| the nodular endophytes of coriaria spp. form a distinct lineage within the genus frankia. | repeated attempts at isolating the frankia endophyte of coriaria spp. have not yielded infective microbial cultures that could fulfil koch's postulates. in order to circumvent the critical isolation step, nodule endophytes of coriaria were characterized directly by means of specific amplification of nodule dna (pcr) followed by sequencing of part of the 16s rdna gene. three closely related sequences were obtained from nodules originating from france, mexico and new zealand, containing unique seq ... | 1992 | 1344993 |
| evidence that some frankia sp. strains are able to cross boundaries between alnus and elaeagnus host specificity groups. | phenotypic and genotypic methods were used to prove the existence of frankia strains isolated from an elaeagnus sp. that are able to cross the inoculation barriers and infect alnus spp. also. repeated cycles of inoculation, nodulation, and reisolation were performed under axenic conditions. frankia wild-type strain ufi 13270257 and three of its coisolates did exhibit complete infectivity and effectiveness on elaeagnus spp. and hippophaë rhamnoides and variable infectivity on alnus spp. microscop ... | 1992 | 1352442 |
| low-frequency restriction fragment analysis of frankia strains (actinomycetales). | low-frequency restriction fragment analysis of more than 100 strains of the genus frankia showed that restriction enzyme drai (recognition site, ttt'aaa) gave rise to large dna fragments (200 to 1,500 kb), which, when they were subjected to cluster analysis, reflected the host plants from which the strains were isolated. our results support the conclusions of lalonde and his colleagues (m. lalonde, l. simon, j. bousquet, and a. seguin, p. 671-680, in h. bothe, f. j. de bruijn, and w. e. newton, ... | 1992 | 1354477 |
| analysis of a ribosomal rna operon in the actinomycete frankia. | the organisation of ribosomal rna-encoding (rrn) genes has been studied in frankia sp. strain ors020606. the two rrn clusters present in frankia strain ors020606 were isolated from genomic banks in phage lambda embl3 by hybridization with oligodeoxyribonucleotide probes. the 5'-3' gene order is the usual one for bacteria: 16s-23s-5s. the two clusters are not distinguishable by restriction enzyme mapping inside the coding section, but vary considerably outside it. sequencing showed that the 16s-r ... | 1992 | 1372279 |
| detection and enumeration of bacteria in soil by direct dna extraction and polymerase chain reaction. | in order to develop a rapid and specific detection test for bacteria in soil, we improved a method based on the polymerase chain reaction (pcr). each step of the protocol, including direct lysis of cells, dna purification, and pcr amplification, was optimized. to increase the efficiency of lysis, a step particularly critical for some microorganisms which resist classical techniques, we used small soil samples (100 mg) and various lytic treatments, including sonication, microwave heating, and the ... | 1992 | 1444380 |
| relationship between electroporation conditions, electropermeability and respiratory activity for frankia strain acn14a. | the use of electroporation for introducing macromolecules into intact cells of the actinomycete frankia was investigated. electropermeability was demonstrated by the uptake of dextran (70 kda) molecules labeled with fluorescein isothiocyanate (fitc) inside frankia cells. upon pulsation with an exponentially decaying electric field, the cell membranes became permeable. loading increased with initial pulsed electric field strength and capacitance. increased loading efficiency was inversely related ... | 1992 | 1521778 |
| high-molecular-mass multicatalytic proteinase complexes produced by the nitrogen-fixing actinomycete frankia strain br. | a major-high-molecular mass proteinase and seven latent minor proteinases were found in cell extracts and in concentrates of culture medium from frankia sp. strain br after nondenaturing electrophoresis in mixed gelatin-polyacrylamide gels. all of these complexes showed multicatalytic properties. their molecular masses and their sedimentation coefficients varied from 1,300 kda (28s) to 270 kda (12s). the electroeluted 1,300-kda proteinase complex dissociated into 11 low-molecular-mass proteinase ... | 1992 | 1537794 |
| nucleotide sequence of nifd from frankia alni strain ari3: phylogenetic inferences. | the complete nucleotide sequence of the nifd gene encoding the alpha subunit of component i of nitrogenase from frankia alni strain ari3 was determined. the coding region is 1,458 bp in length and encodes a polypeptide of 486 residues with a predicted molecular weight of 53,500. phylogenetic inferences with 12 complete published nifd sequences were drawn using a variety of approaches. frankia nifd clusters with proteobacteria rather than with clostridium pasteurianum, the other gram-positive bac ... | 1992 | 1584016 |
| identification of a nodd-like gene in frankia by direct complementation of a rhizobium nodd-mutant. | clones from a frankia at4 gene bank were pooled into groups and mass conjugated into a nodd mutant of rhizobium leguminosarum bv. viciae by triparental matings. when peas were inoculated with the pooled transconjugants, nodulation was observed. a plasmid, pat2gx containing frankia dna, was isolated from bacteria recovered from these nodules. this plasmid was shown to complement a nodd mutant of r. leguminosarum bv. viciae. thus pat2gx contains a frankia gene that is functionally equivalent to no ... | 1992 | 1603071 |
| nitrogenase activity and growth of frankia in batch and continuous culture. | frankia grown in batch culture was unable to maintain a high rate of nitrogenase activity and, once a peak level was reached, activity rapidly declined. addition of 5 mm carbon source of cultures or transfer to fresh medium was followed by brief recovery of nitrogenase activity. the extent of recovery decreased as additions or transfers were made to progressively older cultures. daily addition of fresh medium (dilution rate = 0.125 day-1) allowed frankia to be maintained in continuous, derepress ... | 1992 | 1611555 |
| identification of casuarina-frankia strains by use of polymerase chain reaction (pcr) with arbitrary primers. | free-living n2-fixing frankia strains isolated from casuarina sp. were investigated for genomic polymorphism. we used six 10-mer oligonucleotides as single arbitrary primers (ap) for the polymerase chain reaction (pcr) in order to amplify random dna fragments in the genome of free-living frankia strains. agarose-gels of the amplified genomic dna revealed that two of the six arbitrary primers showed polymorphism in the eight different frankia genomes. analysis of the ap-pcr products showed 9 poly ... | 1992 | 1612411 |
| extraction of ribosomal rna from soil for detection of frankia with oligonucleotide probes. | sequences of 16s rrna of the nitrogen-fixing frankia strain ag45/mut15 and the ineffective frankia strain agb1.9 were used to design a genus-specific oligonucleotide probe. hybridization experiments of this frankia probe and a second probe, specific for nif+-frankia strains only, were used to detect frankia specific target sequences in rna isolations from soil. a method is described for direct isolation of rna from a loamy soil and a peat. yields of about 10 ng rna/g wet soil are obtained withou ... | 1990 | 1726879 |
| frankia genus-specific characterization by polymerase chain reaction. | the polymerase chain reaction (pcr) is an in vitro procedure for primer-directed enzymatic amplification of specific template nucleic acid sequences. in order to determine whether a given actinomycete isolated from an actinorhiza (nodule) belongs to the genus frankia or is a contaminant, we have developed a test based on the pcr. primers complementary to sequences of two dna regions corresponding to the nif genes (nifh and nifd) and the rrna genes (16s and 23s) were specifically chosen to differ ... | 1991 | 1781685 |
| enzymes of ammonia assimilation in hyphae and vesicles of frankia sp. strain cpi1. | frankia spp. are filamentous actinomycetes that fix n2 in culture and in actinorhizal root nodules. in combined nitrogen-depleted aerobic environments, nitrogenase is restricted to thick-walled spherical structures, frankia vesicles, that are formed on short stalks along the vegetative hyphae. the activities of the nh4(+)-assimilating enzymes (glutamine synthetase [gs], glutamate synthase, glutamate dehydrogenase, and alanine dehydrogenase) were determined in cells grown on nh4+ and n2 and in ve ... | 1990 | 1968454 |
| screening of symbiotic frankiae for host specificity by restriction fragment length polymorphism analysis. | restriction fragment length polymorphism analysis of numerous frankia strains, using a nifdh probe, separated the strains into three distinct groups based on hybridization patterns. the groups identified in this study were well correlated with host specificity groups identified in earlier cross-inoculation studies. | 1990 | 1971167 |
| molecular cloning, sequencing, and expression of the glutamine synthetase ii (glnii) gene from the actinomycete root nodule symbiont frankia sp. strain cpi1. | in common with other plant symbionts, frankia spp., the actinomycete n2-fixing symbionts of certain nonleguminous woody plants, synthesize two glutamine synthetases, gsi and gsii. dna encoding the bradyrhizobium japonicum gene for gsii (glnii) hybridized to dna from three frankia strains. b. japonicum glnii was used as a probe to clone the glnii gene from a size-selected kpni library of frankia strain cpi1 dna. the region corresponding to the frankia sp. strain cpi1 glnii gene was sequenced, and ... | 1990 | 1975584 |
| streptomyces hygroscopicus has two glutamine synthetase genes. | streptomyces hygroscopicus, which produces the glutamine synthetase inhibitor phosphinothricin, possesses at least two genes (glna and glnb) encoding distinct glutamine synthetase isoforms (gsi and gsii). the glnb gene was cloned from s. hygroscopicus dna by complementation in an escherichia coli glutamine auxotrophic mutant (glna). glnb was subcloned in streptomyces plasmids by insertion into pij486 (pmsg3) and pij702 (pmsg5). both constructions conferred resistance to the tripeptide form of ph ... | 1990 | 1975585 |
| isolation and structure of the lipid envelopes from the nitrogen-fixing vesicles of frankia sp. strain cpi1. | frankia vesicles are differentiated during nitrogen starvation; they contain nitrogenase whether produced by free-living frankiae or by frankiae in actinorhizal root nodules. vesicles are surrounded by envelopes of several monolayers of uncharacterized lipid. it has been suggested that the envelope limits diffusion of o2 into the vesicle cytoplasm, thereby preventing inactivation of nitrogenase. whole vesicles were prepared on sucrose gradients and sonicated, and vesicle envelopes were isolated ... | 1991 | 2002007 |
| phylogenetic relationships among frankia genomic species determined by use of amplified 16s rdna sequences. | actinomycetes of the genus frankia establish a nitrogen-fixing symbiosis with a large number of woody dicotyledonous plants. hundreds of strains isolated from various actinorhizal plants growing in different geographical areas have recently been classified into at least nine genomic species by use of the dna-dna hybridization technique (m.p. fernandez, h. meugnier, p.a.d. grimont, and r. bardin, int. j. syst. bacteriol. 39:424-429, 1989). a protocol based on the amplification and sequencing of 1 ... | 1991 | 2061287 |
| fsei, a new type ii restriction endonuclease that recognizes the octanucleotide sequence 5' ggccggcc 3'. | a type ii restriction endonuclease, designated fsei, has been partially purified from a frankia species (nrrl 18528). this enzyme cleaves adenovirus 2 dna at three sites, but does not cleave the dnas from bacteriophages lambda, t7, and phi x174, the animal virus sv40, puc18 and pbr322. fsei recognizes the octanucleotide sequence 5' ggccgg decreases cc 3' and cleaves as indicated by the arrow. the frequency of occurrence of fsei sites within sequenced regions of the human genome is similar to tha ... | 1990 | 2159636 |
| native agarose-polyacrylamide gel electrophoresis allowing the detection of aminopeptidase, dehydrogenase, and esterase activities at the nanogram level: enzymatic patterns in some frankia strains. | nanogram amounts of soluble aminopeptidases, dehydrogenases, and esterases were detected by nondenaturing ultralow gelling point agarose-polyacrylamide gel electrophoresis (ulga-page). cytosolic fractions from frankia sp. were electrophoresed at 4 degrees c in the presence of co2+, zn2+, or mg2+ ions. then, aminopeptidases and esterases were revealed by simultaneous capture staining by using fast garnet gbc diazonium salt as the chromogenic coupling compound. dehydrogenases were revealed by usin ... | 1990 | 2200309 |
| [construction of frankia genomic libraries and isolation of clones homologous to nodulation genes from rhizobium leguminosarum]. | high molecular genomic dnas were isolated by using the lysozyme plus achromopeptidase system from frankia strains at4, ccol and hr16, the root nodule endophytes of alnus, casuarina and hippophae respectively, and used to construct genomic libraries in plafr1, a broad host range cosmid vector within many gram-negative hosts. the genomic libraries were screened by in situ colony hybridization to identify clones homologous to common nodulation genes of rhizobium leguminosarum, based on the sequence ... | 1990 | 2268450 |
| identification of frankia strains in nodules by hybridization of polymerase chain reaction products with strain-specific oligonucleotide probes. | a set of oligonucleotides has been developed to study the competitivity of two frankia strains in the nodulation of the roots of two host plant species: alnus glutinosa and alnus incana. two 20 mer-oligonucleotides, complementary to highly conserved sequences inside the nifh gene, were used as primers for the polymerase chain reaction (pcr) system in order to amplify microsymbiont dna extracted from actinorhizae. pcr products were analyzed using two strain-specific 15-mer oligonucleotides identi ... | 1990 | 2334247 |
| functioning haemoglobin genes in non-nodulating plants. | haemoglobin has previously been recorded in plants only in the nitrogen-fixing nodules formed by symbiotic association between rhizobium or frankia and legume or non-legume hosts. structural similarities amongst these and animal haemoglobins at the protein and gene level suggested a common evolutionary origin. this suggests that haemoglobin genes, inherited from an ancestor common to plants and animals, might be present in all plants. we report here the isolation of a haemoglobin gene from trema ... | 1988 | 2448639 |
| phylogeny of nitrogenase sequences in frankia and other nitrogen-fixing microorganisms. | the complete nucleotide sequence of a nitrogenase (nifh) gene was determined from a second strain (hrn18a) of frankia, an aerobic soil bacterium. the open reading frame is 870 bp long and encodes a polypeptide of 290 amino acids. the amino acid and nucleotide sequences were compared with 21 other published sequences. the two frankia strains were 96% similar at the amino acid level and 93% similar at the nucleotide level. a number of methods were used to infer phylogenies of these nitrogen fixers ... | 1989 | 2515293 |
| developmental potential of frankia vesicles. | the ability of nitrogenase-containing frankia sp. strain cpi1 vesicles to regrow vegetative hyphae is demonstrated. vesicles attached to hyphae in n2-fixing cpi1 cultures and sucrose gradient-isolated vesicles exhibited hyphal outgrowths when incubated in certain defined liquid media. single or multiple hyphal extensions grew out from the vesicles. | 1989 | 2592353 |
| interaction between hydrogenase, nitrogenase, and respiratory activities in a frankia isolate from alnus rubra. | h2 uptake and h2-supported o2 uptake were measured in n2-fixing cultures of frankia strain ari3 isolated from root nodules of alnus rubra. h2 uptake by intact cells was o2 dependent and maximum rates were observed at ambient o2 concentrations. no hydrogenase activity could be detected in nh4+-grown, undifferentiated filaments cultured aerobically indicating that uptake hydrogenase activity was associated with the vesicles, the cellular site of nitrogen fixation in frankia. hydrogenase activity w ... | 1989 | 2766117 |
| dna restriction patterns and dna-dna solution hybridization studies of frankia isolates from myrica pennsylvanica (bayberry). | sixteen frankia strains were isolated from myrica pennsylvanica (bayberry) root nodules collected at diverse sites in new jersey. restriction pattern analysis of total genomic dna was used to group the isolates into gel groups, and the genetic relatedness among the isolates was evaluated by dna-dna solution hybridization studies. restriction pattern analysis provided a distinctive reproducible fingerprint for each isolate. isolates fell into nine separate groups (strain types). more than one str ... | 1989 | 2802599 |
| physiological, chemical, morphological, and plant infectivity characteristics of frankia isolates from myrica pennsylvanica: correlation to dna restriction patterns. | the filter exclusion method was used to isolate frankia strains from myrica pennsylvanica (bayberry) root nodules collected at diverse sites in new jersey. a total of 16 isolates from five locations were cultured. the isolates were characterized by morphological, chemical, physiological, and plant infectivity criteria and compared with genomic dna restriction pattern data, which were used to assign the isolates into gel groups (see accompanying paper). the isolates from m. pennsylvanica evaluate ... | 1989 | 2802600 |
| isolation and nitrogen-fixing activity of frankia sp. strain cpi1 vesicles. | under n2-fixing conditions in aerobic culture and in symbiosis, frankiae produce spherical, multicellular structures that have been called vesicles. the vesicles have been proposed as the site of nitrogen fixation. we isolated vesicles by using density centrifugation in a single-step sucrose gradient. vesicles migrated out of 50% (wt/vol) sucrose and banded at the 40 to 50% sucrose interface; they were intact, as assessed by transmission electron microscopy, and were free of hyphal contamination ... | 1986 | 2870056 |
| revision of the structures of the benzo[a]naphthacene quinone metabolites g-2n and g-2a from bacteria of the genus frankia. | | 1989 | 2925528 |
| cloning of a multicopy plasmid from the actinorhizad nitrogen-fixing bacterium frankia sp. and determination of its restriction map. | an 8.3-kb multicopy plasmid, pfq31, from the nitrogen-fixing frankia sp. strain ari3, was cloned into escherichia coli plasmid vectors and analysed physically. pfq31 has no detectable sequence homology with another frankia plasmid, pfq32, which is present in the same host. derivatives of pfq31 with an antibotic resistance marker were introduced into streptomyces lividans, which is taxonomically related to frankia, but no stable replication could be achieved. | 1985 | 2989115 |
| the genus frankia: actinomycete symbionts of plants. | biological n2 fixation is performed most effectively by prokaryotic diazotrophs when in mutualistic symbioses with higher plants. the most intensively studied n2-fixing symbioses involve leguminous plants and rhizobia. however, frankia actinomycetes have attracted attention recently because they form root nodules on a broad range of non-legumes and because such nodules fix n2 as effectively as rhizobial nodules. since the frankia symbiosis results from an actinomycetic invasion of plant roots, i ... | 1988 | 3079215 |
| enzyme-linked immunosorbent assay (elisa) as a means of taxonomic analysis of streptomyces and related organisms. | fourteen streptomyces strains from various numerical taxonomic classes and representatives of three other genera of actinomycetes were studied using an indirect enzyme-linked immunosorbent assay (ind-elisa) to determine their serological relationships. the ind-elisa results agreed with those from previous numerical taxonomic analyses and ouchterlony double-diffusion studies. the ind-elisa method is quicker, more quantitative and less subjective than ouchterlony assays and thus should be useful i ... | 1986 | 3098902 |
| evidence for adenylate nucleotide transport (atp-adp translocation) in vesicles of frankia sp. strain ean1pec. | atractyloside and carboxyatractyloside partially inhibited nitrogenase activity (acetylene reduction) by isolated vesicles of frankia strain ean1pec. extracts of disrupted vesicles showed nitrogenase activity that was not affected by the inhibitors. the vesicles accumulated atp by an atractyloside-sensitive mechanism. this inhibition of atp uptake was reversed when vesicles were permeabilized by detergent. uptake of atp was inhibited by excess atp and adp, but not amp or adenosine, and by a calc ... | 1988 | 3164310 |
| conservation of nif sequences in frankia. | southern blots of frankia total dnas were hybridized with nifhdk probes from rhizobium meliloti, klebsiella pneumoniae and frankia strain arl3. differences between strains were noted in the size of the hybridizing restriction fragments. these differences were more pronounced among elaeagnus-compatible strains than among alnus- or casuarina-compatible strains. gene banks constructed for frankia strains eun1f, hrn18a, ced and acon24d were used to isolate nif-hybridizing restriction fragments for s ... | 1988 | 3185502 |
| nucleotide sequence of nifk and partial sequence of nifd from frankia species strain fac1. | | 1988 | 3211766 |
| morphogenesis and fine structure of frankia (actinomycetales): the microsymbiont of nitrogen-fixing actinorhizal root nodules. | | 1987 | 3323105 |
| isolation and nitrogenase activity of vesicles from frankia sp. strain ean1pec. | vesicles, specialized cell structures thought to be the site of nitrogen fixation in the actinorhizal bacteria, were isolated from frankia sp. strain ean1pec by using french pressure disruption of mycelia followed by differential and isopycnic gradient centrifugation. the isolated vesicles reduced acetylene when incubated anaerobically with mg2+ ions, atp, and dithionite. no nitrogenase activity was detected in the disrupted mycelial fractions. vesicles permeabilized by freeze-thaw or detergents ... | 1987 | 3478333 |
| [hybridization of dna from actinomycetes of the genus frankia with nitrogenase structural genes (nifhdk) of klebsiella pneumoniae and nod-genes of rhizobium melioti]. | dna sequence homology with the plasmid psa30 carrying the cloned nifhdk genes from klebsiella pneumoniae was revealed in ten frankia spp. strains, nitrogen-fixing symbionts of non-legumes, irrespective of the strain phenotype (nod+fix+, nod+ fix- or nod- fix?). none of the frankia spp. dnas exhibited homology with the plasmid prmsl26 harbouring the rhizobium meliloti nod-genes encoding for early symbiotic functions. | 1987 | 3553912 |
| effect of o2 on vesicle formation, acetylene reduction, and o2-uptake kinetics in frankia sp. hfpcci3 isolated from casuarina cunninghamiana. | the effect of the partial pressure of oxygen (po2) on the formation of vesicles, which are thought to be the site of n2 fixation in frankia, was studied in hfpcci3, an effective isolate from casuarina cunninghamiana. unlike other actinorhizal root nodules, vesicles are not produced by the endophyte in casuarina nodules. however, in culture under aerobic conditions, large, phase-bright vesicles are formed in hfpcci3 within 20 h following removal of nh+4 from the culture medium and reach peak numb ... | 1985 | 3866636 |
| enzymes of glucose metabolism in frankia sp. | enzymes of glucose metabolism were assayed in crude cell extracts of frankia strains hfpari3 and hfpcci2 as well as in isolated vesicle clusters from alnus rubra root nodules. activities of the embden-meyerhof-parnas pathway enzymes glucokinase, phosphofructokinase, and pyruvate kinase were found in frankia strain hfpari3 and glucokinase and pyruvate kinase were found in frankia strain hfpcci2 and in the vesicle clusters. an nadp+-linked glucose 6-phosphate dehydrogenase and an nad-linked 6-phos ... | 1985 | 3980434 |
| natural variation in symbiotic nitrogen-fixing rhizobium and frankia spp. | a description is given of the natural variation in nitrogen-fixing rhizobium and frankia spp. strains and the ability to form root nodules on compatible host plants. arguments are given for the hypothesis that co-evolution has taken place through mutual interaction of host plants and indigenous rhizobium and frankia populations in the soil leading to most efficient symbiotic associations. the significance of root nodules as selective enrichment cultures of particular strains in natural and culti ... | 1984 | 6397130 |
| [14c]methylammonium transport by frankia sp. strain cpi1. | we describe an nh4+-specific transport system in the n2-fixing symbiotic actinomycete frankia sp. strain cpi1. [14c]methylammonium was used as an nh4+ analog. no specific transport process was detected when cells were grown on high concentrations of nh4+. a transport system with a high affinity for ch3nh3+ was synthesized after 3 to 4 h of nitrogen starvation. methylammonium transport was not significantly inhibited by a variety of amino acids, primary amines, and polyamines. ammonium completely ... | 1984 | 6501218 |
| initiation and ontogeny of vesicles in cultured frankia sp. strain hfpari3. | removal of combined nitrogen from the medium of frankia sp. strain hfpari3 induced the formation of specialized structures, called vesicles, which are the proposed site of nitrogen fixation. after 5 to 6 h of culture on n-free medium, newly formed vesicles, termed provesicles, arose from the tips of some hyphae. these structures were spherical, phase dark, ca. 1.5 to 2.0 micron in diameter, and were not associated with acetylene reduction (nitrogenase) activity. provesicles reached their greates ... | 1984 | 6594327 |
| oxygen protection of nitrogenase in frankia sp. hfpari3. | o2 protection of nitrogenase in a cultured frankia isolate from alnus rubra (hfpari3) was studied in vivo. evidence for a passive gas diffusion barrier in the vesicles was obtained by kinetic analysis of in vivo o2 uptake and acetylene reduction rates in response to substrate concentration. o2 of nh4+-grown cells showed an apparent kmo2 of approximately 1 microm o2. in n2-fixing cultures a second km o2 of about 215 microm o2 was observed. thus, respiration remained unsaturated by o2 at air-satur ... | 1984 | 6595968 |
| factors affecting vesicle formation and acetylene reduction (nitrogenase activity) in frankia sp. cpi1. | vesicle formation and acetylene reduction (nitrogenase activity) were observed when washed hyphae from cultures of frankia sp. cpi1 were transferred to a nitrogen-free medium containing ethylenediaminetetraacetic acid and succinate. succinate could be replaced by malate or fumarate, but not other carbon sources. maximum acetylene reduction and vesicle numbers were observed at a ph of 6.0-6.5, at 25-30 degrees centigrade, and at atmos pheric po2 or somewhat less (5-20 kpa). addition of 1 mm nh ... | 1981 | 6794897 |
| plasmids in frankia sp. | a method to achieve cell lysis and isolate frankia sp. plasmid dna was developed. a screening of frankia sp. strains belonging to different host compatibility groups (alnus sp., elaeagnus sp., ceanothus sp.) showed that, of 39 strains tested, 4 (strains cp11, argn22d, ari3, and eun1f) possessed plasmids ranging in size from 7.1 to 32.2 kilobase pairs as estimated from agarose gel electrophoresis and electron microscopy. a total of 11 plasmids were detected. | 1983 | 6863219 |
| evidence that associated soil bacteria may influence root hair infection of actinorhizal plants by frankia. | nodulation of actinorhizal plants (alnus rubra bong, and others) by isolated frankia strains occurred either at a low frequency or not at all under axenic conditions. but nodulation was achieved under nonsterile conditions and four strains of bacteria were isolated which promoted nodulation when plants were inoculated with the bacteria plus frankia. four strains of pseudomonas cepacia also promoted nodulation. root hair deformation occurred when roots of a. rubra were inoculated with these bacte ... | 1980 | 7459718 |
| characterization of an effective actinorhizal microsymbiont, frankia sp. avci1 (actinomycetales). | the actinomycete, frankia sp. avci1, isolated from root nodules of alnus viridis ssp. crispa was grown in axenic culture and used to inoculate host seedlings. this bacterium has been shown to be an infective and effective nitrogen-fixing microsymbiont which can be distinguished from other frankiae, in vitro, on the basis of size, distinctive morphology, and growth characteristics. cross-inoculation studies indicated that the host range of this symbiont encompasses all of the members of the gener ... | 1980 | 7459721 |
| characterization of an ineffective actinorhizal microsymbiont, frankia sp. eui1 (actinomycetales). | the actinomycete, frankia sp. eui1, isolated from root nodules of elaeagnus umbellata is an infective endophyte but which lacks the ability to form an effective nitrogen-fixing symbiosis with its host. this ineffective organism can be distinguished easily from other frankiae, in vitro, on the basis of size, morphology, and the elaboration of a diffusible pigment. cross-inoculation studies indicated that the host range of this symbiont is narrow and probably restricted to the elaeagnaceae. in all ... | 1980 | 7459722 |
| morphological and molecular characterization of frankia sp. isolates from nodules of alnus nepalensis don. | nodules collected from alnus nepalensis growing in mixed forest stands at three different sites around shillong, were crushed in various culture media to obtain isolates of frankia. the isolates were found to have typical frankia morphology as revealed by the scanning electron microscope. seedlings inoculated with isolates or crushed nodules formed nitrogen fixing nodules. frankia specific dna probes amplified the dna of the tested isolate anpus4. partial nucleotide sequence of the 16s rrna gene ... | 1994 | 7511370 |
| phylogenetic studies on uncultured frankia populations in nodules of datisca cannabina. | part of the 16s rrna gene was amplified directly from uncultured endophyte populations within the root nodules of datisca cannabina and three strains isolated from nodules of alnus glutinosa (agkg'84/4), coriaria nepalensis (cn3), and d. cannabina (dc2). sequence comparison based on 930 nucleotides indicated that the endophyte of d. cannabina nodules belongs to the genus frankia and is highly related to the endophyte of c. nepalensis root nodules. the relatedness of the endophytes of c. nepalens ... | 1994 | 7518733 |
| genetic diversity of datisca cannabina-compatible frankia strains as determined by sequence analysis of the pcr-amplified 16s rrna gene. | the presence of frankia strains in soil samples collected from northern areas of pakistan was detected by inoculating coriaria nepalensis and datisca cannabina plants. the abundance of compatible frankia strains in some areas was indicated by profuse nodulation of the host plants, whereas soil samples from other localities failed to result in nodulation. an oligonucleotide probe (cor/dat) directed against the 16s rrna gene of the endophytes of coriaria and datisca spp. that did not cross-react w ... | 1994 | 7521157 |
| sequences of nifx, nifw, nifz, nifb and two orf in the frankia nitrogen fixation gene cluster. | the actinomycete frankia alni fixes n2 in root nodules of several non-leguminous plants. it is one of the few known n2-fixing members of the high-gc gram+ lineage of prokaryotes. thus, we have undertaken a study of its nitrogen fixation gene (nif) organization to compare with that of the more extensively characterized proteobacteria. a cosmid (pfn1) containing the nif region of fa cpi1 was isolated from a cosmid library using the nifhdk genes of fa cpi1 as a probe. a 4.5-kb bamhi fragment that m ... | 1995 | 7642138 |
| symbiotic and nonsymbiotic hemoglobin genes of casuarina glauca. | casuarina glauca has a gene encoding hemoglobin (cashb-nonsym). this gene is expressed in a number of plant tissues. casuarina also has a second family of hemoglobin genes (cashb-sym) expressed at a high level in the nodules that casuarina forms in a nitrogen-fixing symbiosis with the actinomycete frankia. both the nonsymbiotic and symbiotic genes retained their specific patterns of expression when introduced into the legume lotus corniculatus. we interpret this finding to mean that the controls ... | 1995 | 7756831 |
| pcr on the gram-positive organism frankia without prior dna extraction. | | 1995 | 7785073 |
| cloning of frankia species putative trna(pro) genes and their efficacy for psam2 site-specific integration in streptomyces lividans. | psam2 is a conjugative streptomyces ambofaciens mobile genetic element that can transfer and integrate site specifically in the genome. the chromosomal attachment site (attb) for psam2 site-specific recombination for two frankia species was analyzed. it overlaps putative proline trna genes having a 3'-terminal cca sequence, an uncommon feature among actinomycetes. psam2 is able to integrate into a cloned frankia attb site harbored in streptomyces lividans. the integration event removes the 3'-te ... | 1994 | 7811067 |
| specificity and effectivity in nodulation by frankia on southern hemisphere actinorhiza. | nodulation ability was tested for frankia strains hfpcci3 and el1, and frankia sources a.t. and g.a. from allocasaurina torulosa and gymnostoma australianum, respectively, on a. torulosa miq., casuarina cunninghamiana miq., g. australianum l. johnson and elaeagnus triflora roxb. it was shown that a. torulosa and c. cunninghamiana formed nodules only with the frankia sources obtained from their own host plant, while e. triflora formed nodules with three of the four frankia sources tested. all nod ... | 1995 | 7875571 |
| assessing horizontal transfer of nifhdk genes in eubacteria: nucleotide sequence of nifk from frankia strain hfpcci3. | the structural genes for nitrogenase, nifk, nifd, and nifh, are crucial for nitrogen fixation. previous phylogenetic analysis of the amino acid sequence of nifh suggested that this gene had been horizontally transferred from a proteobacterium to the gram-positive/cyanobacterial clade, although the confounding effects of paralogous comparisons made interpretation of the data difficult. an additional test of nif gene horizontal transfer using nifd was made, but the nifd phylogeny lacked resolution ... | 1995 | 7877490 |
| typing method for n2-fixing bacteria based on pcr-rflp--application to the characterization of frankia strains. | dna sequences of an intergenic spacer (igs) and parts of genes in the nif cluster were amplified by the polymerase chain reaction (pcr) using two primers derived from nifd- and nifk-conserved sequences. the pcr products were cleaved by ten 4-base cutting restriction enzymes and the restriction patterns were used as fingerprints to type frankia strains. the feasability of this pcr-rflp method for typing frankia strains was investigated on frankia reference strains belonging mainly to the elaeagna ... | 1993 | 7910092 |
| differential gene expression in an actinorhizal symbiosis: evidence for a nodule-specific cysteine proteinase. | nodules formed on the roots of actinorhizal plants as a consequence of nitrogen-fixing symbioses with the actinomycete frankia appear to result from modification of the developmental pathway that leads to lateral root formation. presently no information exists about factors that control this developmental switch or, until now, about genes that are differentially expressed as a result of an altered developmental pathway. differential screening of an alnus glutinosa nodule cdna library revealed al ... | 1994 | 7937912 |
| molecular characterization of frankia microsymbionts from spore-positive and spore-negative nodules in a natural alder stand. | among the frankia strains capable of establishing a nitrogen-fixing symbiosis with actinorrhizal plants, in planta sporangial formation is not universal and has led to the distinction between spore-positive (sp+) and spore-negative (sp-) nodules. numerous frankia strains have been isolated in pure culture from sp+ nodules of different host plants, but, although they were able to reinfect their respective host plant, none of them was able to differentiate endophytic sporangia under laboratory con ... | 1994 | 8017920 |
| gene expression in frankia: characterization of promoters. | promoter regions harbouring typical -10 and -35 sites of prokaryotes were isolated from the genome of various species of frankia using an escherichia coli promoter-probe plasmid. these promoter regions initiated transcription in e. coli and streptomyces cells. the consensus promoter sequence for the -10-like site was t a g/a g g/a t and for the -35-like site was t t g t/a c g. despite the gc pressure observed in frankia, functionally important positions in the promoter are conserved. as a conseq ... | 1994 | 8078412 |
| close linkage of genes encoding glutamine synthetases i and ii in frankia alni cpi1. | frankia alni cpi1 has two glutamine synthetases (gss), gsi and gsii. the gsi gene (glna) was isolated from a cosmid library of f. alni cpi1 dna by heterologous probing with glna from streptomyces coelicolor. the glna gene was shown to be located upstream of the gsii gene (glnii) by dna-dna hybridization. the nucleotide sequences of the 1,422-bp cpi1 glna gene and of the 449-bp intervening region between glna and glnii were determined, and the glna amino acid sequence was deduced. in common with ... | 1993 | 8099074 |
| physiology of some actinomycete genera. | actinomycetes are widespread in the environment and are mainly organotrophic. studies of their ecology have been primarily focussed on their detection and isolation, with comparatively little attention to the control mechanisms that determine their occurrence and behaviour in their natural environments. this session provided some diverse examples of approaches to this problem. several actinomycete genera produce motile spores. the significance of flagella proteins and factors influencing spore m ... | 1993 | 8140284 |
| molecular phylogeny of the symbiotic actinomycetes of the genus frankia matches host-plant infection processes. | nucleotide sequences of approximately 213 bp of the nif h-d intergene and the beginning of nifd were determined for symbiotic frankia isolates from the major host-infectivity groups. this region of the nif operon is variable enough to classify most infective frankia strains at the species level. phylogenetic inferences from these sequences are in agreement with the 16s rrna-derived phylogeny of the genus and, thus, are in favor of an intrageneric evolution of nif genes by orthology. phylogenetic ... | 1993 | 8277856 |
| biology of frankia strains, actinomycete symbionts of actinorhizal plants. | frankia strains are n2-fixing actinomycetes whose isolation and cultivation were first reported in 1978. they induce n2-fixing root nodules on diverse nonleguminous (actinorhizal) plants that are important in ecological successions and in land reclamation and remediation. the genus frankia encompasses a diverse group of soil actinomycetes that have in common the formation of multilocular sporangia, filamentous growth, and nitrogenase-containing vesicles enveloped in multilaminated lipid envelope ... | 1993 | 8336669 |
| molecular phylogeny of the genus frankia and related genera and emendation of the family frankiaceae. | the members of the actinomycete genus frankia are nitrogen-fixing symbionts of may species of woody dicotyledonous plants belonging to eight families. several strains isolated from diverse actinorhizal plants growing in different geographical areas were used in this study. the phylogenetic relationships of these organisms and uncharacterized microsymbionts that are recalcitrant to isolation in pure culture were determined by comparing complete 16s ribosomal dna sequences. the resulting phylogene ... | 1996 | 8573482 |
| the cyanobacterium synechococcus sp. strain pcc 7942 contains a second alkaline phosphatase encoded by phov. | a gene (phov) encoding an alkaline phosphatase from synechococcus sp. strain pcc 7942 was isolated by screening a plasmid gene bank for expression of alkaline phosphatase activity in escherichia coli jm103. two independent clones carrying the same alkaline-phosphatase-encoding gene were isolated. one of these clones (pkw1) was further analysed and the nucleotide sequence of a contiguous 3234 bp dna fragment was determined. two complete open reading frames (orf1 and phov) and an incomplete orf3 w ... | 1995 | 8574398 |
| molecular structure of the frankia spp. nifd-k intergenic spacer and design of frankia genus compatible primer. | the nifd-k intergenic spacer (igs) of ari3 and acon24d were found to have a length 265 and 199 nucleotides, respectively. they are markedly less conserved than the two neighbouring genes and have, in some instances, a repeated structure reminiscent of an insertion event. the repeated sequence and the igss have no detectable homology with sequences in dna databanks. the igs has a stem-loop structure with a low folding energy, lower than that between nifh and nifd. no convincing alignment of igs s ... | 1995 | 8574444 |
| hairy root nodulation of casuarina glauca: a system for the study of symbiotic gene expression in an actinorhizal tree. | the purpose of this study was to establish a fast system for producing transgenic actinorhizal root nodules of casuarina glauca. agrobacterium rhizogenes strain a4rs carrying the p35s-gusa-int gene construct was used to induce hairy roots on hypocotyls of 3-week-old c. glauca seedlings. three weeks after wounding, the original root system was excised, and composite plants consisting of transgenic roots on untransformed shoots were transferred to test tubes to be inoculated with frankia. the acti ... | 1995 | 8589409 |
| comparison of 16s ribosomal rna genes in clavibacter michiganensis subspecies with other coryneform bacteria. | nearly complete sequences (97-99%) of the 16s rrna genes were determined for type strains of clavibacter michiganensis subsp. michiganensis, clavibacter michiganensis subsp. insidiosus, clavibacter michiganensis subsp. sepedonicus, and clavibacter michiganensis subsp. nebraskensis. the four subspecies had less than 1% dissimilarity in their 16s rrna genes. comparative studies indicated that the c. michiganensis subsp. shared relatively high homology with the 16s rrna gene of clavibacter xyli. fu ... | 1995 | 8590406 |
| sucrose synthase and enolase expression in actinorhizal nodules of alnus glutinosa: comparison with legume nodules. | two different types of nitrogen-fixing root nodules are known- actinorhizal nodules induced by frankia and legume nodules induced by rhizobia. while legume nodules show a stem-like structure with peripheral vascular bundles, actinorhizal nodule lobes resemble modified lateral roots with a central vascular bundle. to compare carbon metabolism in legume and actinorhizal nodules, sucrose synthase and enolase cdna clones were isolated from a cdna library, obtained from actinorhizal nodules of alnus ... | 1996 | 8602161 |
| morphological, physiological, and molecular characterization of actinomycetes isolated from dry soil, rocks, and monument surfaces. | in an extended study on the biodiversity of rock-dwelling bacteria, the colony and cell morphology, physiology, protein patterns, and 16s rdna sequences of 17 bacterial strains isolated from different surfaces of rocks, stones, and monuments and from various geographical locations were characterized. all except one strain, which was found to be a bacillus, were members of the order actinomycetales. the majority of the strains either were closely related to geodermatophilus obscurus, which was al ... | 1996 | 8661940 |
| amplification of 16s rrna genes from frankia strains in root nodules of ceanothus griseus, coriaria arborea, coriaria plumosa, discaria toumatou, and purshia tridentata. | to study the global diversity of plant-symbiotic nitrogen-fixing frankia strains, a rapid method was used to isolate dna from these actinomycetes in root nodules. the procedure used involved dissecting the symbiont from nodule lobes; ascorbic acid was used to maintain plant phenolic compounds in the reduced state. genes for the small-subunit rrna (16s ribosomal dna) were amplified by the pcr, and the amplicons were cycle sequenced. less than 1 mg (fresh weight) of nodule tissue and fewer than 10 ... | 1996 | 8702283 |
| pcr-restriction fragment length polymorphism identification and host range of single-spore isolates of the flexible frankia sp. strain ufi 132715. | twelve single-spore isolates of the flexible elaeagnus-frankia strain ufi 132715 fulfilled the third and the fourth of koch's postulates on both alnus and elaeagnus axenic plants. seminested nifd-nifk pcr-restriction fragment length polymorphisms provided evidence for the genetic uniformity of the single-spore frankiae with the mother strain and its plant reisolates and allowed their molecular identification directly inside alnus and elaeagnus nodules. the clonal nature of these single-spore-pur ... | 1996 | 8702296 |
| analysis of partial sequences of genes coding for 16s rrna of actinomycetes isolated from casuarina equisetifolia nodules in mexico. | filamentous bacteria isolated from surface-sterilized nodules of casuarina equisetifolia trees in méxico were capable of reducing acetylene, a diagnostic test for nitrogenase, but were unable to nodulate their host. analysis of partial 16s rrna gene sequences suggests that the mexican isolates are not frankia strains but members of a novel clade. | 1996 | 8702297 |
| identification of bacteria in a biodegraded wall painting by denaturing gradient gel electrophoresis of pcr-amplified gene fragments coding for 16s rrna. | medieval wall paintings are often affected by biodecay. an inventory of the existing microorganisms associated with the damage to the paintings is not yet an integral part of the restoration process. this stems from the lack of effective means for such a stocktaking. nevertheless, fungi and bacteria cause severe damage through mechanical processes from growth into the painting and its grounding and through their metabolism. detailed information on the bacterial colonization of ancient wall paint ... | 1996 | 8787403 |
| [infectivity and effectiveness of different strains of frankia spp. on atriplex cordobensis plants]. | frankia is an actinomycete that fixes atmospheric nitrogen in actinorhizal symbiosis (in non-legume plants). atriplex cordobensis is an important chaco arido forage species due to the high nitrogen content. the aim of this paper was to isolate plant endophytes to be utilized as an inoculum in adapted species. a. cordobensis seedlings of 30 days were inoculated with isolated strains of atriplex cordobensis, colletia hystrix, trevoa trinervis, talguenea quinquenervia and 4-6 strains of retanilla e ... | 1996 | 8815458 |
| specific long-chain fatty acids promote optimal growth of frankia: accumulation and intracellular distribution of palmitic and propionic acid | frankia isolates from nodules of the genera casuarina (br, s21, thr), allocasuarina (allo2), and gymnostoma (g80) were found to grow exponentially with high biomass yield and minimal sporangia formation in stirred propionate mineral medium when supplemented either with 2.4 μm palmitic acid (c16:0), pentadecanoic (c15:0), heptadecanoic (c17:0), or linoleic (c18:2, cis 9, 12) fatty acids. strains also grew with lauric (c12:0) or myristic (c14:0) acids, but gave lower biomass yield. stearic acid (c ... | 1996 | 8952945 |
| genetic diversity among frankia strains nodulating members of the family casuarinaceae in australia revealed by pcr and restriction fragment length polymorphism analysis with crushed root nodules. | dna extracted directly from nodules was used to assess the genetic diversity of frankia strains symbiotically associated with two species of the genus casuarina and two of the genus allocasuarina naturally occurring in northeastern australia. dna from field-collected nodules or extracted from reference cultures of casuarina-infective frankia strains was used as the template in pcrs with primers targeting two dna regions, one in the ribosomal operon and the other in the nif operon. pcr products w ... | 1996 | 8975625 |
| the nodular microsymbionts of gymnostoma spp. are elaeagnus-infective frankia strains. | the phylogenetic relationships of frankia strains infective on gymnostoma with other frankia strains was analyzed. partial sequencing of the 16s rdna and use of specific primers showed that the frankia strains present in gymnostoma are phylogenetically close to elaeagnus-infective strains. this finding was confirmed by using the sequences of the hypervariable nifdk intergenic spacer. the strains present in gymnostoma nodules were close to one another. clustered with elaeagnus-infective strains, ... | 1997 | 9097456 |
| phylogenetic characterization of ineffective frankia in alnus glutinosa (l.) gaertn. nodules from wetland soil inoculants. | ineffective frankia endophytes were retrieved from various wet soils by using alnus glutinosa clones as trapping plants. no pure cultures could be isolated from these ineffective nodules. therefore, the phylogenetic position of these endophytes was determined by sequence analysis of cloned pcr products of bacterial 16s rdna, derived from nodules. the results showed that all nodule endophytes belong to a hitherto undescribed cluster of the frankia phylogenetic tree. the position of these uncultur ... | 1997 | 9348704 |
| interaction between frankia and actinorhizal plants. | | 1998 | 9594647 |
| calcium transport by frankia sp. strain ean1pec. | when incubated at 25 degrees c, n2-grown cells of frankia strain ean1pec actively accumulated calcium, while nh4cl-grown cells did not accumulate calcium. when incubated at 0 degrees c, both n2-grown and nh4cl-grown cells did not actively accumulate calcium. inhibitors of respiration inhibited calcium accumulation by n2-grown cells at 25 degrees c. isolated vesicles also accumulated calcium in an energy- and temperature-dependent manner. two lines of evidence show that frankia strain ean1pec has ... | 1998 | 9625783 |
| diversity of frankia strains in root nodules of plants from the families elaeagnaceae and rhamnaceae | partial 16s ribosomal dnas (rdnas) were pcr amplified and sequenced from frankia strains living in root nodules of plants belonging to the families elaeagnaceae and rhamnaceae, including colletia hystrix, elaeagnus angustifolia, an unidentified elaeagnus sp., talguenea quinquenervia, and trevoa trinervis. nearly full-length 16s rdnas were sequenced from strains of frankia living in nodules of ceanothus americanus, c. hystrix, coriaria arborea, and trevoa trinervis. partial sequences also were ob ... | 1998 | 9726914 |
| genetic complementation of rhizobial nod mutants with frankia dna: artifact or reality? | two divergent reports have been published on the genetic complementation of rhizobial nod mutants using frankia dna. in 1991 putative frankia cosmid library clones were reported to restore normal nodulation properties to rhizobium leguminosarum biovar viciae nodd::tn5, but no supporting sequence data were published. in 1992 a second group reported a failure to find any evidence of functional complementation of various rhizobial nod mutants by frankia dna (noda, nodb and nodc). complementation te ... | 1998 | 9829835 |
| analysis of lmw rna profiles of frankia strains by staircase electrophoresis. | an optimized technique of polyacrylamide gel electrophoresis, staircase electrophoresis (sce), was applied to determine the stable low molecular weight rna (lmw rna) profiles of 25 frankia strains from diverse geographic origins and host specificity groups as well as species from other actinomycete genera. application of the technique permits the rapid identification of frankia strains and their differentiation from other actinomycetes. the isolates used in this study were grouped in eight clust ... | 1998 | 9924822 |
| geographic distribution and genetic diversity of ceanothus-infective frankia strains. | little is known about ceanothus-infective frankia strains because no frankia strains that can reinfect the host plants have been isolated from ceonothus spp. therefore, we studied the diversity of the ceonothus-infective frankia strains by using molecular techniques. frankia strains inhabiting root nodules of nine ceanothus species were characterized. the ceanothus species used represent the taxonomic diversity and geographic range of the genus; therefore, the breadth of the diversity of frankia ... | 1999 | 10103225 |
| symbiotic root nodules of the actinorhizal plant datisca glomerata express rubisco activase mrna. | n2-fixing symbiotic root nodules of the actinorhizal host datisca glomerata express dgrca (d. glomerata rubisco activase) mrna, a transcript usually associated with photosynthetic organs or tissues. in northern blots a mature, 1700-nucleotide dgrca mrna was detected in green plant organs (leaves, flowers, and developing fruits) and in nodules but was not detected in roots. a second message of 3000 nucleotides was observed only in nodules. both size classes of transcripts were polyadenylated. the ... | 1999 | 10364392 |
| analysis of frankia evolutionary radiation using glnii sequences. | using a glnii (encoding glutamine synthetase ii) pcr selective screening, a frankia acn14a gene library clone was isolated. a derived glnii-hybridising 2.7-kb hindiii subclone was characterised. identities of 95% and 93% were observed, respectively, with the corresponding frankia cpi1 glni and glnii regions. a variable segment of the glnii region was selected, pcr amplified from various frankia genomes, sequenced, and used to investigate phylogenetic relationships within the genus. glnii phyloge ... | 1999 | 10436920 |
| flavan-containing cells delimit frankia-infected compartments in casuarina glauca nodules. | we investigated the involvement of polyphenols in the casuarina glauca-frankia symbiosis. histological analysis revealed a cell-specific accumulation of phenolics in c. glauca nodule lobes, creating a compartmentation in the cortex. histochemical and biochemical analyses indicated that these phenolic compounds belong to the flavan class of flavonoids. we show that the same compounds were synthesized in nodules and uninfected roots. however, the amount of each flavan was dramatically increased in ... | 1999 | 10482666 |
| natural diversity of frankia strains in actinorhizal root nodules from promiscuous hosts in the family myricaceae. | actinorhizal plants invade nitrogen-poor soils because of their ability to form root nodule symbioses with n(2)-fixing actinomycetes known as frankia. frankia strains are difficult to isolate, so the diversity of strains inhabiting nodules in nature is not known. to address this problem, we have used the variability in bacterial 16s rrna gene sequences amplified from root nodules as a means to estimate molecular diversity. nodules were collected from 96 sites primarily in northeastern north amer ... | 1999 | 10508084 |
| a simple, rapid and non-destructive procedure to extract cell wall-associated proteins from frankia. | a simple cell fractionation procedure was developed to extract cell wall-associated proteins from the nitrogen-fixing actinomycete frankia. the method was based on washing frankia mycelia in 62.5 mm tris-hcl (ph 6.8) buffer supplemented with 0.1% triton x-100 as solubilizing agent. cell wall-associated proteins were efficiently extracted in less than 10 min, recovering approximately 94.5+/-7.44 microg protein per extraction procedure from exponentially growing cells corresponding to 50 ml of cul ... | 2000 | 10576707 |
| distribution of gymnostoma spp. microsymbiotic frankia strains in new caledonia is related to soil type and to host-plant species | the diversity of the frankia strains that are naturally in symbiosis with plants belonging to the gymnostoma genus in new caledonia was investigated. a direct molecular characterization of dna extracted from nodules was performed, followed by characterization by restriction fragment length polymorphism (rflp) of the ribosomal rrs-rrl (16s-23s) intergenic spacer (igs) polymerase chain reaction (pcr)-amplified region. seventeen different patterns were identified among the 358 microsymbiotic strain ... | 1999 | 10620222 |
| molecular phylogenies of plants and frankia support multiple origins of actinorhizal symbioses. | molecular phylogenetic trees were reconstructed from nucleotide sequences of nifh and 16s rdna for frankia and of rbcl for actinorhizal plants. comparison of frankia phylogenetic trees reconstructed using nifh and 16s rdna sequences indicated that subgroupings of both trees correspond with each other in terms of plant origins of frankia strains. the results suggested that 16s rdnas can be utilized for coevolution analysis of actinorhizal symbioses. frankia and plant phylogenetic trees reconstruc ... | 1999 | 10620407 |
| characterization of the 20s proteasome from the actinomycete frankia. | frankia is an actinomycete that fixes atmospheric nitrogen in symbiotic association with the root systems of a variety of non-leguminous plants, denominated actinorhizal plants. information on the biology of proteolysis in frankia is almost non-existent as it is extremely difficult to grow this organism. we have purified 20s proteasomes from frankia strain acn14a/ts-r. it is composed of one alpha-subunit and one beta-subunit, which assemble into the canonical structure of four rings of seven sub ... | 2000 | 10652097 |
| characterization of a casuarina glauca nodule-specific subtilisin-like protease gene, a homolog of alnus glutinosa ag12. | in search of plant genes expressed during early interactions between casuarina glauca and frankia, we have isolated and characterized a c. glauca gene that has strong homology to subtilisin-like protease gene families of several plants including the actinorhizal nodulin gene ag12 of another actinorhizal plant, alnus glutinosa. based on the expression pattern of cg12 in the course of nodule development, it represents an early actinorhizal nodulin gene. our results suggest that subtilisin-like pro ... | 2000 | 10656592 |
| nitrogenase activity in alnus incana root nodules. responses to o(2) and short-term n(2) deprivation. | o(2) and host-microsymbiont interactions are key factors affecting the physiology of n(2)-fixing symbioses. to determine the relationship among nitrogenase activity of frankia-alnus incana root nodules, o(2) concentration, and short-term n(2) deprivation, intact nodulated roots were exposed to various o(2) pressures (po(2)) and ar:o(2) in a continuous flow-through system. nitrogenase activity (h(2) production) occurred at a maximal rate at 20% o(2). exposure to short-term n(2) deprivation in ar: ... | 2000 | 10677448 |