Showing papers by "Leibniz Association published in 1993"

Promoter specificity and deletion analysis of three heat stress transcription factors of tomato.

Abstract: Transient expression assays in transformed tobacco (Nicotiana plumbaginifolia) mesophyll protoplasts were used to test the activity of three tomato heat stress transcription factors, HSF24, HSF8 and HSF30, in a trans-activation and a trans-repression assay. The results document differences between the three HSFs with respect to their response to the configuration of heat stress promoter elements (HSEs) in the reporter construct (promoter specificity) and to the stress regime used for activation. Analysis of C-terminal deletions identified acidic sequence elements with a central tryptophan residue, which are important for HSF activity control. Surprisingly, heterologous HSFs from Drosophila and human cells, but not from yeast, were also functional as heat stress-induced transcription factors in this tobacco protoplast system.

A methyl jasmonate-induced shift in the length of the 5' untranslated region impairs translation of the plastid rbcL transcript in barley.

Abstract: The plant growth substance (-)-jasmonic acid methyl ester (methyl jasmonate, JaMe) affects plastid gene expression at the protein and mRNA levels when applied exogenously to detached leaf segments of Hordeum vulgare L. cv. Salome. Translation of the large subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase (LSU, rbcL gene products) and of the 65 and 68 kDa proteins of photosystem I (psaA and psaB gene products, respectively) ceased, whereas synthesis of the 32 kDa photosystem II protein (D1, psbA gene product) continued in JaMe-treated leaf tissues. These changes were not caused by corresponding alterations in transcript abundances. The loss of LSU protein synthesis, occurring within 24 h of JaMe treatment, correlated with a decline in the in vitro-translatable rbcL mRNA, but contrasted with an almost constant transcript level. The 5' ends of the rbcL transcripts shifted from '-59' in freshly harvested or water-treated leaves to '-94' in JaMe-treated leaf tissues. Transcripts ending at these positions presumably arise from alternative processing of the primary transcript ending at position '-316'. The '-94' transcript contains, within the 5' untranslated region, a 35-base motif with remarkable complementarity to the extreme 3' terminal part of the 16S rRNA, involved in intramolecular base pairing within the ribosome and can associate with 30S but not 70S complexes in organello, suggesting that intermolecular base pairing impairs translation initiation, probably by competing for ribosome binding at the Shine-Dalgarno sequence. In contrast, transcripts ending at '-59' lack the 5' terminal 'extra' sequence and are active in terms of translation initiation.

Midiprep method for isolation of DNA from plants with a high content of polyphenolics.

Abstract: The preparation of high quality DNA from polyphenoliccontaining plants such as field bean (Vicia faba), tomato (Lycopersicon esculentum), and potato (Solanum tuberositm) was difficult, because of DNA degradation mediated by secondary plant products such as phenolic terpenoids and tannins which may bind to DNA and/or RNA after cell lysis (John 1992). Common methods for DNA isolation from such plants either include time consuming and expensive procedures (density gradient centrifugation or chromatography on columns) or yield DNA of poor quality. The method described here is based on modified protocols of Dellaporta et al. (1983) and John (1992). It combines the complexation of polyphenolic compounds by polyvinylpyrrolidone (PVP) following cell lysis and selective precipitation and centrifugation for removal of PVP complexes and DNA recovery. Plant tissues (100 mg leaf, stem) were quickly frozen in liquid nitrogen, powdered with mortar and pestle and transferred into 3 volumes (w/v) extraction buffer (500 mM NaCl, 50 mM Tris/HCl (pH 8.0), 50 mM EDTA, 1 % (v/v) /3-mercaptoemanol; added immediately before use). The mixture was thawed and ice cold 20% stock solution PVP (25 kd, Serva; stored at 2 0 ° Q was added to a final concentration of 6%. The lysate was kept on ice after thawing. Solid SDS was added to a final concentration of 2% (w/v). The extract was slightly mixed and incubated in a waterbath at 65°C for 10 minutes. Then 1/10 vol of 5 M potassium acetate was added followed by 30 minutes incubation on ice and centrifugation (13000xg, 10 minutes, 4 °Q. The supernatant was transferred into a new tube, mixed with 0.6 vol isopropanol by inverting the tubes three times and incubated on ice for 10 minutes. After another centrifugation (13000 Xg, 10 minutes, 4°C) the supernatant was discarded completely. The pellet was dried under vacuum, dissolved in 500 /tl 1XTE (pH 8.0) and extracted once (if necessary twice) with 1 vol of phenol— chloroform -isoamylalcohol (25:24:1). After centrifugation (13000xg, 10 minutes, 20°C) the aqueous phase was transferred and nucleic acids were precipitated in 1 vol isopropanol (20°C, 5 minutes). During this time the tubes were gently inverted at least five times. Finally, the tubes were centrifuged again (13000xg, 4°C, 10 minutes), the pellet was washed in 70% ethanol, dried under vacuum and dissolved in 1 XTE (pH 8.0). The whole procedure can be performed in 2.0 ml tubes. We used this method successfully for different plant species (tomato, potato, field bean) and obtained, depending on the species, about 20-40 /tg of high quality DNA per 100 mg fresh weight (Figure 1A). The method is suitable for the quick isolation of many DNA samples and the DNA is clean enough (OD260/28O = 1 -68) being used directly for restriction, Southern or PCR analysis (Figure 1B-E). Additionally, we used field bean DNA isolated in the described manner for cloning, e.g. library construction.

RFLP mapping of genes affecting plant height and growth habit in rye.

Abstract: RFLP mapping of chromosome 5R in the F3 generation of a rye (Secale cereale L.) cross segregating for gibberellic acid (GA3)-insensitive dwarfness (Ct2/ct2) and spring growth habit (Sp1/sp1) identified RFLP loci close to each of these agronomically important genes. The level of RFLP in the segregating population was high, and thus allowed more than half of the RFLP loci to be mapped, despite partial homozygosity in the parental F2 plant. Eight further loci were mapped in an unrelated F2 rye population, and a further two were placed by inference from equivalent genetic maps of related wheat chromosomes, allowing a consensus map of rye chromosome 5R, consisting of 29 points and spanning 129 cM, to be constructed. The location of the ct2 dwarfing gene was shown to be separated from the segment of the primitive 4RL translocated to 5RL, and thus the gene is probably genetically unrelated to the major GA-insensitive Rht genes of wheat located on chromosome arms 4BS and 4DS. The map position of Sp1 is consistent both with those of wheat Vrn1 and Vrn3, present on chromosome arms 5AL and 5DL, respectively, and with barley Sh2 which is distally located on chromosome arm 7L (= 5HL).

Refined examination of plant metaphase chromosome structure at different levels made feasible by new isolation methods

Abstract: Two methods for isolation of plant metaphase chromosomes are described The first, micromanipulation, allows the isolation of a number of individual chromosomes, which may be used as templates for the generation of chromosome specific DNA libraries and for physical sequence mapping by the polymerase chain reaction (PCR) The second provides, from synchronized meristems, pure chromosome suspensions suitable for flow cytometric analysis and chromosome sorting Restriction endonuclease banding, immunostaining of chromosomal antigens, as well as fluorescence in situ hybridization at high signal to noise ratio were successfully performed on the isolated chromosomes Chromosomes obtained by both protocols were suitable for scanning electron microscopy, the methods should also prove useful for refined analyses of the karyotypes of other plant species

Microdissection and microcloning of the barley (Hordeum vulgare L.) chromosome 1HS.

Abstract: We have applied a refined microdissection procedure to create a plasmid library of the barley (Hordeum vulgare L.) chromosome arm 1HS. The technical improvements involved include synchronization of meristematic root tissue, a metaphase drop-spread technique, paraffin protection of the collection drop to avoid evaporation, and a motorized and programmable microscope stage. Thirteen readily-discernible telocentric chromosomes have been excised from metaphases of synchronized root-tip mitoses. After lysis in a collection drop (2 nl), the DNA was purified, restricted withRsaI, ligated into a vector containing universal sequencing primers, and amplified by the polymerase chain reaction. Finally, the amplified DNA was cloned into a standard plasmid vector. The size of the library was estimated to be approximately 44,000 recombinant plasmids, of which approximately 13% can be utilized for RFLP analysis. Tandem repetitive probes could be rapidly excluded from further analysis after colony hybridization with labelled total barley DNA. Analysis of 552 recombinant plasmids established that: (1) the insert sizes ranged between 70 and 1150 bp with a mean of 250 bp, (2) approximately 60% of the clones contained highly repetitive sequences, and (3) all single- or low-copy probes tested originate from chromosome 1HS. Four probes were genetically mapped, using an interspecificH. vulgare xH. spontaneum F2 population. One of these probes was found to be closely linked to theMla locus conferring mildew resistance.

A complex ensemble of cis -regulatory elements controls the expression of a Vicia faba non-storage seed protein gene

Abstract: We have identified cis-regulatory elements within the 5'-upstream region of a Vicia faba non-storage seed protein gene, called usp, by studying the expression of usp-promoter deletion fragments fused to reporter genes in transgenic tobacco seeds. 0.4 kb of usp upstream sequence contain at least six, but probably more, distinct cis-regulatory elements which are responsible for seemingly all quantitative, spatial and temporal aspects of expression. Expression-increasing and -decreasing elements are interspersed and include an AT-rich sequence, a G-box element and a CATGCATG motif. The latter acts as a negative element in contrast to what has been found for the same motif in legumin- and vicilin-type seed storage protein gene promoters. Seed specificity of expression is mainly determined by the -68/+51 region which confers, however, only very low levels of expression. The data support the combinatorial model of promoter function.

Localization of seed protein genes on flow-sorted field bean chromosomes.

Abstract: Chromosomes from reconstructed field bean (Vicia faba L.) karyotypes were flow-sorted and the DNA was used for the physical localization of seed storage and nonstorage (USP) protein genes using PCR with sequence specific primers. The data were confirmed and refined by using DNA of microisolated chromosomes of other karyotypes as the target for PCR. The specificity of the PCR products was proved by restrictase digestion into fragments of predicted length or by reamplification using ‘nested’ primers. The genes are located within defined regions of chromosome I (USP=unknown seedprotein genes), II (vicilin genes, legumin B3 genes), III (legumin B4 genes), IV (pseudogenes ψ1) and V (legumin A genes and pseudogenes ψ1). Except for the pseudogene derived from the sequence of legumin B4 gene, all members of each gene family are located in one chromosome region exclusively. This approach proved to be useful for localizing genes that cannot be mapped genetically (due to the lack of allelic variants) and might be applied to integrate physical and genetic maps.

Flow karyotyping and sorting of Vicia faba chromosomes.

Abstract: Chromosome suspensions were prepared from formaldehyde-fixed, synchronized Vicia faba root tips. After staining with the DNA intercalating fluorochrome propidium iodide, the suspensions were analysed with a flow cytometer. The resulting histograms of integral fluorescence intensity contained peaks similar to those of theoretical V.faba flow karyotypes. From V. Faba cv ‘Inovec’ (2n = 12) only one peak, corresponding to a single chromosome type (metacentric chromosome), could be discriminated. However, it was found that the peak also contained doublets of acrocentric chromosomes. Bivariate analysis of fluorescence pulse area (chromosome DNA content) and fluorescence pulse width (chromosome length) was necessary to distinguish the metacentric chromosome. To achieve a high degree of purity, a two-step sorting protocol was adopted. During a working day, more than 25 000 metacentric chromosomes (corresponding to 0.2 μg DNA) were sorted with a purity of more than 90%. Such chromosomes are suitable for physical gene mapping by in situ hybridization or via the polymerase chain reaction (PCR) and allow the construction of chromosome-specific DNA libraries. While it was only possible to distinguish and sort one chromosome type from V. Faba cv ‘Inovec’ with the standard karyotype, it was possible to sort with a high degree of purity five out of six chromosome types of the line EFK of V. Faba, which has six pairs of morphologically distinct chromosomes. This result confirmed the possibility of using reconstructed karyotypes to overcome existing problems with the discrimination and flow sorting of individual chromosome types in plants.

Methyl jasmonate represses translation initiation of a specific set of mRNAs in barley

Abstract: Jasmonic acid methyl ester (methyl jasmonate, JaMe) causes accumulation of novel abundant proteins in excised leaf segments of barley, and concomitantly represses synthesis of most pre-existing (‘control’) proteins. The changes in control protein synthesis do not correspond to equivalent alterations at the in vitro translatable mRNA level, suggesting a post-transcriptional mode of regulation. Methyl jasmonate did not interfere with the in vitro translation of either control or JaMe-induced mRNAs. Polysome runoff translation, in combination with two-dimensional separations of the products formed, however, revealed a reduced synthesis of control proteins in JaMe-exposed leaf tissues, in contrast to a continued translation of these polypeptides in water-treated leaf segments. In vitro translation of polysomal RNAs demonstrated the preferential association of control mRNAs with polysomes of water-treated leaf tissues but not with polysomes of JaMe-treated tissues. Polysomes isolated from the latter leaves contained primarily JaMe-induced mRNAs, as shown by in vitro translation and Northern hybridization with gene-specific probes. Treatment of JaMe-incubated leaf tissues with cycloheximide prior to harvesting caused an increase of in vitro translatable control mRNAs recovered from polysomes, thus highlighting an impairment of control protein synthesis by JaMe at the level of translation initiation.

Two cDNAs for Tomato Heat Stress Transcription Factors

Abstract: The remarkable conservation of the heat-stress response from bacterial to plant and animal cells includes the structure and function of the heat-stress proteins as well as the control of their stress-dependent expression (for summaries, see Lindquist and Craig, 1988; Nover, 1991). The definition of a universal heat-stress-responsive promoter element shown to function in practically a11 types of eukaryotic cells (Nover, 1991) led recently to the characterization of the corresponding regulatory genes coding for the HSF (Sorger and Pelham, 1988; Wiederrecht et al., 1988; CIOS et al., 1990; Scharf et al., 1990; Sarge et al., 1991; Schuetz et al., 1991). As expected from the conservation of the promoter element, a11 HSFs are characterized by a similar DNA-binding domain of 93 to 100 amino acid residues and two to three hydrophobic heptad repeats of the Leu-zipper type (for a summary, see Scharf et al., 1993). Southwestern screening of a Xgtll cDNA expression library of tomato (Lycopersicon peruvianum) resulted in the isolation of three different HSF clones. In correspondence with hsf genes of other organisms, one of the tomato genes (hsf8) is constitutively expressed. But expression of the two others (hsf24, hsf30) is induced by heat stress. The hsf24 cDNA sequence was published previously (Scharf et al., 1990). This report concerns the cDNA sequences of hsf8 and hsf30 and some structural features of the corresponding proteins (Table I; Scharf et al., 1993). In contrast to HSF24, the C-terminal activation domains of HSF30 and HSF8 are characterized by a third hydrophobic repeat and extended, negatively charged regions dominated by Asp and Glu. A peculiarity of the HSF30 is the isolation of a family of different clones with varying length of the 3' trailor sequence. They evidently result from aberrant splicing events during the heat-stress period. The genomic clones of a11 three hsf genes contain introns at the corresponding positions (K.-D. Scharf, unpublished data).

Incorporation of microabsorption corrections into Rietveid analysis

Abstract: Surface roughness of planar samples causes an additional attenuation of X-ray diffraction intensity measured in Bragg–Brentano geometry. The decrease of intensity becomes stronger with decreasing scattering angle. This is part of the microabsorption effect. Two quantitative expressions describing the microabsorption effect are incorporated into the DBWS 9006-PC Rietveid program [D. B. Wiles and R. A. Young, J. Appl. Crystallogr. 15, 149–151 (1981)]. The procedure is applied to scattering data obtained from YBa2Cu3O7-powder samples with different degree of surface roughness but approximately identical bulk structure. The procedure is proved to work well. However, the values obtained for the parameters of the temperature factors and the microabsorption effect are correlated, and careful discussion is necessary to interpret the results.

Localization of vicilin genes via polymerase chain reaction on microisolated field bean chromosomes.

Abstract: A new technique is reported for the physical mapping of low copy DNA sequences on plant chromosomes. Individual chromosomes were microisolated and their DNA used as the target for the polymerase chain reaction in order to identify the chromosome carrying a specific gene sequence. The use of defined translocation chromosomes further refined the resolution of the method to a subchromosomal level. To demonstrate the applicability of the procedure genes have been localized coding for vicilin seed storage proteins on the field bean Vicia faba L. in a region which includes the centromere and the proximal parts of the short and the long arms of chromosome II.

Sucrose, cytokinin, and ethylene influence formation of in vitro bulblets in onion and leek

Abstract: In vitro maintenance of plant organs can enhance programs in plant breeding and germplasm resources. In bulbous plants, such as onion (Allium cepa L.) and leek (A. ampeloprasum L.) induction and storage of in vitro bulblets could enable long term maintenance of special genotypes. In vitro cultivated seedlings of onion and leek were induced to form bulblets by increase in sucrose concentration (30, 50, 150 g/1), and addition of benzyladenine (BA-0, 12.5 mg/1), or ethephon (0, 5, 20 days). The highest bulbing ratios were obtained within combinations of sucrose and ethephon treatments. BA caused not only bulb swelling but also an increase of multiple adventitious shoot formation. Increasing the sucrose concentration and treatment with ethephon are used to obtain bulblets for in vitro storage under conditions of slow growth.

The relationship between the activity of various iron-containing and iron-free enzymes and the presence of nicotianamine in tomato seedlings

Abstract: The influence of nicotianamine (NA) and iron on the activities of 4 iron-containing and two iron-free enzymes in leaves and roots of the NA-free tomato mutant chloronerva and its NA-containing wild-type (Lycopersicon esculentum Mill. cv. Bonner Beste) was investigated. Aconitase (EC 4.2.1.3) activity in both leaves and roots was much higher in the mutant under normal iron supply (10 μM FeEDTA) and in wild-type under iron deficiency than in wild-type supplied with 10 μM FeEDTA. Application of NA to chloronerva leaves led to a decrease of aconitase activity in leaves and roots. NA had no effect on the enzyme activity when added to the assay medium. Similar results were obtained for the iron-containing enzymes catalase (EC 1.11.1.6), ascorbate-dependent peroxidase (EC 1.11.1.11) and guaiacol-dependent peroxidase (EC 1.11.1.7) in roots. NA treatment of the mutant leaves decreased enzyme activities in roots down to wild-type values. In vivo NA application had no effect on enzyme activities in leaf extracts. The activities of the iron-free enzymes NAD+-malate dehydrogenase (EC 1.1.1.37) and phosphofructokinase (EC 2.7.1.11) in root and leaf extracts were not influenced by the iron supply to the plants.

Mapping of genes for copper efficiency in rye and the relationship between copper and iron efficiency

Abstract: A 4B/5R wheat-rye translocation line derived from the Danish wheat variety ‘Viking’ was revealed to be highly copper efficient. The chromosomal exchange includes a very small terminal segment of chromosome arm 5RL of rye which was physically mapped by genomic DNA:DNA in situ hybridization and chromosome analysis. The gene for Cu efficiency (Ce) is linked to a dominant hairy neck character from rye (Ha1) and to two rye-specific leaf esterase loci (Est6, Est7), all of which are postulated to map to the distal part of 5RL. Genes coding for mugineic acid synthetase and 3-hydroxymugineic acid synthetase also on chromosome 5R are not included in the 4B/5R translocation and hence map outside the terminal 5R region. These genetic and molecular markers can be useful tools for large-scale screening in wheat breeding programmes.

Overproduction by gene amplification of the multifunctional arom protein confers glyphosate tolerance to a plastid-free mutant of Euglena gracilis.

Abstract: Cells of the plastid-free mutant line of Euglena gracilis var. bacillaris, W10BSmL, can be adapted to glyphosate [N-(phosphonomethyl)glycine] by gradually increasing the concentration of the herbicide in the culture medium. The molecular basis of glyphosate tolerance is the selective ca. ten-fold overproduction of the multifunctional arom protein catalyzing steps 2–6 in the pre-chorismate pathway. Determination of 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase (E.C.2.5.1.19), shikimate:NADP+ oxidoreductase (E.C.1.1.1.25) and shikimate kinase (E.C.2.7.1.71) activities after non-denaturing gel electrophoresis, in combination with two-dimensional separations, revealed an increase in all three enzyme activities associated with overproduction of a 165 kDa protein in cells adapted to 6 mM glyphosate. Further evidence for an involvement of the multifunctional arom protein in aromatic amino acid synthesis in, the plastid-free W10BSmL cells was obtained by Northern hybridization with AR01-, aroA-, aroL- and aroE-specific Saccharomyces cerevisiae gene probes encoding the entire arom protein or parts of the EPSP synthase, shikimate:NADP+ oxidoreductase and shikimate kinase domains, respectively. Overproduction in adapted relative to control cells of a 5.3 kb transcript that cross-hybridized with all of the different probes could be demonstrated. The elevated content of the arom transcript correlated with a selective amplification of two out of five genomic sequences that hybridized with the S. cerevisiae ARO1 gene probe in Southern blots. One of the amplified genomic fragments is assumed to encode the previously identified monofunctional 59 kDa EPSP synthase, which is thought to be an organellar protein, that accumulates to a certain extent in its enzymatically active precursor form of 64.5 kDa in the plastid-free W10BSmL cells.

In situ localization of faba bean and oat legumin-type proteins in transgenic tobacco seeds by a highly sensitive immunological tissue print technique.

Abstract: We have used a highly sensitive immunological tissue print technique to study cell- and tissue-specific expression of heterologous genes in transgenic plants. Primary polyclonal antibodies, raised against legumin of faba bean (Vicia faba L.) and 12S globulin of oat (Avena sativa L.) were used to localize these proteins in transgenic tobacco seeds in a streptavidin-alkaline phosphatase assay in combination with biotinylated secondary antibodies producing a higher sensitivity (by several amplification steps) of the assay. Both storage protein genes were found to be expressed in a specific pattern. While legumin is preferentially accumulated in certain parts of the embryo, the oat legumin-type globulin is restricted to the endosperm. The applied technique is highly sensitive with a resolution power down to the single-cell level and allows rapid screening of large numbers of samples.

Surface phenomena at polymers

Abstract: Polymers with advanced properties can be achieved among other measures by reinforcing with fibrous materials, by polymer blending and surface modification. Using the surface treatment of PP-EPDM injection moulding specimens (washing, flaming, plasma-treatment) an overview on progress in surface analytics is given. It is shown that XPS, contact angle and zeta-potential measurements give corresponding results concerning the composition of the surface region. Additional to the kind of interaction forces at interfaces the mechanical properties of reinforced polymers are governed by sorption layers and electrical phenomena at interfaces. Corresponding results were obtained at chalk filled PE-HD and glass fibre reinforced polyamide.

A role for ethylene in barley plants responding to soil water shortage

Abstract: The influence of water shortage and ethylene (ethephon) application on ear fertility and tillering of barley plants were compared. In both cases, highest sensitivity was observed during jointing and pre-anthesis (Feekes 7–9). The ear initial with the surrounding tissue was identified as the site of ethylene action. Treating this region of barley plants with AVG before wilting partly prevented drought effects. These results, in connection with rising ethylene values in ear-bearing stem segments of wilting barley plants (more obvious in increasing ACC and MACC levels), especially in the drought-sensitive stages, favors a role for ethylene in the development of cereal plants under drought.

Gibberellin status and responsiveness in shoots of tall and dwarf genotypes of diploid rye (Secale cereale)

Abstract: The recessive dwarfing alleles of rye (Secale cereale L.), ct1 and ct2, caused a 35–55% reduction in the length of leaf 2 compared with corresponding tall lines grown at both 10°C and 20°C. The dwarf lines were 45–50% as responsive to applied GA3 as the tall lines at 20°C but the absolute GA-responsiveness of the dwarfs was greater at 10°C than at 20°C. There was no significant difference in the contents of GA19, GA20, GA29, GA1, GA3 and GA8 in the leaf extension zone of tall and dwarf seedlings grown at 20°C. It was concluded that the mechanism whereby GA homeostasis is maintained is functional in both tall and dwarf lines despite marked differences in leaf extension rate. The recessive rye mutations may cause loss of function late in the GA-cell elongation pathway or, alternatively, indirectly affect GA-responsiveness in vegetative tissues. The genetic and physiological evidence indicates that ct1 and ct2 are unrelated to the GA-insensitive Rht genes in hexaploid bread wheat.

Some trichodinid ciliates (Ciliata: Urceolariidae) from common carp and sticklebacks in eastern Germany

Abstract: Summary Trichodina acuta, Lom 1961; T. nigra, Lom 1960; T.pediculus, Ehrenberg 1838; T.perforata, Lom, Golemansky, Grupcheva 1976; T.rostrata, Kulemina 1968; and Trichodinella subtilis, Lom 1959 from common carp as well as Trichodina domerguei domerguei (Wallengren 1897; and T.tenuidens, Faure-Fremiet 1943 from sticklebacks are reported for the first time in eastern Germany.

Synthesis and mass spectral analysis of coenzyme a thioesters of anthranilic acid and its N‐methyl derivative involved in acridone alkaloid biosynthesis

Abstract: Coenzyme A thioesters of anthranilic acid and N-methylanthranilic acid were synthesized. The corresponding N-hydroxysuccinimidyl esters proved to be useful as activated intermediates to prepare anthraniloyl-CoA and N-methylanthraniloyl-CoA. These compounds were characterized by positive and negative ion liquid secondary ion mass spectrometry. Acridone synthase from suspension cultures of Ruta graveolens catalyses the condensation of N-methylanthraniloyl-CoA and malonyl-CoA. The reaction product 1,3-dihydroxy-N-methylacridone was directly identified after the extraction of the assay mixture by electron impact mass spectrometry and capillary gas chromatography.

Genotoxicity studies in semiconductor industry. 1. In vitro mutagenicity and genotoxicity studies of waste samples resulting from plasma etching.

Abstract: Solid waste samples taken from the etching reactor, the turbo pump, and the waste air system of a plasma etching technology line in semiconductor production were studied as to their genotoxic properties in a bacterial repair test, in the Ames/Salmonella microsome assay, in the SOS chromotest, in primary mouse hepatocytes, and in Chinese hamster V79 cell cultures. All three waste samples were found to be active by inducing of unscheduled DNA‐synthesis in mouse hepatocytes in vitro. In the bacterial rec‐type repair test with Proteus mirabilis, waste samples taken from the turbo pump and the vacuum pipe system were not genotoxic. The waste sample taken from the chlorine‐mediated plasma reactor was clearly positive in the bacterial repair assay and in the SOS chromotest with Escherichia coli. Mutagenic activity was demonstrated for all samples in the presence and absence of S9 mix made from mouse liver homogenate. Again, highest mutagenic activity was recorded for the waste sample taken from the plasma reacto...