Science, 1980 Sep 19, 209(4463), 1385 - 91 Tumor DNA structure in plant cells transformed by A . tumefaciens; Zambryski P et al.; Crown gall tumors are induced in plants by infection with the soil bacterium Agrobacterium tumefaciens . Because the tumor induction involves transfer of a portion of the tumor-inducing (Ti) plasmid DNA from the bacterium to the plant cells, this system is of interest for the study of genetic exchange as well as tumor induction . The boundaries of the transferred DNA (T-DNA) have been cloned from transformed plant cells of tobacco . Detailed mapping with restriction enzymes and nucleotide sequence analysis of two independent clones were used to study the molecular structure of the ends of the T-DNA . One clone contains the two ends of the T-DNA joined together; the other contains one end of the T-DNA joined to repetitive plant DNA sequences . These studies provide direct evidence that the T-DNA can be integrated into the plant genome . In addition, the data suggest that in the plant, T-DNA can be tandemly repeated . Sequence analysis of the junction of crown gall clone 1 reveals several direct repeats as well as an inverted repeat; these structures may be involved in the transfer of the DNA from Agrobacterium to plant cells. J Bacteriol, 1980 Sep, 143(3), 1295 - 306 Interactions between octopine and nopaline plasmids in Agrobacterium tumefaciens; Hooykaas PJ et al.; Transfer of octopine Ti plasmids to strains already carrying an octopine Ti plasmid was found to occur at the same (high) frequency as transfer to Ti plasmid lacking recipients, showing that resident Ti plasmids do not exhibit entry exclusion towards incoming Ti plasmids . The resident octopine Ti plasmid was lost by the recipient after the entrance of the incoming Ti plasmid, which is indicative of the incompatibility between the Ti plasmids . Octopine Ti plasmids were found to become established only infrequently in recipients with a nopaline Ti plasmid and, vice versa, nopaline Ti plasmids were only rarely established in recipients with an octopine Ti plasmid . Rare clones in which the incoming octopine (nopaline) Ti plasmid had been established despite the presence of a nopaline (octopine) Ti plasmid appeared to harbor cointegrates consisting of the entire incoming Ti plasmid and the entire resident Ti plasmid . The integration event invariably had occurred in a region of the plasmids that is highly conserved in evolution and that is essential for oncogenicity . These results show that octopine and nopaline Ti plasmids cannot be maintained as separate replicons by one and the same cell . Therefore, be definition, these plasmids belong to the same incompatibility group, which has been names inc Rh-1 . Agrobacterial non-Ti octopine and nopaline plasmids were found to belong to another incompatibility group . The tumorigenic properties of strains harboring two different Ti plasmids, in a cointegrate structure, were indicative of the virulence genes of both of them being expressed . The agrobacterial non-Ti octopine and nopaline plasmids did not influence the virulence properties encoded by the Ti plasmid. Ukr Biokhim Zh, 1980 Sep-Oct, 52(5), 647 - 51 {Biological properties of Agrobacterium tumefaciens RNA-polymerase . I . Isolation of RNA-polymerase from Agrobacterium tumefaciens 8628}; Iarchenko VV et al.; RNA-polymerase is isolated from Agrobacterium tumefaciens 8628 . When fractioning the protein extract by DEAE-cellulose, RNA-polymerase is separated into three fractions eluated with 0.15, 0.165, and 0.185 M KCI . Their electrophoresis in polyacrylamide gel shows that the composition of subunits in the second and third fractions is, in principle, similar to that of Escherichia coli RNA-polymerase, but the first fraction protein distribution pattern differs from he mentioned fractions . The data obtained may evidence for the presence of several RNA-polymerases forms in virulent strains of agrobacteria. Infect Immun, 1980 Sep, 29(3), 859 - 62 Chemical structure and inhalation toxicity of lipopolysaccharides from bacteria on cotton; Helander I et al.; Lipopolysaccharides from different bacteria isolated from cotton were purified and chemically analyzed . Their pulmonary toxicity to animals was tested in inhalation tests . Lipopolysaccharides from Agrobacterium and Xanthomonas were shown to differ from the others in that they contained no heptose and no non-hydroxylated fatty acids with a chain length of 12, 14, or 16 carbon atoms . Lipopolysaccharides from Pseudomonas putida, Enterobacter agglomerans, and Klebsiella oxytoca were found to cause an influx of polymorphonuclear leukocytes into the airways . Lipopolysaccharides from Agrobacterium sp . and Xanthomonas sinensis caused no significant invasion . The data point to substances in both the lipid A part and the core part of the lipopolysaccharides being responsible for the capacity to induce leukocyte invasion into the airways. Plasmid, 1980 Sep, 4(2), 196 - 204 Expression of Ti-plasmid DNA in E . coli: comparison of homologous fragments cloned from Ti plasmids of Agrobacterium strains C58 and Ach5; Schweitzer S et al.; Fragments of two Ti plasmids from Agrobacterium tumefaciens were cloned and studied for cross-hybridization . Homologous fragments were further investigated for areas of strong homology and mapped with various restriction enzymes . The fragments were inserted in two directions and the recombinant plasmid was brought into E . coli strains producing minicells . About five proteins were found to be coded by those fragments of the Ti plasmids. Gene, 1980 Sep, 10(4), 329 - 38 IS-like element IS8 in RP4 plasmid and its involvement in cointegration; Depicker A et al.; The structure of the cointegrate plasmids formed by fusion of RP4 and the tumour-inducing plasmid (pTi) of Agrobacterium tumefaciens was analyzed . In all of the nine independently isolated pTi::RP4 cointegrates, the integration occurred at the same site on the RP4 genome . Moreover, a 1.2 Md (1750 bp) RP4 sequence (IS8) was directly repeated at both junction sites of the two replicons . The insertion of RP4 generated deletions, starting from the IS8 sequence and extending into the Ti part of the cointegrate . Dissociation of the cointegrates resulted in wild-type RP4 and Ti-plasmids with the IS8 sequence inserted at the original RP4 insertion site . The processes of integration and dissociation and the genetic properties of the cointegrates indicate that the IS8 sequence has unique characteristics defining a new insertion sequence. Plasmid, 1980 Sep, 4(2), 184 - 95 Localization of the replication control region on the physical map of the octopine Ti plasmid; Koekman BP et al.; A series of small plasmids has been derived from the octopine plasmid pTi-B6 by in vitro manipulation . The smallest plasmid that is able to replicate in Agrobacterium tumefaciens contains the ampicillin-resistance determinant from Tn1, coupled to a piece of DNA that is homologous to HpaI fragment number 11 of the octopine Ti plasmid pTi-Ach 5 . The incompatibility functions are also specified by this region. Eur J Biochem, 1980 Jun, 107(2), 475 - 83 Cytochromes c-556 from three genetic races of Agrobacterium . Purification and comparison of their properties; Van Beeumen J et al.; 1 . The soluble cytochromes c-556 from three strains of Agrobacterium tumefaciens, B6, II Chrys and Apple 185 have been purified to homogeneity . The strains are representative members of the three main genetic races of Agrobacterium . The purity of the final preparations was established by electrophoresis with an without sodium dodecyl sulphate, by analytical isoelectric focusing and ultracentrifugation, and by N-terminal analysis . 2 . Properties of these cytochromes were compared wih those of cytochrome c-556 from A . tumefaciens, strain B2a, a member of the same genetic race as strain B6 . The four cytochromes are monohaem proteins with molecular weights of about 12300 (determined by four different methods) . The isoelectric points of those from strains B6 and B2a are identical at pH 5.5, but they differ from the cytochromes of the other genetic races: cytochrome c-556 from strain Apple 185 is more acidic (ph 5.2) and that from strain II Chrys more basic (pH 6.2) . The cytochromes from strains b6 and B2a have very similar but not identical amino acid compositions; both of them differ more from Apple 185 than from II Chrys c-556 . 3 . Comparison of the tryptic, chymotryptic and thermolytic fingerprints of cytochrome c-556 from strains B2a and II Chrys reveals strong homology between the primary structures of these cytochromes . Therefore and because of the sequence identity of the first eight residues, the cytochromes c-556 from strains II Chrys, B6 and B2a are most likely C-terminal haem-bound, of the same type as the cytochrome c' from photosynthetic bacteria. C R Seances Acad Sci D, 1980 May 5, 290(17), 1173 - 6 {Preparation and properties of new catabolic substrates for two types of oncogenic plasmids of Agrobacterium tumefaciens}; Tempe J et al.; Reduction of the Schiff bases formed between glucose, mannose or galactose with glutamic acid yields products related both structurally and biologically to agropine and to a derivative of agropine present in crown gall tumours . The catabolism of these compounds is coded for by octopine and agropine Ti-plasmids of Agrobacterium tumefaciens. J Bacteriol, 1980 Apr, 142(1), 243 - 8 Beta-2-linked glucans secreted by fast-growing species of Rhizobium; York WS et al.; Fast-growing species of Rhizobium were found to secrete low-molecular-weight beta-2-linked glucans when cultured in synthetic liquid medium . These glucans are quite similar to beta-2-linked glucans produced by species of Agrobacterium . No reducing terminus was detected in these glucans. J Bacteriol, 1980 Mar, 141(3), 1127 - 33 Diversity among B6 strains of Agrobacterium tumefaciens; Hamada SE et al.; A total of 20 laboratory substrains of Agrobacterium tumefaciens strain B6 were compared with respect to six characteristics, including 3-ketolactose production, lysogeny, octopine catabolism, tumorigenic host range, and plasmid content . Within this group of strains diversity was found for all characteristics except 3-ketolactose production . Six substrains were lysogenized with an omega-type phage, whereas one substrain appeared neither sensitive to nor lysogenized with this bacteriophage . All but two substrains catabolized octopine and induced tumors on carrot disks . These 18 substrains harbor deoxyribonucleic acid sequences homologous to pTiB6-806 . The two substrains unable to catabolize octopine were nontumorigenic and lacked detectable Ti plasmid sequences . Of the 20 substrains, 13 also contained sequences homologous to the cryptic plasmid pAtB6-806; 2 of the 18 substrains tumorigenic on carrots failed to induce tumors on Kalanchoe leaves . Their inability to induced tumors on this host, could not be correlated with lysogeny, with the presence or absence of pAtB6-806, or with the very large cryptic plasmid recently described . The Ti plasmids from these two strains were indistinguishable from pTiB6-806 by restriction enzyme analysis and could genetically convert a cured A . tumefaciens strain to tumorigenicity on both plant species . The results with these two strains suggest that parameters of tumorigenicity, such as host range, may be controlled by the bacterial chromosome. Can J Biochem, 1980 Mar, 58(3), 213 - 8 Evolutionary relationship between Halobacterium cutirubrum and eukaryotes determined by use of aminoacyl-tRNA synthetases as phylogenetic probes; Kwok Y et al.; The cross-species reactivities between tRNAs and aminoacyl-tRNA synthetases have been employed as a basis to estimate the relatedness of various prokaryotes to the eukaryotes . The tRNA of Halobacterium cutirubrum, unlike that of other prokaryotes tested, including Agrobacterium tumefaciens, Arthrobacter luteus, Bacillus subtilis, Bacillus stearothermophilus, Escherichia coli, Micrococcus luteus, Myxococcus xanthus, Rhodopseudomonas spheroides, and Thermus aquaticus, was found to share with yeast, rat liver, and wheat germ tRNA a distinct preference for aminoacylation by eukaryotic synthetases from yeast as opposed to prokaryotic synthetases from either E . coli or R . spheroides . These results suggest that phylogenetically H . cutirubrum is more closely related to the eukaryotes than to the eubacteria. J Bacteriol, 1980 Mar, 141(3), 1134 - 41 Hairy root: plasmid encodes virulence traits in Agrobacterium rhizogenes; White FF et al.; Agrobacterium rhizogenes strain 15834, which incites hairy root disease in plants, harbors three large plasmids: pAr15834a (107 x 10(6) daltons), pAr15834b (154 x 10(6) daltons), and pAr15834c (258 x 10(6) daltons) . Kanamycin-resistant transconjugants were selected in a cross of kanamycin-resistant derivate of strain 15834 and an avirulent recipient . The transconjugants belonging to one class were virulent and contained all three donor plasmids . These transconjugants also acquired sensitivity to the bacteriocin agrocin 84 . The loss of plasmids from virulent transconjugants during growth at 37 degrees C indicated that virulence genes reside on pAr15834b, whereas agrocin 84 sensitivity genes reside on pAr15834a . The pathology induced by the virulent transconjugants containing only pAr15834b was identical to that produced by the wild-type strain of A . rhizogenes . Restriction endonuclease fragment analysis of plasmids from the transconjugants and the donor revealed that pAr15834c is a cointegrate of pAr15834a and pAr15834b . Kanamycin-resistant transconjugants belonging to a second class were avirulent and contained an altered form of pAr15834b . Strain 15834 can utilize octopine . However, this trait was not detected in any of the transconjugants . Octopine is not synthesized by infected plant tissue. J Bacteriol, 1980 Feb, 141(2), 996 - 8 Identification of two glutamine synthetases in Agrobacterium; Fuchs RL et al.; Two distinct glutamine synthetases have been identified in Agrobacterium and in the fast-growing rhizobia . A limited survey indicates that GSII may be found only in the Rhizobiaceae family. J Bacteriol, 1980 Jan, 141(1), 129 - 36 Transposition of Tn904 encoding streptomycin resistance into the octopine Ti plasmid of Agrobacterium tumefaciens; Klapwijk PM et al.; A transfer-deficient derivative of plasmid RP1-pMG1 was isolated after insertion of Mu cts62 . The Tra- R plasmid was used to donate Tn904, encoding streptomycin resistance, to Ti plasmid pAL102 harbored by Agrobacterium tumefaciens Ach5 . Under conditions promoting high Ti transfer frequencies, 155 strains were isolated in which the streptomycin marker coupled with Ti plasmid in further transfer experiments . These isolates represent stable insertions of Tn904 into the Ti plasmid . In addition, 19 strains were isolated in which the insertion of Tn904 was apparently unstable . The frequency of stable Tn904 transpositions was estimated to be 3 x 10(4-) per transferred Ti plasmid . Evidence was obtained that Tn904 readily may transpose from the Ti plasmid into the bacterial chromosome . The strains carrying Ti plasmids with stable insertions were characterized with respect to virulence, octopine degradation, octopine synthesis in induced tumors, and Ti plasmid transfer . Thirteen of the strains were found to be affected in tumor-inducing ability. Mol Gen Genet, 1980, 179(1), 223 - 6 Plasmid DNA of Agrobacterium tumefaciens detected in a presumed habituated tobacco cell line; Yang F et al.; 'Tabac anergie' tissue has been used by many investigators as a habituated tobacco cell line . In this study, we have found sequences which are homologous to approximately 9 megadaltons of an Agrobacterium octopine-type plasmid in DNA isolated from 'Tabac anergie' tissue . These T-DNA sequences were shown to be the same 'core DNA' sequences found to be present in several other unorganized tumor lines which have been studied in our laboratory . The T-DNA was also shown to be integrated into plant DNA . Thus, the 'Tabac anergie' tissue is a crown gall tumor induced by a strain of Agrobacterium tumefaciens containing an octopine-type plasmid . These results indicate that the plants regenerated from 40 clones of the 'Tabac anergie' line by Sacristan and Melchers (1977) were actually reverted plants obtained from an unorganized crown gall tumor, kept in culture for more than 25 years . It is necessary to re-evaluate observations and conclusions which have been based upon 'Tabac anergie' being a habituated tissue. Folia Microbiol (Praha), 1980, 25(6), 476 - 82 Rhizosphere microflora and colonization of wheat roots by Gaeumannomyces graminis var . tritici after foliar application of urea and benomyl; Vrany J et al.; The effect of foliar application of 2% urea and 0.6% benomyl on changes in colonization of the rhizosphere by microorganisms and of roots by the fungus Gaeumannomyces graminis (Sacc.) Arx et Olivier var . tritici Walker was followed in vegetation glass-house experiments . Treatment with a urea solution resulted in increased counts of bacteria (82%), Pseudomonas fluorescens (46%), Agrobacterium sp . (31%) and antagonistic bacteria with respect to the used fungus isolate and in a decreased occurrence of micromycetes (63%) . Treatment of wheat with a benomyl solution resulted in an increased count of bacteria (43%) and a decreased occurrence of P . fluorescens (16%), Agrobacterium sp . (50%) and fungi (67%) . After treatment with both compounds the infection of roots by G . graminis considerably decreased as compared with untreated plants . The results are discussed from the point of view of the effect of application of the studied compounds to upper parts of wheat on the microflora colonizing its roots. Nature, 1979 Dec 20-27, 282(5741), 870 - 2 Primary structure of a chloramphenicol acetyltransferase specified by R plasmids; Shaw WV et al.; Naturally occurring isolates of chloramphenicol-resistant bacteria commonly synthesise chloramphenicol acetyltransferase (EC 2.3.28; CAT) in amounts which are sufficient to account for the resistance phenotype and often harbour plasmids which carry the structural gene for CAT . The findings of CAT in such diverse prokaryotes as Proteus mirabilis, Agrobacterium tumefaciens, Streptomyces sp., and a soil Flavobacterium has led to speculation concerning the origin and evolution of the more commonly observed CAT variants specified by plasmids in clinically important bacteria . To provide a more solid basis for studying the evolution and spread of CAT within prokaryotes we chose to determine the complete amino acid sequence of a type I variant of CAT, the variant known to be associated with most F-like plasmids conferring chloramphenicol resistance . The sequence has been determined by combining the results obtained from manual and automated sequential degradation with those obtained by mass spectrometry of peptides generated by enzymatic digestion . The directly determined primary structure is identical with that predicted by the DNA sequence analysis of the chloramphenicol resistance transponson Tn9 known to specify a type I variant of chloramphenicol acetyltransferase. Nucleic Acids Res, 1979 Dec 11, 7(7), 1837 - 49 Rapid mapping of transposon insertion and deletion mutations in the large Ti-plasmids of Agrobacterium tumefaciens; Dhaese P et al.; A procedure is presented, that has allowed the rapid assignment of transposon Tn1 and Tn7 insertion sites in the large (130 Md) nopaline Ti-plasmid pTiC58, to specific restriction enzyme fragments . Total bacterial DNA is isolated from Agrobacterium tumefaciens strain C58 mutants that carry a transposon in their Ti-plasmid, and digested with an appropriate restriction endonuclease . The fragments are separated on an agarose gel, denatured and transferred to nitrocellulose filters . These are hybridized against purified wild type pTiC58, or against segments of PTiC58, cloned in E . coli using pBR322 as a vector plasmid . DNA sequences homologous to the probe are detected by autoradiography, thus generating a restriction enzyme pattern of the plasmid from a digest of total bacterial DNA . Mutant fragments can be readily identified by their different position compared to a wild type reference . This protocol eliminates the need to separate the large plasmid from chromosomal DNA for every mutant . In principle, it can be applied to the restriction enzyme analysis of insertion or deletion mutants in any plasmid that has no extensive homology with the chromosome. Eur J Biochem, 1979 Oct 15, 100(2), 609 - 18 Characterization and comparison of chloramphenicol acetyltransferase variants; Zaidenzaig Y et al.; 1 . Variants of chloramphenicol acetyltransferase from a variety of bacterial species have been isolated and purified to homogeneity . They constitute a heterogeneous group of proteins as judged by analytical affinity and hydrophobic ('detergent') chromatography, native and sodium dodecyl sulfate electrophoresis, sensitivity to sulfhydryl specific reagents, steady state kinetic analysis, and reaction with antisera . 2 . The most striking observation is that three variants of chloramphenicol acetyltransferase (R factor type III, Streptomyces acrimycini, and Agrobacterium tumefaciens) possess an apparent subunit molecular weight (24,500) which is significantly greater than that of all other variants examined (22,500) . The three atypical variants are not identical since they show marked differences in a number of important parameters . 3 . Although the fundamental mechanism of catalysis may prove to be identical for all chloramphenicol acetyltransferase variants, there is a wide range of sensitivity to thiol-directed inhibitors among the enzymes studied . 4 . Amino acid sequence analysis of the N-termini of selected variants suggests that the qualitative differences among chloramphenicol acetyltransferase variants is a reflection of structural heterogeneity which is most marked in comparisons between variants from Gram-positive and Gram-negative species. J Biochem Biophys Methods, 1979 Oct, 1(5), 299 - 308 Small-scale techniques for the analysis of recombinant plasmids; Hepburn AG et al.; Using the cloning of part of the T-DNA of pTiC58 from Agrobacterium tumefaciens as an example, techniques are described which enable recombinant plasmids to be mapped and used as hybridization probes . In all cases the starting material is a colony of cells grown on an agar plate which is then subjected to lysis by lysozyme and Triton X-100 in volumes of the order of 300 microliters thus eliminating the need for handling and centrifuging liquid cultures under restrictive containment conditions. Antimicrob Agents Chemother, 1979 Sep, 16(3), 293 - 6 Purification and characterization of agrocin 84; Thompson RJ et al.; A procedure for the rapid purification of milligram quantities of agrocin 84, a bacteriocin-like compound produced by Agrobacterium radiobacter strain K-84, has been developed . This procedure, which employs charcoal adsorption, ion-exchange, sieving chromatography, and continuous-flow electrophoresis, can yield agrocin 84 which is 65% pure on a dry weight basis . The purest preparations were strongly ultraviolet absorbing, with a maximum at 264 nm (epsilon 7.0/264 = 22,675 cm2 - M-1) and a minimum at 227 nm (ratio of 264 to 227 nm, 6.00) . As has been reported, agrocin 84 contains an unusual phosphoramidate or 6-N-acyl linkage to adenine . Adenine, glucose, and phosphate are present in a 1:1:2 molar ratio . The molecular weight was estimated to be 1,350. Biochemistry, 1979 Aug 21, 18(17), 3755 - 60 Purification and characterization of the crown gall specific enzyme nopaline synthase; Kemp JD et al.; Nopaline synthase of sunflower (Helianthus annuus L.) crown gall tissue induced by Agrobacterium tumefaciens strain C58 or T37 (nopaline utilizers) was purified to homogeneity as judged by analytical disc gel electrophoresis . The native enzyme elutes from a column of Ultrogen AcA 34 as a single peak with an estimated molecular weight of 158,000 . The dissociated enzyme migrates on NaDodSO4-polyacrylamide gels as a single band with a molecular weight of 40,000 . Thus, the native enzyme appears to be composed of four equal-weight subunits . Nopaline synthesizing activity is found exclusively in crown gall tissues induced by strains of A . tumefaciens that utilize nopaline (e.g., C58 and T37) . We found the same tissue specificity for the purified protein that we believe represents nopaline synthase . The results of kinetic studies of the purified enzyme are consistent with a ter-bi rapid-equilibrium random-order mechanism . Nopaline synthase is probably responsible for the in vivo synthesis of both N2-(1,3-dicarboxypropyl)arginine (nopaline) and N2-(1,3-dicarboxypropyl)ornithine (ornaline) in crown gall tissues since substrate specificities and Km values do not change during purification. J Bacteriol, 1979 Aug, 139(2), 591 - 6 Host range conferred by the virulence-specifying plasmid of Agrobacterium tumefaciens; Loper JE et al.; The host range of Agrobacterium tumefaciens 1D1109, known to induce crown gall only on grapevine (Vitis spp.), was extended to include many plant species by transferring a tumor-inducing plasmid (pTi) from strain 1D1, a broad-host-range pathogen . The pTi plasmid was mobilized by the conjugative plasmid pRK2, which was inserted into 1D1 by mating with Escherichia coli J53(pRK2) . The resulting transconjugants were screened for their ability to induce crown gall tumors on hosts other than grapevine by inoculation into sunflower . Transconjugants that were virulent on sunflower were then tested on 36 different host plants and compared with host-limited strain 1D1109 and the donor strain . Two transconjugants induced tumors on the same 28 plant species as those of the original plasmid donor 1D1(pRK2) (pTi) . These results show that pRK2 promoted transfer of the pTi plasmid and suggest that the pTi plasmid rather than the A . tumefaciens chromosome determined the host range of the pathogen . Insertion of pRK2 alone did not extend the host range of strain 1D1109 . Insertion of pS-a into A . tumefaciens 1D1 by mating with E . coli J53-1 (pS-a) resulted in the concomitant loss of pTi and virulence . There appears to be incompatibility between pTi and pS-a. J Bacteriol, 1979 Aug, 139(2), 424 - 31 Negative control of octopine degradation and transfer genes of octopine Ti plasmids in Agrobacterium tumefaciens; Klapwijk PM et al.; The regulatory system that controls the expression of the Ti plasmid-borne octopine degradation (uad) and transfer (tra) genes in Agrobacterium tumefaciens was studied . A deletion mutant derived from the cointegrate plasmid R702::Ti-B6S3 was isolated, which was compatible with a wild-type Ti plasmid and which had retained the uad genes . By means of this mutant plasmid pAL116, it was possible to make cells diploid for the uad genes . pAL116 was introduced into Rec- strains that contained different types of regulation mutants for the uad and tra genes . The repression pattern that was found in this complementation analysis indicated that the uad and tra operons are controlled by a common repressor system . Several results indicated that there may be additional transcriptional relations between both operons . The corresponding genes of the non-tumorigenic octopine plasmid pAt-AG60 appeared to be controlled by a repressor related to that of the octopine Ti plasmid. J Bacteriol, 1979 Jul, 139(1), 280 - 6 R-plasmid-mediated chromosomal gene transfer in Agrobacterium tumefaciens; Hamada SE et al.; Although several techniques are available for transferring the Ti plasmids from one strain of agrobacterium tumefaciens to another, there are no reproducible methods for analysis of chromosomal markers in this phytopathogen . The R plasmid, R68.45, is known to show chromosomal mobilizing ability in several bacterial genera including the closely related Rhizobia . R68.45 was transferred into the prototrophic A . tumefaciens strain 15955 . Ten kanamycin-resistant transconjugant clones were tested for chromosomal mobilizing ability by mating with strain SA10, rifampin- and streptomycin-resistant histidine auxotroph of strain 15955 . Of the 10 donor clones, 2 showed high chromosomal mobilizing ability . Between 1,000 and 2,000 His+ colony-forming units per ml were obtained, a value 10 to 20 times greater than can be accounted for by spontaneous reversion . Sequential recloning and matings resulted in the isolation of relatively stable donor cultures . Chromosome gene transfer is dependent upon the presence in the donor of R68.45 . Donors lacking an R plasmid or harboring the closely related plasmid RP4 failed to yield His+ transconjugants . With strain SA11, a methionine auxotroph of strain SA10, coinheritance of histidine and methionine independence could be demonstrated . Approximately half of the transconjugants also inherited R68.45 . These results indicate that A . tumefaciens 15955 is capable of undergoing host chromosomal genetic exchange. Mol Gen Genet, 1979 Jun 7, 173(2), 171 - 5 Isolation of a recombination deficient Agrobacterium tumefaciens mutant; Klapwijk PM et al.; The isolation of a recombination deficient (Rec-) strain of Agrobacterium tumefaciens is described . Strain LBA 4011 was mutagenized with nitrosoguanidine and after segregation 18,000 colonies were replica plated and UV irradiated . Twentytwo UV sensitive strains were isolated and tested for methylmethanesulphonate (MMS) sensitivity . Six of these strains were more MMS-sensitive than LBA 4011 . A Ti plasmid that was genetically marked with Tn 1 (CbR) was introduced in these strains and the rescue of the CbR marker during superinfection with an incompatible cointegrate plasmid Ti::R 702 was determined . One strain exhibited a large reduction in rescue frequency . It is concluded that the latter strain was recombination deficient . This property did not influence the induction of plant tumours. Infect Immun, 1979 Jun, 24(3), 920 - 4 Choriogonadotropin-like antigen in an anaerobic bacterium, Eubacterium lentum, isolated from a rectal tumor; Acevedo HF et al.; Using the indirect fluorescein-labeled and indirect peroxidase-antiperoxidase-labeled immunohistochemical techniques, and utilizing both antiserum specific for the beta-subunit of choriogonadotropin and antiserum for the total hormone, we have demonstrated the presence of a choriogonadotropin-like immunoreactive material in a strain of Eubacterium lenthum that was originally isolated from a rectal tumor . In contrast, both immunohistochemical reactions were negative when applied to a strain of Corynebacterium parvum and to pathogenic and nonpathogenic strains of Agrobacterium tumefaciens . Our results demonstrate for the first time the expression of the choriogonadotropin-like antigen in an obligate anaerobe and support our previous findings that the choriogonadotropin like material appears to be expressed only in "cancer-associated bacteria" but that not all bacteria associated with the malignant neoplasms have the capacity to express the antigen, at least in amounts detectable by immunohistochemistry. Proc Natl Acad Sci U S A, 1979 Jun, 76(6), 2828 - 32 Transcription of Ti plasmid-derived sequences in three octopine-type crown gall tumor lines; Gurley WB et al.; Total RNA isolated from three octopine-type crown gall lines contains sequences homologous to specific regions of the tumor-inducing (Ti) plasmid of Agrobacterium tumefaciens strain 15955 . A comparison of transcripts in these three tumor lines suggests that tumor cells transcribe various sequences within a sector of plasmid DNA of 13 x 10(6) daltons and that transcription may not be uniform across the plasmid derived sequences (T-DNA) . Transcription of T-DNA by octopine-type tumors occurs at four major sites . The levels of transcription occurring at three of these sites appear to vary considerably among the three tumor lines investigated . Part of this variability may reflect differences in the organization and copy number of T-DNA . One of the transcription sites maps within a region of DNA with common sequence homology with all Ti plasmids . Varying amounts of transcript homologous to this region of T-DNA are present in all three tumor lines . It is suggested that transcription of these conserved sequences in the plant may have significance regarding the mechanism of tumorigenesis. Gene, 1979 May, 6(1), 43 - 50 A new site-specific endonuclease showing phenotypical crypticity in a tumorigenic strain of Agrobacterium tumefaciens; Roizes G et al.; AtuBVI, an endonuclease showing new site-specificity, has been isolated from the tumorigenic strain IIBV7 of Agrobacterium tumefaciens, and is undetectable in the non-tumorigenic sister strain IIBNV6 . AtuBVI degrades IIBV7 DNA in vitro and should, therefore, be regarded as being phenotypically cryptic in the bacterial cell; it also shows anomalous behavior under cerain incubation conditions . These properties point to a possible role for this enzyme in the insertion of exogenous Ti-plasmid DNA into plant tissues during tumorigenesis. Proc R Soc Lond B Biol Sci, 1979 Apr 11, 204(1155), 251 - 66 Interactions and DNA transfer between Agrobacterium tumefaciens, the Ti-plasmid and the plant host; Schell J et al.; Agrobacterium tumefaciens is a gram-negative bacterium with the unique capacity to induce neoplasmic transformations in dicotyledonous plants . Recently, both the mechanism and the biological significance of this transformation have been elucidated . Agrobacterium tumefaciens strains contain a large extrachromosomal DNA plasmid (the Ti-plasmid) . This Ti-plasmid is responsible for the oncogenic properties of Agrobacterium strains . A particular segment of the Ti-plasmid, containing information determining the tumorous growth pattern and the synthesis of so-called 'opines', e.g . octopine (N-alpha-(D-1-carboxyethyl)-L-arginine) and nopaline (N-alpha-(1,3-dicarboxypropyl)-L-argine), is transferred and stably maintained and expressed in the transformed plant cells . This phenomenon can be understood as a 'genetic colonization' of the plant cells by bacterial plasmid DNA so that the transformed plant cells will produce and secrete into the medium amino acid derivatives (the opines) that Ti-plasmid carrying agrobacteria can selectively use as carbon and nitrogen sources. J Biol Chem, 1979 Mar 25, 254(6), 1860 - 5 Agrobactin, a siderophore from Agrobacterium tumefaciens; Ong SA et al.; A siderophore (microbial iron transport compound) was isolated from low iron cultures of Agrobacterium tumefaciens B6 . The substance was characterized as a threonyl peptide of spermidine acylated with 3 residues of 2,3-dihydroxybenzoic acid, the carbonyl group of 1 residue of the latter participating in an oxazoline ring with the beta-hydroxyl of the threonine moiety . The compound, N-{3-(2,3-dihydroxybenzamido)propyl}-N-{4-(2,3-dihydroxybenzamido)butyl}-2-(2,3-dihydroxyphenyl)-trans-5-methyl-oxazoline-4-carboxamide, was given the trivial name agrobactin . Exposure to acid opened the oxazoline ring to afford agrobactin A . Ferric agrobactin A and agrobactin A itself, but not agrobactin or its ferric complex, had some capacity to feed iron to enterobactin-deficient strains of Escherichia coli and Salmonella typhimurium . Agrobactin was produced by A . tumefaciens in response to iron deficiency and was able to reverse the iron starvation in this organism precipitated by the presence of a ferric complexing agent not utilized by the cells. Can J Microbiol, 1979 Mar, 25(3), 291 - 7 Isolation of a non-tumor-inducing mutant of the Ti plasmid of Agrobacterium tumefaciens strain B6; Rapp BJ et al.; A nonpathogenic mutant of Agrobacterium tumefaciens strain B6 was isolated and its properties compared with the parental strain in an effort to localize the mutation . Both B6 and its mutant (B6-95) had similar colony color and morphology, were ketolactose positive, utilized octopine, and contained plasmid DNA . Kinetic analysis of DNA reannealing showed that total DNA homology and plasmid DNA homology between B6 and B6-95 was at least 90% . The length of both plasmids was found to be 58 micrometer . Plasmid DNA from both B6 and the mutant was digested with endonucleases and the fragments separated by agarose gel electrophoresis . In all cases the pattern for B6 was identical with that of B6(-95) . The Ti plasmid from B6 and the mutant was transferred to an avirulent, plasmidless strain of A . tumefaciens by in vitro conjugation and transformation . All of the B6 transconjugants and transformants were virulent, whereas all of the mutant transconjugants and transformants were avirulent . Electrophoretic patterns of endonuclease-digested plasmid DNA from transformants were identical to those of plasmid DNA from B6 . Therefore, we conclude that the virulence mutation lies on the Ti plasmid. J Bacteriol, 1979 Feb, 137(2), 1020 - 1 Crown gall teratoma formation is plasmid and plant controlled; Gresshoff PM et al.; Experiments using different species of the plant Nicotiana and strains of the bacterium Agrobacterium tumefaciens showed that teratoma formation from crown galls was dependent on the combination of bacterial Ti plasmid and host plant used. Infect Immun, 1979 Feb, 23(2), 298 - 304 Tumor induction by Agrobacterium tumefaciens prevented in Vigna sinensis seedlings systemically infected by ribonucleic acid viruses; Saedi D et al.; Cowpea (Vigna sinensis) seedlings failed to develop tumors after being inoculated with crown gall bacteria (Agrobacterium tumefaciens) if, at times earlier than 1 day later, they were inoculated on the primary leaves with a cowpea mosaic virus that systemically infects them . Inoculation with buffer or with a virus that is restricted to a localized infection, or to which the cowpea is immune, did not interfere with the subsequent development of tumors . The virus infection did not appear to affect directly the titer of A . tumefaciens in the inoculation sites . Nor did mixing of virus particles with A . tumefaciens prevent subsequent appearance of tumors . The influence of virus infection extended across grafts (into tissue that is not susceptible to the virus) and there prevented tumor formation . The sap from infected plants, but not purified virus, decreased tumor formation on carrot disks . Systemic virus infection may induce in cowpeas a translocated substance that prevents tumor induction by A . tumefaciens. Can J Microbiol, 1979 Feb, 25(2), 185 - 91 Polymyxin resistance in Agrobacterium tumefaciens and its effect on crown gall tumor induction; Liao CH et al.; Polymyxin-resistant (PBLr) mutants of Agrobacterium tumefaciens A6, B6, and B6M were isolated from polymyxin-sensitive (PBLs) parent strains in a defined medium containing 600 microgram of polymyxin B sulfate per millilitre . The weight and number of tumors induced by PBLr mutants on a variety of host plants such as carrot, potato, and pinto bean were 45--75% less than those induced by PBLs wild types . The crude cell envelopes (CCE) prepared from both PBLs and PBLr bacteria were inhibitory for tumor initiation when they were applied before or during the inoculation of viable tumorigenic bacteria, but not when they were applied 30 min after the inoculation of infectious bacteria . The potency to inhibit the tumor initiation by the CCE prepared from PBLs cells was approximately 50% higher than that by the equal amount of the CCE prepared from PBLr cells . The concentration of CCE preparations required to reduce tumor induction 50% in carrot and pinto bean was determined to be 2.6 mg/mL and 4.0--6.2 mg/mL for the CCE derived from PBLs and PBLr cells, respectively . These data suggest that the envelope structure or composition of PBLs and PBLr cells is distinct, and that the acquisition of resistance to polymyxin by agrobacteria modifies envelope structure or components which are essential for tumor initiation. C R Seances Acad Sci D, 1979 Jan 8, 288(1), 147 - 50 {Stimulation of induction or inhibition of crown-gall tumor development by RNA-fragments U2 . Interference by auxin}; Le Goff L et al.; RNA-fragments U2 obtained by mild degradation with RNase U2 of ribosomal RNA containing A and G nucleotides in excess are capable of exhibiting either a stimulatory effect on the induction of Crown-gall tumors or an inhibitory action on their subsequent development . These different effects are dependent on the moment at which RNA-fragments were introduced into wounded Pea seedlings infected by Agrobacterium tumefaciens B6 . The results obtained in vitro and in vivo suggest that an interaction between auxin and RNA-fragments U2 may take place, either increasing the tumor induction or inhibiting the proliferation of tumourous cells. Appl Environ Microbiol, 1979 Jan, 37(1), 127 - 30 Low-intensity microwave radiation and the virulence of Agrobacterium tumefaciens strain B6; Moore HA et al.; When virulent cells of Agrobacterium tumefaciens strain B6 were exposed to low-level microwave radiation at a frequency of 10,000 MHz and an intensity of 0.58 mW/cm2 for 30 to 120 min, a 30 to 60% decrease in their ability to produce tumors on potato and turnip disks was observed . This microwave exposure did not affect the viability of these bacteria or their ability to attach to a tumor-binding site nor did it induce thermal shock . This loss of virulence was reversible within 12 h. Zentralbl Bakteriol Naturwiss, 1979, 134(6), 551 - 4 Crown gall: economic importance and control; de Cleene M; Many plants of economic importance are possible hosts for Agrobacterium tumefaciens, the causal organism of the crown gall tumor disease . Damage has been reported on stone fruit (Australia), vineyard (Hungary, Bulgaria), lettuce (Brasil) .. . In Western-Europe, crown gall seems to be of less economic importance for plants growing in the open air . However, plants cultivated in greenhouses have a greater chance to be tumorized, because of the more favourable circumstances for tumor induction . Modern treatments are based on the inactivation or killing of the tumorigenic organism at the time of the wounding of the host plants. Zentralbl Bakteriol Naturwiss, 1979, 134(4), 335 - 42 A study of the tumorogenesis of Agrobacterium tumefaciens Conn . on some plant species of Iran; Shokraii EH et al.; This paper is a survey and comparative type of study on the tumorogenetic effect of Agrobacterium tumefaciens on some plant species of Iran . The results obtained indicate that the tumor-inducing property of this micro-organism is not common to all plant species studied; moreover no tumor was initiated on the mature leaves by the bacteria . The results obtained with the local varieties of the susceptible plants show some qualitative and quantitative differences as compared with the works of other investigators, especially with regard to the formation of secondary tumors . The enhancing effect of indolyl-3-acetic-acid (IAA) on initiation, size, and number of primary and secondary tumors, induced by Agrobacterium, was also investigated and the results, to a certain degree, confirm those obtained by other workers . Viability of the bacteria in the tumors was also measured and the results obtained confirm the view that a continuous and active presence of the bacteria is essential for growth and development of the tumors. Zentralbl Bakteriol Naturwiss, 1979, 134(5), 423 - 8 {The spreading of Agrobacterium strains in soft-agar (author's transl)}; Beiderbeck R et al.; In a diluted synthetic medium solidified by 0.17% agar populations of Agrobacterium spread with a velocity of 0 to 20 mm/24 hours . This spreading is a consequence of chemotactic movement and cell division . Different bacterial strains spread with a characteristic velocity each . Loss of the TI-plasmid leaves the spreading behaviour unimpaired . It is changed after the introduction of virulence by Kerr transfer or after prolonged culture in D-amino acids. Zentralbl Bakteriol Naturwiss, 1979, 134(5), 381 - 9 Association between Azotobacter and other soil bacteria and its effect on nitrogen fixation; Abd-el-Malek Y et al.; The association between A . vinelandii and either Agrobacterium sp . or Micrococcus sp., which are usually found as contaminants in Azotobacter cultures, was investigated . In comparison with pure cultures, association increased the microbiol counts in addition to increasing nitrogen fixation rates and efficiency . In liquid cultures higher Azotobacter densities were observed in the top 5 cm of the column concomitant with lowering the economic coefficient of utilization of carbonaceous compounds, which resulted in low efficiency of nitrogen fixation . In deep layers, lower amounts of nitrogen gain were obtained, but higher efficiencies of N2-fixation were recorded . In sand cultures, the biggest amounts of fixed nitrogen were in the 5--15 cm layer of the soil column and in deeper layers economic utilization of sugars occurred, but nitrogen gain sharply decreased. Folia Microbiol (Praha), 1979, 24(3), 262 - 8 Effect of bacterial polysaccharides on the growth of Gaeumannomyces graminis var . tritici and wheat roots; Lasik J et al.; Agrobacterium sp . and related species which in the soil and in the rhizosphere of wheat accompany the fungus Gaemannomyces graminis var . tritici and cause take-all of the wheat roots produced polysaccharides in pure cultures (glucans, mannoglucans and galactomannoglucans) . These polysaccharides were utilized better by the mycelium of G . graminis than glucose and polysaccharides of plant origin that occurred on the surface of wheat roots (the so-called mucigel) . At lower concentrations these bacterial polysaccharides stimulated growth of wheat roots, higher concentrations (more than 0.1%) were inhibitory . Bacteria inoculated on the surface of wheat first inhibited and then stimulated the development of the plants and their growth . Changes in the growth rate of wheat, the rhizosphere of which was colonized by bacteria simultaneously with the fungus G . graminis and also some changes in the course of the disease of wheat roots caused by the fungus can be explained by the inhibitory or stimulatory effect of polysaccharides of accompanying bacteria. Folia Microbiol (Praha), 1979, 24(2), 182 - 4 Genetic mapping of the bacteriophage PS8 of Agrobacterium tumefaciens; Kubickova D et al.; Genetic mapping of the chromosome of the bacteriophage PS8 of Agrobacterium tumefaciens using temperature sensitive (ts) mutants of the bacteriophage is described. Folia Microbiol (Praha), 1979, 24(3), 253 - 61 Microorganisms in the rhizosphere of wheat colonized by the fungus Gaeumannomyces graminis var . tritici; Bednarova M et al.; The population of microorganisms in wheat rhizosphere changed in the presence of the fungus Gaeumannomyces graminis var . tritici causing the take-all of wheat . In the majority of cases when the soil was artificially contaminated by the fungus, both the number of bacteria in the rhizosphere and the bacteria/fungi ratio temporarily increased . At the beginning bacteria growing in the presence of NH4+ predominated, later bacteria utilizing organic N-substances prevailed . Pseudomonas fluorescens and the related species colonized the rhizosphere and the soil to a greater extent in the presence of G . graminis . The wheat rhizosphere with G . graminis was found to contain a higher level of the slime-producing bacterium Agrobacterium spp.; this microorganism occurred on hyphal surfaces (in hyphosphere) of both G . graminis growing in soil and Mucor spp . Changes in microbial populations in the wheat rhizosphere during the first stage of colonization by G . graminis can be partly explained by a simultaneous rhizosphere colonization by microorganisms which accompany this fungus in soil . In the period of increase in the number of bacteria in rhizosphere a temporary stimulation of wheat growth was observed. J Bacteriol, 1978 Dec, 136(3), 909 - 15 Multiple genes coding for octopine-degrading enzymes in Agrobacterium; Montoya AL et al.; Most biotype 2 strains of Agrobacterium tumefaciens and A . radiobacter which utilize nopaline also degrade octopine . In all such strains studied, the ability to degrade octopine did not appear to be transferred to plasmidless recipient cells under conditions of plasmid transfer in which the ability to utilize nopaline was transferred . An octopine-degrading mutant was isolated in a strain cured of its plasmid, suggesting that genes of octopine degradation may have a chromosomal location in some strains . In strains in which octopine utilization is coded by plasmid genes, octopine degradation was always inducible, whereas in strains which degrade both octopine and nopaline, octopine utilization was constitutive although nopaline degradation was inducible . When plasmids coding for octopine-utilizing ability were transformed into a strain containing either a nopaline- or null-type plasmid, transformants able to degrade octopine were either not observed or were unstable upon purification . All of these data suggest that plasmids associated with virulence are incompatible with one another, and therefore imply that the major groups of plasmids associated with virulence have a common origin. J Bacteriol, 1978 Dec, 136(3), 1178 - 83 Tumor-inducing (Ti) plasmids of Agrobacterium share extensive regions of DNA homology; Drummond MH et al.; Labeled Ti plasmid DNAs from diverse Agrobacterium strains were hybridized to Southern blots of pTi-B6-806 plasmid DNA digest fragments of known map order . The map location of DNA sequences common to all Ti plasmids was found to be extensive, consistent with the view that Ti plasmids have evolved from a common ancestral plasmid. Infect Immun, 1978 Nov, 22(2), 516 - 22 Plasmid-dependent attachment of Agrobacterium tumefaciens to plant tissue culture cells; Matthysse AG et al.; Kinetic, microscopic, and biochemical studies show that virulent Ti (tumor inducing)-plasmid-containing strains of Agrobacterium attach to normal tobacco and carrot tissue culture cells . Kinetic studies showed that virulent strains of A . tumefaciens attach to the plant tissue culture cells in increasing numbers during the first 1 to 2 h of incubation of the bacteria with the plant cells . Five Ti-plasmid-containing virulent Agrobacterium strains showed greater attachment to tobacco cells than did five avirulent strains . Light and scanning electron microscopic observations confirmed that virulent strains showed little attachment . Bacterial attachment was blocked by prior incubation of the plant cells with lipopolysaccharide extracted from A . tumefaciens, but not from A . radiobacter, suggesting that bacterial lipopolysaccharide is one of the components involved in the attachment process . At least one other bacterial product may be required for attachment in tissue culture because the virulent A . tumefaciens NT1, which lacks the Ti plasmid, does not itself attach to tobacco cells, but its lipopolysaccharide does inhibit the attachment of virulent strains. J Bacteriol, 1978 Nov, 136(2), 775 - 85 Coordinated regulation of octopine degradation and conjugative transfer of Ti plasmids in Agrobacterium tumefaciens: evidence for a common regulatory gene and separate operons; Klapwijk PM et al.; By using the analog noroctopine, mutants of agrobacterium tumefaciens were isolated with altered regulation patterns for the Ti plasmid-borne octopine utilization genes . These could be divided into three classes: (i) strains with a constitutive level of octopine enzymes and a high degree of spontaneous Ti transfer; (ii) one strain with constitutive octopine enzymes but no spontaneous Ti transfer; and (iii) strains with an altered inducibility in which, contrary to the wild-type Ti plasmid, conjugation and octopine utilization were induced by noroctopine . These results are best explained by the activity of a common regulatory gene . In a second step, using homo-octopine, mutants were isolated with lesions preventing the utilization of octopine . All mutations were plasmid borne and did not prevent the induction of tumors . Plasmids of two isolates were characterized by large deletions resulting in a decreased virulence and the absence of octopine in the tumor . With a plasmid carrying an inserted transposon Tn1, a significant number of strains were isolated which were unable both utilize octopine and to transfer the Ti plasmid . This suggests that there may be another common factor--presumably positive--between these traits . Transfer-negative mutants were still virulent . This seems to exclude a role for the conjugative transfer during the process of plant tumor induction . A way to test octopine oxidase by the use of permeable cells is described. Pathol Biol (Paris), 1978 Nov, 26(8), 507 - 12 {The classification of Agrobacterium and Rhizobium phages (author's transl)}; Ackermann HW; All phages studied are tailed, belong to six morphological groups, and are classified by morphological and serological properties and by physico-chemical parameters of the virion and its nucleic acid . Four species of Agrobacterium and 12 species of Rhizobium phages are described, and their relationship with enterobacteria phages discussed . They include 68 viruses, whereas 60 poorly known phages have not been classified. Tsitol Genet, 1978 Sep-Oct, 12(5), 409 - 13 {Proliferative activity of normal and tumorous plant tissues cultivated in vitro}; Troian VM et al.; Proliferative pools of Helianthus tuberosus L . explants tissues were studied using autoradiography with 3H-thymidine in the course of normal growth in vitro and tumorous growth induced by Agrobacterium tumefaciens . It is determined that on the 3d or 4th day of tumorous transformation the number of cycling cells reaches 30% whereas that of normally growing explants showed 10-11% . No changes were observed in 3H-thymidine transport during this period. Proc Natl Acad Sci U S A, 1978 Sep, 75(9), 4097 - 101 DNA modifying enzymes of Agrobacterium tumefaciens: effect of DNA topoisomerase, restriction endonuclease, and unique DNA endonuclease on plasmid and plant DNA; LeBon JM et al.; Extracts from Agrobacterium tumefaciens strain ID135 contain three enzymes that have been characterized and partially purified . The first enzyme, a DNA topoisomerase, appeared to relax only negatively twisted DNA . The second enzyme, Atu I, a type II restriction endonuclease, generated the identical DNA digestion pattern as EcoRII when several DNAs were used . The third enzyme, endonuclease A, showed a preference for superhelical DNAs as substrates . When plasmid pCK135DNA, obtained from the virulent strain IDI135 of A . tumefaciens, or plant DNA was exposed to the three enzymes, changes in DNA patterns were observed due to either conformational changes or digestion of the DNAs . These enzymes may function in vivo in the processing and incorporation of bacterial DNA in plant cells. Br J Ind Med, 1978 Aug, 35(3), 204 - 7 Bacterial contamination of cotton and cotton dust and effects on the lung; Rylander R et al.; Bacterial contamination of various parts of the cotton plant and of cotton from different mills was investigated . The predominant bacterial species were Gram-negative rods mainly of the Enterobacter genus . When guinea pigs inhaled strains of these bacteria cultivated from cotton, a strong leucocyte mobilising capacity was found for Pseudomonas and Enterobacter but not for Agrobacterium or Bacillus species . The aetiology of the development of pulmonary symptoms after inhalation of bacteria-containing dusts and subsequent production of endotoxins is discussed. Proc Natl Acad Sci U S A, 1978 Aug, 75(8), 3796 - 800 Proteins conferred by the virulence-specifying plasmid of Agrobacterium tumefaciens C-58; Sonoki S et al.; Membrane-associated and periplasmic proteins of Agrobacterium tumefaciens C-58 were compared with those from avirulent (nontumrigenic) derivative strains by slab and two-dimensional gel electrophoresis . Two proteins (Per-I and Per-2), with a molecular weight of 37,500 and 37,300, respectively, were detected in the supernatant fraction of cells of strain C-58 treated with EDTA and lysozyme in which a 117-megadalton plasmid confers virulence on the organism . The same proteins are missing in an avirulent plasmid-free derivative of C-58 . When this derivative is mated with C-58, the resulting transconjugants regain the large C-58 plasmid together with the restoration of virulence and the expression of Per-1 and Per-2 proteins . When the transconjugants were cured of their plasmid, they concomitantly lost their virulence and Per-1 and Per-2 . The functional roles of these proteins are unknown, but they are associated with the outer membrane and periplasmic fraction of the Agrobacterium cell . If directly involved in tumorigenesis, these proteins are not the sole determinants of tumorigenicity because they are synthesized in an avirulent derivative of C-58 that carries a deletion in the plasmid in the region conferring the tumorigenic phenotype . These results strongly suggest that the Per-1 and Per-2 proteins are plasmid-coded gene products . The possible roles of these proteins in specifying host range and host-cell attachment are also discussed. Mol Gen Genet, 1978 Jul 25, 163(3), 335 - 8 In vivo transfer of the ti-plasmid of Agrobacterium tumefaciens to Escherichia coli; Holsters M et al.; The Ti-plasmids are naturally self-transmissible from their normal host Agrobacterium to E . coli . They are however unable to stably establish themselves as a replicon in E . coli . It is nevertheless possible to study the Ti-plasmids in E . coli with the help of Ti::RP4 cointegrate plasmids that transfer and maintain themselves very efficiently in E . coli . An E . coli harbouring such a Ti::RP4 plasmid is unable to catabolize octopine and unable to induce crown-gall tumours on plants. Mol Gen Genet, 1978 Jul 11, 163(2), 181 - 7 Transfection and transformation of Agrobacterium tumefaciens; Holsters M et al.; The freeze thaw transfection procedure of Dityatkin et al . (1972) was adapted for the transfection and transformation of A . tumefaciens . Transfection of the strains B6S3 and B6-6 with DNA of the temperate phage PS8cc186 yielded a maximum frequency of 2 10(-7) transfectants per total recipient population . In transformation of the strain GV3100 with the P type plasmid RP4 a maximum frequency of 3.5 10(-7) transformants per total recipient population was obtained . Agrobacterium Ti-plasmids were introduced in the strain GV3100 with a maximal efficiency of 4.5 10(-8) . These experiments provide further evidence that the Ti-plasmid is responsible for the oncogenic properties of A tumefaciens and for its capacity to induce "opine" synthesis in Crown-gall plant cells. J Bacteriol, 1978 Jul, 135(1), 227 - 38 Isolation of large bacterial plasmids and characterization of the P2 incompatibility group plasmids pMG1 and pMG5; Hansen JB et al.; Large plasmids from Agrobacterium tumefaciens, Salmonella typhimurium, Escherichia coli, Pseudomonas putida, and Pseudomonas aeruginosa were routinely and consistently isolated using a procedure which does not require ultracentrifugation but includes steps designed to separate large-plasmid DNA from the bacterial folded chromosome . It also selectively removes fragments of broken chromosome . A variety of large plasmids was readily visualized with agarose gel electorphoresis, including five between 70 and 85 megadaltons (Mdal) in size, six between 90 and 143 Mdal, one that was larger than 200 Mdal, and one that was larger than 300 Mdal . This isolation procedure allowed initial estimation of the molecular sizes of the two IncP2 plasmids, pMG1 and pMG5, which were 312 and 280 Mdal, respectively . A standard curve for size determination by gel electrophoresis including plasmids between 23 and 143 Mdal in size did not extrapolate linearly for plasmids of the 300-Mdal size range . Unique response of different plasmids to the isolation procedure included sensitivity of IncP1 plasmids to high pH and the co-isolation of a 20-Mdal "cryptic" plasmid in conjunction. J Bacteriol, 1978 Feb, 133(2), 518 - 26 Transfer of nitrogen fixation genes from a bacterium with the characteristics of both Rhizobium and Agrobacterium; Skotnicki ML et al.; Strain T1K, reported to be Rhizobium trifolii strain T1 carrying the drug resistance plasmid RU-1drd, was able to transfer a cluster of nif+ genes to Escherichia coli K-12 . Additional genetic material, resembling the gal-chlA region of E . coli, was also transferred from strain T1K . The segregation pattern of these transferred genes suggested that they were on a plasmid . Although strain TIK was able to nodulate red and white clover, it also formed very slow-growing galls on tomato stems and shared many physiological properties with Agrobacterium tumefaciens, to which it seemed more closely related than to R . trifolii . The R . trifolii hybrid T1 (R1-19drd), constructed by conjugation, did not share any of these properties of both A . tumefaciens . Thus, strain T1K appears to be a bacterium with properties of both A . tumefaciens and R . trifolii and with the capacity to transfer nif+ genes and other functions which it may have "cloned" from another bacterium such as Klebsiella. Microbios, 1978, 23(92), 115 - 26 Effect of sublethal heat injury on tumour induction and RNA synthesis in Agrobacterium tumefaciens; Sobota AE; When cells of Agrobacterium tumefaciens are subjected to sublethal heat injury at 45 degrees C for 20 min, less than 5% of the viable population retain their ability to initiate tumour formation on Kalanchoe daigremontiana . If the cells are then incubated in phosphate buffer at 27 degrees C for 2 h, tumour initiation returns to control levels . Inhibitors of DNA and protein synthesis had little effect on the recovery of tumour initiation after heat injury . Rifamycin, a specific inhibitor of RNA synthesis, dramatically reduced recovery of tumour formation . During the heating process large amounts of RNA leaked from the cells which correlated with a degradation of rRNA . The addition of Mg to the heating buffer reduced the loss of RNA into the medium and the degradation of rRNA and tumour initiation was retained at control levels . It is concluded that while current evidence indicates that DNA is probably the transforming agent, RNA synthesis is an important component of the induction process. Zentralbl Bakteriol Naturwiss, 1978, 133(7-8), 674 - 9 Production of adventitious root primordia on hypocotyls of castor bean seedling, infected with Agrobacterium tumefaciens; Abo-El-Dahab MK et al.; The development of sterile secondary tumours on hypocotyls of castor bean seedlings, inoculated with any of the ten isolates of Agrobacterium tumefaciens tested, were observed below the site of the primary tumours . Histopathological studies performed in the present work indicate that the observed secondary tumours were adventitious root primordia and not the ordinary type of secondary tumours . According to the available literature such findings are reported here for the first time . All the tested isolates of the present study were also able to initiate well defined roots in conjunction with crown gall (teratomas) on Bryophyllum crenata and Kalanchoe marmorata, but not in tomato. Can J Microbiol, 1977 Nov, 23(11), 1554 - 61 Studies on Agrobacterium tumefaciens . VIII . Avirulence induced by temperature and ethidium bromide; Lin BC et al.; When tumorigenic strains of Agrobacterium tumefaciens were subcultured at temperatures between 31.5 and 37 degrees C or in broth containing ethidium bromide, they lost their capacity to induce tumors in tomato plants . The sensitivities of curing virulence (tumorigenicity) depended on the density of the population of cells, fewer cells (100/ml) being more sensitive to curing than higher densities (10(6)/ml) . The loss of virulence need not require the total loss of the virulence-specifying plasmid, but may result from a loss of a small segment of that plasmid . Virulent strains made avirulent by temperature or ethidium bromide treatment still harbor a large plasmid of 70-80 megadaltons size compared with the 100- to 120-megadalton plasmid in the untreated strains. J Bacteriol, 1977 Sep, 131(3), 741 - 4 Zeatin ribonucleosides in the transfer ribonucleic acid of Rhizobium leguminosarum, Agrobacterium tumefaciens, Corynebacterium fascians, and Erwinia amylovora; Cherayil JD et al.; Until recently, the presence in transfer ribonucleic acid (tRNA) of the hydroxylated cytokinin ribosylzeatin {N6-(4-hydroxy-3-methylbut-2-enyl)adenosine}was thought to be unique to higher plants . This extension of work from several laboratories indicates the presence of 2-methylthioribosylzeatin in the tRNA of the plant-associated bacteria Rhizobium leguminosarum, Agrobacterium tumefaciens, and Corynebacterium fascians, but not in that of Erwinia amylovora . This cytokinin has the cis configuration, as is normally found in the tRNA's of plants . The tRNA thionucleotide patterns in these bacteria are different from those of Escherichia coli, Bacillus subtilis, and Salmonella typhimurium, which contain the unhydroxylated analogs of ribosylzeatin or 2-methylthioribosylzeatin. Brookhaven Symp Biol, 1977 May 12-20, (29), 36 - 49 Transfer, maintenance, and expression of bacterial Ti-plasmid DNA in plant cells transformed with A . tumefaciens; Schell J et al.; The mechanism of induction of the plant cancer crown gall by Agrobacterium tumefaciens has been briefly described . The salient points are as follows . 1 . Large plasmids of molecular weight (100 to 150) S 10(6), called Ti-plasmids, are essential to the transformation process . 2 . Ti-plasmids carry a DNA segment that can be transferred to, and maintained and expressed in, transformed plant cells . 3 . This DNA segment has been identified both by direct hybridization experiments between Ti DNA fragments and crown gall DNA and by the study of a deletion mutant of a Ti-plasmid . 4 . Indirect evidence suggests that genes involved in the synthesis of abnormal amino acids (such as octopine and nopaline) by crown gall cells, and known to be carried on the Ti-plasmids, are in fact located on the DNA segment that is transferred to the plant cells . 5 . Ti-plasmids are efficient conjugative plasmids, since they can promote their own transfer by conjugation to various plasmid-free bacterial strains . Their conjugative properties may be involved also in the Ti DNA transfer from Agrobacterium to plant cells . 6 . Preliminary evidence indicates that the transferable segment of the Ti-plasmid has the structure of a transposon, since it appears to be flanked by a sequence exhibiting most of the properties of the sequences that border the known bacterial drug-resistance gene transposons. J Clin Microbiol, 1977 Feb, 5(2), 172 - 7 Comparison of thirty-seven strains of Vd-3 bacteria with Agrobacterium radiobacter: morphological and physiological observations; Riley PS et al.; Thirty-seven cultures of Vd-3 bacteria, isolated from clinical specimens, were characterized morphologically and physiologically . The cultures produced positive reactions when tested for oxidase, urease, nitrate reduction, phenylalanine deaminase, oxidative metabolism of carbohydrate substrates, and 3-ketolactose production . These peritrichously flagellated microorganisms were isolated primarily from the respiratory tract . When compared to authentic strains of Agrobacterium, they appeared to be most similar to A . radiobacter . Gas-liquid chromatography of trimethylsilyl derivatives of whole-cell hydrolysates of some of the Vd-3 strains and A . radiobacter yielded nearly identical elution patterns . The Vd-3 cultures were identified as probable strains of A . radiobacter . A method is presented for differentiating cultures of A . radiobacter from other similar bacteria encountered in clinical specimens . Although these bacteria rarely occur in clinical specimens, the clinical microbiologist should be familiar withe their outstanding characteristics. J Bacteriol, 1977 Feb, 129(2), 830 - 5 Induction of D-aldohexoside:cytochrome c oxidoreductase in Agrobacterium tumefaciens; Nakamura LK et al.; D-Aldohexopyranoside:cytochrome c oxidoreductase (ACO) was strongly induced by cellobiose, alpha-methylglucoside, beta-methylglucoside, kojibiose, and sophorose . Induction was rapid, and ACO was readily detectable within 10 min after addition of cellobiose as inducer . Although not measurable for 30 to 40 min after addition of inducer, once started, the rate of induction with alpha-methylglucoside equaled or even exceeded that obtained with cellobiose . Induction by sucrose, maltose, alpha-alpha-trehalose, melibiose, and lactose was weak . In general, the active ACO inducers were poor glycosidase inducers; the converse also appeared to be true . Although ACO induction was not repressed by D-glucose, it was repressed by succinate, malate, and fumarate. Zentralbl Bakteriol Parasitenkd Infektionskr Hyg, 1977, 132(1), 55 - 66 {The effect of biocides on the microflora of soils and their degradation . I . The selection of suitable biocides and ways of selective influences in soil-microorganisms (author's transl)}; Hoflich G; The influence of 544 biocides on soil-microflora was investigated by a special plate-test and by a soil-test . Fungi were particularly sensitive to active substances . They were more inhibited by a greater number of substances, by lower concentrations and by a larger time-interval than bacteria . A differentiated sensitivity of fungi becomes apparent . The pseudomonads, a species of Agrobacter (AIA), flavobacteria and some coryneforme bacteria were relatively resistant . Actinomyces responded similar to fungi . The plate-test is suitable as preliminary test for the selection of substances retarding the degradation of straw . These organisms already favoured by treatments with active substance locate in higher quantities in such soils where the biological balance was disturbed in after the injection . Therefore, the effect of the active substance exceeds that of the injection . The displacement-effect by bacteria resistant to active substances and little active against cellulose plays a minor role in opposite to bacteria active against cellulose, because bacteria don't develop any homogeneous protective coat . A priority effect is therefore excluded. J Bacteriol, 1977 Jan, 129(1), 76 - 80 Plasmids in avirulent strains of Agrobacterium; Merlo DJ et al.; Twelve strains of Agrobacterium radiobacter isolated from naturally occurring crown galls or soil were found to be avirulent on sunflower, tomato, Kalanchoe, and carrot . Eleven strains contained plasmids of molecular weights 77 X 10(6) to 182 X 10(6) as determined by electron microscopy . One strain contained only a smaller plasmid (50 X 10(6) daltons) . Several strains had both large and small (ca . 11 X 10(6) daltons) plasmids; one strain contained two large plasmids (112 X 10(6) and 136 X 10(6) daltons) . Hybridization reactions of virulence plasmids from Agrobacterium tumefaciens strains C58 and A6 with plasmids from each of the A . radiobacter strains revealed that some A . radiobacter plasmids had less than 10% homology to either the C58 or A6 plasmids . Plasmids from some strains had approximately 50% homology with the C58 plasmid, but only one A . radiobacter plasmid contained more than 10% homology to the A6 plasmid . The presence of large plasmids in A . radiobacter strains did not correlate with sensitivity to agrocin 84; however, the utilization of the amino acid derivatives octopine and nopaline was generally correlated to partial base sequence homology to the C58 plasmid . We conclude that all large plasmids found in Agrobacterium strains are not virulence associated, although they may share base sequence homology with a virulence-associated plasmid . Further, plasmids from tumorigenic strains may be more closely related by base sequence homology to plasmids from nonpathogenic strains than to plasmids from other pathogenic strains. J Bacteriol, 1977 Jan, 129(1), 101 - 7 Octopine and nopaline metabolism in Agrobacterium tumefaciens and crown gall tumor cells: role of plasmid genes; Montoya AL et al.; Crown gall tumors produced octopine or nopaline or neither compound, depending on the bacterial strain that incited the tumor . The genes specifying production of octopine or nopaline by the tumor were transferred to recipient bacterial strains when the large plasmid associated with virulence was transferred by either conjugation or deoxyribonucleic acid-mediated transformation . Our results, which confirm the work of others (Bomhoff et al., 1976; Goldman et al., 1968; Petit et al., 1970), indicate that, in general, the strains that utilize octopine induce tumors that synthesize octopine, and those that utilize nopaline induce tumors that synthesize nopaline . However, there were several notable exceptions . One class utilized both octopine and nopaline, but the tumors induced by these strains produced only nopaline . Another class utilized nopaline, but their tumors synthesized neither nopaline nor octopine . Mutants were isolated from a number of either octopine- or nopaline-utilizing strains that no longer could utilize the relevant guanido amino acid . These strains, which were mutant in the gene specifying octopine or nopaline oxidase, still retained the permease for these amino acids as well as virulence . Tumors induced by these mutants still synthesized approximately the same levels of octopine and nopaline as tumors induced by their parents . These results suggest that the plasmid gene that determines production of octopine or nopaline by the tumor is distinct from the plasmid gene that determines their catabolism by the bacteria. Zentralbl Bakteriol Parasitenkd Infektionskr Hyg, 1977, 132(4), 369 - 76 Effect of three nematicides on the growth of some phytopathogenic bacteria and fungi; El-Khadem M et al.; The effect of three nematicides, aldicarb, fensulfothion, and phenamiphos at four concentrations (1, 5, 25, and 125 ppm) was tested on the growth of five bacteria, Agrobacterium tumefaciens, Corynebacterium fascians, Erwinia carotovora, Pseudomonas solanacearum, and Streptomyces scabies and four fungi, Fusarium oxysporum f . sp . vasinfectum, Fusarium solani, Rhizoctonia solani, and Sclerotium bataticola . Of the bacteria, P . solanacearum was most affected by the chemicals at all concentrations, while E . carotovora was least affected . Fensulfothion was generally the most effective nematicide on the bacteria tested, while phenamiphos was the least effective . Similarly, the effect of the chemicals on the fungi tested varied greatly . F . solani and R . solani were generally most affected, followed by F . oxysporum, while S . bataticola was least affected . Of the chemicals tested, phenamiphos was generally the most effective, followed by fensulfothion, while aldicarb was the least effective. Mikrobiyol Bul, 1976 Oct, 10(4), 523 - 9 {Animal and plant cancers produced by viruses and bacteria}; Okuyan M; In this review the animal and plant cancers produced by viruses : (onkeorna, adeno, herpes, papova, pox, reovirus, Fig 1-6), bacteria : (Agrobacterium tumefaciens, Fig . 7), fungi : (Plasmodiophora brassicae, and nematode : (meloidgyne) are discussed. Can J Microbiol, 1976 Oct, 22(10), 1583 - 5 Physical characteristics of DNA from bacteriophages of Agrobacterium tumefaciens; Manasse RJ et al.; DNA was extracted from isolates of bacteriophages grown on virulent and avirulent strains of Agrobacterium tumefaciens . Molecular weights of DNA from phages isolated from the virulent A . tumefaciens (IIBV7) were about 41.5 X 10(6) daltons, while those from the avirulent A . tumefaciens (IIBNV6) were about 32.5 X 10(6) daltons . The buoyant densities of the four DNA's ranged from 1.7086 to 1.7089 g/cm3, values that were not significantly different . DNA-DNA hybridization studies also indicated that the four phages were closely related . Attempts to induce tumors with phage DNA were unsuccessful. Tsitol Genet, 1976 Sep-Oct, 10(5), 465 - 8 {Relationship between crown-gall plant tumors and the cell cycle}; Sarnatskaia VV et al.; It is established that under conditions of the culture in vitro the greatest amount of crown-gall swellings on topinambur and carrot explants is formed with Agrobacterium tumefaciens inoculation 4 and 6 hrs after the tissue extraction and planting, which corresponds to the G1-phase of the 1st cellular cycle . In the inoculated tissue cells entrance to the S-phase is accelerated and the maximal number of labelled nuclei is found 10 hrs earlier. J Gen Microbiol, 1976 Sep, 96(1), 155 - 63 Isolation and characterization of Agrobacterium tumefaciens mutants affected in the utilization of octopine, octopinic acid and lysopine; Klapwijk PM et al.; Using an enrichment procedure, mutant strains of Agrobacterium tumefaciens were isolated that lacked the ability to utilize octopine as a nitrogen source . Of 55 such isolates, 44 were unable to utilize several amino acids; the remaining 11 strains were altered solely in their ability to utilize octopine, octopinic acid and lysopine . It is concluded that only the latter were plasmid mutations . Among them, there was a high, but no absolute, correlation with avirulence . All strains contained the T1 plasmid . All virulent strains showed active transport of octopine when they had previously been grown in medium containing octopine, whereas the avirulent strains failed to show such transport . All the virulent mutants induced tumours containing octopine . The results are discussed in relation to the hypothesis that the genes which code for the octopine synthesizing enzymes in the tumour are of bacterial origin. J Bacteriol, 1976 Sep, 127(3), 1331 - 6 Conjugation in Agrobacterium tumefaciens in the absence of plant tissue; Levin RA et al.; A general, reliable conjugation system for Agrobacterium tumefaciens in the absence of plant tissue is described in which A . tumefaciens can serve either as the donor or recipient of plasmid deoxyribonucleic acid with reasonable efficiency . Plasmid RP4 was transferred from Escherichia coli to A . tumefaciens and from strain of A . tumefaciens . Both RP4 and the A . tumefaciens virulence-associated plasmids were detected by alkaline sucrose gradients in A . tumefaciens strains A6 and C58 after mating with E . coli J53(RP4) . The pathogenicity (tumor foramtion) of strains A6 and C58 and the sensitivity of strain C58 to bacteriocin 84 were unaffected by the acquistion of RP4 by the Agrobacterium strains . Plasmid R1drd-19 was not transferred to A . tumefaciens . Transformation experiments with plasmid deoxyribonucleic acid were unsuccessful, even though, in the case of RP4, conjugation studies showed taht the deoxyribonucleic acid was compatible with that of the recipient strains. Genetics, 1976 Aug, 83(4), 609 - 18 RP4 promotion of transfer of a large Agrobacterium plasmid which confers virulence; Chilton MD et al.; Introduction of RP4 plasmid into Agrobacterium tumefaciens promotes the transfer on solid medium of large virulence-associated plasmids from virulent donor strains to a plasmidless avirulent recipient . Exconjugants were selected for the ability to utilize octopine or nopaline as the sole source of arginine, traits which are coded for by virulence-associated plasmids in the strains employed here . All exconjugants retained the arginine auxotrophy of the recipient strain, and were resistant to ampicillin and kanamycin, drugs to which RP4 confers resistance . Five exconjugant clones from one cross were shown by alkaline sucrose gradient analysis to contain both RP4 plasmid and the large virulence-associated plasmid of the donor strain . All five exconjugants exhibited virulence on carrot, sunflower and kalanchoe plants . These results indicate that virulence and the ability to degrade octopine are plasmid-borne traits in A . tumefaciens strains 15955 and A6, and extend the evidence that large plasmids in A . tumefaciens are vectors of virulence genes. Mol Biol Rep, 1976 Jul, 2(6), 497 - 506 Particular small size RNA and RNA fragments from different origins as tumor inducing agents in Datura stramonium; Beljanski M et al.; Particular RNA fragments obtained by action of pancreatic ribonuclease on purified RNAs originating from species totally unrelated to Agrobacterium tumefaciens (Escherichia coli, rabbit, monkey) are capable of inducing the formation of transplantable tumorous tissue when introduced at wounded sites in inverted stems of Datura stramonium maintained under axenic conditions on a medium containing auxin and kinetin . Reovirus RNA and a small size RNA (5-6S) isolated from RNA bound RNA directed DNA polymerase from Escherichia coli also induced the appearance of tumorous tissues which grow on solid synthetic medium in the absence of auxin and kinetin. Mol Gen Genet, 1976 May 7, 145(2), 177 - 81 Octopine and nopaline synthesis and breakdown genetically controlled by a plasmid of Agrobacterium tumefaciens; Bomhoff G et al.; Several nopaline degrading strains and one octopine degrading strain are shown to loose oncogenicity as well as the ability to utilize these guanidine compounds when they are cured of their TI plasmid . To investigate whether the specific genes involved in the utilization of one or the other compound are located on the plasmid, plasmid-transfer experiments have been performed . The plasmid from a nopaline degrading strain has been transferred to a naturally non oncogenic Agrobacterium namely A . radiobacter . Furthermore, the plasmid from an octopine degrading strain has been transferred to a plasmid-cured strain which originally had the capacity to utilize nopaline . Both kinds of experiments prove that the TI plasmid determines the strain specificity with regard to the utilization of either octopine or nopaline . They also demonstrate that the synthesis of either octopine or nopaline in crown gall cells is also determined by genes located on the TI plasmid harboured by the transforming A . tumefaciens strains. Mikrobiologiia, 1976 May-Jun, 45, 561 - 3 {The presence of Agrobacterium tumefaciens in lucerne root nodules}; Imshenetskii AA et al.; Agrobacterium tumefaciens does not penetrate into nodules on the roots of lucerne with the active strain of nodule bacterium as was established with the aid of genetic markers and plant selection . A nodule, whose shape was not typical and which did not fix nitrogen, was formed on the root of lucerne inoculated with the culture of Agrobacterium tumefaciens treated with UV . A bacterial strain isolated from the nodule was identical to A . tumefaciens according to its resistance to streptomycin and several cultural properties . Upon repeated inoculation with the isolated strain, nodules were formed in 50% cases. Can J Microbiol, 1976 May, 22(5), 694 - 701 {A RNA extract from oncogenic and non oncogenic strains of Agrobacterium tumefaciens is an indispensable element for the induction of tumors in Datura stramomium}; Le Goff L et al.; An RNA bound to the reverse transcriptase of Agrobacterium tumefaciens has been isolated and shown to be oncogenic for stem tissues of Datura stramonium grown under axenic conditions . The tumorous nature of the cellular change induced by the infectious rna was demonstrated by serial grafts of tumors on Datura stems and by cultivation of tumorous tissue in vitro on a medium without supplemental auxins and cytokinins . Active cellular proliferation within tissues of Datura stems was a prerequisite for expression of the oncogenic potential of the RNA . Further, infectious RNA was isolated from avirulent and attenuated strains of Agrobacterium tumefaciens including attenuated derivatives of strain AC58 which have been "heat-cured" of the plasmid associated with virulence . It is proposed that the infectious RNA is an essential but not the sole component of the tumor-inducing mechanism of the crown-gall bacterium. Infect Immun, 1976 Apr, 13(4), 1080 - 3 Role of Agrobacterium cell envelope lipopolysaccharide in infection site attachment; Whatley MH et al.; Lipopolysaccharide (LPS) isolated from Agrobacterium tumefaciens inhibited tumor induction by virulent bacteria . LPS from site-binding strains was not effective if added to the plant wound shortly after the bacteria, and LPS from avirulent, non-site-binding strains of Agrobacterium was not inhibitory regardless of the order of addition . However, LPS and whole cells of avirulent strains NT1 and IIBNV6, which lack of Agrobacterim virulence plasmid, were inhibitory . Chromosomal deoxyribonucleic acid thus determines specificity of this essential component of the Agrobacterium infection process. J Bacteriol, 1976 Apr, 126(1), 157 - 65 Evidence for diverse types of large plasmids in tumor-inducing strains of Agrobacterium; Currier TC et al.; Homology between the large plasmids of 15 pathogenic Agrobacterium strains isolated from various parts of the world has been measured and was found to vary over a wide range, from 3 to 100% . Two genetically distinct groups of plasmids can be identified: one closely related to the plasmid of A . tumefaciens A6, an octopine-utilizing strain, and the other closely related to the plasmid of A . tumefaciens C-58, a nopaline-utilizing strain . The plasmids of four Agrobacterium strains do not belong to either group . One of these four strains utilizes octopine, one utilizes nopaline, and two utilize neither . Three strains contained two large plasmids . In one of these strains, the two plasmids were not homologous to one another . Chromosomal homologies for the Agrobacterium strains surveyed also vary over a wide range, but do not correlate with plasmid homologies . Neither do plasmid homologies correlate with any numerical classification scheme . The significance of these plasmid homology studies for crown gall tumorigenesis is considered. Differentiation, 1976 Mar 16, 6(1), 53 - 8 Isoenzymes of acid phosphatase and non-specific esterases in cultures of neoplastic and normal tobacco tissues; Abrams BB; Axenic cultures of normal, habituated and crown gall teratoma were grown under varying conditions to examine the effects of environment on the expression of neoplastic character . Acid phosphatase patterns on polyacrylamide gels did not vary greatly among tissues although there were differences in acid phosphatase activity between various strains of Agrobacterium tumefaciens, the bacteria which cause crown gall . Certain esterase isoenzymes were found only in tissues grown on specific media, while others were tissue-specific but independent of the nature of the medium . Comparisons of liquid and solid grown cultures revealed that culture conditions also influence esterase expression . Both sunflower and tobacco crown gall tissue contained an esterase not found in habituated or normal tissues, and similar in electrophoretic mobility to an esterase found in extracts of the bacteria that had induced the tumors . The basic difference between the three tissue types studied is the manner in which they respond to a given environment. Nucleic Acids Res, 1976 Feb, 3(2), 449 - 63 On the isolation of TI-plasmid from Agrobacterium tumefaciens; Ledeboer AM et al.; An efficient lysis method for Agrobacterium cells was developed, which allows a reproducible isolation of the tumor inducing (TI)-plasmid . The lysis method is based on the sensitivity of this bacterium to incubation with lysozyme, n-dodecylamine,EDTA, followed by Sarkosyl, after growth in the presence of carbenicillin . We also present a procedure for the isolation of the TI-plasmid on a large scale, that might be used for the mass isolation of other large plasmids which like the TI-plasmid, can not be cleared with earlier described procedures . The purity of the plasmid preparations was determined with DNA renaturation kinetics, which method has the advantage that the plasmid need not to be in the supercoiled or open circular form. Antonie Van Leeuwenhoek, 1976, 42(1-2), 13 - 24 L-Sorbose metabolism in Agrobacterium tumefaciens; Van Keer C et al.; The pathway of L-sorbose metabolism in Agrobacterium tumefaciens strain B6 was determined to be: L-sorbose leads to D-glucitol (sorbitol) leads to D-fructose leads to D-fructose-6-phosphate leads to D-glucose-6-phosphate . The reduction of L-sorbose and the oxidation of D-glucitol were mediated by NADPH- and NAD+-linked oxidoreductases, respectively . The intermediates, D-glucitol and D-fructose, were isolated from in vitro reaction mixtures by column chromatography on Dowex 1-borate, and identified enzymatically . D-Fructose was identified chemically by its 1H-NMR spectrum and the IR spectrum and the melting point of the fructosazone . D-Glucitol was characterized chemically by the melting point and the IR spectrum of its hexaacetate . A . tumefaciens ICPB TT111, a representative of another genetic race of Agrobacterium, lacked L-sorbose reductase and therefore failed to grow on L-sorbose; it grew normally on D-glucitol. Microbios, 1976, 17(70), 231 - 7 Studies on the bacteriophage PS8 of Agrobacterium tumefaciens (Smith and Townsend) Conn: physico-chemical properties of its DNA; Knopf UC; DNA from the bacteriophage PS8 was extracted and purified . The buoyant density was determined was 1.716 cm3/g . The guanine-cytosine content was calculated to be 57% . DNA molecules which looked like circles were found among linear strands in an electron-microscopic study . With an endonuclease from Streptomyces albus G the DNA was digested to 19 fragments, with molecular weights ranging from 600 to 7,400 daltons . The molecular weight of the DNA was determined to be 38.8 X 10(6) daltons +/- 8.7%. Folia Microbiol (Praha), 1976, 21(5), 371 - 7 Properties of the cured oncogenic strain 37400 of Agrobacterium tumefaciens; Bezdek M et al.; The properties of the 37400 oncogenic strain of Agrobacterium tumefaciens are described . This strain was derived from the VI lysogenic strain originally isolated by Hamilton from a Zinnia elegans tumour . Strain 37400 has a number of properties which render it suitable for quantitative and genetic studies . It is cured of prophages and can serve as a universal sensitive indicator for a number of phages isolated from various lysogenic strains of Agrobacterium tumefaciens . Its good growth properties in synthetic media and at elevated temperatues enable the isolation of auxotrophic mutants and temperature sensitive phage mutants . Preliminary experiments show that strain 37400 will serve as suitable starting material for conjugation experiments under defined conditions. Histochem J, 1976 Jan, 8(1), 87 - 92 Soluble proteins and hydrolases during crown-gall induction in the tomato, Lycopersicon esculentum; Sheikh KM et al.; Soluble proteins isolated from tissues of the tomato Lycopersicon esculentum, after inoculation with Agrobacterium tumefaciens to induce tumours, have been examined by gel electrophoresis and cytochemically . Changes that occur include the suppression of host enzymes, the appearance of bacterial enzymes in the host tissues and the appearance of new enzyme bands in the affected cells . These changes are detectable within 6 hr of infection and prior to evident morphological changes, and may be explained as derepression and repression of host genes, or the expression of released bacterial genes in the host cells. J Bacteriol, 1975 Dec, 124(3), 1220 - 6 On the question of integration of Agrobacterium tumefaciens deoxyribonucleic acid by tomato plants; Hanson RS et al.; Treatment of tomato plants with Agrobacterium tumefaciens causes subsequently administered {3H}thymidine to be preferentially incorporated into a satellite deoxyribonucleic acid (DNA) whose buoyant density is between that of bacterial DNA (rho = 1.718 g/cm3) and plant main band DNA (rho = 1.692 g/cm3) . Satellite DNA upon shearing or sonic treatment releases fragments of higher and lower buoyant density, as reported by earlier investigators . The satellite has no significant base sequence homology with A . tumefaciens DNA, for its rate of reassociation is not accelerated by the addition of high concentrations of the latter . Tomato DNA isolated from shoots or from leaf nuclei accelerates renaturation of labeled satellite DNA . We conclude that the intermediate density labeled DNA is a plant satellite and not the product of covalent joining of bacterial and plant DNA as suggested by earlier investigators. Arch Int Physiol Biochim, 1975 Dec, 83(5), 871 - 7 Particulate cytochrome c in Agrobacterium tumefaciens; Van den Branden C et al.; In Agrobacterium tumefaciens the main part of c-type cytochromes is tightly bound to the bacterial cell envelope structures . Several techniques were attempted to solubilize these cytochromes . The highest yield of cytochromes released is obtained by treatment of particle suspensions with 5% Triton X-100 . Further purification confirms that the proteins are not really solubilized, but still aggregated in small heterogeneous complexes . Chromatography on a CM-cellulose column demonstrates that at least three different c-type cytochromes are present: cyt c-550, cyt c-552 and cyt c-556. J Gen Microbiol, 1975 Nov, 91(1), 177 - 82 An enrichment technique for auxotrophs of Agrobacterium tumefaciens using a combination of carbenicillin and lysozyme; Klapwijk PM et al.; A procedure to enrich for auxotrophic and fermentation mutants of Agrobacterium tumefaciens is described . The method is based on the amplification of the killing power of carbenicillin by the addition of lysozyme . Isolation frequencies of some types of mutants are presented, with and without the application of the proposed procedure . The yield of mutants is usually enhanced a hundredfold per enrichment treatment. Appl Microbiol, 1975 Nov, 30(5), 731 - 7 Carbohydrate catabolism of selected strains in the genus Agrobacterium; Arthur LO et al.; Radiorespirometric and enzyme analyses were used to reveal the glucose-catabolizing mechanisms functioning in single strains of seven presumed Agrobacterium species . The Entner-Doudoroff and pentose cycle pathways functioned in A . radiobacter, A . tumefaciens, A . rubi, and A . rhizogenes . Whereas both catabolic pathways were utilized to an almost equal degree in the A . radiobacter and A . tumefaciens strains, use of the Entner-Doudoroff pathway predominated in the A . rubi and A . rhizogenes strains . A stellulatum catabolized glucose almost solely through the Entner-Doudoroff pathway . In A . pseudotsugae and A . gypsophilae, glucose was metabolized mainly through the Emden-Meyerhof-Parnas pathway; the pentose phosphate pathway was also utilized. Can J Microbiol, 1975 Oct, 21(10), 1647 - 50 Exopolysaccharide depolymerases induced by Rhizobium bacteriophages; Barnet YM et al.; Enzymes induced by two Rhizobium trifolii bacteriophages caused depolymerization of exopolysaccharides from most R . trifolii and R . leguminosarum strains tested, but did not, in general, attack the exopolysaccharides of R . meliloti, the slow-growing rhizobia, or Agrobacterium . Ca2+ and (or) Mg2+ were required for enzyme activity . In all strains tested, depolymerization of exopolysaccharide occurred when there was successful phage infection, but depolymerization also occurred with exopolysaccharides from nonsusceptible strains. Can J Microbiol, 1975 Oct, 21(10), 1622 - 34 Effect on microorganisms of volatile compounds released from germinating seeds; Schenck S et al.; Volatile compounds evolved from germinating seeds of slash pine, bean, cabbage, corn, cucumber, and pea were evaluated for their ability to support growth of microorganisms in liquid mineral salts media lacking a carbon source . Growth of eight bacteria was measured turbidimetrically and of six fungi as dry weight of mycelium . Volatiles caused increased growth of Pseudomonas fluorescens, Bacillus cereus, Erwinia carotovora, Agrobacterium tumefaciens, A . radiobacter, Rhizobium japonicum, Mucor mucedo, Fusarium oxysporum f . conglutinans, Trichoderma viride, and Penicillium vermiculatum but not of Sarcina lutea, Serratia marcescens, Chaetomium globosum, or Schizophyllum commune . Spores of Trichoderma viride showed higher germination in the presence of volatiles . Effects on growth were apparent only during the first 3 or 4 days after planting the seeds . Killed or dried seeds had no effect . The volatiles did not support microbial growth in the absence of nitrogen nor did they supply growth factors . Passing volatiles through KMnO4 or hydrazone reduced growth of the bacteria, indicating that oxidizable organic compounds, primarily aldehydes, were the active components . The volatiles were not absorbed by sterile soil, clay minerals, or water, but they were absorbed by non-steril soil and activated charcoal. J Gen Microbiol, 1975 Oct, 90(2), 191 - 202 Factors influencing the formation and stability of D-glucoside 3-dehydrogenase activity in cultures of Agrobacterium tumefaciens; Kurowski WM et al.; D-glucoside 3-dehydrogenase specific activity in Agrobacterium tumefaciens was maximal towards the end of the exponential growth phase of batch cultures; over 90% of the activity disappeared within the next 15 h . Manganese ions, although essential for growth of the organism, strongly repressed D-glucoside 3-dehydrogenase synthesis in sucrose medium but had little effect when the carbon source was methyl alpha-D-glucoside . D-Glucoside 3-dehydrogenase activity increased linearly with increasing specific growth rate in chemostat cultures limited by carbon, nitrogen, phosphate or manganese when methyl alpha-D-glucoside was the carbon source . High enzyme activity was found with sucrose as carbon source only when the growth medium was manganese-limited . D-Glucoside 3-dehydrogenase activity disappeared from A . tumefaciens incubated in carbon- and nitrogen-free medium or in nitrogen-free medium containing succinate, but on continued incubation the activity returned and was then stable . The recovery of activity could be prevented by chloramphenicol or erythromycin . Bacteria containing the recovered dehydrogenase activity could not convert sucrose to 3-ketosucrose when oxygen acted as the terminal electron acceptor, but produced 3-ketosucrose at the normal rate in the presence of ferricyanide . D-Glucoside 3-dehydrogenase activity disappeared irreversibly from bacteria incubated in nitrogen-free medium containing sucrose . Loss of activity followed first order kinetics in bacteria taken from nitrogen-, phosphate- or manganese-limited chemostat steady states; an accelerating rate of decay occurred in cells grown under carbon-limitation . 8-Hydroxyquinoline, chloramphenicol, erythromycin, 2,4-dinitrophenol and manganese ions could reduce the rate of decay. Hoppe Seylers Z Physiol Chem, 1975 Aug, 356(8), 1251 - 8 Purification and properties of cytochrome c-556 from Agrobacterium tumefaciens B2a; Van den Branden C et al.; Cytochrome c-556 from Agrobacterium mefaciens B2a was isolated in a pure, homoneous state . The best purification procedure volved ammonium sulphate fractionation, delting on Sephadex G-25, column chromatographic fractionation on DEAE- and CM-cellulose, and gel filtration on Sephadex G-75 superfine . Substitution of the CM-cellulose step by isoelectric focusing was successful . The purity of the final preparation is warranted by the purity index value, the electrophoretic patterns in the absence and presence of sodium dodecylsulphate, the sedimentation profile and the N-terminal amino acid analysis (alanine) . The absorption spectrum of reduced cytochrome c-556 has maxima at 318, 419, 526 and 555.5 nm . The molar extinction coefficient for the alpha-band is 20 200M-1cm-1 . The isoelectric point, determined both by preparative and analytical isoelectric focusing, is 5.55 +/- 0.10 . The molecular weight of cytochrome c-556 was determined by gel filtration as 12000 and by dodecylsulphate gel electrophoresis as 11 500. Mol Gen Genet, 1975 Jul 10, 138(4), 345 - 9 Agrocin 84 sensitivity: a plasmid determined property in Agrobacterium tumefaciens; Engler G et al.; It was shown for some oncogenic Agrobacterium tumefaciens strains that agrocin 84 sensitivity is determined by the presence of a large closed circular DNA plasmid, called the Ti-plasmid . Whereas wild-type strain C58 is agrocin 84 sensitive, all Ti-plasmid cured derivatives were found to be fully resistant . Moreover all independently isolated agrocin 84 resistant colonies were stably non-oncogenic and plasmid negative . In a growth experiment carried out at 37 degrees C it was shown that the kinetics of appearance of non-oncogenic cells on the one hand and of agrocin 84 resistant cells on the other were identical . The fact that not all oncogenic, plasmid harbouring, Agrobacterium tumefaciens strains are sensitive to agrocin 84, points to the possibility that the genes determining agrocin 84 sensitivity are not essential for tumor-inducing ability. Biochem J, 1975 Jul, 149(1), 23 - 30 Structure and biosynthesis of the ribosomal ribonucleic acids from the oncogenic bacterium Agrobacterium tumefaciens; Grienenberger JM et al.; The rRNA of the oncogenic bacterium Agrobacterium tumefaciens was extracted by several methods and analysed by polyacrylamide-gel electrophoresis . The large rRNA of this bacterium is degraded in vivo during the maturation of the ribosome . The influence of Mg2+ and denaturation on degradation of 23S RNA was studied . In pulse and chase experiments, we identified two precursors of the rRNA with mol.wts . of 1.04 x 10(6) and 0.70 x 10(6) . From studies of the structure of the large rRNA, we propose that it could have arisen from a gene duplication . This structure is discussed in relation to a recent hypothesis involving such gene duplication as a means of origin of 23S rRNA. Biochem J, 1975 Jul, 149(1), 17 - 22 The ribosomal ribonucleic acid of Agrobacterium tumefaciens; Schuch W et al.; The 23S rRNA of Agrobacterium tumefaciens contains at least two nicks which result in the formation of RNA components with mol.wts . of 0.52 X 10(6) and 0.48 X 10(6) . Thus under the usual conditions of extraction and analysis, no 23S rRNA was recovered from the bacterium . The experiments show that 23S rRNA is synthesized as a continuous chain, in which one or two nicks are formed almost immediately near the ends of the molecule and an additional nick in the middle at a later time. Nucleic Acids Res, 1975 Jul, 2(7), 1153 - 61 Reversed phase chromatography of isoaccepting tRNA's from healthy and crown gall tissues from Nicotiana tabacum; Cornelis P et al.; RPC 5 (Reversed Phase Chromatography) of aminoacyl-tRNA's from healthy and crown gall (induced by Agrobacterium tume-faciens strain B6) tobacco tissues were compared for eleven amino acids . For ten amino acids: alanine, arginine, glutamic acid, glycine, isoleucine, leucine, lysine, methionine, tyrosine, and valine, no qualitative or quantitative differences could be detected between aminoacyl-tRNA's from both sources . Phenylalanyl-tRNA's from crown gall tissues gave two peaks on RPC 5; the minor early eluting species (peak 1) was always absent in elution profiles of phenylalanyl-tRNA's from healthy tissues or from tobacco leaves . After the "Y" base was removed by pH 2.9 treatment, peak 2 of phenylalanine tRNA was shifted to the position of peak 1. J Bacteriol, 1975 Jul, 123(1), 255 - 64 Plasmid required for virulence of Agrobacterium tumefaciens; Watson B et al.; The irreversible loss of crown gall-inducing ability of Agrobacterium tumefaciens strain C-58 during growth at 37 C is shown to be due to loss of a large plasmid (1.2 X 10-8 daltons) . The gene responsible for this high rate of plasmid loss at elevated temperatures seems to be located on the plasmid . In addition, another spontaneous avirulent variant, A . tumefaciens strain IIBNV6 is shown to lack the virulence plasmid which its virulent sibling strain, IIBV7, possesses . Deoxyribonucleic acid reassociation measurements prove that the plasmid is eliminated, not integrated into the chromosome, in both of the avirulent derivatives . Transfer of virulence from donor strain C-58 to avirulent recipient strain A136 results from the transfer of a plasmid, which appears identical to the donor plasmid by deoxyribonucleic acid reassociation measurements . The transfer of virulence in another cross, K27 X A136, was also shown to result from the transfer of a large plasmid . These findings establish unequivocally that the large plasmid determines virulence . Two additional genetic determinants have been located on the virulence plasmid of A . tumefaciens strain C-58: the ability to utilize nopaline and sensitivity to a bacteriocin produced by strain 84 . The latter trait can be exploited for selection of avirulent plasmid-free derivatives of strain C-58 . The trait of nopaline utilization appears to be on the virulence plasmid also in strains IIBV7 and K27. Arch Microbiol, 1975 Jun 22, 104(2), 197 - 9 Growth dynamics of Agrobacterium tumefaciens in chemostat cultures limited by carbon source and mineral nutrients; Kurowski WM et al.; Agrobacterium tumefaciens was grown in a chemostat in a chemically-defined medium which hs alpha-methyl D-glucoside, magnesium, manganese, phosphate or urea as the growth-limiting nutrient . Steady-state biomass concentrations were dependent on the specific growth rate of the organism when alpha-methyl D-glucoside, manganese or phosphate were growth-limiting nutrients . During magnesium-limited growth, large undamped oscillations in biomass concentration occurred . In all chemostat cultures a variant organism was selected which had lost the ability to grow in the medium supplied, bur survived on products of carbon metabolism derived from the wild-type. Biochim Biophys Acta, 1975 May 16, 390(3), 264 - 75 Attempts to detect Agrobacterium tumefaciens and bacteriophage PS8 DNA in crown gall tumors by DNA-DNA-filter hybridization; Farrand SK et al.; A systematic study of the DNA-DNA-filter reaction is presented which measures its ability to detect small amounts of simple DNA (bacterial or bacteriophage) in model mixtures of DNA immobilized on filters . Saturation curves show qualitatively that significant binding occurs when there is 10% Agrobacterium tumefaciens DNA on the filter but not 1% . PS8 bacteriophage DNA is detectable at a level of 0.1% . True saturation is not attained in the bacterial DNA reaction : radioactivity bound represents only 3% of the theoretical saturation value . The bacteriophage DNA reactions attain 15-30% of the expected saturation value . When crown gall tumor DNA filters were tested for the presence of A . tumefaciens or PS8 bacteriophage DNA by saturation reactions, an apparently significant amount of binding was observed compared with usual background levels for heterologous DNA filters . However thermal dissociation profiles revealed that no well-matched duplexes were formed . Normal tobacco callus DNA filters exhibited the same type of binding of labeled DNA to a similar extent (50-100% as much as tumor DNA filters) . Both types of DNA-filters bound Bacillus subtilis and bacteriophage T4 DNA as efficiently as A . tumefaciens and PS8 DNA . The high non-specific background binding of labeled DNA by filters containing DNA isolated from plant tissue culture materials is ascribed to low single strand molecular weight of the filterbound DNA . This study provides no evidence for foreign DNA in crown gall tumors, and raises objections to the interpretation of the data of earlier investigators (Quetier, F., Huguet, T . and Guille, E . (1969) Biochem, Biophys . Res, Commun . 34, 128-133 and Srivastava, B.I.S . (1970) Life Sci . 9, 889-892) who claimed to detect A . tumefaciens DNA in crown gall tumors by DNA-DNA-filter hybridization. J Gen Microbiol, 1975 Apr, 87(2), 333 - 42 Identification and grouping of bacteria by numerical analysis of their electrophoretic protein patterns; Kersters K et al.; Improved methods for the identification and grouping of bacteria by polyacrylamide gel electrophoresis of soluble proteins are described . Electrophoretic protein patterns were obtained in rigorously standardized comditions . The results were much more reproducible than any described previously . Some of the factors affecting reproducibility were; growth conditions, time and speed of centrifugation of extracts, and conditions of gel electrophoresis . Protein patterns were compared by computing correlation coefficients from normalized densitometric tracings and clustering the strains by the unweighted average pair group method . As model systems, both Agrobacterium and Zymomonas were used because of differences in the sharpness of the peaks . The methodwas applied to 42 Agrobacterium strains . The agreement with the results of clustering by either phenotypic tests or DNA:DNA hybridization was excellent . Computerized comparisons of electrophoretic protein patterns can be a fast, easy and powerful tool for classification and identification of bacteria. J Virol,