Publications

[nitrogenase, hydrogenase and nitrate reductase activities, oxygen consumption, and atp content in nodules formed by strains of rhizobium leguminosarum 128c53 and 300 in symbiosis with pea plants].	the nitrogenase activity, nitrate reductase activity and oxygen uptake as well as the hydrogen incorporation and atp content were examined in the root nodules and bacteroids, respectively, formed by rhizobium leguminosarum strains 128c53 (hydrogenase positive) and 300 (hydrogenase negative) in symbiosis with pisum sativum plants grown in the presence of 2 mm kno3. the strain 128c53 showed the greatest values for all parameters analyzed, except for the nitrate reductase activity, which was higher ...	1986	3078142
construction of a tn5 derivative determining resistance to gentamicin and spectinomycin using a fragment cloned from r1033.	a physical and genetic map of the incp plasmid r1033 was constructed: restriction fragments were subcloned and antibiotic resistance genes were located. the map is consistent with previous reports that r1033 is a derivative of rp4 carrying a 16-kb transposon tn1696 which contains the antibiotic-resistance determinants present on r1033 but not on rp4. a bamhi fragment from r1033, determining resistance to gentamicin, spectinomycin and streptomycin, was cloned into tn5, replacing the central bg/ii ...	1986	3030896
[characteristics of derivatives of the plasmid rp4 in a broad range of hosts with altered properties of maintenance and inheritance].	hydroxylamine-induced mutants of the plasmid ppd6 (8.4 kb) were isolated which are resistant to high doses of tetracycline. one of the plasmids studied--ppd21 is a multicopy mutant, another one, ppd12 is a dimeric form of the ppd6 plasmid. the ppd12 plasmid is very unstable, its derivative, ppd13 spontaneous mutant acquiring stability but not the ability to resolve dna multimeric forms into monomeric forms. multicopy bireplicon ppd619 plasmid was constructed by joining in vitro ppd6 and puc19 pl ...	1986	3026896
integration of the delta-endotoxin gene of bacillus thuringiensis into the chromosome of root-colonizing strains of pseudomonads using tn5.	the delta-endotoxin gene (tox) from bacillus thuringiensis subsp. kurstaki hd-1 was cloned into tn5 and the resulting tn5-tox element transposed from a vector plasmid into the chromosome of six corn-root-colonizing strains of pseudomonas fluorescens and agrobacterium radiobacter. chromosomal integration of the tox gene maximized stability and minimized the potential for horizontal transfer of the tox gene to other bacterial species. expression of the tox gene was demonstrated by western blot ana ...	1986	3026918
nucleotide sequence of the virulence gene virg of the agrobacterium tumefaciens octopine ti plasmid: significant homology between virg and the regulatory genes ompr, phob and dye of e. coli.	the entire nucleotide sequence of the virg locus, from the octopine ti plasmid of agrobacterium tumefaciens strain 15955, has been determined. the virg gene is 801 nucleotides in length and has one open reading frame which encodes a protein of mr 29,995. the virg gene is involved in the transcriptional activation of the ti plasmid vir-loci, which occurs after induction by specific compounds present in plant exudate. sequence analysis of the agrobacterium virg protein showed significant homology ...	1986	3027669
a spontaneous insertion in the agrocin sensitivity region of the ti-plasmid of agrobacterium tumefaciens c58.	a spontaneous agrocin-resistant mutant of agrobacterium tumefaciens strain c58 was shown to have an insertion of 1.2 kb in the agrocin-sensitivity region of ptic58. the insertion was cloned from the ti-plasmid, and a subclone containing only dna internal to the insertion was used to probe the ti-plasmid and chromosomal dna of the wild-type strain c58. the probe showed homology to chromosomal sequences but showed no homology to wild-type ptic58. homology was also detected with chromosomal sequenc ...	1986	3027729
studies of the structure and functional organization of foreign dna integrated into the genome of nicotiana tabacum.	in transgenic plants obtained either by agrobacterium tumefaciens-mediated transformation or by direct dna transfer, the structure of integrated chimeric donor dna remains stable during vegetative proliferation, during sexual transmission, and under various selection conditions. we correlate the level of expression of the introduced gene in independent transformants and their offspring with the particular arrangement and modification of their integrated dnas. genetic analysis of transgenic plant ...	1986	3028737
organization of the adenyl cyclase (cya) locus of rhizobium meliloti.	a cya-like gene encoding adenyl cyclase from rhizobium meliloti was localized to a 0.8-kb psti-ecori fragment by subcloning experiments. experiments in escherichia coli 'maxicells' identified a r. meliloti cya gene product of 28 kda, which is significantly smaller than the corresponding protein from enteric bacteria. a control region for the expression of the cya gene in e. coli was found on an adjacent 2.6-kb bglii-bamhi sequence by insertional mutagenesis with tn5 and phage mudi (apr lac). the ...	1986	3021593
characterization of three genomic loci encoding rhizobium sp. strain ors571 n2 fixation genes.	sixty-five independent, n2 fixation-defective (nif-) vector insertion (vi) mutants were selected, cloned, and mapped to the ors571 genome. the recombinant nif::vi plasmids obtained in this way were used as dna hybridization probes to isolate homologous phages from a genomic library of ors571 constructed in lambda embl3. genomic maps were drawn for three ors571 nif gene loci. forty-five nif::vi mutants in genomic nif locus 1 defined two gene clusters separated by 8 kilobase pairs (kb) of dna. in ...	1986	3001035
nucleotide sequence analysis of tl-dna of agrobacterium rhizogenes agropine type plasmid. identification of open reading frames.	we have determined the nucleotide sequence of the ri tl-dna region from an agrobacterium rhizogenes agropine-type plasmid using subcloned regions from the essentially identical ri tl-dnas from strains a4 and hri. this sequenced region of 21,126 base pairs (bp) contains the complete tl-dna region of the ri plasmid as determined by analysis of tl-dna borders in the genome of infected, clonal, convolvulus arvensis plants. the left and right borders of the tl-dna are flanked by 25-bp sequences which ...	1986	3001043
plasmid vectors for the genetic analysis and manipulation of rhizobia and other gram-negative bacteria.		1986	3005803
dna sequence of rhizobium trifolii nodulation genes reveals a reiterated and potentially regulatory sequence preceding nodabc and nodfe.	the rhizobium trifolii nod genes required for host-specific nodulation of clovers are located on 14 kb of sym (symbiotic) plasmid dna. analysis of the nucleotide sequence of a 3.7 kb portion of this region has revealed open reading frames corresponding to the nodabcdef genes. a dna sequencing technique, using primer extension from within tn5, has been used to determine the precise locations of tn5 mutations within the nod genes and the phenotypes of the corresponding mutants correlate with their ...	1986	3008100
expression of a bean storage protein 'phaseolin minigene' in foreign plant tissues.	using the phaseolin gene and its cdna counterpart we constructed a mutant phaseolin gene lacking the five introns but retaining its natural 5' and 3' plant-regulatory sequences. this mutant phaseolin gene (minigene) was inserted into the ti-plasmid of agrobacterium tumefaciens strain 15955 which allowed its transfer and integration into the tobacco genome. full-length and correctly initiated phaseolin mrna was found among the poly(a)+rna isolated from plant callus transformed with the minigene c ...	1986	3009275
activity of t-dna borders in plant cell transformation by mini-t plasmids.	by using a binary vector system, we examined the requirements for border sequences in t-dna transformation of plant genomes. mini-t plasmids consisting of small replicons with different extents of ptit37 t-dna were tested for plant tumor-inducing ability in agrobacterium tumefaciens strain lba4404 containing helper plasmid pal4404 (which encodes virulence genes needed for t-dna transfer). assays of these bacteria on carrot disks, kalanchoë leaves, and sr1 nicotiana tabacum plantlets showed that ...	1986	3009403
nodulation inhibition by rhizobium leguminosarum multicopy nodabc genes and analysis of early stages of plant infection.	during analysis of early events in the infection and nodulation of vicia hirsuta roots inoculated with normal and mutant strains of rhizobium leguminosarum and strains containing cloned nodulation (nod) genes, a number of novel observations were made. (i) alternating zones of curled and straight root hairs were seen on roots of v. hirsuta inoculated with the wild-type strain of r. leguminosarum. this phasing of root hair curling was not seen if plants were grown under continuous light or continu ...	1986	3009408
effects of k+ on the proton motive force of bradyrhizobium sp. strain 32h1.	in previous studies, respiring bradyrhizobium sp. strain 32h1 cells grown under 0.2% o2, conditions that derepress n2 fixation, were found to have a low proton motive force of less than -121 mv, because of a low membrane potential (delta psi). in contrast, cells grown under 21% o2, which do not fix n2, had high proton motive force values of -175 mv or more, which are typical of respiring bacteria, because of high delta psi values. in the present study, we found that a delta psi of 0 mv in respir ...	1986	3009414
genetic locus in rhizobium japonicum (fredii) affecting soybean root nodule differentiation.	a genetic locus in fast-growing rhizobium japonicum (fredii) usda 191 (fix+ on several contemporary soybean cultivars) was identified by random tn5 mutagenesis as affecting the development and differentiation of root nodules. this mutant (mu042) is prototrophic and shows no apparent alterations in its surface properties. it induces aberrant nodules, arrested at the same early level of differentiation, on all its host plants. an 8.1-kilobase ecori fragment containing tn5 was cloned from mu042. in ...	1986	3009416
[role of temperate phage in bacterial dissociation].	the analysis of literary and own data testifies that the dissociants may appear in bacteria population from spontaneous mutations and transfer of genetic material (conjugation, transformation, transduction). the phage conversion and different dna reorganizations within a cell where prophage plays an active role, probably introduce the largest contribution into the dissociative transitions of variants which occur with high frequency (about 10(-2)-10(-4). the dissociation of various bacteria has b ...	1986	3011128
sequence and domain relationships of ntrc and nifa from klebsiella pneumoniae: homologies to other regulatory proteins.	we have determined the nucleotide sequences of two genes from klebsiella pneumoniae, nifa, the nif-specific activator of transcription and ntrc, the bifunctional regulatory protein involved in 'nitrogen control'. these sequences differ significantly from those previously published. in particular, nifa extends 40 codons beyond the stop codon reported earlier. this extension encodes a putative dna-binding domain strongly homologous to the rhizobium meliloti nifa protein and to some extent to the n ...	1986	3011408
multiple mutations in the transferred regions of the agrobacterium rhizogenes root-inducing plasmids.	agrobacterium rhizogenes induces root formation at the site of inoculation in plants and inserts fragments of its ri plasmid into the plant nuclear dna. the transferred region (t-dna) of the ri plasmid of the a. rhizogenes strain a4 is made of two fragments, namely tl and tr; the latter harbors a sequence homology with the tms loci (responsible for auxin synthesis) of a. tumefaciens. on daucus carota slices, single insertion mutations on the tl region of a. rhizogenes do not confer a mutant phen ...	1986	3012616
second symbiotic megaplasmid in rhizobium meliloti carrying exopolysaccharide and thiamine synthesis genes.	using physical and genetic data, we have demonstrated that rhizobium meliloti su47 has a symbiotic megaplasmid, prmesu47b, in addition to the previously described nod-nif megaplasmid prmesu47a. this plasmid includes four loci involved in exopolysaccharide (exo) synthesis as well as two loci involved in thiamine biosynthesis. mutations at the exo loci have previously been shown to result in the formation of nodules which lack infection threads (inf-) and fail to fix nitrogen (fix-). thus, both me ...	1986	3013840
mobilization of tn5 insertions from rhizobium fredii by pjb3ji.	techniques for in vivo cloning were used with the fast-growing nitrogen-fixing soybean microsymbiont r. fredii usda 191. selection for transfer of tn5 insertions from r. fredii usda 191 containing the gene-mobilizing plasmid pjb3ji provided recombinants at up to 400 times the background mutation level. these techniques may be useful for future genetic analysis of r. fredii.	1986	3015025
genetic rearrangements of a rhizobium phaseoli symbiotic plasmid.	different structural changes of the sym plasmid were found in a rhizobium phaseoli strain that loses its symbiotic phenotype at a high frequency. these rearrangements affected both nif genes and tn5 mob insertions in the plasmid, and in some cases they modified the expression of the bacterium's nodulation ability. one of the rearrangements was more frequent in heat-treated cells, but was also found under standard culture conditions; other structural changes appeared to be related to the conjugal ...	1986	3015875
the presence of repeated dna sequences and a partial restriction map of the psym of rhizobium fredii usda193.	the large, 350-kb sym (symbiotic) plasmid prjausda193 of rhizobium fredii was examined to determine the frequency of repeated sequences present and to produce a physical and genetic map of a large region of the plasmid. a novel hybridization method, the southern cross, revealed that the plasmid prjausda193 contained many repeated sequences and assisted in restriction enzyme mapping of a 100-kb region containing nod genes. a cosmid clone bank was prepared with the broad-host-range cosmid pvk102. ...	1986	3016780
the genetic and transcriptional organization of the vir region of the a6 ti plasmid of agrobacterium tumefaciens.	the genetic transformation of plant cells by agrobacterium tumefaciens is mediated by the genes of the ti plasmid vir region. to determine the genetic and transcriptional organization of the vir region of ptia6, vir plasmid clones were saturated with insertion mutations of a tn3-lacz transposon. this element is both an insertion mutagen and a reporter for the expression of the sequences into which it has inserted. one hundred and twenty-four vir::tn3-lac insertions were analyzed for their mutage ...	1986	3017694
nucleotide sequence of an insertion sequence (is) element identified in the t-dna region of a spontaneous variant of the ti-plasmid ptit37.	we have identified and determined the nucleotide sequence of an is element (is136) of agrobacterium tumefaciens. this is the first is element isolated and sequenced from a nopaline type ti-plasmid. our is element has 32/30 bp inverted repeats with 6 mismatches, is 1,313 bp long and generates 9 bp direct repeats upon integration. is136 has 3 main open reading frames (orf's). only orf1 (159 codons) is preceded by sequences that are proposed to serve functional roles in transcriptional and translat ...	1986	3018677
restriction maps and homologies of the three plasmids of agrobacterium rhizogenes strain a4.	agrobacterium rhizogenes strain a4 is a virulent agropine-type strain possessing three plasmids: plasmid a (para4a, 180 kb) is not necessary for plant transformation, plasmid b (250 kb) is the root-inducing plasmid (pria4), and plasmid c (para4c) is a cointegrate of para4a and pria4. the total plasmid dna (para4) of strain a4 was cloned in the cosmid phsg262 and the library obtained was used to establish bamhi maps of the three plasmids. the plasmids a and ri have an apparently identical region ...	1986	3018814
the nodi gene product of rhizobium leguminosarum is closely related to atp-binding bacterial transport proteins; nucleotide sequence analysis of the nodi and nodj genes.	the nucleotide sequence of a 2-kb fragment immediately downstream of the nodabc genes of the rhizobium leguminosarum symbiotic plasmid prl1ji has been determined. genes corresponding to the two open reading frames identified are named nodi and nodj. tn 5 insertions into these genes result in a "nodulation-delayed" phenotype. the predicted amino acid sequence of the nodi gene shows considerable homology to inner-membrane-located gene products involved in active transport systems in escherichia co ...	1986	3019841
location of the right boundary of the virulence region on agrobacterium tumefaciens plasmid ptic58 and a host-specifying gene next to the boundary.	the right boundary of the virulence (vir) region of the nopaline plasmid ptic58 of agrobacterium tumefaciens was determined by transposon insertion, cartridge emplacement, and deletion mutagenesis. genetic complementation with mutant and wild-type alleles led to the identification of the vire locus at the right boundary, which was located about 6 kilobases from the left border of the segment of dna that is transferred into the plant genome. vire is 2.0 kilobases long and encodes at least one pro ...	1986	3019998
genetic manipulations in rhizobium meliloti utilizing two new transposon tn5 derivatives.	two derivatives of the prokaryotic transposon tn5 were constructed in vitro. in tn5-233, the central area of tn5, which carries resistance to kanamycin/neomycin, bleomycin and streptomycin, is replaced by a fragment carrying resistance to the aminocyclitol antibiotics gentamycin/kanamycin and streptomycin/spectinomycin. in tn5-235, the escherichia coli beta-galactosidase gene is inserted within the streptomycin resistance gene of tn5, and constitutively expressed from a tn5 promoter. both constr ...	1986	3020382
characterization and cloning of two rhizobium leguminosarum genes coding for glutamine synthetase activities.	we have demonstrated that rhizobium leguminosarum strain lpr1105 contains a heat stable and a heat labile glutamine synthetase (ec 6.3.1.2) activity similar to those described for other rhizobiaceae. most of the activity is heat stable when this strain is grown on glutamine as sole nitrogen source, but most is heat labile when grown on nitrate. using a gene bank of r. leguminosarum dna we have isolated two clones, which code for heat stable (p7d9) and heat labile (p4f7) glutamine synthetase acti ...	1986	2878969
nucleotide sequence of rhizobium meliloti rcr2011 genes involved in host specificity of nodulation.	a 6 kb dna segment of the r. meliloti 2011 psym megaplasmid, which contains genes controlling host specificity of root hair infection and of nodulation, was cloned and sequenced. the dna sequence analysis, in conjunction with previous genetic data, allowed identification of four nod genes designated as e, f, g and h. nodh is divergently transcribed with respect to nodfe and nodg. a conserved nucleotide sequence was found around 200 bp upstream of the translation start of nodf, nodh and noda. thi ...	1986	3020515
the vird operon of agrobacterium tumefaciens encodes a site-specific endonuclease.	tumor formation by agrobacterium tumefaciens involves the transfer and integration of a defined segment (t-dna) of tumor-inducing (ti) plasmid dna into the plant nuclear genome. a set of plasmid genes outside the t-dna, the vir genes, are thought to mediate the transfer process. we report here that the vird operon encodes a site-specific endonuclease that cleaves at a unique site within each of the 24 bp direct repeats that flank the t-dna. the endonuclease function was further localized to the ...	1986	3021341
t-dna and opine synthetic loci in tumors incited by agrobacterium tumefaciens a281 on soybean and alfalfa plants.	we report here the molecular characterization of transferred dna (t-dna) in leguminous tumors incited by agrobacterium tumefaciens a281 harboring the tumor-inducing plasmid ptibo542. the t-dna is composed of two regions named tl (left portion)-dna and tr (right portion)-dna, in accordance with the nomenclature for the octopine strains. tl-dna is defined by several internal hindiii restriction fragments totaling 10.8 kilobase pairs (kbp) in uncloned soybean and alfalfa tumors. alfalfa tumor dna m ...	1986	3023301
upstream sequences required for efficient expression of a soybean heat shock gene.	a soybean gene (gmhsp17.5-e) encoding a small heat shock protein was introduced into primary sunflower tumors via t-dna-mediated transformation. rna blot hybridizations and s1-nuclease hybrid protection studies indicated that the heat shock gene containing 3.25 kilobases of 5'-flanking sequences was strongly transcribed in a thermoinducible (40 degrees c) manner. transcriptional induction also occurred to a lesser extent upon treatment of whole tumors with sodium arsenite and cdcl2. basal (26 de ...	1986	3023855
cloning and regulation of erwinia herbicola pigment genes.	the genes coding for yellow pigment production in erwinia herbicola eho10 (atcc 39368) were cloned and localized to a 12.4-kilobase (kb) chromosomal fragment. a 2.3-kb avai deletion in the cloned fragment resulted in the production of a pink-yellow pigment, a possible precursor of the yellow pigment. production of yellow pigment in both e. herbicola eho10 and pigmented escherichia coli clones was inhibited by glucose. when the pigment genes were transformed into a cya (adenylate cyclase) e. coli ...	1986	3023282
overlapping transcription of the nifa regulatory gene in rhizobium meliloti.	gene fusions were used to demonstrate complex overlapping transcriptional controls of the regulatory gene nifa in rhizobium meliloti bacteroids isolated from alfalfa root nodules. gene nifa has previously been shown to be transcribed from promoter pnifa and to be required for activation of promoters p1 (nifhdk) and p2 (fixabc) during symbiotic nitrogen fixation with alfalfa. p2 is located approximately 4 kb upstream from nifa and is shown in this report to be responsible for at least one-half of ...	1986	3472992
delay of disease development in transgenic plants that express the tobacco mosaic virus coat protein gene.	a chimeric gene containing a cloned cdna of the coat protein (cp) gene of tobacco mosaic virus (tmv) was introduced into tobacco cells on a ti plasmid of agrobacterium tumefaciens from which tumor inducing genes had been removed. plants regenerated from transformed cells expressed tmv mrna and cp as a nuclear trait. seedlings from self-fertilized transgenic plants were inoculated with tmv and observed for development of disease symptoms. the seedlings that expressed the cp gene were delayed in s ...	1986	3457472
analysis of agrobacterium tumefaciens virulence mutants in leaf discs.	the leaf disc transformation system provides a simple means to score expression of various t-dna markers within days of infection by agrobacterium tumefaciens as well as long-term selection for growth of transformed callus and shoots. in this report, we describe the application of this system to evaluation of marker transfer and integration in a comprehensive set of defined avirulent mutants of a. tumefaciens. we conclude that virc is not essential when the t-dna is present on a binary vector. t ...	1986	3458219
the right border region of ptit37 t-dna is intrinsically more active than the left border region in promoting t-dna transformation.	deletions of border regions of t-dna on agrobacterium ti plasmid or mini-t plasmid have shown the right border region of ptit37 t-dna to be more active than the left border region in promoting t-dna transformation. in this study we examine the possibility that the apparent difference in activity of left and right border regions may be due to position or orientation differences between the left and right borders with respect to the transferred onc genes. we have constructed eight similar single-b ...	1986	3459162
immunological homology between the membrane-bound uptake hydrogenases of rhizobium japonicum and escherichia coli.	two polypeptides present in aerobic and anaerobic cultures of escherichia coli hb101 were shown to cross-react with antibodies to the 30- and 60-kilodalton (kda) subunits of the uptake hydrogenase of rhizobium japonicum. the cross-reactive polypeptides in a series of different e. coli strains are of mrs ca. 60,000 and 30,000, and both polypeptides are present in proportion to measurable hydrogen uptake (hup) activity (r = 0.95). the 60-kda polypeptide from e. coli hb101 comigrated on native gels ...	1986	3511036
molecular basis for the auxin-independent phenotype of crown gall tumor tissues.	the transfer of specific ti (tumor-inducing) plasmid sequences, the t-dna, from agrobacterium tumefaciens to a wide range of plants results in the formation of crown gall tumors. these tissues differ from most plant cells in that they can be grown in vitro in the absence of added phytohormones. here, data are presented that offer an explanation for the auxin-independent phenotype of crown gall tissues. it is shown that crude cell-free extracts prepared from three bacterial species harboring ptia ...	1986	3511528
promoters of agrobacterium tumefaciens ti-plasmid virulence genes.	the dna sequences of the promoter and 5' upstream regions of six agrobacterium tumefaciens ti-plasmid encoded virulence (vir) genes were determined. the transcription initiation sites were mapped by the s1 nuclease protection assay. in the -10 region, the vir promoters share a consensus sequence that is homologous to a dna sequence found in the same region of e. coli promoters. in contrast, the -35 region sequences are variable. several vir genes contain two common hexanucleotide sequences, 5'cg ...	1986	3513123
signal exchange in plant-microbe interactions.		1986	3523189
microaerophily and oxygen toxicity.		1986	3535642
competition for nodulation of legumes.		1986	3535643
assignment of symbiotic developmental phenotypes to common and specific nodulation (nod) genetic loci of rhizobium meliloti.	rhizobium meliloti nodulation (nod) genes required for specific infection and nodulation of alfalfa have been cloned. transposon tn5 mutagenesis defined three nod regions spanning 16 kilobases of the psym megaplasmid. genetic and cytological studies of 62 nodulation-defective mutants allowed the assignment of symbiotic developmental phenotypes to common and specific nod loci. root hair curling was determined by both common (region i) and specific (region iii) nod transcription units; locus iiib ...	1986	3023297
isolation of tobacco dna segments with plant promoter activity.	we constructed a promoter probe vector, pgvl120, to isolate plant dna segments with promoter activity in tobacco. plant nuclear dna sau3a fragments were inserted in front of the npt-ii sequence, and a mixture of recombinant plasmids was mobilized to agrobacterium sp. and used to transform tobacco protoplasts. by kanamycin selection, transformed plant cell lines containing npt-ii t-dnas were isolated. eight of these cell lines were regenerated and analyzed for the levels of npt-ii activity in ste ...	1986	3540612
[conjugation transfer of the bireplicon plasmid pspa044 into rhizobiaceae bacteria].	we have demonstrated the possibility of hybrid plasmid pspa044 conjugative transfer from e. coli cells into different rhizobium species. the bireplicon plasmid, constructed earlier in our laboratory, consisting of pbr325 and hindiii fragment 13 of the nopaline plasmid ptic58 was mobilized for transfer by the helper plasmid prk2013 with the frequency about 10(-4). we conclude the hybrid plasmid pspa044 to be able to replicate stably in rhizobiaceae cells.	1986	3540635
regulation of nitrogen fixation genes.		1986	3545064
modification of t-dna of nopaline ti plasmid by intermediary vector and utilization of agrocin 84 sensitivity as simple criterion of conjugation transfer of modified ti plasmid.	the chloramphenicol resistance gene from psa was introduced into t-dna of pti t37 of agrobacterium tumefaciens by cointegration with intermediary plasmid based on pbr322. the resulting intermediary vector was mobilized to a. tumefaciens t37 by conjugative plasmid prk2. the rk2 plasmid also forms contegrates with pti due to the tn3 transposon which was used for the mobilization of modified pti into plasmid-less a. tumefaciens strain. transconjugants were selected on the basis of their antibiotic ...	1986	3519390
fate of selectable marker dna integrated into the genome of nicotiana tabacum.	to compare the effects of different transformation methods on the integration behavior and structural stability of integrated foreign genes in plant cells, tobacco protoplasts were transformed with escherichia coli plasmid plgv2103neo dna using the ca phosphate dna coprecipitation technique. parallel transformations were done by cocultivation with agrobacterium tumefaciens harboring the ti plasmid derivatives pgv3850::2103neo or pgv3850::1103neo. a comparison of the fine structure of the integra ...	1986	3519133
critical evaluation of the automicrobic system gram-negative identification card for identification of glucose-nonfermenting gram-negative rods.	during a 6-month study we critically evaluated the accuracy of the automicrobic system gram-negative identification card (vitek systems, inc., hazelwood, mo.) in identifying glucose-nonfermenting gram-negative bacilli by testing 419 selected isolates in parallel with a conventional reference method. of 356 isolates included in the automicrobic system profile, a total of 307 (86.2%) were correctly identified, 36 (10.1%) were not identified, and 13 (3.7%) were misidentified. fifty-eight of 63 (92% ...	1986	3517050
expression and regulation of the escherichia coli glutamate dehydrogenase gene (gdh) in rhizobium japonicum.	the glutamate dehydrogenase (gdh) gene of escherichia coli was transferred into an ammonium assimilation deficient mutant (asm-) of rhizobium japonicum (cj9) using plasmid prp301, a broad host range derivative of rp4. exconjugants capable of growth on ammonia as sole n-source occurred at a frequency of 6.8 x 10(-6). assimilatory gdh (nadp+) activity was detected in the strain carrying the e. coli gdh gene and the pattern of ammonia assimilation via gdh was similar to that of the asm+ wild type s ...	1986	3516109
nucleotide sequence and expression of a pseudomonas savastanoi cytokinin biosynthetic gene: homology with agrobacterium tumefaciens tmr and tzs loci.	the nucleotide sequence of a pseudomonas trans-zeatin producing gene (ptz) from the pck1 plasmid of pseudomonas syringae pv. savastanoi strain 1006 has been determined. this gene confers upon e. coli the ability to synthesize and secrete several cytokinins including trans-zeatin, iso-pentenyladenine and their respective n9-ribosyl derivatives. sequence analysis indicates an open reading frame encoding a protein of 234 amino acids with a molecular weight of 26,816. significant sequence homology i ...	1986	3515320
a gene essential for agrobacterium virulence is homologous to a family of positive regulatory loci.	the vir region of agrobacterium tumefaciens spans at least six transcriptional loci required for crown gall tumorigenesis. the transcriptional induction of two of these vir loci in response to cocultivation with tobacco suspension cells was measured by using bacteria containing mutations in each of the six vir loci located on the ti plasmid. induction of these vir genes occurred only in bacteria that had functional copies of vira and virg. the nucleic acid sequence of a 1.25-kilobase clone encom ...	1986	3022288
transformation of the genomic expression of plant cells.	agrobacterium-induced transformation of plant cells results from integration of t-dna of the ti or ri plasmids into the genome of susceptible plants. expression of t-dna genes induces physiological changes in transformed cells which modify normal plant development to produce proliferations characteristic of crown gall and hairy root diseases. understanding of the molecular basis of the transformation events associated with these examples of naturally occurring genetic engineering of plant cells, ...	1986	3544312
pairwise perturbation of flagellin subunits. the structural basis for the differences between plain and complex bacterial flagellar filaments.	although plain and complex bacterial flagellar filaments differ in their physical properties and helical symmetry, they both appear to derive from a common underlying structure. analysis of electron micrographs of complex filaments of rhizobium lupini revealed that the unit cell has twice the length of that of plain filaments, with a corresponding reduction in helical symmetry whereby the six-start helical family present in plain filaments collapses into a three-start family. mass per unit lengt ...	1986	3537316
a binary vector for transferring genomic libraries to plants.	the transformation of mutant plants with a complete recombinant library derived from wild-type dna followed by assay of transformed plants for complementation of the mutant phenotype is a promising method for the isolation of plant genes. the small genome of arabidopsis thaliana is a good candidate for attempting this so-called shotgun transformation. we present the properties of an a. thaliana genomic library cloned in a binary vector, pc22. this vector, designed to introduce genomic libraries ...	1986	3534794
a cell-free system from rhizobium meliloti to study the specific expression of nodulation genes.	an in vitro transcription-translation system was developed using cell-free extracts from the symbiotic nitrogen-fixing bacterium rhizobium meliloti strain 41. conditions for preparation of the 30,000 x g supernatant extract and for measurement of protein-synthesizing activity were determined and compared to the activity of an escherichia coli cell-free system. genes expressed in the free-living or in the symbiotic state were studied. the product of a reca-like gene (41-kda protein) was synthesiz ...	1986	3533532
initial interactions of agrobacterium tumefaciens with plant host cells.	infections of wounded dicotyledonous plants by agrobacterium tumefaciens result in the formation of crown gall tumors. the initial step in tumor formation is the site-specific attachment of the bacteria to the host cells. the mechanism of recognition and attachment in this interaction has been studied in detail. current information on the nature of the bacterial binding sites, the nature of the host receptors, the role of bacterial cellulose fibrils, and the genetics of bacterial attachment will ...	1986	3533427
endogenous lectins from cultured soybean cells: isolation of a protein immunologically cross-reactive with seed soybean agglutinin and analysis of its role in binding of rhizobium japonicum.	incubation of rhizobium japonicum with the cultured soybean cell line sb-1, originally derived from the roots of glycine max, resulted in specific adhesion of the bacteria to the plant cells. this binding interaction appears to be mediated via carbohydrate recognition, since galactose can inhibit the heterotypic adhesion but glucose cannot. affinity chromatography, on a sepharose column derivatized with n-caproyl-galactosamine, of the supernatant fraction of a sb-1 cell suspension after enzymati ...	1986	3528167
a plant flavone, luteolin, induces expression of rhizobium meliloti nodulation genes.	the symbiotic interaction of rhizobium meliloti and alfalfa results in the formation of nitrogen-fixing root nodules. rhizobium meliloti nodabc genes are required for the early host responses of cortical cell divisions and root hair curling. the induction of nodabc expression by alfalfa exudates demonstrates host-symbiont signaling at an early stage in nodule development. the inducer molecule for nodabc expression was isolated from plant exudate by constructing a nodabc-lacz fusion to monitor th ...	1986	3738520
reversible inactivation of the o2-labile hydrogenases from azotobacter vinelandii and rhizobium japonicum.	hydrogenases catalyze the reversible activation of dihydrogen. the hydrogenases from the aerobic, n2-fixing microorganisms azotobacter vinelandii and rhizobium japonicum are nickel- and iron-containing dimers that belong to the group of o2-labile enzymes. exposure of these hydrogenases to o2 results in an irreversible inactivation; therefore, these enzymes are purified anaerobically in a fully active state. we describe in this paper an electron acceptor-requiring and ph-dependent, reversible ina ...	1986	3525552
the effect of the dissolved oxygen concentration and anabolic limitations on the behaviour of rhizobium ors571 in chemostat cultures.	chemostat cultures of rhizobium ors571 limited by the supply of oxygen or an anabolic substrate contained poly-beta-hydroxybutyrate (phb). low amounts of phb (about 10%) were present in ammonia- or nitrate-limited cultures; higher amounts were found in mg++-limited cultures (about 20%) and in oxygen-limited nitrogen-fixing cultures (37%). a method is described to calculate yatp values (g phb-free biomass . mol-1 atp) from the ysucc values (g dry wt . mol-1 succinate) measured. ysucc and yatp val ...	1986	3524445
aerobic purification of hydrogenase from rhizobium japonicum by affinity chromatography.	we purified active hydrogenase from free-living rhizobium japonicum by affinity chromatography. the uptake hydrogenase of r. japonicum has been treated previously as an oxygen-sensitive protein. in this purification, however, reducing agents were not added nor was there any attempt to exclude oxygen. in fact, the addition of sodium dithionite to aerobically purified protein resulted in the rapid loss of activity. purified hydrogenase was more stable when stored under o2 than when stored under ar ...	1986	3519580
a family of related atp-binding subunits coupled to many distinct biological processes in bacteria.	many biological processes are coupled to atp hydrolysis. we describe here a class of closely related atp-binding proteins, from several bacterial species, which are associated with a variety of cellular functions including membrane transport, cell division, nodulation in rhizobium and haemolysin export. these proteins comprise a family of structurally and functionally related subunits which share a common evolutionary origin, bind atp and probably serve to couple atp hydrolysis to each of these ...	1986	3762694
biological nitrogen fixation: recent advances and future prospects.	current research on nitrogen fixation is basic to finding the knowledge needed for agriculture research in the future. genetic engineering is the best approach to increase biological nitrogen fixation and recent developments hold promise for this technology. this concept employing atmospheric nitrogen fixation instead of fertilizer to grow food and feed crops, while a complex engineering task, is possible. the opportunities and difficulties are discussed.	1986	3704206
enhanced instrumental sensitivity and selectivity for aminopeptidase profiling.	laser-excited fluorimetry has been applied to the identification of bacteria and fungus. the instrumental sensitivity and selectivity of the aminopeptidase profiling method has been enhanced by the use of laser excitation in conjunction with improved spectral and temporal background rejection. the linear dynamic range for the aminopeptidase technique has been increased by achieving a reduced lower limit of detection of the fluorescent tag, beta-naphthylamine. standard aminopeptidase methodology ...	1986	3706731
molecular cloning and expression of rhizobium fredii usda 193 nodulation genes: extension of host range for nodulation.	dna hybridization with the cloned nodulation region of rhizobium meliloti as a probe revealed dna homology with four hindiii fragments, 12.5, 6.8, 5.2, and 0.3 kilobases (kb) in size, of the symbiotic plasmid prjausda193. both hybridization and complementation studies suggest that the common nodulation genes nodabc and nodd of r. fredii usda 193 are present on the 5.2-kb hindiii and 2.8-kb ecori fragments, respectively, of the sym plasmid. both fragments together could confer nodulation ability ...	1986	3782034
the hypervirulence of agrobacterium tumefaciens a281 is encoded in a region of ptibo542 outside of t-dna.	we used a binary-vector strategy to study the hypervirulence of agrobacterium tumefaciens a281, an l,l-succinamopine strain. strain a281 is hypervirulent on several solanaceous plants. we constructed plasmids (pcs65 and pcs277) carrying either the transferred dna (t-dna) or the remainder of the tumor-inducing (ti) plasmid (peha101) from this strain and tested each of these constructs in trans with complementary regions from heterologous ti plasmids. hypervirulence on tobacco could be reconstruct ...	1986	3782037
tomato golden mosaic virus a component dna replicates autonomously in transgenic plants.	phenotypically normal petunia plants carrying chromosomal inserts of either the tomato golden mosaic virus (tgmv) a or the b component dna, as single or tandem inserts, were obtained using an agrobacterium tumefaciens ti plasmid-based transformation system. southern hybridization analysis revealed that the tandem, direct-repeat a plants contained free single and double stranded a component dnas. no free b component dna was detected in plants carrying tandem repeats of the b component. progeny of ...	1986	3708687
effect of fungicide application on soybean-rhizobia symbiosis and isolation of fungicide-resistant strains of rhizobia japonicum.		1986	3719119
congo red absorption and cellulose synthesis by rhizobiaceae.	congo red uptake by rhizobium colonies from yeast extract-mannitol-mineral salts-congo red-agar plates was related with the cellulose content in the cell capsule of the bacteria.	1986	3789702
sustained ethylene production in agrobacterium-transformed carrot disks caused by expression of the t-dna tms gene products.	agrobacterium-infected carrot disks continually produced elevated levels of ethylene. ethylene production was mediated by the elevated levels of auxin synthesized in transformed tissues.	1986	3722126
enzymes of the beta-ketoadipate pathway are inducible in rhizobium and agrobacterium spp. and constitutive in bradyrhizobium spp.	protocatechuate is a universal growth substrate for members of the family rhizobiaceae, and these bacteria utilize the aromatic compound via the beta-ketoadipate pathway. this report describes transcriptional controls exercised by different subgroups of the rhizobiaceae over five enzymes that catalyze consecutive reactions in the pathway: protocatechuate oxygenase (ec 1.13.11.3), beta-carboxy-cis,cis-muconate lactonizing enzyme (ec 5.5.1.2), gamma-carboxymuconolactone decarboxylase (ec 4.1.1.44) ...	1986	3941043
osmotic adaptation by gram-negative bacteria: possible role for periplasmic oligosaccharides.	the cyclic (1----2)-beta-d-glucans produced by species of agrobacterium and rhizobium resemble the membrane-derived oligosaccharides of escherichia coli in their periplasmic localization, intermediate size, and (1----2)-beta-d-glucan backbones. the regulation of the biosynthesis of cyclic (1----2)-beta-d-glucan by agrobacterium tumefaciens is now shown to parallel the osmotic regulation of membrane-derived oligosaccharide biosynthesis in escherichia coli. this result suggests a general role for ...	1986	3941890
role of plant root exudate and sym plasmid-localized nodulation genes in the synthesis by rhizobium leguminosarum of tsr factor, which causes thick and short roots on common vetch.	in a previous paper it was shown that cocultivation of rhizobium leguminosarum with the plant vicia sativa subsp. nigra on solid medium causes a changed mode of growth of the plant roots, resulting in thick and short roots (tsr). the sym plasmid present in the bacterium appeared to be essential for causing tsr (a. a. n. van brussel, t. tak, a. wetselaar, e. pees, and c. a. wijffelman, plant sci. lett. 27:317-325, 1982). in the present paper, we show that a role in causing tsr is general for sym ...	1986	3944060
in vitro synthesis of a lipid-linked acetylated and pyruvilated oligosaccharide in rhizobium trifolii.	edta-treated rhizobium trifolii cells (strain na30) incorporate radioactivity from (14c) labeled udp-clc, udp-clca, acetyl-coa and/or phosphoenol pyruvate into chloroform: methanol: water (1:2:0.3) extracts. the incorporation products have properties of prenyl-phospho-sugars; mild alkaline hydrolysis of these extracts produce cyclic phosphate esters suggesting the presence of a diphosphate bridge, and mild acid or catalytic reduction-alkaline phosphatase treatments release four main components a ...	1986	3947325
alterations in lipid composition of membranes from rhizobium meliloti exposed to parathion.		1986	3947765
identification of pyruvated monosaccharides in polysaccharides by gas-liquid chromatography mass spectrometry.	twelve bacterial polysaccharides of known structure containing a representative range of pyruvated monosaccharides, were methanolysed, trimethylsilylated, and analysed by g.l.c. and g.l.c.-m.s. except for 3,4-o-(1-carboxyethylidene)-l-rhamnose, which was unusually labile, the pyruvic acid substituents were largely retained during methanolysis and the me3si derivatives of the resulting pyruvated methyl glycosides gave distinctive g.l.c. peaks with characteristic mass spectra. the pyranose rings o ...	1986	3955562
location and identity of the acyl substituents on the extracellular polysaccharides of rhizobium trifolii and rhizobium leguminosarum.	the basic structures of the extracellular polysaccharides of rhizobium leguminosarum and rhizobium trifolii were found to be identical, but their acylation patterns differ. liquid hydrogen fluoride at -40 degrees degrades the two polysaccharides to a series of oligosaccharides representing the repeating units of the polysaccharides and their higher homologs. at -23 degrees, it degrades the polymers to a mixture of oligosaccharides from which a tetrasaccharide constituting a unit of the backbone ...	1986	3955563
arginine catabolism in agrobacterium strains: role of the ti plasmid.	we present a study of the enzymatic activities involved in the pathway for arginine catabolism by agrobacterium tumefaciens. nitrogen from arginine is recovered through the arginase-urease pathway; the genes for these two activities are probably chromosomally born. arginase was found to be inducible during growth in the presence of arginine or ornithine. urease was constitutively expressed. ornithine, resulting from the action of arginase on arginine, could be used as a nitrogen source via trans ...	1986	3957872
nodulation of legumes by rhizobium: the recognized root?		1986	3768953
agrobacterium tumefaciens and the susceptible plant cell: a novel adaptation of extracellular recognition and dna conjugation.		1986	3768954
transport of gamma-butyrobetaine in an agrobacterium species isolated from soil.	an agrobacterium sp. isolated from soil by selective growth on gamma-butyrobetaine (gamma-trimethylaminobutyrate) as the sole source of both carbon and nitrogen has been shown to possess an inducible transport system for this growth substrate. this transport system has a kt of 0.5 microm and a maximal velocity of 3.8 nmol/min per mg (dry weight). the influx of gamma-butyrobetaine is optimal at ph 8.5 and operates against a concentration gradient. the transport system shows a high specificity for ...	1986	3782024
mapping and cloning of a fla-che region of the rhizobium meliloti chromosome.	we constructed a genetic map of the fla-che region of the rhizobium meliloti chromosome using cotransduction with bacteriophage phi m12. several other chromosomal markers located in the general area are included in the map. we isolated plasmids carrying wild-type dna inserts that complement the mapped mutations from a genomic library carried in the broad-host-range vector plafr1. the complementation data obtained from the clones confirmed the contransduction map and clarified the exact order of ...	1986	3782025
correlation between extracellular fibrils and attachment of rhizobium leguminosarum to pea root hair tips.	as part of a project meant to characterize molecules involved in nodulation, a semiquantitative microscopic assay was developed for measuring attachment of rhizobium leguminosarum cells to pea root hair tips, i.e., the site at which r. leguminosarum initiates nodulation. this form of attachment, designated as cap formation, was dependent on the incubation ph and growth phase, with optimal attachment at ph 7.5 and with bacteria in the early stationary phase of growth. addition of glucose to the g ...	1986	3782027
mutations in rhizobium phaseoli that lead to arrested development of infection threads.	two rhizobium phaseoli mutants, isolated previously by tn5 mutagenesis, elicited infection threads which ceased development prematurely, usually within root hairs. these infection threads were wide, globular, and otherwise altered in morphology, compared with normal infection threads. anatomy and division of the root cortical cells during initial stages of nodule morphogenesis appeared normal. however, later nodule differentiation deviated considerably from normal development, and release of bac ...	1986	3782040
biosynthesis of rhizobium trifolii capsular polysaccharide: enzymatic transfer of pyruvate substitutions into lipid-bound saccharide intermediates.	the activity of capsular polysaccharide pyruvyltransferase catalyzing the pyruvylation of acidic heteropolysaccharide was measured in rhizobium trifolii 843 and 0403 rif. this enzyme activity was determined with edta-treated cells, uridine diphosphate-sugar precursors, and phosphoenol [1-14c]pyruvate. activity was measured by the incorporation of radioactivity into organic solvent-soluble glycoconjugates. enzymatic pyruvylation of capsular polysaccharide occurred from phosphoenolpyruvate at the ...	1986	3782043
molecular characterization of a host-range-determining locus from agrobacterium tumefaciens.	the virulence loci play an essential role in tumor formation by agrobacterium tumefaciens. this study focused on the virc locus, which affects the host range agrobacterium species. virc mutants display an attenuated or avirulent phenotype on certain host plants, but remain fully virulent on other plant hosts. the nucleotide sequence revealed that the virc locus of ptia6nc is an operon consisting of two open reading frames. these two open reading frames, designated virc1 and virc2, encode protein ...	1986	3759904
biosynthesis of a galactose-and galacturonic acid-containing polysaccharide in rhizobium meliloti.	previous work showed that two different strains derived from a culture of rhizobium meliloti 102f51 differed with respect to phage specificity, agglutinability by alfalfa seed lectin, and synthesis of a galactose-containing polysaccharide (r. a. ugalde, h. handelsman, and w. j. brill, j. bacteriol. 166:148-154, 1986). inner membranes from the more competitive strain incorporated galactose from udp-galactose when a thermostable factor was present. this factor has now been identified as udp-galact ...	1986	3759905
the kinetics of the reactions of parasponia andersonii hemoglobin with oxygen, carbon monoxide, and nitric oxide.	hemoglobin i was isolated from nodules formed on the roots of parasponia andersonii inoculated with rhizobium strain cp 283. the rate of oxygen dissociation from parasponia hemoglobin increases about 12-fold between ph 4 and 7, with apparent pk 6.4, to reach a limiting value of 14.8s-1. the optical spectrum of oxyhemoglobin in the visible region is also dependent on ph with pk near 6.4. the rate constant for oxygen combination with parasponia hemoglobin increases about 7-8-fold between ph 4 and ...	1986	3759986
time required for tumor induction by agrobacterium tumefaciens.	cellulose-minus mutants of agrobacterium tumefaciens retain virulence but can be removed from wound sites by washing with water. washing of bryophyllum diagremontiana leaves inoculated with a cellulose-minus mutant was used to determine the minimum time the bacteria must be present for tumor induction. this time was 4 to 8 h.	1986	3767365
fractionation of rhizobium leguminosarum cells into outer membrane, cytoplasmic membrane, periplasmic, and cytoplasmic components.	rhizobium leguminosarum cells were separated into four distinct fractions by using density gradient centrifugation for the separation of the outer and cytoplasmic membranes and lysozyme-edta treatment of whole cells for the isolation of the periplasmic and cytoplasmic fractions. these methods allowed the subcellular localization of r. leguminosarum proteins.	1986	3745116
galactose metabolism in rhizobium meliloti l5-30.	data from previous studies of rhizobium meliloti mutants have been consistent with the catabolism of hexoses via the entner-doudoroff pathway. however, galactose metabolism was not impaired in those mutants. we show here by enzymatic assay and by identification of a galactose mutant lacking 2-keto-3-deoxy-6-phosphogalactonate aldolase that the de ley-doudoroff pathway is used for galactose metabolism. mutants in this pathway have not been previously reported for any organism.	1986	3745118
two gene clusters of rhizobium meliloti code for early essential nodulation functions and a third influences nodulation efficiency.	a plafr1 cosmid clone (ppp346) carrying the nodulation region of the symbiotic plasmid prme41b was isolated from a gene library of rhizobium meliloti 41 by direct complementation of a nod- deletion mutant of r. meliloti. agrobacterium tumefaciens and rhizobium species containing ppp346 were able to form ineffective nodules on alfalfa. the 24-kilobase insert in ppp346 carries both the common nodulation genes and genes involved in host specificity of nodulation. it was shown that these two regions ...	1986	3745124
formation in rhizobium and agrobacterium spp. of a 235-kilodalton protein intermediate in beta-d(1-2) glucan synthesis.	beta-d(1-2) glucan was synthesized by agrobacterium and rhizobium spp. in vitro with enzymes from the internal membranes upon the addition of udf glucose and mg2+ or mn2+. an intermediate containing protein and beta-d(1-2) glucan was formed during the reaction. it could be precipitated with trichloroacetic acid or separated by polyacrylamide gel electrophoresis under denaturing conditions. after detection with coomassie blue or a radioactive substrate, the intermediate appeared as a 235-kilodalt ...	1986	3745125
rhizobium sp. strain ors571 grows synergistically on n2 and nicotinate as n sources.	rhizobium sp. strain ors571 conducts synergistic, free-living n2 fixation and nicotinate oxidation. explicitly, ors571 is able to fix n2 aerobically because 6-oh-nicotinate acts as an intracellular o2 sink. because 6-oh-nicotinate oxidation is mandatory for aerobic, free-living n2 fixation and because the synergistic processes yield ammonium from substrates (as the nitrogen source for growth), ors571 is not a diazotroph.	1986	3753598
control of a futile urea cycle by arginine feedback inhibition of ornithine carbamoyltransferase in agrobacterium tumefaciens and rhizobia.	in agrobacterium tumefaciens and rhizobia arginine can be used as the sole nitrogenous nutrient via degradation by an inducible arginase. these microorganisms were found to exhibit arginine inhibition of ornithine carbamoyltransferase activity. this inhibition is competitive with respect to ornithine (km for ornithine = 0.8 mm; ki for arginine = 0.05 mm). this type of urea cycle regulation has not been observed among other microorganisms which degrade arginine via an arginase. the competitive pa ...	1986	3758074