TitleAbstractYear(sorted ascending)
infection studies with actinomyces scabies. 194621027519
the susceptibility of some potato varieties to common scab (actinomyces scabies thaxt. güssow) in different soils. 194918138376
[effect of calcium carbonate on the activity of actinomyces scabies (thaxt.) güss., a pathogenic factor in ordinary scab in potatoes]. 195114887593
staining streptomyces scabies in lesions of common scab of potato. 195413146404
a study of cross antagonisms among some actinomycetes active against streptomyces scabies and helminthosporium sativum. 195424542890
pathogenicity of tyrosinase-deficient mutants of streptomyces scabies. 195613316599
[contribution to the classification of actinomycetes. xvii. actinomyces scabies (thaxter) waksman]. 195613387629
some observations of the metabolism of streptomyces scabies. 195713472516
apparent cytoplasmic inheritance of tyrosinase competence in streptomyces scabies. 196113708419
tyrosinase inheritance in streptomyces scabies. i. genetic recombination.gregory, kenneth f. (ontario agricultural college, guelph, ontario, canada), and jay c. c. huang. tyrosinase inheritance in streptomyces scabies. i. genetic recombination. j. bacteriol. 87:1281-1286. 1964.-mutants derived from streptomyces scabies strain a26 recombined with other derivatives of a26, but not with nine other strains of s. scabies nor with eight strains of other streptomycetes. most of the spore progeny of heterogenomic mycelia formed from complementary diauxotrophic strains of s. ...196414188703
tyrosinase inheritance in streptomyces scabies. ii. induction of tyrosinase deficiency by acridine dyes.gregory, kenneth f. (ontario agricultural college, guelph, ontario, canada), and jay c. c. huang. tyrosinase inheritance in streptomyces scabies. ii. induction of tyrosinase deficiency by acridine dyes. j. bacteriol. 87:1287-1294. 1964.-growth in minimal medium containing 1 mug of acriflavine per ml resulted in a large increase (up to 62%) in the frequency of tyrosinase-deficient (tye(-)) mutants in all of ten strains of streptomyces scabies and eight unidentified streptomycetes studied. this in ...196414188704
virus enhancement with a growth product of streptomyces scabies. i. production and properties of scaben. 19684971463
virus enhancement with a growth product of streptomyces scabies. ii. increased release of coxsackievirus b5 from hep-2 monolayers treated with scaben. 19685681522
[electron microscopy studies on nuclear structures of non-fixed spores of a streptomyces scabies (thaxter) waksman et henrici strain]. 19715160390
effect of three nematicides on the growth of some phytopathogenic bacteria and fungi.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, wh ...1977143857
effect of some organic phosphorus and carbamate pesticides on streptomyces scabies.of all the organic phosphorus and carbamate pesticides, tested on streptomyces scabies, thimet, chlorothion, dithane m-45, and karathane, were effective at relatively low concentrations (1, 20, 16, and 115 ppm). minimal inhibitory concentrations of these pesticides were the same in vitro as well as in vivo. the other organic phosphorus and carbamate compounds tested were less effective under the laboratory conditions of these tests.1978664939
simultaneous loss of multiple differentiated functions in aerial mycelium-negative isolates of streptomycetes.germination and outgrowth of spores of streptomyces alboniger, streptomyces scabies, and streptomyces violaceus-ruber in the presence of intercalating dyes resulted in a high frequency (2 to 20%) of occurrence of aerial mycelium-negative (amy-) isolates. coincident with the appearance of the amy- trait was the loss of several differentiated functions, including the characteristic pigments and earthy odor of the wild types. all s. alboniger, 27% of s. scabies, and 39% of the s. violaceus-ruber am ...1979422514
purification and characterization of a novel extracellular esterase from pathogenic streptomyces scabies that is inducible by zinc.native polyacrylamide gels of extracellular proteins produced by several streptomyces isolates grown with suberin were assayed in situ for esterase activity. two pathogenic isolates of streptomyces scabies from different geographical regions were found to produce a similar esterase activity that was not produced by nonpathogenic strains. after treatment with edta, suberin no longer induced esterase production. expression was restored when edta-treated suberin was supplemented with zinc. the opti ...19873571156
cloning, sequencing, and regulation of expression of an extracellular esterase gene from the plant pathogen streptomyces scabies.the gene that encodes the extracellular esterase produced by streptomyces scabies has been cloned and sequenced. the gene was identified by hybridization to a synthetic oligonucleotide that corresponds to the amino-terminal amino acid sequence determined for the secreted form of the esterase. nucleotide sequence analysis predicted a 345-amino-acid open reading frame, a putative ribosome-binding site, and 39 amino acids at the amino terminus of the sequence that is not found in the secreted prote ...19902254271
ssbi, an isoschizomer of hindiii isolated from streptomyces scabies. 19911648209
diversity among streptomyces strains causing potato scab.eighty streptomyces isolates, including 35 potato scab-inducing strains and 12 reference strains of streptomyces scabies, were physiologically characterized by a total of 329 miniaturized tests. overall similarities of all strains were determined by numerical taxonomy, with the unweighted average linkage (upgma) algorithm and simple matching (s(sm)) and jaccard (s(j)) coefficients used as measures for similarity. three cluster groups (a to c) were defined at a similarity level of 80.1% (s(sm)); ...199216348823
heterologous expression and secretion of a streptomyces scabies esterase in streptomyces lividans and escherichia coli.the esterase gene from streptomyces scabies fl1 was cloned and expressed in streptomyces lividans on plasmids pij486 and pij702. in s. lividans, the esterase gene was expressed during later stages of growth and was regulated by zinc, as is seen with s. scabies. the 36-kda secreted form of the esterase was purified from s. lividans. n-terminal amino acid sequencing indicated that the processing site utilized in s. lividans for the removal of the signal sequence was the same as that recognized for ...19921556063
crystallization and preliminary crystallographic data of a streptomyces scabies extracellular esterase.x-ray quality single crystals of an extracellular esterase from pathogenic streptomyces scabies were obtained by the hanging drop method. the crystals are monoclinic (space group c2, a = 161.1 a, b = 51.2 a, c = 124.2 a, beta = 100.6 degrees) with two molecules related by a noncrystallographic dyad in the asymmetric unit, with a solvent content of approximately 64%. the diffraction pattern from fresh crystals extends beyond 2 a resolution using sealed tube cuk alpha radiation. the study has been ...19921404370
identification of a protein-binding sequence involved in expression of an esterase gene from streptomyces scabies.expression of an esterase gene from streptomyces scabies is regulated by zinc in both streptomyces scabies and streptomyces lividans. a specific protein-binding site was identified on an esterase promoter fragment by using an s-30 extract from s. scabies. the location of the protein-binding site was determined by gel shift assays of promoter deletion fragments and by dnase i footprinting analysis. the protein-binding site maps from nucleotides -59 to -81 relative to the start of transcription. a ...19921624423
regulation and secretion of an extracellular esterase from streptomyces scabies.production of a heat-stable, extracellular esterase by streptomyces scabies is regulated by zinc ions. the esterase-encoding gene (est) from s. scabies was cloned and expressed in streptomyces lividans. in s. lividans, expression of the est gene is also regulated by zn2+, and the esterase is efficiently secreted in this organism. the sequence of the est gene suggests that a 39-amino acid signal peptide is removed during secretion of this protein. deletion analysis has indicated that the hydropho ...19921612447
dna relatedness among strains of the sweet potato pathogen streptomyces ipomoea (person and martin 1940) waksman and henrici 1948.dna relatedness among 28 putative strains of streptomyces ipomoea from geographically diverse locations and the type strain, nrrl b-12321, was determined spectrophotometrically. the data confirm that these 28 strains are not closely related genetically to the plant-pathogenic species streptomyces scabies (39% dna relatedness) or streptomyces acidiscabies (17% dna relatedness) or any other major blue-spored streptomyces species (less than 30% dna relatedness). of the 29 strains examined, 4 could ...19921610178
detection of micro-organisms in soil after in situ hybridization with rrna-targeted, fluorescently labelled oligonucleotides.rrna sequences were used as targets for synthetic oligonucleotides labelled with the fluorescent dye tetramethylrhodamine isothiocyanate (tritc) for in situ hybridizations to detect micro-organisms directly in soils that have different contents of soil minerals and organic material. introduced pseudomonas aeruginosa cells were directly fixed in soils and applied to slides after separation of large soil minerals only. remaining soil minerals (clay minerals) and organic material (up to 8%) did not ...19921379623
cloning and sequencing of a secy homolog from streptomyces scabies.the complete dna sequence of the streptomyces scabies (ss) secy homolog and partial sequences of adjacent upstream and downstream open reading frames (orfs) have been determined. the nucleotide sequence of a 2-kb region predicts a polypeptide of 437 amino acids in length with homology to the secy protein family. the ss secy homolog lies upstream from a sequence that has homology to the adenylate kinase gene (adk) family. the translational stop codon of the putative secy orf overlaps the predicte ...19957557484
a novel variant of the catalytic triad in the streptomyces scabies esterase.the crystal structure of a novel esterase from streptomyces scabies, a causal agent of the potato scab disease, was solved at 2.1 a resolution. the tertiary fold of the enzyme is substantially different from that of the alpha/beta hydrolase family and unique among all known hydrolases. the active site contains a dyad of ser 14 and his 283, closely resembling two of the three components of typical ser-his-asp(glu) triads from other serine hydrolases. proper orientation of the active site imidazol ...19957773790
biochemical and molecular characterization of the extracellular esterase from streptomyces esterase of streptomyces diastatochromogenes was purified to homogeneity from culture filtrate. the purified enzyme had a molecular mass of 30,862 +/- 5.8 da, as determined by electrospray mass spectrometry. the esterase-encoding gene was cloned on a 5.1-kb mboi fragment from s. diastatochromogenes genomic dna into streptomyces lividans tk23 by using plasmid vector pij702. nucleotide sequence analysis predicted a 978-bp open reading frame, esta, encoding a protein of 326 amino acids, a potent ...19968606158
contribution of cutinase serine 42 side chain to the stabilization of the oxyanion transition state.cutinase from the fungus fusarium solani pisi is a lipolytic enzyme able to hydrolyze both aggregated and soluble substrates. it therefore provides a powerful tool for probing the mechanisms underlying lipid hydrolysis. lipolytic enzymes have a catalytic machinery similar to those present in serine proteinases. it is characterized by the triad ser, his, and asp (glu) residues, by an oxyanion binding site that stabilizes the transition state via hydrogen bonds with two main chain amide groups, an ...19968555209
unusual antimicrobial compounds from aeollanthus buchnerianus.using bioassay guided isolation, three novel 12 carbon polyoxygenated fatty acids and a novel abietane diterpene have been isolated from the chloroform extract of aerial parts of aeollanthus buchnerianus (lamiaceae). rigorous spectroscopic methods were used for compound identification. (z,z)-8zeta-acetoxy-5zeta-hydroxydodeca-2,6-dienoic acid and (z,z)-5zeta, 8zeta-dihydroxydodeca-2,6-dienoic acid inhibited the spore germination of cladosporium cucumerinum (both with minimum inhibitory dose (mid) ...19968608820
mutational analysis of the streptomyces scabies esterase signal peptide.ten site-directed mutations affecting the predicted 39-amino-acid signal peptide of the streptomyces scabies esterase were used to examine start-codon usage and esterase secretion in s. lividans. the first of two in-frame aug codons was preferred for translation initiation. removal of 2 of the 4 positively charged amino acids at the amino terminus of the signal peptide reduced esterase expression more than 100-fold; however, deletion of all 4 charged residues reduced expression by only 2- to 5-f ...19968920191
phylogenetic analysis of streptomyces spp. causing potato scab based on 16s rrna sequences.the complete 16s rrna sequences of 12 strains of streptomyces spp., including potato scab pathogens, were determined. among the strains of streptomyces scabies that were isolated from diverse geographical areas and differed in melanoid pigment production, either no difference or one difference in sequence was observed. the sequence of s. scabies was most similar to the sequences of streptomyces diastatochromogenes, streptomyces bottropensis, and streptomyces neyagawaensis, which belong to the di ...19968934906
cloning and sequencing of the secy homolog from streptomyces lividans 1326.two conserved regions of secy proteins from six gram+ bacteria were exploited in a pcr-based strategy for isolating a secy homolog from streptomyces lividans (sl). the nucleotide sequence of part of a 3.8-kb fragment showed that the secy homolog is flanked, at the 5' end, by the gene encoding ribosomal protein l15 and, at the 3' end, by an adenylate kinase-encoding gene. the deduced gene product of secy would have 437 amino acids (aa) and an m(r) of 47,200. sl secy shows 89.5, 56.1, 42 and 40% i ...19968918265
cloning and expression of a gene from streptomyces scabies encoding a putative pathogenicity factor.we cloned a 9.4-kb dna fragment from streptomyces scabies atcc 41973 that allows the nonpathogen streptomyces lividans 66 tk24 to necrotize and colonize potato tuber slices and produce scab-like symptoms on potato minitubers. deletion analysis demonstrated that activity was conferred by a 1.6-kb dna region. sequence analysis of a 2.4-kb dna fragment spanning the dna region necessary for activity revealed three open reading frames (orfs). the deduced amino acid sequence of orf1, designated orftnp ...19979401037
structure of the haemagglutinin-esterase-fusion glycoprotein of influenza c virus.the spike glycoproteins of the lipid-enveloped orthomyxoviruses and paramyxoviruses have three functions: to recognize the receptor on the cell surface, to mediate viral fusion with the cell membrane, and to destroy the receptor. in influenza c virus, a single glycoprotein, the haemagglutinin-esterase-fusion (hef) protein, possesses all three functions. in influenza a and b, the first two activities are mediated by haemagglutinin and the third by a second glycoprotein, neuraminidase. here we rep ...19989817207
selection and characterization of microorganisms utilizing thaxtomin a, a phytotoxin produced by streptomyces scabiesthaxtomin a is the main phytotoxin produced by streptomyces scabies, a causal agent of potato scab. thaxtomin a is a yellow compound composed of 4-nitroindol-3-yl-containing 2,5-dioxopiperazine. a collection of nonpathogenic streptomycetes isolated from potato tubers and microorganisms recovered from a thaxtomin a solution were examined for the ability to grow in the presence of thaxtomin a as a sole carbon or nitrogen source. three bacterial isolates and two fungal isolates grew in thaxtomin a- ...19989797282
pathogenicity of streptomyces scabies mutants altered in thaxtomin a production.abstract to investigate the role of thaxtomin a in the pathogenicity of streptomyces scabies, mutants altered in thaxtomin a production were obtained by n-methyl-n'-nitro-n-nitrosoguanidine mutagenesis. mutants of s. scabies ef-35 could be differentiated according to levels of thaxtomin production. mutants m1, m8, and m19 produced 2 to 20 times less thaxtomin a in oat bran medium than did ef-35. m1 and m19 were deficient in tryptophan catabolism. thaxtomin production was reduced by about 300 tim ...199818944924
characterization of an insertion sequence element associated with genetically diverse plant pathogenic streptomyces spp.streptomycetes are common soil inhabitants, yet few described species are plant pathogens. while the pathogenicity mechanisms remain unclear, previous work identified a gene, nec1, which encodes a putative pathogenicity or virulence factor. nec1 and a neighboring transposase pseudogene, orftnp, are conserved among unrelated plant pathogens and absent from nonpathogens. the atypical gc content of nec1 suggests that it was acquired through horizontal transfer events. our investigation of the genet ...199910049389
dna relatedness among strains of streptomyces pathogenic to potato in france: description of three new species, s. europaeiscabiei sp. nov. and s. stelliscabiei sp. nov. associated with common scab, and s. reticuliscabiei sp. nov. associated with netted scab.the genomic relatedness was evaluated by dna-dna hybridization for 23 strains (21 were pathogenic and two were saprophytic strains) isolated from lesions of common and netted scab in france and 19 strains from other countries, including type strains of streptomyces species. three genomospecies were defined within the conventional species of streptomyces scabies, and these genomospecies were different from other pathogenic described species (streptomyces acidiscabies, streptomyces caviscabies) ba ...200010826791
analysis of alkali-lignin in a paper mill effluent decolourised with two streptomyces strains by gas chromatography-mass spectrometry after cupric oxide degradation.alkali-lignin samples obtained from an untreated paper mill effluent and from the effluent decolourised by the strains streptomyces avermitilis cect 3339 and streptomyces scabies uah 51 were analysed by gas chromatography-mass spectrometry (gc-ms) after cupric oxide degradation. the analysis of the depolymerisation products of the alkali-lignin from the decolourised effluents showed a strain specific modification of the aromatic moiety of the alkali-lignin. moreover, both strains were able to br ...200111442046
taxonomic study on nonpathogenic streptomycetes isolated from common scab lesions on potato tubers.numerical analysis was carried out to compare sixteen nonpathogenic actinomycetes isolated from common scab lesions on potato tubers with streptomyces scabiei type strain as well as with other streptomycete groups. these isolates were divided into two classes according to their level of similarity with s. scabiei. isolates resembling s. scabiei were associated with s. griseoruber or with s. violaceusniger while isolates exhibiting less than 61% of similarity with s. scabiei were phenotypically r ...200111822683
herbicidal properties of the thaxtomin group of phytotoxins.the thaxtomins are a group of phytotoxins generated by the bacterium streptomyces scabies (the main causal organism of potato common scab). available members of the group were assessed for herbicidal activity by a variety of standard tests. test results indicated that thaxtomin a, the predominant member, was also the most physiologically active. injury symptoms in most instances were similar to those caused by known cellulose biosynthetic inhibitors such as dichlobenil and isoxaben. although tes ...200111368592
isolation and characterization of two types of actinophage infecting streptomyces scabies.two types of actinophages, phi s and phi l, were isolated from soil samples by using streptomyces scabies, a potato scab pathogen, as indicator strain. the phages were partially characterized according to their physicochemical properties, plaques and particles morphology, and their host range; this varied from narrow (for phi s) to wide (for phi l). the adsorption rate constants of the phi s and phi l were 3.44 and 3.18 pl/min, and their burst sizes were 1.61 and 3.75 virions per ml, respectivel ...200111898342
competition and antibiosis in the biological control of potato scab.nonpathogenic, antibiotic-producing streptomycetes have been shown to reduce potato scab when added to disease-conducive soil. spontaneous mutants of the pathogenic streptomyces scabies rb4 that are resistant to at least one antibiotic activity produced by the nonpathogenic suppressive isolates streptomyces diastatochromogenes strain ponssii and s. scabies ponr have been isolated. to determine the importance of antibiosis in this biocontrol system, these mutants were investigated for their abili ...200111358173
isolation and characterization of two types of actinophages infecting streptomyces scabies mr13.two types of actinophages, phi s and phi l, were isolated from soil samples by using streptomyces scabies mr13, a potato scab pathogen, as an indicator strain. the phages were partially characterized according to their physicochemical properties, plaques and particles morphology and their host-range. the host-range of these phages was narrow for phi s and wide for phi l. the adsorption rate constants of the phi s and phi l were 3.44 x 10(-9) and 3.18 x 10(-9) ml/min, and their burst sizes were 1 ...200212512256
effect of amino acids on thaxtomin a biosynthesis by streptomyces scabies.the regulatory effect of amino acids on the production of thaxtomin a, a phytotoxin produced by streptomyces scabies, was investigated. tryptophan had an important inhibitory effect on the toxin biosynthesis in all five strains of s. scabies tested. two other aromatic amino acids (tyrosine and phenylalanine) also inhibited thaxtomin a biosynthesis, while aliphatic amino acids did not cause an important decline in thaxtomin a production. methylation of tryptophan prevented or reduced the inhibito ...200212030709
cultivation-independent population analysis of bacterial endophytes in three potato varieties based on eubacterial and actinomycetes-specific pcr of 16s rrna genes.abstract endophytic bacteria are ubiquitous in most plants and colonise plants without exhibiting pathogenicity. studies on the diversity of bacterial endophytes have been mainly approached by characterisation of isolates obtained from internal tissues. despite the broad application of culture-independent techniques for the analysis of microbial communities in a wide range of natural habitats, little information is available on the species diversity of endophytes. in this study, microbial commun ...200219709181
antagonistic properties of two recombinant strains of streptomyces melanosporofaciens obtained by intraspecific protoplast fusion.intraspecific protoplast fusion was used to produce stable prototrophic recombinants of streptomyces melanosporofaciens ef-76, a biocontrol agent of plant disease producing geldanamycin. two recombinant strains (fp-54 and fp-60) that differed with regard to their antagonistic properties against bacillus cereus atcc 14579, streptomyces scabies ef-35 and phytophthora fragariae var. rubi 390 were characterized. fp-60 lost the ability to inhibit the in vitro growth of these microbial strains while f ...200312883869
an arabidopsis mutant resistant to thaxtomin a, a cellulose synthesis inhibitor from streptomyces species.thaxtomin a is a phytotoxin produced by streptomyces scabies and other streptomyces species, the causative agents of common scab disease in potato and other taproot crops. at nanomolar concentrations, thaxtomin causes dramatic cell swelling, reduced seedling growth, and inhibition of cellulose synthesis in arabidopsis. we identified a mutant of arabidopsis, designated txr1, that exhibits increased resistance to thaxtomin as a result of a decrease in the rate of toxin uptake. the txr1 gene was id ...200312897252
phylogenetic analysis of streptomyces spp. isolated from potato scab lesions in korea on the basis of 16s rrna gene and 16s-23s rdna internally transcribed spacer sequences.the 16s rrna gene sequences for 34 strains, including 11 isolates, were determined to classify scab-causing streptomyces spp. and relatives isolated from potato scab lesions collected in jeju, korea. the 16s-23s rdna internally transcribed spacer (its) sequences were determined to investigate whether the 16s-23s its region is useful for analysing intra- and interspecific relationships in these bacteria. on the basis of phylogenetic analysis of 16s rrna gene sequences, most of the isolates were c ...200414742481
endophytic bacterial communities of field-grown potato plants and their plant-growth-promoting and antagonistic study the effect of plant growth on potato-associated bacteria, the composition and properties of bacteria colonizing the endosphere of field-grown potato were analyzed by a multiphasic approach. the occurrence and diversity of potato-associated bacteria were monitored by a cultivation-independent approach, using terminal restriction fragment length polymorphism analysis of 16s rdna. the patterns obtained revealed a high heterogeneity of community composition and suggested the existence of pl ...200415213748
biotransformation of the streptomyces scabies phytotoxin thaxtomin a by the fungus aspergillus niger.of several hundred microorganisms randomly selected from the environment, only a fungal isolate identified as aspergillus niger van tiegham var. niger was found to transform the phytotoxin thaxtomin a to much less toxic metabolites. the rate and extent of transformation of thaxtomin a was tested under a variety of conditions, including different growth media, biomass concentrations, incubation periods, and shaker speeds. under optimum conditions the fungus converted thaxtomin a into two major an ...200415052314
characterization of streptomyces scabies mutants deficient in melanin biosynthesis.streptomyces scabies, a causal agent of common scab, produces both melanin and a secondary metabolite called thaxtomin a. to establish a possible relation between melanin and thaxtomin a production in s. scabies, we carried out n-methyl-n'-nitro-n-nitrosoguanidine (ntg) mutagenesis and isolated 11 melanin-negative mutants of s. scabies ef-35. these mutants were characterized for thaxtomin a production, pathogenicity, sporulation, and stress resistance. nine of these mutants showed a significant ...200415644924
isolation and characterisation of antibiotic producing microorganisms in composted nigerian soil.compost samples obtained from different locations within the premises of the university of lagos were analysed to determine the presence and types of antibiotic-producing bacteria, fungi and actinomycetes using nutrient agar, potato dextrose agar and starch casein nitrate agar respectively as culture media. a variety of bacteria were isolated and these included staphylococcus aureus, b. subtilis, b. pumilis, b. lactesporus, b. megaterium, b. pulvifaciens, b. licheniformis, streptococus spp., cor ...200415847340
biological control agent of common scab disease by antagonistic strain bacillus sp. identify an antagonistic strain against streptomyces scabiei and to characterize the antibiotic agent. the efficacy of the isolated strain in controlling common scab disease was also evaluated.200515960681
rare trisubstituted sesquiterpenes daucanes from the wild daucus carota.phytochemical and biological investigation of the roots of the wild daucus carota ssp. carota afforded three new and four known compounds, including four sesquiterpenes daucane esters (1-3 [new], and 4), one polyacetylene (5), one sesquiterpene coumarin (6), and sitosterol glucoside. the structures of the new compounds were determined by comprehensive nmr studies, including dept, cosy, noesy, hmqc and hmbc analyses. based on an agar diffusion assay, 1, 2 and 4-6 were screened and found to contai ...200515964039
a large, mobile pathogenicity island confers plant pathogenicity on streptomyces species.potato scab is a globally important disease caused by polyphyletic plant pathogenic streptomyces species. streptomyces acidiscabies, streptomyces scabies and streptomyces turgidiscabies possess a conserved biosynthetic pathway for the nitrated dipeptide phytotoxin thaxtomin. these pathogens also possess the nec1 gene which encodes a necrogenic protein that is an independent virulence factor. in this article we describe a large (325-660 kb) pathogenicity island (pai) conserved among these three p ...200515686551
variation in antibiosis ability, against potato pathogens, of bacterial communities recovered from the endo- and exoroots of potato crops produced under conventional versus minimum tillage systems.the culturable component of bacterial communities found in the endoroot and associated exoroot (root zone soil) was examined in potatoes (solanum tuberosum l.) grown under either conventional or minimum tillage systems. bacterial species--abundance relationships were determined and in vitro antibiosis ability investigated to discover whether tillage practice or bacteria source (endo- or exoroot) influenced bacterial community structure and functional versatility. antibiosis abilities against phy ...200516234863
thaxtomin a induces programmed cell death in arabidopsis thaliana suspension-cultured cells.thaxtomin a is the main phytotoxin produced by streptomyces scabiei, the causative agent of common scab disease of potato. pathogenicity of s. scabiei is dependent on the production of thaxtomin a which is required for the development of disease symptoms, such as growth inhibition and cell death. we investigated whether thaxtomin a-induced cell death was similar to the hypersensitive cell death that often occurs in response to specific pathogens or phytotoxins during the so-called hypersensitive ...200516025344
streptomyces turgidiscabies and streptomyces reticuliscabiei: one genomic species, two pathogenic groups.three strains of streptomyces reticuliscabiei and two strains of streptomyces turgidiscabies were analysed, together with reference and type strains of other streptomyces species, for phenotypic traits, dna-dna relatedness, comparison of 16s rrna gene sequences and presence of necrotic protein gene (nec1) homologues in order to clarify their phylogenetic relationships. a numerical analysis of phenotypic characteristics showed that s. reticuliscabiei and s. turgidiscabies belong to the same clust ...200617158976
evolution of plant pathogenicity in streptomyces.among the multitude of soil-inhabiting, saprophytic streptomyces species are a growing number of plant pathogens that cause economically important diseases, including potato scab. streptomyces scabies is the dominant pathogenic species worldwide, but is only one of many that cause very similar disease symptoms on plants. molecular genetic analysis is beginning to identify the mechanisms used by plant pathogenic species to manipulate their hosts. the nitrated dipeptide phytotoxin, thaxtomin, inhi ...200616719719
effect of acidic electrolyzed water on the viability of bacterial and fungal plant pathogens and on bacterial spot disease of tomato.acidic electrolyzed water (aew), known to have germicidal activity, was obtained after electrolysis of 0.045% aqueous solution of sodium chloride. freshly prepared aew (ph 2.3-2.6, oxidation-reduction potential 1007-1025 mv, and free active chlorine concentration 27-35 ppm) was tested in vitro and (or) on tomato foliage and seed surfaces for its effects on the viability of plant pathogen propagules that could be potential seed contaminants. foliar sprays of aew were tested against bacterial spot ...200617110959
edaphic soil levels of mineral nutrients, ph, organic matter, and cationic exchange capacity in the geocaulosphere associated with potato common scab.abstract in order to determine possible relationships between geocaulosphere soil properties and severity of common scab of potato caused by streptomyces scabies, soils were collected from representative commercial potato fields in canada: in simcoe and dufferin counties, ontario and across prince edward island (pei) in august 2004. soils immediately adjacent to tubers were sampled and analyzed for select edaphic factors and for pathogen presence using polymerase chain reaction (pcr) tests with ...200718944172
a novel teichoic acid from the cell wall of streptomyces sp. vkm ac-2275.the cell wall of a pathogenic strain streptomyces sp. vkm ac-2275 isolated from potato tubers infected by scab contains a teichoic acid related to poly(glycosylpolyol phosphate) with a repeating unit established by chemical and nmr spectroscopic methods. about 60% of l-rhamnose residues bear an o-acetyl group at o-2 and 20% of the internal glucose residues contain an additional phosphate at c-4. the polymer is built of 5-6 units. this structure is found in bacteria for the first time. the strain ...200716949058
recommendation for the conservation of the name streptomyces scabies. request for an opinion.the primary streptomycete inciting common scab of potato was first legitimately described by thaxter in 1892 as 'oospora scabies', preserving the spelling of an epithet in use since 1846. the name streptomyces scabies, dating to 1948, was revived in 1989, but changed to streptomyces scabiei in 1997 to follow grammatical convention. considering the long-established use and general recognition of 'scabies', it is proposed that the original epithet be conserved.200717911322
detection of the nec1 virulence gene and its correlation with pathogenicity in streptomyces species on potato tubers and in soil using conventional and real-time evaluate the virulence gene nec1 as a reliable marker for the detection of pathogenic streptomyces species on potato tubers and in soil samples using conventional and real-time quantitative pcr assays.200717381752
the arac/xyls regulator txtr modulates thaxtomin biosynthesis and virulence in streptomyces scabies.streptomyces scabies is the best studied of those streptomycetes that cause an economically important disease known as potato scab. the phytotoxin thaxtomin is made exclusively by these pathogens and is required for virulence. here we describe regulation of thaxtomin biosynthesis by txtr, a member of the arac/xyls family of transcriptional regulators. the txtr gene is imbedded in the thaxtomin biosynthetic pathway and is located on a conserved pathogenicity island in s. scabies, s. turgidiscabie ...200717919290
disruption of sscr encoding a gamma-butyrolactone autoregulator receptor in streptomyces scabies nbrc 12914 affects production of secondary metabolites.we report the cloning and sequence analysis of a gamma-butyrolactone autoregulator regulatory island that includes an sscr gene encoding the gamma-butyrolactone autoregulator receptor from streptomyces scabies nbrc 12914, a plant pathogenic strain. gamma-butyrolactone autoregulators trigger secondary metabolism, and sometimes morphological differentiation in the gram-positive genus streptomyces through binding to a specific autoregulator receptor. this gene cluster showed close similarity to oth ...200818500630
streptomyces deccanensis sp. nov., an alkaliphilic species isolated from soil.a novel actinomycete strain, das-139t, was isolated from a soil sample collected from gulbarga, karnataka province, india. the isolate was characterized by white to grey aerial mycelium. long spore chains were found on the aerial mycelium and the aerial mycelium was composed of non-motile spores with hairy surfaces. the cell wall of strain das-139t contained ll-diaminopimelic acid isomer as the diagnostic diaminoacid indicating that the cell wall was of chemotype-i. the predominant menaquinones ...200818450694
identification and functional analysis of genes controlling biosynthesis of identify the genes for biosynthesis of the off-flavor terpenoid alcohol, 2-methylisoborneol (2-mib), the key genes encoding monoterpene cyclase were located in bacterial genome databases by using a combination of hidden markov models, protein-family search, and the sequence alignment of their gene products. predicted terpene cyclases were classified into three groups: sesquiterpene, diterpene, and other terpene cyclases. genes of the terpene cyclase group that form an operon with a gene encod ...200818492804
assessment of common scab-inducing pathogen effects on potato underground organs via computed tomography scanning.common scab caused by streptomyces scabies is a major bacterial disease of potato (solanum tuberosum). its best known symptom is superficial lesions on the surface of progeny potato tubers, observed at harvesting. in this study, effects of s. scabies on space occupancy by underground organs and on structural complexity of root systems are investigated during growth via computed tomography (ct) scanning. two groups of potato plants were grown in a greenhouse in middle-sized plastic pots. using a ...200818943458
thaxtomin biosynthesis: the path to plant pathogenicity in the genus streptomyces.streptomyces species are best known for their ability to produce a wide array of medically and agriculturally important secondary metabolites. however, there is a growing number of species which, like streptomyces scabies, can function as plant pathogens and cause scab disease on economically important crops such as potato. all of these species produce the phytotoxin thaxtomin, a nitrated dipeptide which inhibits cellulose synthesis in expanding plant tissue. the biosynthesis of thaxtomin involv ...200818392685
synthesis and uptake of the compatible solutes ectoine and 5-hydroxyectoine by streptomyces coelicolor a3(2) in response to salt and heat stresses.streptomyces coelicolor a3(2) synthesizes ectoine and 5-hydroxyectoine upon the imposition of either salt (0.5 m nacl) or heat stress (39 degrees c). the cells produced the highest cellular levels of these compatible solutes when both stress conditions were simultaneously imposed. protection against either severe salt (1.2 m nacl) or heat stress (39 degrees c) or a combination of both environmental cues could be accomplished by adding low concentrations (1 mm) of either ectoine or 5-hydroxyectoi ...200818849444
yest: a new rhamnogalacturonan acetyl esterase from bacillus subtilis.yest, a putative protein from bacillus subtilis atcc 6633 that has been provisionally classified as a rhamnogalacturonan acetyl esterase (rgae) in ce-12 family, was cloned, expressed in escherichiacoli rosetta (de3), and purified. the enzyme is monomeric with a molecular mass of 37 kda and presents thermophilic properties similar to rgae from aspergillus aculeatus, although yest is more alkaliphilic. the study of inhibitors confirmed the importance of the his and the nucleophilic ser for the est ...200817957779
antimycin a-producing nonphytopathogenic streptomyces turgidiscabies from detect if substances with mammalian cell toxicity are produced by streptomyces turgidiscabies and streptomyces scabiei isolated from potato scab lesions.200818070040
distinguishing bacterial pathogens of potato using a genome-wide microarray approach.a set of 9676 probes was designed for the most harmful bacterial pathogens of potato and tested in a microarray format. gene-specific probes could be designed for all genes of pectobacterium atrosepticum, c. 50% of the genes of streptomyces scabies and c. 30% of the genes of clavibacter michiganensis ssp. sepedonicus utilizing the whole-genome sequence information available. for streptomyces turgidiscabies, 226 probes were designed according to the sequences of a pathogenicity island containing ...200819018999
streptomyces scabies 87-22 possesses a functional tomatinase.the actinomycete streptomyces scabies 87-22 is the causal agent of common scab, an economically important disease of potato and taproot crops. sequencing of the s. scabies 87-22 genome revealed the presence of a gene with high homology to the gene encoding the alpha-tomatine-detoxifying enzyme tomatinase found in fungal tomato pathogens. the toma gene from s. scabies 87-22 was cotranscribed with a putative family 1 glycosyl hydrolase gene, and purified toma protein was active only on alpha-tomat ...200818835993
effect of potato suberin on streptomyces scabies proteome.two-dimensional (2d) page was used to detect proteins induced in streptomyces scabies by potato suberin, a lipidic plant polymer. nineteen up-regulated proteins were excised from 2d gels and analysed by n-terminal sequencing or tandem mass spectrometry (ms/ms). four of the up-regulated proteins could be linked to the bacterial response to stress (aldh, groes, terd and lexa). specific metabolic pathways seemed to be activated in the presence of suberin, as shown by the increased expression of spe ...200819019004
genetic diversity of streptomyces spp. causing common scab of potato in eastern canada.common scab is an important disease of potato caused by streptomyces scabies and other closely related species. in this study, the genetic diversity of streptomyces spp. causing common scab of potato in eastern canada was for the first time investigated. forty-one streptomyces spp. isolates were retrieved from necrotic lesions of potato tubers harvested from different regions of the canadian provinces new-brunswick, nova scotia and prince-edward-island. most isolates were closely related to know ...200818947953
an early ca2+ influx is a prerequisite to thaxtomin a-induced cell death in arabidopsis thaliana cells.the pathogenicity of various streptomyces scabies isolates involved in potato scab disease was correlated with the production of thaxtomin a. since calcium is known as an essential second messenger associated with pathogen-induced plant responses and cell death, it was investigated whether thaxtomin a could induce a ca2+ influx related to cell death and to other putative plant responses using arabidopsis thaliana suspension cells, which is a convenient model to study plant-microbe interactions. ...200819015217
development of a genotyping method for potato scab pathogens based on multiplex pcr.scab disease significantly damages potato and other root crops. streptomyces scabiei, s. acidiscabiei, and s. turgidiscabiei are the best-known causal agents of this disease. we have developed a novel genotyping method for these potato scab pathogens using multiplex pcr, whose benefits include rapid and easy detection of multiple species. we designed a species-specific primer set (6 primers, 3 pairs) for the 16s rrna genes and 16s-23s its regions of these potato scab pathogens. the specificity o ...200818776692
against conservation of specific epithets formed wrongly as nominative nouns in apposition.together with 31 other incorrectly formed (i.e. as nominative nouns in apposition) specific epithets, the epithet of streptomyces scabies was corrected to streptomyces scabiei in taxonomic notes published in 1997 and 1998. a subsequent request for an opinion, published in 2001, to reinstate the incorrect epithets for ten of these species was denied by the judicial commission in 2002. in 2007, a further request for an opinion was submitted to the judicial commission which proposed the conservatio ...200818523205
genetic and physiological determinants of streptomyces scabies pathogenicity.summary common scab is a severe disease worldwide affecting tap root crops and potato tubers. it is caused by soil-borne filamentous bacteria belonging to the genus streptomyces. streptomycetes usually are saprophytic microorganisms, but a few species have acquired the ability to infect underground plant tissues. the predominant causal agent of potato scab worldwide is streptomyces scabies. the production of phytotoxins called thaxtomins is essential for the virulence of common scab-causing agen ...200919694949
streptomyces scabiei and its toxin thaxtomin a induce scopoletin biosynthesis in tobacco and arabidopsis thaliana.streptomyces scabiei is the predominant causal agent of common scab of potato in north america. the virulence of common scab-causing streptomycetes relies on their capacity to synthesize thaxtomins. in this study, the effects of s. scabiei infection and of thaxtomin a, the main toxin produced by s. scabiei, were tested for the elicitation of plant defense molecules in the model plants tobacco (nicotiana tabacum) and arabidopsis thaliana. tobacco leaves infected with spores of s. scabiei strain e ...200919859716
hopanoids are not essential for growth of streptomyces scabies 87-22.hopanoids are triterpenoic, pentacyclic compounds that are structurally similar to sterols, which are required for normal cell function in eukaryotes. hopanoids are thought to be an important component of bacterial cell membranes because they control membrane fluidity and diminish passive diffusion of ions, and a few taxons modulate their hopanoid content in response to environmental stimuli. however, to our knowledge, mutational studies to assess the importance of hopanoids in bacterial physiol ...200919502399
two different signaling pathways for thaxtomin a-induced cell death in arabidopsis and tobacco by2.thaxtomin a (txt) is a phytotoxin produced by all plant-pathogenic streptomyces scabies involved in the potato scab disease. their pathogenicity was previously correlated with the production of txt. calcium is known to be an essential second messenger associated with pathogen-induced plant responses and cell death. we have effectively shown that in arabidopsis thaliana cell suspensions, txt induces an early short lived ca(2+) influx which is involved in the cell death process and other txt-induc ...200919649193
streptomyces scabies 87-22 contains a coronafacic acid-like biosynthetic cluster that contributes to plant-microbe interactions.plant-pathogenic streptomyces spp. cause scab disease on economically important root and tuber crops, the most important of which is potato. key virulence determinants produced by these species include the cellulose synthesis inhibitor, thaxtomin a, and the secreted nec1 protein that is required for colonization of the plant host. recently, the genome sequence of streptomyces scabies 87-22 was completed, and a biosynthetic cluster was identified that is predicted to synthesize a novel compound s ...201020064060
biodegradation of 5-nitroanthranilic acid by bradyrhizobium sp. strain js329.biodegradation of synthetic compounds has been studied extensively, but the metabolic diversity required for catabolism of many natural compounds has not been addressed. 5-nitroanthranilic acid (5naa), produced in soil by streptomyces scabies, is also the starting material for synthetic dyes and other nitroaromatic compounds. bradyrhizobium js329 was isolated from soil by selective enrichment with 5naa. when grown on 5naa, the isolate released stoichiometric amounts of nitrite and half of the st ...201020081004
the ability of pseudomonas sp. lbum 223 to produce phenazine-1-carboxylic acid affects the growth of streptomyces scabies, the expression of thaxtomin biosynthesis genes and the biological control potential against common scab of potato.streptomyces scabies causes common scab, an economical disease affecting potato crops world-wide, for which no effective control measure exists. this pathogen produces the plant toxin thaxtomin a, which is involved in symptom development on potato tubers. a biological control approach that can limit s. scabies growth and repress thaxtomin production represents an attractive alternative to classical control strategies. pseudomonas sp. lbum 223 produces phenazine-1-carboxylic acid (pca), an antibi ...201021073487
involvement of the plant polymer suberin and the disaccharide cellobiose in triggering thaxtomin a biosynthesis, a phytotoxin produced by the pathogenic agent streptomyces scabies.streptomyces scabies is a gram-positive soil bacterium recognized as the main causal agent of common scab. pathogenicity in streptomyces spp. depends on their capacity to synthesize phytotoxins called thaxtomins. genes involved in biosynthesis of these secondary metabolites are known to be induced by cellobiose, a plant disaccharide. however, growth of s. scabies in a minimal medium containing cellobiose as a carbon source is very poor and only generates traces of thaxtomins. the effect of suber ...201019968554
rapid and specific method for evaluating streptomyces competitive dynamics in complex soil communities.quantifying target microbial populations in complex communities remains a barrier to studying species interactions in soil environments. quantitative pcr (qpcr) assays were developed for quantifying pathogenic streptomyces scabiei and antibiotic-producing streptomyces lavendulae strains in complex soil communities. this assay will be useful for evaluating the competitive dynamics of streptomycetes in soil.201020080993
the twin arginine protein transport pathway exports multiple virulence proteins in the plant pathogen streptomyces scabies.summary streptomyces scabies is one of a group of organisms that causes the economically important disease potato scab. analysis of the s. scabies genome sequence indicates that it is likely to secrete many proteins via the twin arginine protein transport (tat) pathway, including several proteins whose coding sequences may have been acquired through horizontal gene transfer and share a common ancestor with proteins in other plant pathogens. inactivation of the s. scabies tat pathway resulted in ...201020487278
streptomyces turgidiscabies car8 contains a modular pathogenicity island that shares virulence genes with other actinobacterial plant pathogens.streptomyces turgidiscabies car8 is an actinobacterium that causes the economically important disease potato scab. pathogenesis in this species is associated with a mobile pathogenicity island (paist) that site specifically inserts into the baca gene in streptomyces spp. here we provide the 674,223 bp sequence of paist, which consists of two non-overlapping modules of 105,364 and 568,859 bp. these modules are delimited by three copies of an 8 bp palindromic sequence (ttcatgaa), that also is the ...201021087627
what does it take to be a plant pathogen: genomic insights from streptomyces species.plant pathogenicity is rare in the genus streptomyces, with only a dozen or so species possessing this trait out of the more than 900 species described. nevertheless, such species have had a significant impact on agricultural economies throughout the world due to their ability to cause important crop diseases such as potato common scab, which is characterized by lesions that form on the potato tuber surface. all pathogenic species that cause common scab produce a family of phytotoxins called the ...201020396949
isolation and characterization of antagonistic fungi against potato scab pathogens from potato field soils.potato scab is a serious plant disease caused by several streptomyces sp., and effective control methods remain unavailable. although antagonistic bacteria and phages against potato scab pathogens have been reported, to the best of our knowledge, there is no information about fungi that are antagonistic to the pathogens. the aim of this study was to isolate fungal antagonists, characterize their phylogenetic positions, determine their antagonistic activities against potato scab pathogens, and hi ...201020653777
multilocus sequence analysis of phytopathogenic streptomyces species.the identification and classification of species within the genus streptomyces is difficult because there are presently 576 species with validly published names and this number increases every year. the value of the application of multilocus sequence analysis scheme to the systematics of streptomyces species has been well demonstrated in several recently published papers. in this study the sequence fragments of 4 housekeeping genes, atpd, reca, rpob, and trpb, were determined for the type strain ...201021112986
habituation to thaxtomin a in hybrid poplar cell suspensions provides enhanced and durable resistance to inhibitors of cellulose synthesis.thaxtomin a (ta), a phytotoxin produced by the phytopathogen streptomyces scabies, is essential for the development of potato common scab disease. ta inhibits cellulose synthesis but its actual mode of action is unknown. addition of ta to hybrid poplar (populus trichocarpa x populus deltoides) cell suspensions can activate a cellular program leading to cell death. in contrast, it is possible to habituate hybrid poplar cell cultures to grow in the presence of ta levels that would normally induce ...201021143977
tryptophan regulates thaxtomin a and indole-3-acetic acid production in streptomyces scabiei and modifies its interactions with radish seedlings.the virulence of streptomyces scabiei, the causal agent of common scab, depends mainly on the production of the toxin thaxtomin a. s. scabiei also produces indole-3-acetic acid (iaa), but the role of this hormone in the interaction between pathogenic streptomycetes and plants has not yet been elucidated. tryptophan is a biosynthetic precursor of both iaa and thaxtomin a. in this study, the effect of tryptophan on thaxtomin a and iaa production as well as its effect on the transcription of the co ...201121521002
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