Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| the map position of sym-plasmid regions expressed in the bacterial and endosymbiotic form of rhizobium leguminosarum. | 1982 | 6179109 | |
| the ti plasmids of agrobacterium. | 1982 | 6276093 | |
| molecular cloning of rhizobium trifolii genes involved in symbiotic nitrogen fixation. | dna sequences responsible for the development and maintenance of symbiotic nitrogen fixation have been identified and isolated from rhizobium trifolii. symbiotically-defective strains were generated by random mutagenesis with the transposon tn5. the defective genes which give rise to the mutant phenotype have been cloned into bacterial plasmids and used as hybridization probes to isolate the corresponding wild-type genes from a clone bank of r. trifolii dna. symbiotic genes cloned in this manner ... | 1982 | 6286830 |
| genetic map of the crown gall suppressive incw plasmid psa. | a genetic map of the w incompatibility group plasmid psa has been prepared through the construction of deletion derivatives of psa and the cloning of various fragments of psa in pbr322. phenotypic analysis of these derivatives has identified the location of genes encoding resistance to chloramphenicol, sulfonamides, spectinomycin, streptomycin, kanamycin, gentamycin, and tobramycin. information sufficient for the replication of the plasmid in both escherichia coli and agrobacterium tumefaciens i ... | 1982 | 6287164 |
| directed transposon tn5 mutagenesis and complementation analysis of rhizobium meliloti symbiotic nitrogen fixation genes. | an 18 kb region adjacent to and surrounding the genes for nitrogenase (nif) was cloned from the genome of the symbiotic nitrogen-fixing species rhizobium meliloti. a total of 31 tn5 insertions in the nif region were constructed and assayed for their effect on symbiotic nitrogen fixation (fix phenotype). fix- insertions were found in two clusters, one 6.3 kb region not containing essential symbiotic genes. the locations of at least three transcription units containing fix genes were deduced from ... | 1982 | 6288262 |
| electron transport components involved in hydrogen oxidation in free-living rhizobium japonicum. | membranes from free-living rhizobium japonicum were isolated to study electron transport components involved in h2 oxidation. the h2/o2 uptake rate ratio in membranes was approximately 2. the electron transport inhibitors antimycin a, cyanide, azide, hydroxylamine, and 2-n-heptyl-4-hydroxyquinoline-n-oxide (hqno) inhibited h2 uptake and h2-dependent o2 uptake significantly. h2-reduced minus o2-oxidized absorption difference spectra revealed peaks at 551.5, 560, and 603 nm, indicating the involve ... | 1982 | 6288665 |
| on the operon structure of the nitrogenase genes of rhizobium leguminosarum and azotobacter vinelandii. | the transcription of the nitrogenase genes in rhizobium leguminosarum was studied by analysing total cellular rna from bacteroids for the presence of nitrogenase messenger rna. the rna was separated by agarose gel electrophoresis and blotted onto nitrocellulose filters. messenger rna for nitrogenase was detected by hybridization with probes derived from plasmid psa30, a recombinant plasmid carrying the nitrogenase genes of klebsiella pneumoniae. in the same way nitrogenase mrna was detected in r ... | 1982 | 6289264 |
| construction of a broad host range cosmid cloning vector and its use in the genetic analysis of rhizobium mutants. | we have constructed a cosmid derivative of the low copy-number broad host-range cloning vector prk290 (ditta et al., 1980) by inserting a 1.6-kb bg/ii fragment containing lambda cos into the unique bg/ii site in prk290. the new vector, plafr1, is 21.6 kb long, confers tetracycline resistance, contains a unique ecori site, and can be mobilized into and stably replicates within many gram-negative hosts. we constructed a clone bank of rhizobium meliloti dna in plafr1 using a partial ecori digest. t ... | 1982 | 6290332 |
| t-dna organization in homogeneous and heterogeneous octopine-type crown gall tissues of nicotiana tabacum. | octopine-type tumor tissue was obtained both by infection of plants or isolated protoplasts with agrobacterium tumefaciens and by somatic hybridization of normal and crown gall tobacco cells. analysis of t-dna by southern blotting of clones and uncloned tissue reveals that, whereas tumors induced on plants are heterogeneous mixtures of cells differing in t-dna organization, each tissue derived from transformed protoplasts or from somatic hybridization is homogeneous. detailed analysis of t-dna o ... | 1982 | 6291777 |
| agrobacterium tumefaciens mutants affected in attachment to plant cells. | an analysis of agrobacterium tumefaciens mutants with tn5 insertions in chromosomal dna showed that the chromosome of a. tumefaciens codes for a specific ability of this bacterium to attach to plant cells. this ability is associated with tumorigenesis by a. tumefaciens, the ability of avirulent a. tumefaciens to inhibit tumorigenesis, and the ability to adsorb certain phages. a second class of chromosomal mutations affects tumorigenesis without altering the ability to attach to plant cells. the ... | 1982 | 6292165 |
| wide host range cloning vectors: a cosmid clone bank of an agrobacterium ti plasmid. | 1982 | 6292969 | |
| method for the transfer of large cryptic, non-self-transmissible plasmids: ex planta transfer of the virulence plasmid of agrobacterium rhizogenes. | 1982 | 6292973 | |
| microbial envelope proteins related to iron. | 1982 | 6293371 | |
| genetic isolation and physical characterization of pagk84, the plasmid responsible for agrocin 84 production. | 1982 | 6294705 | |
| siderophore production by phytopathogenic microbial species. | 1982 | 6218783 | |
| partial purification and properties of membrane-bound atpase in agrobacterium tumefaciens. | 1982 | 6220646 | |
| isrm1: a rhizobium meliloti insertion sequence that transposes preferentially into nitrogen fixation genes. | after transposon tn5 mutagenesis, a high proportion of rhizobium meliloti symbiotic mutants do not contain tn5 insertions in symbiotic genes. instead, the mutations in these strains are correlated with the presence of an endogenous insertion sequence (isrm1) in nitrogen fixation (nif) or symbiotic genes which are adjacent to the nif genes. isrm1 is 1.4 kb and transposes to at least three restriction fragments in the nif region at a frequency between 10(-2) and 10(-3). a nif region restriction fr ... | 1982 | 6296251 |
| symbiotic nitrogen fixation: molecular cloning of rhizobium genes involved in exopolysaccharide synthesis and effective nodulation. | a transposon (tn5)-induced mutant (strain anu437) of rhizobium trifolii was isolated in which no water-soluble exopolysaccharide (eps) could be detected. this mutant was also incapable of forming nitrogen-fixing root nodules on clover plants. molecular cloning has demonstrated that the tn5 transposon was responsible for both of these mutant phenotypes and that there is a direct correlation between eps synthesis in this bacterial strain and its ability to carry out symbiotic nitrogen fixation. in ... | 1982 | 6296257 |
| t-dna of the agrobacterium ti and ri plasmids. | the study of t-dna transmission from agrobacterium ti or ri plasmid into the genomes of higher plant cells has revealed much about the consequences of transformation. it is now clear that the transformed phenotype is caused by hormonal changes produced directly or indirectly by t-dna genes. the opine synthases are enzymes encoded in t-dna that function in the plant cell. our level of understanding of t-dna-encoded functions is already sufficient to reveal clear and feasible ways to exploit t-dna ... | 1982 | 6297376 |
| variation in hormone autonomy and regenerative potential of cells transformed by strain a66 of agrobacterium tumefaciens. | mutant agrobacterium tumefaciens strain a66 is shown to differ from its wild-type progenitor (strain a6) by a spontaneous 2.7 kb dna insert into the t-dna region of its ti plasmid. tobacco stems transformed by a66 exhibit an attenuated response characterized by slow growth and shoot proliferation. clonal analysis demonstrates that this response is due to an alteration in the growth and regenerative potential of transformed cells, rather than to variation in the frequency of fully autonomous cell ... | 1982 | 6297775 |
| physical and genetic characterization of symbiotic and auxotrophic mutants of rhizobium meliloti induced by transposon tn5 mutagenesis. | we have physically and genetically characterized 20 symbiotic and 20 auxotrophic mutants of rhizobium meliloti, the nitrogen-fixing symbiont of alfalfa (medicago sativa), isolated by transposon tn5 mutagenesis. a "suicide plasmid" mutagenesis procedure was used to generate tn-5-induced mutants, and both auxotrophic and symbiotic mutants were found at a frequency of 0.3% among strains containing random tn5 insertions. two classes of symbiotic mutants were isolated: 4 of the 20 formed no nodules ... | 1982 | 6274841 |
| clustering of nitrogen fixation (nif) genes in rhizobium meliloti. | a cloned 17.3-kilobase region of the rhizobium meliloti genome with homology to the klebsiella pneumoniae nitrogenase structural genes was studied. limits on the extent of homology were determined. transposon mutagenesis of this region of the genome verified that it contained functional nif genes, some transposon insertions resulted in a defective symbiotic phenotype, whereas others had no noticeable effect on symbiotic competence. the relative position of insertions yielding these two phenotypi ... | 1982 | 6274844 |
| carriers in electron transport from molecular hydrogen to oxygen in rhizobium japonicum bacteroids. | an investigation has been conducted to identify electron transport carriers that participate in the oxidation of h2 by h2 uptake-positive strains of rhizobium japonicum bacteroids. we have observed that the reduced form of dibromothymoquinone at a concentration of 0.2 mm strongly inhibited h2 uptake, endogenous respiration, and c2h2 reduction by bacteroid suspensions. reduced dibromothymoquinone, however, failed to inhibit the transfer of electrons from h2 to methylene blue under anaerobic condi ... | 1982 | 6277845 |
| effects of iron deficiency on heme biosynthesis in rhizobium japonicum. | the effects of iron deficiency on heme biosynthesis in rhizobium japonicum were examined. iron-deficient cells had a decreased maximum cell yield and a decreased cytochrome content and excreted protoporphyrin into the growth medium. the activities of the first two enzymes of heme biosynthesis, delta-aminolevulinic acid synthase (ec 2.3.1.37) and delta-aminolevulinic acid dehydrase (ec 4.2.1.24), were diminished in iron-deficient cells, but were returned to normal levels upon addition of iron to ... | 1982 | 6277847 |
| rhizobium japonicum mutants that are hypersensitive to repression of h2 uptake by oxygen. | the synthesis of an h2 oxidation system in free-living rhizobium japonicum wild-type strain sr is repressed by oxygen. maximal h2 uptake rates were obtained in strain sr after derepression in 11 microm or less dissolved oxygen. oxygen levels above 45 microm completely repressed h2 uptake in strain sr. five r. japonicum mutant strains that are hypersensitive to repression or h2 oxidation by oxygen were derived from strain sr. the mutants were obtained by screening h2 uptake-negative mutants that ... | 1982 | 6277861 |
| metal coordination centres of class ii cytochromes c. | the class ii cytochromes rhodospirillum molischianum cytochrome c', rhodopseudomonas palustris cytochrome c556 and agrobacterium tumefaciens (b2a) cytochrome c556 have been investigated with a variety of spectroscopic techniques. the cytochrome c' was found to be high-spin and the two cytochromes c556 were found to be mainly low-spin and sx-coordinate with the fifth and sixth ligands being histidine and methionine. the implications of the different types of iron coordination are discussed. | 1982 | 6279397 |
| transformation of rhizobium meliloti 41 with plasmid dna. | plasmid pgv1106, a derivative of the wide-host-range plasmid s-a of the w incompatibility group, was introduced into rhizobium meliloti 41 by plasmid-mediated mobilization to overcome the restriction of foreign dna. the mobilized plasmid pkk2 differed from the original pgv1106 by an extra piece of dna of 1.3 kilobase pairs which supposedly originated from pjb3ji used for mobilization. if pkk2 was isolated from r. meliloti 41, it could be successfully reintroduced by transformation. the transform ... | 1982 | 6279558 |
| construction and application of r prime plasmids, carrying different segments of an octopine ti plasmid from agrobacterium tumefaciens, for complementation of vir genes. | 1982 | 6281831 | |
| a functional map of the replicator region of the octopine ti plasmid. | 1982 | 6281832 | |
| organization and expression of leghaemoglobin genes. | leghaemoglobin genes in soybean (glycine max) are present as a moderately reiterated family of sequences. since there are identical restriction site patterns of these sequences in dna isolated from leaf, root, or nodule tissue, the data suggest that no major changes in the organization or methylation of leghaemoglobin genes occur during their induction. cloned soybean leghaemoglobin-cdna cross hybridized with rna from root nodules of kidney bean (phaseolus vulgaris), and to a lesser extent, of p ... | 1982 | 6282418 |
| octopine ti-plasmid deletion mutants of agrobacterium tumefaciens with emphasis on the right side of the t-region. | 1982 | 6283573 | |
| restriction endonuclease mapping of a rhizobium leguminosarum sym plasmid. | 1982 | 6285400 | |
| molecular genetics of symbiotic nitrogen fixation. | 1982 | 6286135 | |
| transport and catabolism of d-mannose in rhizobium meliloti. | rhizobium meliloti l5-30 grows on d-mannose as the sole carbon source. the catabolic pathway of d-mannose was characterized. the following activities were present: mannose transport system, mannokinase, and mannosephosphate isomerase. several mannose-negative mutants were selected; they were classified into three functional groups: group i, mannokinase and mannosephosphate isomerase defective: group ii, mannokinase defective; and group iii, mannosephosphate isomerase defective. mannose uptake wa ... | 1982 | 6286588 |
| units of genetic expression in the virulence region of a plant tumor-inducing plasmid of agrobacterium tumefaciens. | the effect of a large number of tn3 insertions in the vir region of the ti plasmid ptia6nc on the virulence of agrobacterium was determined. the vir- insertions were mapped in three of the five loci that have been defined previously. merodiploid rec- strains carrying one insertion mutation on the ti plasmid and another insertion mutation (or the homologous wild-type region) on a compatible plasmid were constructed and used in complementation tests for virulence in test plants. this analysis has ... | 1982 | 6298572 |
| occurrence of l-lysine epsilon-dehydrogenase in agrobacterium tumefaciens. | a novel amino acid dehydrogenase catalyzing the oxidative deamination of the epsilon-amino group of l-lysine was found in the crude extract of agrobacterium tumefaciens icr 1660. the enzyme required nad(+) and was specific for l-lysine. the enzyme was optimally active at about ph 9.7. | 1982 | 6801024 |
| r68.45 mediated chromosomal gene transfer in agrobacterium tumefaciens. | a large plasmid enables its host agrobacterium tumefaciens to cause tumorous condition in a wide variety of dicotyledonous plants[see ooms et al. gene 14:33--50 (1981) )). the location and role of chromosomal genes in this phenomenon are not known. as the first stage in studying this aspect, a project was initiated to investigate the chromosomal genetics of the bacterium. r68.45, a p group plasmid, was chosen as a transmission agent. after a preliminary assessment it was decided to use c58 as a ... | 1982 | 6808964 |
| lytic effects of edta & lysozyme on virulent & avirulent strains of agrobacterium tumefaciens. | 1982 | 6809600 | |
| requirement for carbon dioxide for nonsymbiotic expression of rhizobium japonicum nitrogenase activity. | the expression and maintenance of nitrogenase (c(2)h(2)) activity in growing, microaerobic liquid cultures of rhizobium japonicum 3i1b110 was found to be stringently dependent on the sustained supply of co(2). this requirement for co(2) appeared to exceed the basal requirement for growth and was not related to effects on ph. | 1982 | 6811563 |
| enhancement of specific nitrogenase activity in azospirillum brasilense and klebsiella pneumoniae, inhibition in rhizobium japonicum under air by phenol. | specific nitrogenase activity in azospirillum brasilense atcc 29145 in surface cultures under air is enhanced from about 50 nmol c2h4 x mg protein -1 x h-1 to 400 nmol c2h4 by the addition of 1 mm phenol. 0.5 and 2 mm phenol added increase the rate 5-fold and 4-fold. this enhancement effect is observed only between 2 and 3 days after inoculation, with only a small reduction of the growth of the cells by the phenol added. in surface cultures under 1% o2, nitrogenase activity is slightly reduced b ... | 1982 | 6812526 |
| fate in model ecosystems of microbial species of potential use in genetic engineering. | the changes in populations of staphylococcus aureus, bacillus subtilis, salmonella typhimurium, klebsiella pneumoniae, agrobacterium tumefaciens, rhizobium meliloti, and saccharomyces cerevisiae were measured after their introduction into samples of sewage, lake water, and soil. enumeration of small populations was possible because the strains used were resistant to antibiotics in concentrations and combinations such that few species native to these ecosystems were able to grow on agar containin ... | 1982 | 6814361 |
| relationship between nif plasmids of fast-growing rhizobium species and ti plasmids of agrobacterium tumefaciens. | by use of the southern blot hybridization technique the extent of dna homology was determined between the nif plasmid of a number of fast-growing rhizobium species and ti plasmids of the octopine (ptiach5) and nopaline (ptic58) type. dna sequences common to these plasmids were located on functional maps of the ti plasmids. no homology between nif plasmids and the t region of ti plasmids was detected. | 1982 | 7061382 |
| regulation of tryptophan genes in rhizobium leguminosarum. | twelve tryptophan auxotrophs of rhizobium leguminosarum were characterized biochemically. they were grown in complex and minimal media with several carbon sources, in both limiting and excess tryptophan. missing enzyme activities allowed assignment of all mutant to the trpe, trpd, trpb, or trpa gene, confirming earlier results with the same mutants (johnston et al., mol. gen. genet. 165:323-330, 1978). in regulatory experiments, only the first enzyme of the pathway, anthranilate synthase, respon ... | 1982 | 7061383 |
| mechanism of regulation of glucose transport in rhizobium leguminosarum. | multiple glucose transport systems were distinguished in rhizobium leguminosarum. we found nonlinear lineweaver-burk plots for the uptake of glucose, 2-deoxy-d-glucose, and alpha-methyl-d-glucoside, and this implied the existence of at least two uptake mechanisms. different patterns of inhibition of 2-deoxy-d-glucose uptake and alpha-methyl-d-glucoside uptake at 0.1 mm by various carbohydrates revealed differences in the stereospecificities of the transport systems. osmotic shock treatment aboli ... | 1982 | 7061388 |
| complementation analysis of agrobacterium tumefaciens ti plasmid mutations affecting oncogenicity. | a wide host range cosmid vector has been constructed by insertion of the lambda cos site into the plasmid prk2501. this cosmid, which is maintained in agrobacterium tumefaciens and is compatible with the ti plasmid, has been used to make a clone bank of the a. tumefaciens ptia6 plasmid. several ptia6 cosmids have been used to complement tn5-induced ti plasmid mutations. five avirulent mutations which map outside of the region of the plasmid maintained in plant tumours (t-dna) could be complement ... | 1982 | 7061395 |
| megaplasmids in the plant-associated bacteria rhizobium meliloti and pseudomonas solanacearum. | using analytical and preparative methods, we demonstrated the presence of megaplasmids with molecular weight larger than 450 x 10(6) in the two plant-associated bacteria rhizobium meliloti and pseudomonas solanacearum. such giant plasmids were found in 8 of 9 p. solanacearum strains tested and in all of the 18 r. meliloti strains tested. | 1982 | 7061401 |
| genetic transformation of rhizobium leguminosarum by plasmid dna. | we demonstrated the genetic transformation of rhizobium leguminosarum by r68.45 plasmid dna by freezing and thawing cell suspensions in the presence of r68.45 plasmid dna and 20 mm mgcl2. clones resistant to kanamycin and tetracycline were recovered at a frequency of 10(-8) per recipient cell. no colonies that were doubly drug resistant were recovered in parallel control experiments. | 1982 | 7061403 |
| d-glucosaminate dehydratase from agrobacterium radiobacter. physicochemical and enzymological properties. | the bacterial distribution of d-glucosaminate dehydratase [ec 4.2.1.26] was investigated and agrobacterium radiobacter (iam 1526) was found to have the highest enzyme activity. the enzyme was formed inducibly in a glycerol-urea medium by d-glucosamine, d-galactosamine, and d-glucosamine, but not by d-mannosamine. the enzyme purified from the cells grown in the glucosamine-glycerol-urea medium was shown to be homogeneous by ultracentrifugation. the molecular weight was determined to be about 66,0 ... | 1982 | 7068563 |
| [physiological and biochemical characteristics of the cells of a carrot gall tumor developing in weightlessness]. | the paper presents the results of experiments with the carrot tissues infected with agrobacterium tumefaciens flown onboard the biosatellite cosmos-1129 in cooperation with the us scientists. postflight, the respiratory activity of tumour cells was determined and k+ and na+ permeability of cell membranes was measured. the resulting data give evidence that in weightlessness the development of the carrot gall tumour is accompanied by changes in the above physiological and biochemical parameters. t ... | 1982 | 7070038 |
| secretion of trans-zeatin by agrobacterium tumefaciens: a function determined by the nopaline ti plasmid. | 1982 | 7073755 | |
| em5400, a family of monobactam antibiotics produced by agrobacterium radiobacter. ii. isolation and structure determination. | 1982 | 7076578 | |
| molecular mechanism for loss of nodulation properties of rhizobium trifolii. | of 18 rhizobium trifolii strains tested, 12 showed a high frequency of loss of nodulation ability after incubation in cultures at elevated temperatures. a correlation between loss of nodulation ability and loss of a large plasmid was demonstrated for r. trifolii. in some nonnodulating (nod-) mutants, deletions occurred instead of total elimination of the plasmid molecule. the maximum curing effect was observed in bacteria incubated at 35 degrees c. after 4 or more days of incubation at this temp ... | 1982 | 7076625 |
| ti plasmids as gene carriers. | 1982 | 7079762 | |
| characteristics of ti plasmids from broad-host-range and ecologically specific biotype 2 and 3 strains of agrobacterium tumefaciens. | agrobacterium tumefaciens strains isolated from crown gall tumors on grapevines in california were consistently of the biotype 3 group. all 11 of these strains were limited in their host range and harbored ti plasmids with molecular masses between 119 and 142 megadaltons (mdal) as well as a larger cryptic plasmid of greater than 200 mdal; occasionally a smaller cryptic plasmid of 65 mdal was also present. ti plasmids o these strains have dna sequences in common with ti plasmids of octopine and n ... | 1982 | 7085561 |
| identification and mobilization by cointegrate formation of a nodulation plasmid in rhizobium trifolii. | a nodulation plasmid, prtr-514a, of molecular size 180 megadaltons (mdal) was identified in rhizobium trifolii strain nzp514. this plasmid was absent in both spontaneous and heat-cured nod- derivatives of nzp514, and these strains were unable to induce root hair curling. the ability to nodulate clover was transferred from the wild-type strain to a nod- derivatives, pn104, with the broad-host-range plasmid r68.45 (39 megadaltons) at a cotransfer frequency of about 4 x 10(-3). most of the nod+ tra ... | 1982 | 7085562 |
| structural studies of alfalfa roots infected with nodulation mutants of rhizobium meliloti. | alfalfa roots infected with four nodulation defective (nod-) mutants of rhizobium meliloti which were generated by transposon tn5 mutagenesis were examined by light and electron microscopy. in one class of nod- mutants, which we can nonreactive, the bacteria did not induce root hair curling or penetrate host cells. in a second class of nod- mutants, which we call reactive, the bacteria induced some root hair curling and entered root epidermal cells, although no infection threads were formed. in ... | 1982 | 7085566 |
| positive selection of nodulation-deficient rhizobium phaseoli. | a high proportion of rhizobium phaseoli mutants that survived infection with phage f1 were found to be nodulation deficient. two that were examined in detail had internal defects in addition to the expected surface defects. one internal defect was in the enzyme phosphoglucose isomerase. the use of phages to select appropriate mutants should apply generally in any system in which surface components are involved. | 1982 | 7085572 |
| lipid-bound saccharides in rhizobium meliloti. | the lipid-bound saccharides formed by incubation of uridine diphosphate glucose with a particulate enzyme of rhizobium meliloti were studied. they behaved like polyprenyl diphosphate saccharides when treated with ammonia or hot phenol, when catalytically hydrogenated, and on deae-cellulose chromatography. the saccharide moieties obtained after heating at ph 2 for 10 min at 100 degrees c were separated with a gel filtration column. the following compounds were detected: galactose, glucosyl beta 1 ... | 1982 | 7085601 |
| regions of homology between tumorigenic plasmids from agrobacterium rhizogenes and agrobacterium tumefaciens. | 1982 | 7089090 | |
| plasmids and stability of symbiotic properties of rhizobium trifolii. | a conjugal plasmid which encodes both peak nodulation genes and nitrogenase genes, and which is labeled with the transposon tn5, was transferred to a wild-type rhizobium trifolii strain to examine the stability and expression of the host range and fixation (fix+) phenotypes. transconjugates were isolated which were shown to initially form nitrogen-fixing nodules (nod+ fix+) on both clovers and peas. these hybrid strains were then repeatedly passaged through either pea or clover nodules or onto a ... | 1982 | 7096265 |
| heme biosynthesis in rhizobium. identification of a cloned gene coding for delta-aminolevulinic acid synthetase from rhizobium meliloti. | a symbiotically important gene system in rhizobial species is the heme biosynthetic pathway. a mutant having reduced levels of delta-aminolevulinic acid synthetase, the first unique enzyme in this pathway, was obtained in rhizobium meliloti 102f34 by n-methyl-n'-nitro-n-nitrosoguanidine mutagenesis. enzyme activity ranged from 3-13% of the wild type. alfalfa plants inoculated with the rhizobium synthetase mutant grew no better than uninoculated controls and formed only small white nodules which ... | 1982 | 7096330 |
| structural analysis of complex carbohydrates using high-performance liquid chromatography, gas chromatography, and mass spectrometry. | 1982 | 7098937 | |
| properties of rhizobium leguminosarum isolated from various regions of morocco. | twenty-eight isolates of rhizobium leguminosarum capable of nodulating broad-bean (vicia faba l. var. major) were collected throughout morocco and characterized by using morphological, physiological, biochemical and serological tests. the properties of isolates from within a given climatic zone varied as much as the properties of isolates from different zones. the isolates were adapted to desiccation, but were not adapted to temperatures higher than 37 degrees c. a high degree of heterogeneity w ... | 1982 | 7103311 |
| tumor induction by agrobacterium tumefaciens: analysis of the boundaries of t-dna. | molecular cloning has been used to isolate the ends of that portion of the tumor-inducing (ti) plasmid of agrobacterium tumefaciens which has been designated t-dna and which has been transferred to the genome of tobacco crown gall tumor cells. analysis of the dna sequences of the plant border clones compared with the corresponding sequences of the ti plasmid suggests that the mechanism of transferred dna integration and subsequent stabilization is precise at the right border and imprecise on the ... | 1982 | 7108407 |
| [antibiotic resistance of nodular bacteria]. | the effect of several antibiotics on 4 rapid-growing rhizobia, i. e. r. phaseoli, r. leguminosarum, r. trifolii and r. meliloti and 3 slow growing rhizobia, i. e. r. vigna, r. japonicum and r. lupini was studied. it was shown that 4 of the species, i. e. r. meliloti, r. japonicum, r. vagna and r. lupini had multiple drug resistance. a tetracycline resistant mutant mc of r. japonicum was isolated. | 1982 | 7114827 |
| tumor reversal in plants. | 1982 | 7122580 | |
| nitrogen fixation (nif) genes and large plasmids of rhizobium japonicum. | the location of structural nitrogen-fixation genes was determined for the slow- and fast-growing types of rhizobium japonicum. slow-growing r. japonicum strains do not harbor structural nif genes, homologous to nifd and nifh, on large plasmids (100 to 200 megadaltons). in contrast, all fast-growing r. japonicum strains, except prc194, contain structural nif genes on large plasmids. | 1982 | 7130134 |
| identification of structural proteins of rhizobium meliloti temperate phage 16-3. | the structural proteins of rhizobium meliloti temperate phage 16-3 have been analysed by means of polyacrylamide gel electrophoresis, isoelectric focusing and agarose gel electrophoresis. five major and five minor proteins were identified and characterized with respect to their size, isoelectric point and their distribution between the head ad tail of the phage particle. the synthesis of structural proteins was studied by one- and two-dimensional gel electrophoresis. | 1982 | 7130949 |
| passage of bacterial dna into host cells during in vitro transformation of nicotiana tabacum by agrobacterium tumefaciens. | tumorigenic and non-tumorigenic strains of agrobacterium tumefaciens were labelled with tritiated thymidine and added separately to suspension cultures of x-d line habituated tobacco cells. the subsequent association of bacteria with plant host cells and the passage of bacteria and bacterial dna into these cells was examined by conventional light and electron microscopy and light microscope autoradiography. the results suggest that both strains of bacterium enter damaged host cells (via wall les ... | 1982 | 7144594 |
| identification of the sym plasmid of rhizobium leguminosarum strain 1001 and its transfer to and expression in other rhizobia and agrobacterium tumefaciens. | 1982 | 7146147 | |
| dna from the a6s/2 crown gall tumor contains scrambled ti-plasmid sequences near its junctions with plant dna. | the a6s/2 tumor incited on tobacco by agrobacterium tumefaciens harboring the octopine-type a6 ti plasmid contains one insert of ti-plasmid sequences (the t dna). this 13 kb insert is derived from a colinear sequence in the ti plasmid (the t region) and becomes attached to plant dna in the nucleus of the host cell. we have determined the dna sequence encompassing the left end of the t region of the a6 ti plasmid and the corresponding portion of the a6s/2 t dna. the two sequences are identical fo ... | 1982 | 7151163 |
| nucleotide sequence and transcript map of the agrobacterium tumefaciens ti plasmid-encoded octopine synthase gene. | we have determined the complete nucleotide sequence of the gene for the crown gall enzyme, octopine synthase. the sequence was derived from cloned fragments of the agrobacterium tumefaciens ti plasmid ach5. it displayed a continuous open reading frame encoding a polypeptide chain of 358 amino acids. the nucleotide positions corresponding to the 5' end and poly(a) addition site of the mature octopine synthase mrna from a tobacco tumor cell line were determined by s1 nuclease mapping. two sequence ... | 1982 | 7153687 |
| multiple transcripts of t-dna detected in nopaline crown gall tumors. | crown gall plant tumors contain neoplastic cells transformed by incorporation of a foreign dna element, t-dna, derived from a large tumor-inducing plasmid in the inciting agrobacterium strain. t-dna is covalently joined to the nuclear dna of the tumor cell, and rna transcripts from t-dna are present in polyadenylated form on polysomes. this paper presents a detailed analysis of those parts of t-dna transcribed in a nopaline-type tobacco teratoma, bt37, whose t-dna has been mapped and cloned. nor ... | 1982 | 7153688 |
| nopaline synthase: transcript mapping and dna sequence. | the dna sequence of the nopaline synthase gene (nos) from agrobacterium tumefaciens ti plasmid ptit37 and adjacent regions up to the right border of the t-dna was determined. the 5' and 3' termini of the polyadenylated nos mrna, isolated from a t37 tobacco teratoma tumor line, were localized by s1 mapping. the final mrna is unspliced, encoded by a region of about 1450 bp, and specifies an open reading frame of 413 amino acids. potential transcriptional signals in the 5' flanking dna, such as cat ... | 1982 | 7153689 |
| [preliminary trial of the cultivation of winged beans (psophocarpus tetragonolobus) in guatemala and variations in their chemical composition]. | there is no reliable information concerning the cultivation practices of winged bean cultivars in the area; therefore, it was considered of interest to participate in the first international winged bean trial, which was peformed according to a standardized procedure. the planting site was located at 90 degrees longitude and 15 degrees latitude, and 250 meters above sea level, in a hot-humid environment. sowing was performed in the middle of november, under continuous irrigation until april. duri ... | 1982 | 7181624 |
| coated and smooth vesicles in the biogenesis of cell walls, plasma membranes, infection threads and peribacteroid membranes in root hairs and nodules of white clover. | 1982 | 7183700 | |
| rhizobium japonicum mutants defective in symbiotic nitrogen fixation. | rhizobium japonicum strains 3i1b110 and 61a76 were mutagenized to obtain 25 independently derived mutants that produced soybean nodules defective in nitrogen fixation, as assayed by acetylene reduction. the proteins of both the bacterial and the plant portions of the nodules were analyzed by two-dimensional polyacrylamide gel electrophoresis. all of the mutants had lower-than-normal levels of the nitrogenase components, and all but four contained a prominent bacteroid protein not observed in wil ... | 1982 | 6956566 |
| indoleacetic acid complementation and its relation to host range specifying genes on the ti plasmid of agrobacterium tumefaciens. | host range variations were noted when 23 wild-type strains of agrobacterium tumefaciens were tested on 27 different plant species. because we have shown previously that host range specificity is conferred by the pti plasmid, these variations in host specificity implicated genetic differences among pti plasmids within the a. tumefaciens population that was tested. host specificity was independent of the type of opine utilized and biotype of the strain used. these data suggested that separate gene ... | 1982 | 6962315 |
| em5400, a family of monobactam antibiotics produced by agrobacterium radiobacter. i. taxonomy, fermentation and biological properties. | 1982 | 6978878 | |
| use of plasmid r68.45 for constructing a circular linkage map of the rhizobium trifolii chromosome. | plasmid r68.45 was used to promote conjugal transfer of chromosomal markers in rhizobium trifolii rs55. analysis of two-factor and three-factor crosses among r. trifolii strains enabled construction of a circular linkage map of the r. trifolii chromosome, containing 17 nutritional and resistance markers. | 1982 | 6947977 |
| phenotypic expression of mutations in a wide-host-range r plasmid in escherichia coli and rhizobium meliloti. | eight different derivatives of r plasmid rp1 with thermosensitive mutations affecting maintenance in escherichia coli and pseudomonas aeruginosa were introduce into rhizobium meliloti. none of the plasmids showed a thermosensitive character in r. meliloti. on the other hand, a certain deletion mutation in rp1 was found to cause plasmid instability in rhizobia and agrobacteria, but not in e. coli. | 1982 | 7037750 |
| ultrastructure of gram-negative cotton bacteria with different pulmonary toxicities. | the shedding of outer membrane material was observed by electron microscopy in typical gram-negative cotton bacteria, except agrobacterium sp. this finding is in accordance with the relative pulmonary toxicities of these bacteria. the presence of capsules did not seem to be correlated with the acute pulmonary toxicity of the bacteria. | 1982 | 7054127 |
| pulmonary toxicity of endotoxins: comparison of lipopolysaccharides from various bacterial species. | lipopolysaccharides from three gram-negative bacteria isolated from bale cotton and piggery air were analyzed for their chemical composition, and their pulmonary toxicity for guinea pigs, lethal toxicity for mice, and pyrogenicity for rabbits were measured. lipopolysaccharides from enterobacter agglomerans and citrobacter freundii had closely related chemical compositions; both were pyrogenic for rabbits and caused a dose-dependent influx of polymorphonuclear leukocytes into the airways of guine ... | 1982 | 7056574 |
| ferrisiderophore reductase activity in agrobacterium tumefaciens. | reduction of the iron in ferriagrobactin by the cytoplasmic fraction of agrobacterium tumefaciens strictly required nadh as the reductant. addition of flavin mononucleotide and anaerobic conditions were necessary for the reaction; when added with flavin mononucleotide, magnesium was stimulatory. this ferrisiderophore reductase activity may be a part of the iron assimilation process in a. tumefaciens. | 1982 | 7056702 |
| reconstitution of h2 oxidation activity from h2 uptake-negative mutants of rhizobium japonicum bacteroids. | an in vitro reconstitution of both methylene blue and oxygen-dependent h2 uptake activity from extracts of hup- (h2 uptake-negative) mutant strains of rhizobium japonicum bacteroids is described. cell-free extracts prepared from bacteroids formed from two different hup- mutants were mixed, and active h2 oxidizing particles formed. extracts from each mutant alone did not oxidize h2. the source of the components required for the complementation were soluble. mixing of membrane particles from the t ... | 1982 | 7056758 |
| uptake hydrogenase activity and atp formation in rhizobium leguminosarum bacteroids. | the role of uptake hydrogenase was studied in rhizobium leguminosarum bacteroids from the nodules of pisum sativum l. cv. homesteader. uptake hydrogenase activity, measured by the 3h2 uptake method, was dependent on o-consumption and was similar to h2 uptake measured by gas chromatography. km for o2 of 0.0007 atm (0.0709 kpa) and a km for h2 of 0.0074 atm (0.7498, kpa) were determined. h2 increased the rate of endogenous respiration by isolates with uptake hydrogenase (hup+) but had no effect on ... | 1982 | 7047503 |
| characterization and structural study of the dna-binding protein hrm from rhizobium meliloti. | 1982 | 7049166 | |
| application of two new methods for cleavage of polysaccharides into specific oligosaccharide fragments. structure of the capsular and extracellular polysaccharides of rhizobium japonicum that bind soybean lectin. | the extracellular polysaccharide produced by the bacterium rhizobium japonicum has been implicated in the recognition between symbionts which takes place in the association of r. japonicum with soybean. the complete primary structure of the polysaccharide produced by r. japonicum strain 3i1b 138 has been determined by a combination of conventional and unconventional methods. the polymer contains glucose, mannose, and galacturonic acid in the molar ratio of 2:1:1 and contains a varying proportion ... | 1982 | 7199046 |
| the odd couple. | 1982 | 7201965 | |
| soluble aldehyde dehydrogenase and metabolism of aldehydes by soybean bacteroids. | a soluble aldehyde dehydrogenase (ec 1.2.1.3) was partially purified from rhizobium japonicum bacteroids and from free-living r. japonicum 61a76. the enzyme was activated by nad+, nadh, and dithiothreitol, and it reduced nad(p)+. acetaldehyde, propionaldehyde, butyraldehyde, benzaldehyde, and succinic semialdehyde were substrates. the km for straight-chain aldehydes decreased with increasing carbon chain length. the aldehyde dehydrogenase was inhibited by 6-cyanopurine, but not by metronidazole. ... | 1982 | 7202001 |
| possible adverse effects of antibiotic therapy in plants. | 1982 | 6750754 | |
| transposon mutagenesis in rhizobia which can nodulate both legumes and the nonlegume parasponia. | the successful use of transposon mutagenesis in a slow-growing rhizobium permitted the isolation of auxotrophic and symbiotically defective mutants. in these mutants, it was shown that different single-copy tn5 insertions had occurred. mutant phenotypes indicated that the control of nitrogenase activity in vitro and in planta is different. | 1982 | 16345924 |
| nodulation efficiency of legume inoculation as determined by intrinsic antibiotic resistance. | patterns of intrinsic resistance and susceptibility to different levels of antibiotics were determined for strains of both fast- and slow-growing rhizobia. these patterns were stable to plant passage when they were used to identify rhizobium strains in nodule suspensions or nodule isolates. the method of identification by intrinsic resistance and susceptibility patterns was reliable for identifying strains in field nodules when strains were first isolated from the nodules to provide a standard i ... | 1982 | 16345969 |
| recognition of leguminous hosts by a promiscuous rhizobium strain. | the lima bean (phaseolus lunatus l.) and the pole bean (phaseolus vulgaris l.) are nodulated by rhizobia of two different cross-inoculation groups. rhizobium sp. 127e15, a cowpea-type rhizobium, can induce effective nodules on the lima bean and partially effective nodules on the pole bean. rhizobium phaseoli 127k14 can induce effective nodules on the pole bean but does not reciprocally nodulate the lima bean. root hairs of the lima bean when inoculated with rhizobium sp. 127e15 showed tip curlin ... | 1982 | 16345975 |
| relative efficacy of different alfalfa cultivar-rhizobium meliloti strain combinations for symbiotic nitrogen fixation. | five rhizobium meliloti isolates known to have different capabilities for expression of nitrogenase activity under symbiotic conditions were used to inoculate four representative medicago sativa cultivars under aseptic conditions. nitrogenase activities and respiratory activity were measured for whole plants and excised nodules. dry weights and nodule numbers were also recorded after 4 weeks of growth in plastic pouches on a nitrogen-free nutrient medium. hydrogen evolution and acetylene reducti ... | 1982 | 16345986 |
| legume-rhizobium interactions: cowpea root exudate elicits faster nodulation response by rhizobium species. | preinfection events in legume-rhizobium symbiosis were analyzed by studying the different nodulation behaviors of two rhizobial strains in cowpeas (vigna sinensis). log-phase cultures of rhizobium sp. strain 1001, an isolate from the plant nodule, initiated host responses leading to infection within 2 h after inoculation, whereas log-phase cultures of rhizobium sp. strain 32h1 took at least 7 h to trigger a discernible response. the delay observed with strain 32h1 could be eliminated by incubati ... | 1982 | 16345989 |
| accumulation of amino acids in rhizobium sp. strain wr1001 in response to sodium chloride salinity. | rhizobium sp. strain wr1001, isolated from the sonoran desert by eskew and ting, was found to be able to grow in defined medium containing nacl up to 500 mm, a concentration approaching that of sea water. therefore, it is a valuable strain for studying the biochemical basis of salt tolerance. intracellular free glutamate was found to increase rapidly in response to osmotic stress by nacl. it accounted for 88% of the amino acid pool when the bacterium was grown in 500 mm nacl. the role of glutama ... | 1982 | 16346049 |
| succinate-induced morphology of rhizobium trifolii 0403 resembles that of bacteroids in clover nodules. | morphological changes which accompany nutrient enrichment of rhizobium trifolii 0403 were studied. assays of cell number and size coupled with scanning electron microscopy and immunofluorescence microscopy showed that succinate induces cells to stop dividing in vitro and to swell either in the cell center or at one cell pole. the extent and frequency of in vitro cell swelling were in direct relation to the concentration of succinate added to the enrichment medium. the in vitro swelling of cells ... | 1982 | 16346058 |
| growth-related substituent changes in exopolysaccharides of fast-growing rhizobia. | pyruvic acid and o-acetyl groups are the major noncarbohydrate substituents in exopolysaccharides (eps) produced by fast-growing species of rhizobium. eps substituent variations were observed among strains of the same species. the amounts of these substituents also varied with culture age; pyruvic acid increased in the eps of all four species, whereas o-acetyl increased in rhizobium trifolii and r. leguminosarum eps, decreased in r. meliloti eps, and remained constant in r. phaseoli eps. the use ... | 1982 | 16346062 |
| root surface association in relation to nodulation of medicago sativa. | nine strains of rhizobium meliloti, ranging in competitive ability on medicago sativa from excellent to poor in autoclaved soils, were paired in 29 combinations and used to inoculate m. sativa in a liquid rooting medium. a positive correlation (r = 0.545) between strain ratios in nodules after 28 days and root surface cell ratios after 7 days was determined. two cell fractions from the root surface, representing loosely and firmly adhering cells, were investigated. infectivity was linked to the ... | 1982 | 16346071 |