induces conformational changes in the protein that lead to modulation of kinase activity. we show by protein cross-linking that the c-terminal histidine kinase module of agp1 mediates stable dimerization. the fragment agp1-m15, which comprises the chromophore module but lacks the histidi ... | 2007 | 17335289 |
| inhibition of lipid a biosynthesis as the primary mechanism of chir-090 antibiotic activity in escherichia coli. | the deacetylation of udp-3-o-[(r)-3-hydroxymyristoyl]-n-acetylglucosamine (udp-3-o-acyl-glcnac) by lpxc is the committed reaction of lipid a biosynthesis. chir-090, a novel n-aroyl-l-threonine hydroxamic acid, is a potent, slow, tight-binding inhibitor of the lpxc deacetylase from the hyperthermophile aquifex aeolicus, and it has excellent antibiotic activity against pseudomonas aeruginosa and escherichia coli, as judged by disk diffusion assays. we now report that chir-090 is also a two-step sl ... | 2007 | 17335290 |
| evolving ideas of legume evolution and diversity: a taxonomic perspective on the occurrence of nodulation. | legumes evolved about 60 million years ago (ma), and nodulation 58 ma. nonnodulation remains common in caesalpinioideae, with smaller numbers in mimosoideae and papilionoideae. the first type of infection by bacteria may have been at junctions where lateral roots emerged, followed by formation of infection threads to confine bacteria and convey them to some cells in the developing nodule, where they were generally released into symbiosomes. infection threads were a prerequisite for root-hair inf ... | 2007 | 17335493 |
| metal induction of a paxillus involutus metallothionein and its heterologous expression in hebeloma cylindrosporum. | * metallothioneins are small polypeptides involved in metal tolerance of many eukaryotes. here we characterized the pimt1 gene, coding for a metallothionein from the ectomycorrhizal fungus paxillus involutus. * expression of pimt1 in p. involutus under metal stress conditions was measured by northern blot and rt-pcr analyses. the full-length cdna was used to perform functional complementation in yeast mutant strains and agrotransformation of hebeloma cylindrosporum. * heterologous expression in ... | 2007 | 17335505 |
| silencing of beta-carotene hydroxylase increases total carotenoid and beta-carotene levels in potato tubers. | beta-carotene is the main dietary precursor of vitamin a. potato tubers contain low levels of carotenoids, composed mainly of the xanthophylls lutein (in the beta-epsilon branch) and violaxanthin (in the beta-beta branch). none of these carotenoids have provitamin a activity. we have previously shown that tuber-specific silencing of the first step in the epsilon-beta branch, lcy-e, redirects metabolic flux towards beta-beta carotenoids, increases total carotenoids up to 2.5-fold and beta-caroten ... | 2007 | 17335571 |
| nuclear labeling of coccidioides posadasii with green fluorescent protein. | coccidioidomycosis is a mild to life-threatening disease in otherwise healthy humans and other mammals caused by the fungus coccidioides spp. understanding the development of the unique dimorphic life cycle of coccidioides spp. and its role in pathogenesis has been an area of research focus. however, nuclear behavior during the saprobic and parasitic life cycle has not been studied intensively. in this study, green fluorescent protein (gfp) was fused to histone h1 and introduced into coccidioide ... | 2007 | 17344520 |
| characterization and transient replication of tomato leaf curl virus defective dnas. | distinct subgenomic dna species known as defective (df) dna molecules were found in plants infected with tomato leaf curl virus (tlcv). four df dnas derived from tlcv type and darwin 1 strains were found to contain large deletions that disrupt all of the viral genes required for viral replication, encapsidation and spread. however, the viral origin of replication (ori), including the replication-associated protein (rep) binding domains, was present in all four df dnas. co-agroinfection of leaf s ... | 2007 | 17347773 |
| genome-wide functional analysis of pathogenicity genes in the rice blast fungus. | rapid translation of genome sequences into meaningful biological information hinges on the integration of multiple experimental and informatics methods into a cohesive platform. despite the explosion in the number of genome sequences available, such a platform does not exist for filamentous fungi. here we present the development and application of a functional genomics and informatics platform for a model plant pathogenic fungus, magnaporthe oryzae. in total, we produced 21,070 mutants through l ... | 2007 | 17353894 |
| molecular diversity of legume root-nodule bacteria in kakadu national park, northern territory, australia. | symbiotic relationships between leguminous plants (family fabaceae) and nodule-forming bacteria in australia native ecosystems remain poorly characterized despite their importance. most studies have focused on temperate parts of the country, where the use of molecular approaches have already revealed the presence of bradyrhizobium, ensifer (formerly sinorhizobium), mesorhizobium and rhizobium genera of legume root-nodule bacteria. we here provide the first molecular characterization of nodulatin ... | 2007 | 17356689 |
| quorum-sensing regulation in rhizobia and its role in symbiotic interactions with legumes. | legume-nodulating bacteria (rhizobia) usually produce n-acyl homoserine lactones, which regulate the induction of gene expression in a quorum-sensing (or population-density)-dependent manner. there is significant diversity in the types of quorum-sensing regulatory systems that are present in different rhizobia and no two independent isolates worked on in detail have the same complement of quorum-sensing genes. the genes regulated by quorum sensing appear to be rather diverse and many are associa ... | 2007 | 17360278 |
| cell-cell communication in the plant pathogen agrobacterium tumefaciens. | the plant pathogen agrobacterium tumefaciens induces the formation of crown gall tumours at wound sites on host plants by directly transforming plant cells. this disease strategy benefits the bacteria as the infected plant tissue produces novel nutrients, called opines, that the colonizing bacteria can use as nutrients. almost all of the genes that are required for virulence, and all of the opine uptake and utilization genes, are carried on large tumour-inducing (ti) plasmids. the observation mo ... | 2007 | 17360279 |
| [obtaining marker-free transgenic soybean plants with optimal frequency by constructing three t-dnas binary vector]. | obtaining marker-free plants with high efficiency will benefit the environmental release of transgenic crops. to achieve this point, a binary vector pnb35svip1 with three t-dnas was constructed by using several mediate plasmids, in which one copy of bar gene expression cassette and two copies of vip1 gene expression cassette were included. eha101 agrobacterium strain harboring the final construct was applied to transform soybean (glycine max) cotyledon nodes. through 2 - 3 months regeneration an ... | 2007 | 17366903 |
| traa, trac and trad autorepress two divergent quorum-regulated promoters near the transfer origin of the ti plasmid of agrobacterium tumefaciens. | whole-genome transcriptional profiling experiments were performed to identify the complete set of trar-regulated genes in isogenic a. tumefaciens strains containing an octopine-type or nopaline-type ti plasmid. most of the known trar-regulated genes as well as a number of new inducible genes were identified. surprisingly, some known members of this regulon showed both weaker induction and weak levels of expression than we had predicted based upon earlier studies. in particular, traa was expresse ... | 2007 | 17367394 |
| caspase-resistant vird2 protein provides enhanced gene delivery and expression in plants. | agrobacterium tumefaciens vird2 protein is one of the key elements of agrobacterium-mediated plant transformation, a process of transfer of t-dna sequence from the agrobacterium tumour inducing plasmid into the nucleus of infected plant cells and its integration into the host genome. the vird2 protein has been shown to be a substrate for a plant caspase-like protease activity (pclp) in tobacco. we demonstrate here that mutagenesis of the vird2 protein to prevent cleavage by pclp increases the ef ... | 2007 | 17370074 |
| hrt and nutrients affect bacterial communities grown on recirculation aquaculture system effluents. | in a recirculation aquaculture system the drumfilter effluent can be used as substrate for heterotrophic bacterial production, which can be recycled as feed. because the bacteria might contain pathogens, which could reduce its suitability as feed, it is important to characterize these communities. bacteria were produced in growth reactors under different conditions: 7 h hydraulic retention time (hrt) vs. 2 h, sodium acetate vs. molasses, and ammonia vs. nitrate. the community of the drumfilter e ... | 2007 | 17371322 |
| characterization of t-dna insertion patterns in the genome of rice blast fungus magnaporthe oryzae. | agrobacterium tumefaciens-mediated transformation (atmt) has been proven to be a powerful strategy for gene disruption in plants and fungi. patterns associated with transferred dna (t-dna) integration in plants and yeast have been studied comprehensively, whereas no detailed analysis of t-dna integration has been reported yet in filamentous fungi. here, we reported the t-dna insertion patterns in the genome of filamentous fungus magnaporthe oryzae. using atmt, a t-dna tagged population consistin ... | 2007 | 17372735 |
| [the pssa gene encodes udp-glucose: polyprenyl phosphate-glucosyl phosphotransferase initiating biosynthesis of rhizobium leguminosarum exopolysaccharide]. | symbiotic nitrogen-fixing bacteria rhizobium leguminosarum by. viciae vf39 secrete an acidic heteropolysaccharide, the biosynthesis of which involves the stage of polyprenyl diphosphate octasaccharide formation, with its carbohydrate fragment corresponding to the repeating polymer unit. the amino acid analysis of the product of the pssa gene, we have earlier identified, showed its homology to bacterial polyisoprenyl phosphate hexose 1-phosphate transferases catalyzing the formation of phosphodie ... | 2007 | 17375671 |
| the quorum-sensing transcription factor trar decodes its dna binding site by direct contacts with dna bases and by detection of dna flexibility. | trar of agrobacterium tumefaciens is a member of the luxr family of transcriptional regulators, and binds to specific dna sequences (tra boxes) at target promoters of the tumour-inducing (ti) plasmid. each tra box has a pronounced dyad symmetry, and each subunit of a trar dimer binds to one half of a tra box via a helix-turn-helix (hth) dna binding motif. structural analysis has suggested that trar makes extensive sequence-specific contacts with tra box dna. in this study, we tested these predic ... | 2007 | 17376086 |
| symbiosis-induced cascade regulation of the mesorhizobium loti r7a virb/d4 type iv secretion system. | the mesorhizobium loti r7a symbiosis island contains genes encoding a virb/d4 type iv secretion system (t4ss) similar to that of agrobacterium tumefaciens. this system has host-dependent effects on symbiosis that probably are due to translocation of two effector proteins, msi059 and msi061, into host cells. here we report that, as in a. tumefaciens, the m. loti vir genes are transcriptionally regulated by a vira/virg two-component regulatory system. a virgn54d mutant gene of m. loti caused const ... | 2007 | 17378428 |
| rhizobium-initiated rice growth inhibition caused by nitric oxide accumulation. | isolates of rhizobium leguminosarum bv. trifolii (the clover root-nodule endosymbiont) from the nile river delta have been found to infect rice roots and colonize the intercellular spaces of the rice roots. some of these isolates inhibit rice seedling growth but one in particular, r4, has been found in rice roots which develop and grow normally. we present evidence that the induced growth inhibition is due to a toxic accumulation of nitric oxide (no), from the reduction of nitrate, and suggest t ... | 2007 | 17378431 |
| rhizobium tropici response to acidity involves activation of glutathione synthesis. | rhizobium tropici ciat899 displays intrinsic tolerance to acidity, and efficiently nodulates phaseolus vulgaris at low ph. by characterizing a gshb mutant strain, glutathione has been previously demonstrated to be essential for r. tropici tolerance to acid stress. the wild-type gshb gene region has been cloned and its transcription profile has been characterized by using quantitative real-time pcr and transcriptional gene fusions. activation of the gshb gene under acid-stress conditions was demo ... | 2007 | 17379738 |
| suppressor of rna silencing encoded by the monopartite tomato leaf curl java begomovirus. | we previously isolated the monopartite begomovirus tomato leaf curl java virus (tolcjav) and satellite dnabeta02 from the same naturally infected tomato source in indonesia. tolcjav induced mild leaf curl symptoms in nicotiana benthamiana plants; dnabeta02 encoded the betac1 gene and produced severe leaf curl symptoms when co-inoculated with tolcjav in n. benthamiana. however, dnabeta02mbetac1, which contains a frame shift mutation, did not induce severe symptoms in n. benthamiana when co-inocul ... | 2007 | 17385070 |
| response of inoculated foliar fed pea plants (pisum sativum l.) to reduced mo supply. | the application of nutrients to the roots and leaves of inoculated pea plants grown under conditions of reduced mo supply was studied. pea plants (pisum sativum l.) were grown on liquid nutrient solution excluding mo from the media until the 35th day under glasshouse conditions. plants were inoculated with the bacterial suspension of rhizobium leguminosarum bv. vicae, strain d293 at approximately 10(8) cells per cm3. the foliar fertilizer agroleaf was applied at 0.3% concentration. changes in th ... | 2007 | 17385546 |
| mesorhizobium albiziae sp. nov., a novel bacterium that nodulates albizia kalkora in a subtropical region of china. | a novel mesorhizobium group associated with albizia kalkora [wang et al. (2006), syst appl microbiol 29, 502-517] was further characterized. the seven strains in this group showed similar protein patterns and were different from defined mesorhizobium species in sds-page of whole-cell proteins. the representative strain ccbau 61158(t) formed a novel mesorhizobium lineage in phylogenetic analyses of 16s rrna, atpd, glnii and nifh genes. however, its nodc gene sequence was more similar to that of r ... | 2007 | 17551028 |
| establishment of an efficient agrobacterium tumefaciens-mediated leaf disc transformation of thellungiella halophila. | thellungiella halophila is a salt-tolerant close relative of arabidopsis, which is adopted as a halophytic model for stress tolerance research. we established an agrobacterium tumefaciens-mediated transformation procedure for t. halophila. leaf explants of t. halophila were incubated with a. tumefaciens strain eha105 containing a binary vector pcambia1301 with the hpt gene as a selectable marker for hygromycin resistance and an intron-containing beta-glucuronidase gene as a reporter gene. follow ... | 2007 | 17551729 |
| highly efficient agrobacterium-mediated transformation of embryogenic cell suspensions of musa acuminata cv. mas (aa) via a liquid co-cultivation system. | a high efficient protocol of agrobacterium-mediated transformation of musa acuminata cv. mas (aa), a major banana variety of the south east asia region, was developed in this study. male-flower-derived embryogenic cell suspensions (ecs) were co-cultivated in liquid medium with agrobacterium strain eha105 harboring a binary vector pcambia2301 carrying nptii and gusa gene in the t-dna. depending upon conditions and duration of co-cultivation in liquid medium, 0-490 transgenic plants per 0.5 ml pac ... | 2007 | 17551731 |
| tryptophan-dependent production of indole-3-acetic acid (iaa) affects level of plant growth promotion by bacillus amyloliquefaciens fzb42. | phytohormone-like acting compounds previously have been suggested to be involved in the phytostimulatory action exerted by the plant-beneficial rhizobacterium bacillus amyloliquefaciens fzb42. analyses by high-performance liquid chromatography and gas chromatography-mass spectrometry performed with culture filtrates of fzb42 demonstrated the presence of indole-3-acetic acid (iaa), corroborating it as one of the pivotal plant-growth-promoting substances produced by this bacterium. in the presence ... | 2007 | 17555270 |
| involvement of a soybean atp-binding cassette-type transporter in the secretion of genistein, a signal flavonoid in legume-rhizobium symbiosis. | legume plants have an ability to fix atmospheric nitrogen into nutrients via symbiosis with soil microbes. as the initial event of the symbiosis, legume plants secrete flavonoids into the rhizosphere to attract rhizobia. secretion of flavonoids is indispensable for the establishment of symbiotic nitrogen fixation, but almost nothing is known about the membrane transport mechanism of flavonoid secretion from legume root cells. in this study, we performed biochemical analyses to characterize the t ... | 2007 | 17556512 |
| the rhizobium etli opt operon is required for symbiosis and stress resistance. | rhizobium etli is a gram-negative root-colonizing soil bacterium capable of fixing nitrogen while living in symbiosis with its leguminous host phaseolus vulgaris. a genome-wide screening for r. etli symbiotic mutants revealed a r. etli operon encoding an oligopeptide abc-transporter (opt), two reda homologous genes and one redb gene. expression analysis showed this opt operon to be transcribed both under free-living and symbiotic conditions and expression levels were demonstrated to be growth-ph ... | 2007 | 17564602 |
| the novel alkali tolerance function of tfxg in sinorhizobium meliloti. | tfxg, one of the tfxabcdefg cluster genes that code for trifolitoxin (tfx) production, was initially described in rhizobium leguminosarum bv. trifolii t24. although several genes in the tfx family have functions related to tfx production or resistance to tfx, the function of tfxg is largely unknown. using cdna-amplified fragment length polymorphism (cdna-aflp) analysis, we found that expression of the tfxg gene dramatically increased under alkaline culture conditions in sinorhizobium meliloti cc ... | 2007 | 17566711 |
| context analysis of termination codons in mrna that are recognized by plant nmd. | the nonsense-mediated mrna decay (nmd) system is an rna surveillance system that degrades mrnas possessing premature translation termination codons (ptcs). although nmd factors are well conserved in eukaryotes, it is speculated that the contexts of those termination codons that are subject to nmd are different depending on the organism. context analysis of termination codons that are recognized by the plant nmd system would clarify nmd target mrnas in plants, and contribute to our understanding ... | 2007 | 17567637 |
| integration of rotation and piston motions in coiled-coil signal transduction. | a coordinated response to a complex and dynamic environment requires an organism to simultaneously monitor and interpret multiple signaling cues. in bacteria and some eukaryotes, environmental responses depend on the histidine autokinases (hks). for example, vira, a large integral membrane hk from agrobacterium tumefaciens, regulates the expression of virulence genes in response to signals from multiple molecular classes (phenol, ph, and sugar). the ability of this pathogen to perceive inputs fr ... | 2007 | 17573470 |
| physiological and expression analyses of agrobacterium tumefaciens trxa, encoding thioredoxin. | exposure of agrobacterium tumefaciens to menadione, cumene hydroperoxide, and diamide strongly induced trxa expression. the trxa mutant showed a reduction in the aerobic growth rate and plating efficiency and was cytochrome c oxidase negative. atypically, the mutant has decreased resistance to menadione but an increased h2o2 resistance phenotype. | 2007 | 17573482 |
| molecular analysis of agrobacterium t-dna integration in tomato reveals a role for left border sequence homology in most integration events. | studies in several plants have shown that agrobacterium tumefaciens t-dna can integrate into plant chromosomal dna by different mechanisms involving single-stranded (ss) or double-stranded (ds) forms. one mechanism requires sequence homology between plant target and sst-dna border sequences and another double-strand-break repair in which preexisting chromosomal dsbs "capture" dst-dnas. to learn more about t-dna integration in solanum lycopersicum we characterised 98 t-dna/plant dna junction sequ ... | 2007 | 17574477 |
| production and secretion of resveratrol in hairy root cultures of peanut. | resveratrol and its derivatives are natural stilbenes associated with many health benefits that include those conferred by their antioxidant and anticancer properties. while stilbenes can be recovered as an extract from a selected number of plants, these products are not suitable for many applications in the food/pharmaceutical sectors due to high levels of impurities as well as the overall low concentration of resveratrol and its derivatives in the extract. to deliver a highly defined and enric ... | 2007 | 17574636 |
| high-speed gel microelectrophoresis, a new and easy approach for detection of pcr-amplified microbial dna from environmental and clinical samples in microgels using conventional equipment. | microelectrophoresis allows the detection of dna bands using minimal amounts of sample in a short time, but commonly requires the use of special equipment which is not available in all laboratories. this fact has limited the application of this technique in microbiology despite its advantages. in this work, we describe a new approach to perform gel microelectrophoresis, named high-speed gel microelectrophoresis (hsgme), and its application for rapid detection of bacteria, protozoa and viruses in ... | 2007 | 17576229 |
| [fruit-specific rnai-mediated lcy gene enhances content of lycopene in tomatoes silencing]. | tomatoes ( lycopersicon esculentum mill.) are the principal dietary source of lycopene which is one of carotenoid and is highly beneficial in preventing some diseases such as the cancer and the heart disease. suppressing the expression of lcy gene, the main gene regulating the transformation of the lycopene, is a convenient and effective way to enhance the content of lycopene. the primers were designed according to the gene sequence(u46919)and (x86452) in genbank. the fruit-specific promoter--ph ... | 2007 | 17577988 |
| production and composition of extracellular polysaccharide synthesized by a rhizobium isolate of vigna mungo (l.) hepper. | an extracellular polysaccharide (eps) was produced by a rhizobium sp. isolated from the root nodules of vigna mungo (l.) hepper. maximum eps production (346 mg l(-1)) was when the yeast extract basal medium was supplemented with mannitol (1%), biotin (1.5 mg l(-1)) and asparagine (0.3%). ribose (53%) and mannose (47%) were the principle monomers of the eps. chemical, chromatographic and spectroscopic analysis showed that this polymer, which has man(4)rib(1) as an oligomeric subunit, has an appar ... | 2007 | 17487547 |
| auxin and nitric oxide control indeterminate nodule formation. | rhizobia symbionts elicit root nodule formation in leguminous plants. nodule development requires local accumulation of auxin. both plants and rhizobia synthesise auxin. we have addressed the effects of bacterial auxin (iaa) on nodulation by using sinorhizobium meliloti and rhizobium leguminosarum bacteria genetically engineered for increased auxin synthesis. | 2007 | 17488509 |
| characterization of agrobacterium tumefaciens dna ligases c and d. | agrobacterium tumefaciens encodes a single nad+-dependent dna ligase and six putative atp-dependent ligases. two of the ligases are homologs of ligd, a bacterial enzyme that catalyzes end-healing and end-sealing steps during nonhomologous end joining (nhej). agrobacterium ligd1 and atuligd2 are composed of a central ligase domain fused to a c-terminal polymerase-like (pol) domain and an n-terminal 3'-phosphoesterase (pe) module. both ligd proteins seal dna nicks, albeit inefficiently. the ligd2 ... | 2007 | 17488851 |
| high efficiency poplar transformation. | with the completion of the poplar tree genome database, populus species have become one of the most useful model systems for the study of woody plant biology. populus tremuloides (quaking aspen) is the most wide-spread tree species in north america, and its rapid growth generates the most abundant wood-based biomass out of any other plant species. to study such beneficial traits, there is a need for easier and more efficient transformation procedures that will allow the study of large numbers of ... | 2007 | 17492451 |
| arabidopsis vire2 interacting protein2 is required for agrobacterium t-dna integration in plants. | agrobacterium tumefaciens-mediated genetic transformation is an efficient tool for genetic engineering of plants. vire2 is a single-stranded dna binding agrobacterium protein that is transported into the plant cell and presumably protects the t-dna from degradation. using a yeast two-hybrid system, we identified arabidopsis thaliana vire2-interacting protein2 (vip2) with a not domain that is conserved in both plants and animals. furthermore, we provide evidence supporting vip2 interaction with v ... | 2007 | 17496122 |
| agrobacterium-mediated insertional mutagenesis of the ochratoxigenic fungus aspergillus westerdijkiae. | aspergillus westerdijkiae is a potent ochratoxin a (ota) producer that has been found in coffee beans. ota is known to have nephrotoxic effects and carcinogenic potential in animal species. here we report for the first time the agrobacterium-mediated transformation for aspergillus westerdijkiae and the generation of ochratoxin-defective mutants. conidia were transformed to hygromycin b resistance using strain agl-1 of agrobacterium tumefaciens. the obtained transformation frequency was up to 47 ... | 2007 | 17496961 |
| bioformulation of burkholderia sp. mssp with a multispecies consortium for growth promotion of cajanus cajan. | the present work was undertaken to formulate an effective bioformulation using burkholderia sp. strain mssp, a known plant-growth-promoting rhizobacterium. mssp was tagged with the reporter gene of green fluorescent protein (gfp) to monitor its population in cost-effective solid carriers, including sugarcane-bagasse, sawdust, cocoa peat, rice husk, wheat bran, charcoal, and rock phosphate, and paneer-whey as liquid carrier. physical and chemical properties of different low-cost carrier materials ... | 2007 | 17496969 |
| diverse bacteria isolated from root nodules of trifolium, crotalaria and mimosa grown in the subtropical regions of china. | to analyze the diversity and relationships of rhizobia in the subtropical and tropical zones of china, we characterized 67 bacterial strains isolated from root nodules of five legume species in the genera trifolium, crotalaria and mimosa . pcr-amplified 16s rdna rflp, numerical taxonomy, sds-page of whole cell proteins, sequencing of 16s rdna and dna-dna hybridization grouped the isolates into 17 lineages belonging to bradyrhizobium, mesorhizobium, rhizobium, sinorhizobium and burkholderia, as w ... | 2007 | 17497134 |
| analysis of a lea gene promoter via agrobacterium-mediated transformation of the desiccation tolerant plant lindernia brevidens. | an agrobacterium tumefaciens-based transformation procedure was developed for the desiccation tolerant species lindernia brevidens. leaf explants were infected with a. tumefaciens strain gv3101 harbouring a binary vector that carried the hygromycin resistance gene and an egfp reporter gene under the control of a native dehydration responsive lea promoter (lb2745pro). pcr analysis of the selected hygromycin-resistant plants revealed that the transformation rates were high (14/14) and seeds were o ... | 2007 | 17497152 |
| agrobacterium para/mind-like virc1 spatially coordinates early conjugative dna transfer reactions. | agrobacterium tumefaciens translocates t-dna through a polar virb/d4 type iv secretion (t4s) system. virc1, a factor required for efficient t-dna transfer, bears a deviant walker a and other sequence motifs characteristic of para and mind atpases. here, we show that virc1 promotes conjugative t-dna transfer by stimulating generation of multiple copies per cell of the t-dna substrate (t-complex) through pairwise interactions with the processing factors vird2 relaxase, virc2, and vird1. virc1 also ... | 2007 | 17505518 |
| biofilm formation by plant-associated bacteria. | plants support a diverse array of bacteria, including parasites, mutualists, and commensals on and around their roots, in the vasculature, and on aerial tissues. these microbes have a profound influence on plant health and productivity. bacteria physically interact with surfaces to form complex multicellular and often multispecies assemblies, including biofilms and smaller aggregates. there is growing appreciation that the intensity, duration, and outcome of plant-microbe interactions are signif ... | 2007 | 17506679 |
| rhizobialide: a new stearolactone produced by mesorhizobium sp. ccnwgx022, a rhizobial endophyte from glycyrrhiza uralensis. | the endophytic strain mesorhizobium sp. ccnwgx022 was isolated from licorice (glycyrrhiza uralensis fisch.) grown in the arid and semi-arid regions of northwest china. the new stearic acid derived gamma-lactone 1, named rhizobialide (= (5s)-4,5-dihydro-5-(8-oxotetradecyl)furan-2(3h)-one), was isolated from the petroleum-ether extract of the fermentation broth of this strain. the structure of 1 was elucidated on the basis of spectroscopic and mass-spectrometric analysis. this is the first report ... | 2007 | 17510984 |
| purification and primary structure of novel lipid transfer proteins from germinated lentil (lens culinaris) seeds. | a subfamily of eight novel lipid transfer proteins designated as lc-ltp1-8 was found in the lentil lens culinaris. lc-ltp2, lc-ltp4, lc-ltp7, and lc-ltp8 were purified from germinated lentil seeds, and their molecular masses (9268.7, 9282.7, 9121.5, 9135.5 daltons) and complete amino acid sequences were determined. the purified proteins consist of 92-93 amino acid residues, have four disulfide bonds, and inhibit growth of agrobacterium tumefaciens. total rna was isolated from germinated lentil s ... | 2007 | 17511608 |
| towards a molecular genetic system for the pathogenic fungus paracoccidioides brasiliensis. | we herein report the development of a molecular toolbox for the dimorphic fungus paracoccidioides brasiliensis, specifically a more efficient transformation and a gene expression system. we evaluated several parameters that influence agrobacterium tumefaciens-mediated transformation (atmt), such as co-cultivation conditions and host cell susceptibility. our results show that cellular recovery and air drying of a. tumefaciens:p. brasiliensis mixtures are essential for atmt. overall, our data indi ... | 2007 | 17512227 |
| the influence of the long chain fatty acid on the antagonistic activities of rhizobium sin-1 lipid a. | the lipid a from nitrogen-fixing bacterial species rhizobium sin-1 is structurally unusual due to lack of phosphates and the presence of a 2-aminogluconolactone and a very long chain fatty acid, 27-hydroxyoctacosanoic acid (27ohc28:0), moiety. this structurally unusual lipid a can antagonize tnf-alpha production by human monocytes induced by escherichia coli lps. to establish the relevance of the unusual long chain 27-hydroxyoctacosanoic acid for antagonistic properties, a highly convergent stra ... | 2007 | 17513113 |
| agrobacterium-mediated transformation of a low glutelin mutant of 'koshihikari' rice variety using the mutated-acetolactate synthase gene derived from rice genome as a selectable marker. | we have developed an efficient rice transformation system that uses only rice genome-derived components. the transgenic 'koshihikari' rice, low-glutelin mutant a123, is capable of accumulating large amounts of bioactive peptides in the endosperm. agrobacterium-mediated transformation using the mutated-acetolactate synthase (mals) gene expressed under the control of the callus-specific promoter (csp) as a selectable marker was used to introduce gfp and an anti-hypertensive hexapeptide into 'koshi ... | 2007 | 17516071 |
| high efficiency agrobacterium rhizogenes-mediated transformation of saponaria vaccaria l. (caryophyllaceae) using fluorescence selection. | a highly efficient and convenient method for the agrobacterium rhizogenes-dependent production of transformed roots of saponaria vaccaria l. (caryophyllaceae) is described. the parameters tested and optimized include s. vaccaria cultivar, explant type, agrobacterium rhizogenes strain and culture conditions. for cotransformation using additional recombinant t-dna-containing a. rhizogenes strains, use of neomycin phosphotransferase and enhanced green fluorescent protein genes as selectable markers ... | 2007 | 17516073 |
| growth and rutin production in hairy root cultures of buckwheat (fagopyrum esculentum m.). | buckwheat (fagopyrum esculentum moench.) is a potentially important source of rutin, a natural flavonoid with antihyperglycemic, antihypertensive, and antioxidative properties. to examine in vitro production of rutin, we established a hairy root culture of buckwheat by infecting leaf explants with agrobacterium rhizogenes r1000, and tested the growth conditions and rutin production rates of these cultures. ten hairy root clones were established; their growth and rutin production rates ranged fro ... | 2007 | 17516253 |
| conformation of cytoskeletal elements during the division of infected lupinus albus l. nodule cells. | lupin nodule cells maintain their ability to divide for several cycles after being infected by endosymbiotic rhizobia. the conformation of the cytoskeletal elements of nodule cells was studied by fluorescence labelling, immunocytochemistry, and laser confocal and transmission electron microscopy. the dividing infected cells showed the normal microtubule and actin patterns of dividing plant cells. the clustered symbiosomes were tethered to the spindle-pole regions and moved to the cell poles duri ... | 2007 | 17525079 |
| functional characterization of the sinorhizobium meliloti acetate metabolism genes acea, smc00767, and glcb. | the genes encoding malate synthase (glcb) and isocitrate lyase (acea) and a 240-bp open reading frame (smc00767) located downstream of acea were isolated and functionally characterized in sinorhizobium meliloti. independent and double interposon mutants of each gene were constructed, and the corresponding phenotypes were analyzed. acea mutants failed to grow on acetate, and mutants deficient in smc00767 were also affected in acetate utilization. in contrast, mutants deficient in glcb grew on ace ... | 2007 | 17526694 |
| diversity and geographical distribution of rhizobia associated with lespedeza spp. in temperate and subtropical regions of china. | eighty-eight root-nodule isolates from lespedeza spp. grown in temperate and subtropical regions of china were characterized by a polyphasic approach. nine clusters were defined in numerical taxonomy and sds-page analysis of whole cell proteins. based upon further characterizations of amplified 16s rdna restriction analysis (ardra), pcr-based restriction fragment length polymorphism of ribosomal igs, 16s rdna sequence analysis and dna-dna hybridization, these isolates were identified as bradyrhi ... | 2007 | 17530227 |
| context dependence in the coevolution of plant and rhizobial mutualists. | several mechanisms are expected to rapidly rid mutualisms of genetic variation in partner quality. variation for mutualist quality, however, appears to be widespread. we used a model legume-rhizobium mutualism to test for evidence that context-dependent selection may maintain variation in partner quality. in a greenhouse experiment using 10 natural populations of medicago truncatula and two strains of sinorhizobium medicae, we detected significant genotype x genotype (g x g) interactions for pla ... | 2007 | 17535796 |
| the genetic diversity of rhizobia associated with dalea purpurea vent. in fragmented grasslands of west-central minnesota. | the increase in human population and the spread of agriculture over the past 150 years have transformed the landscape in west-central minnesota into a mosaic of agricultural fields and urban land, leaving only remnants of the once dominant prairie ecosystem. limited natural habitat in this fragmented landscape threatens the diversity and abundance of native legumes and could impact the size and function of associated belowground microbial populations. in this study, boxa1r pcr and 16s rrna gene ... | 2007 | 17538644 |
| phenotypic and molecular characterization of chickpea rhizobia isolated from different areas of tunisia. | several phenotypic markers were used in this study to determine the biodiversity of rhizobial strains nodulating cicer arietinum l. in various areas of tunisia. they include symbiotic traits, the use of 21 biochemical substrates, and tolerance to salinity and ph. in addition, restriction fragment length polymorphisms (rflps) of pcr-amplified 16s rdna were compared with those of reference strains. numeric analysis of the phenotypic characteristics showed that the 48 strains studied fell into thre ... | 2007 | 17538653 |
| characterization of symbiotic and endophytic bacteria isolated from root nodules of herbaceous legumes grown in qinghai-tibet plateau and in other zones of china. | qinghai-tibet plateau is the highest place in the world and the environment in that plateau is hard for animals and plants, with low temperature, low concentration of oxygen and high solar radiation. in this study, 61 root nodule isolates from vicia, oxytropis, medicago, melilotus and onobrychis species grown in qinghai-tibet plateau and in loess plateau were comparatively characterized. based upon the results of numerical taxonomy, ardra, aflp, dna-dna hybridization and 16s rdna sequencing, the ... | 2007 | 17541555 |
| agrobacterium tumefaciens-mediated transformation of narcissus tazzeta var. chinensis. | phytoene synthase (psy), as a key regulatory enzyme for carotene biosynthesis, plays an important role in regulating color formation in many species. in the present study, a protocol was developed for the transformation of narcissus tazzeta var chinensis using agrobacterium tumefaciens strain lba4404 harboring a binary vector pcambia1301 plasmid which contained an antisense phytoene synthase gene, a reporter beta-glucuronidase gene and a selectable marker hygromycin phosphotransferase gene. effe ... | 2007 | 17541598 |
| the pyda-pydb fusion gene produces an active dioxygenase-hydrolase that degrades 3-hydroxy-4-pyridone, an intermediate of mimosine metabolism. | the objective of this research was to construct a pyda-pydb hybrid gene that encodes a functional dioxygenase-hydrolase (pyda-pydb) fusion protein for degradation of 3-hydroxy-4-pyridone (hp). hp is an intermediate in both synthesis and degradation of mimosine, a toxic amino acid produced by the tree legume leucaena leucocephala. computer-generated models of the fusion proteins suggested that joining of pyda and pydb with 0, 3, or 7 glycine residues as a linker should produce a functional pyda-p ... | 2007 | 17390132 |
| rhizobium cellulosilyticum sp. nov., isolated from sawdust of populus alba. | during a study of polysaccharide-hydrolysing bacteria present in different plant sources, two strains were isolated from pulverized decaying wood of populus alba and classified in the genus rhizobium on basis of their almost complete 16s rrna gene sequences. their closest phylogenetic relatives were rhizobium galegae usda 4128(t) and rhizobium huautlense s02(t), with 98.2 and 98.1 % 16s rrna gene sequence similarity, respectively. reca and atpd sequence analysis showed that these species have le ... | 2007 | 17392217 |
| osmoadaptative responses in the rhizobia nodulating acacia isolated from south-eastern moroccan sahara. | four strains of rhizobia nodulating acacia were isolated from the moroccan desert soil by trapping with seedlings of acacia gummifera and acacia raddiana, and were studied for their ability to tolerate high salinity and dryness conditions. the strains mdsmc 2, mdsmc 18 and mdsmc 50 were halotolerant (they tolerated up to 1 m nacl) and they accumulated glutamate and mannosucrose. the synthesis of the latter solute, which is the major endogenous osmolyte, is partially repressed in the presence of ... | 2007 | 17298361 |
| peritonitis due to multiresistant rhizobium radiobacter. | 2007 | 17299163 | |
| production of transgenic strawberries by temporary immersion bioreactor system and verification by tail-pcr. | strawberry (fragaria x ananassa) is an economically important soft fruit crop with polyploid genome which complicates the breeding of new cultivars. for certain traits, genetic engineering offers a potential alternative to traditional breeding. however, many strawberry varieties are quite recalcitrant for agrobacterium-mediated transformation, and a method allowing easy handling of large amounts of starting material is needed. also the genotyping of putative transformants is challenging since th ... | 2007 | 17309794 |
| transient beta-glucuronidase expression in lily (lilium longflorum l.) pollen via wounding-assisted agrobacterium-mediated transformation. | a pollen-based transient expression system has been developed. lily pollen grains, wounded by vigorous shaking in the presence of aluminum oxide particles, were transformed by infiltration with agrobacterium tumefaciens lba4404 cells harboring the beta-glucuronidase (gus) gene construct, pbi121. in histochemical and fluorometric gus analysis, the wounding processes allowed efficient transformation and, in cdna blot hybridization, gus mrna synthesis was clearly detected. lily pollen with appropri ... | 2007 | 17310322 |
| living without fur: the subtlety and complexity of iron-responsive gene regulation in the symbiotic bacterium rhizobium and other alpha-proteobacteria. | the alpha-proteobacteria include several important genera, including the symbiotic n(2)-fixing "rhizobia", the plant pathogen agrobacterium, the mammalian pathogens brucella, bartonella as well as many others that are of environmental or other interest--including rhodobacter, caulobacter and the hugely abundant marine genus pelagibacter. only a few species--mainly different members of the rhizobia--have been analyzed directly for their ability to use and to respond to iron. these studies, howeve ... | 2007 | 17310401 |
| identification and characterization of a nodh ortholog from the alfalfa-nodulating or191-like rhizobia. | nodulation of medicago sativa (alfalfa) is known to be restricted to sinorhizobium meliloti and a few other rhizobia that include the poorly characterized isolates related to rhizobium sp. strain or191. distinctive features of the symbiosis between alfalfa and s. meliloti are the marked specificity from the plant to the bacteria and the strict requirement for the presence of sulfated lipochitooligosaccharides (nod factors [nfs]) at its reducing end. here, we present evidence of the presence of a ... | 2007 | 17313165 |
| bacillus megaterium rhizobacteria promote growth and alter root-system architecture through an auxin- and ethylene-independent signaling mechanism in arabidopsis thaliana. | soil microorganisms are critical players in plant-soil interactions at the rhizosphere. we have identified a bacillus megaterium strain that promoted growth and development of bean (phaseolus vulgaris) and arabidopsis thaliana plants. we used arabidopsis thaliana as a model to characterize the effects of inoculation with b. megaterium on plant-growth promotion and postembryonic root development. b. megaterium inoculation caused an inhibition in primary-root growth followed by an increase in late ... | 2007 | 17313171 |
| sensitive whole-cell biosensor suitable for detecting a variety of n-acyl homoserine lactones in intact rhizosphere microbial communities. | to investigate quorum sensing in rhizosphere soil, a whole-cell biosensor, agrobacterium tumefaciens(pahl-ice), was constructed. the biosensor responded to all n-acyl homoserine lactones (ahls) tested, except c(4) homoserine lactone, with a minimum detection limit of 10(-12) m, as well as to both exogenously added ahls and ahl-producing bacterial strains in soil. this highly sensitive biosensor reveals for the first time the increased ahl availability in intact rhizosphere microbial communities ... | 2007 | 17400771 |
| ubiquinone-10 production using agrobacterium tumefaciens dps gene in escherichia coli by coexpression system. | ubiquinone (coenzyme q; abbreviation, uq) acts as a mobile component of the respiratory chain by playing an essential role in the electron transport system, and has been widely used in pharmaceuticals. the biosynthesis of uq involves 10 sequential reactions brought about by various enzymes. in this study we have cloned, expressed the decaprenyl diphosphate synthase, designated dps gene, from agrobacterium tumefaciens, and succeeded in detecting uq-10 in addition to innate uq-8 in escherichia col ... | 2007 | 17401144 |
| interaction of an ihf-like protein with the rhizobium etli nifa promoter. | the nifa gene fulfills an essential role in the regulation of nitrogen fixation genes in rhizobium etli. transcription analysis of the nifa gene, assessed using promoter deletions, indicated an oxygen-independent expression, threefold higher during symbiosis as compared with free-living conditions. electrophoretic mobility shift assays using those nifa promoter deletion fragments, which were actively transcribed, demonstrated the specific interaction with r. etli cellular protein(s) resulting in ... | 2007 | 17403047 |
| rational design of inhibitors of vira-virg two-component signal transduction. | vira-virg two-component system regulates the vir (virulence) operon in response to specific host factors (xenognosins) in the plant pathogen agrobacterium tumefaciens. using whole cell assays, stable inhibitors inspired by the labile natural benzoxazinone inhibitor hdmboa are developed. it is found that aromatic aldehydes represent a minimal structural unit for activity. in particular, 3-hydroxy-4,6-dimethoxy-3h-isobenzofuran-1-one (hdi) was found to have the highest activity, making it the most ... | 2007 | 17470391 |
| molecular basis of transcriptional antiactivation. tram disrupts the trar-dna complex through stepwise interactions. | conjugative transfer of agrobacterium ti plasmids is regulated by trar, a quorum-sensing activator. quorum dependence requires tram, which binds to and inactivates trar. in this study, we showed that trar and tram form a 151-kda stable complex composed of two trar and two tram dimers both in vitro and in vivo. when interacted with trar bound to tra box dna, wild-type tram formed a nucleoprotein complex of 77 kda composed of one dimer of each protein and dna. the complex converted to the 151-kda ... | 2007 | 17475619 |
| [a study of the competitive properties of the aluminum-tolerant strain rhizobium leguminosarum bv. trifolii 9-4a by the antibiotic resistance method]. | the virulence, competitive ability, and symbiotic efficiency of 2 rhizobium leguminosarum bv. trifolii strains--the wild aluminum tolerant strain 9-4a and the commercial strain 348a-were compared when introducing their variants marked with antibiotic resistance into the rhizosphere of red clover (trifolium pratense l.) plants. high virulence and competitive ability of the strain tolerant to aluminum was demonstrated by a concurrent inoculation of the seeds with these two strains. the resistance ... | 2007 | 17476807 |
| [active oxygen species in pea seedlings during the interactions with symbiotic and pathogenic microorganisms]. | the level of active oxygen species (aos)--superoxide anion radical (o2*-) and hydrogen peroxide (h2o2)--in pea (pisum sativum l.) cultivar marat seedlings was studied upon their inoculation with symbiotic (rhizobium leguminosarum bv. viceae strain ciam 1026) and pathogenic (pseudomonas syringae pv. pisi sackett) microorganisms. different patterns of the changes in aos in pea seedlings during the interactions with the symbiont and the phytopathogen were recorded. it is assumed that o2*- and h2o2 ... | 2007 | 17476814 |
| genetic diversity of rhizobia associated with vicia faba in three ecological regions of china. | great genetic diversity was revealed among 75 rhizobal isolates associated with vicia faba grown in chinese fields with aflp, ardra, 16s rdna sequencing, dna-dna hybridization, box-pcr and rflp of pcr-amplified nodd and nodc. most of the isolates were rhizobium leguminosarum, and six isolates belonged to an unnamed rhizobium species. in the homogeneity analysis, the isolates were grouped into three clusters corresponding to (1) autumn sowing (subtropical) region where the winter ecotype of v. fa ... | 2007 | 17479251 |
| controlling the sucrose concentration increases coenzyme q10 production in fed-batch culture of agrobacterium tumefaciens. | the production yield of coenzyme q(10) (coq(10)) from the sucrose consumed by agrobacterium tumefaciens kccm 10413 decreased, and high levels of exopolysaccharide (eps) accumulated after switching from batch culture to fed-batch culture. therefore, we examined the effect of sucrose concentration on the fermentation profile by a. tumefaciens. in the continuous fed-batch culture with the sucrose concentration maintained constantly at 10, 20, 30, and 40 g l(-1), the dry cell weight (dcw), specific ... | 2007 | 17479258 |
| optimization of human papillomavirus type 16 (hpv-16) l1 expression in plants: comparison of the suitability of different hpv-16 l1 gene variants and different cell-compartment localization. | virus-like particle-based vaccines for high-risk human papillomaviruses (hpvs) appear to have great promise; however, cell culture-derived vaccines will probably be very expensive. the optimization of expression of different codon-optimized versions of the hpv-16 l1 capsid protein gene in plants has been explored by means of transient expression from a novel suite of agrobacterium tumefaciens binary expression vectors, which allow targeting of recombinant protein to the cytoplasm, endoplasmic re ... | 2007 | 17412974 |
| regioselective and enzymatic production of gamma-resorcylic acid from resorcinol using recombinant escherichia coli cells expressing a novel decarboxylase gene. | a recombinant escherichia coli, expressing the rdc gene, which encodes a gamma-resorcylic acid decarboxylase (rdc) reversibly catalyzing regioselective carboxylation of resorcinol derived from rhizobium radiobacter wu-0108, converted 20 mm resorcinol to gamma-resorcylic acid with a 44% (mol/mol) yield at 30 degrees c for 7 h. the recombinant e. coli cells were recyclable at least five times for use as biocatalysts. | 2007 | 17415666 |
| antitumor and antibacterial activity of ethylacetate extract of ludwigia hyssopifolia linn and its active principle piperine. | an alkaloid constituent 1-[5-(1,3-benzodioxol-5-yl)-1-oxo-2,4-pentadienyl]piperidine, trivial name piperine was isolated from ludwigia hyssopifolia linn. (family-onagraceae). the ethylacetate extract of the plant and the isolated compound piperine were studied for antitumor and in vitro antibacterial activity. ethylacetate extract showed 73.05 and 84.14% inhibition of agrobacterium tumefaciens-induced crown gall tumor formation in potato disc. piperine exhibited antitumor activity with ic50 valu ... | 2007 | 17416568 |
| nitrogen fixation control under drought stress. localized or systemic? | legume-rhizobium nitrogen fixation is dramatically affected under drought and other environmental constraints. however, it has yet to be established as to whether such regulation of nitrogen fixation is only exerted at the whole-plant level (e.g. by a systemic nitrogen feedback mechanism) or can also occur at a local nodule level. to address this question, nodulated pea (pisum sativum) plants were grown in a split-root system, which allowed for half of the root system to be irrigated at field ca ... | 2007 | 17416644 |
| replication-independent long-distance trafficking by viral rnas in nicotiana benthamiana. | viruses with separately encapsidated genomes could have their genomes introduced into different leaves of a plant, thus necessitating long-distance trafficking of the viral rnas for successful infection. to examine this possibility, individual or combinations of genome segments from the tripartite brome mosaic virus (bmv) were transiently expressed in leaves of nicotiana benthamiana plants using engineered agrobacterium tumefaciens. bmv rna3 was found to traffic from the initial site of expressi ... | 2007 | 17416731 |
| monitoring circadian rhythms in arabidopsis thaliana using luciferase reporter genes. | arabidopsis thaliana is internationally adopted as the model plant species for molecular genetics. as such a huge range of resources are available for its study. arabidopsis does not display any obvious circadian rhythms; however, rhythms in gene expression can be readily detected. for this reason the promoters of rhythmically expressed genes have been fused to the firefly luciferase gene. using this reporter gene we have developed a number of automated techniques for monitoring luciferase activ ... | 2007 | 17417007 |
| root hair curling and rhizobium infection in medicago truncatula are mediated by phosphatidylinositide-regulated endocytosis and reactive oxygen species. | the symbiotic relationships between legumes and rhizobacteria involve extensive signalling between the two organisms. studies using genetic, biochemical, and pharmacological approaches have demonstrated the involvement of calcium and reactive oxygen species in the establishment of symbiotic interactions. in the early stage of the interactions rhizobia grow as infection thread within host root hairs and are internalized into the plant cells via endocytosis. it is shown here that inoculation of me ... | 2007 | 17420174 |
| rhizobium etli ce3 bacteroid lipopolysaccharides are structurally similar but not identical to those produced by cultured ce3 bacteria. | rhizobium etli ce3 bacteroids were isolated from phaseolus vulgaris root nodules. the lipopolysaccharide (lps) from the bacteroids was purified and compared with the lps from laboratory-cultured r. etli ce3 and from cultures grown in the presence of anthocyanin. comparisons were made of the o-chain polysaccharide, the core oligosaccharide, and the lipid a. although lps from ce3 bacteria and bacteroids are structurally similar, it was found that bacteroid lps had specific modifications to both th ... | 2007 | 17420254 |
| agrobacterium-mediated viral vector-amplified transient gene expression in nicotiana glutinosa plant tissue culture. | a viral vector based on the bean yellow dwarf virus was investigated for its potential to increase transient gene expression. an intron-containing gus reporter gene and the cis-acting viral regulatory elements were incorporated in the viral vector and could be complemented by the viral replication-associated proteins provided on a secondary vector. all vectors were delivered to nicotiana glutinosa plant cell suspension or hairy root cultures via auxotrophic agrobacterium tumefaciens. cell cultur ... | 2007 | 17425328 |
| a simplified method for the analysis of transcription factor-promoter interactions that allows high-throughput data generation. | transient expression systems are intensively used to study the transactivation potential of transcription factors and to confirm target promoters. here we present a novel system based on the high-efficiency transformation of cultured arabidopsis thaliana cells by agrobacteria. to demonstrate the potential of this system, we compared it with a commonly used protoplast transfection assay, and studied the regulation of phenylpropanoid biosynthetic pathway genes by various transcription factors. bot ... | 2007 | 17425717 |