Verteilung und systematik der freilebenden nematoden des neusiedlersees

Systematics and distribution pattern of the free living nematodes in the benthos of Neusiedlersee outside the reed belt are described. 26 species have been found some of which demonstrate a distinct horizontal distribution pattern, correlated with the wind influence on benthic conditions in the lake. Detailed systematic account is given of the species found, especially the genera Udonchus Cobb and Monhystrella Cobb, as well as of the following species: Plectus andrassy Timm 1971, Paraphanolaimus microstomus (Daday, 1905), Monhystera spp., Theristus flevensis Schuurmans-Stekhoven, 1935, Tripyla glomerans Bastian 1865, Tobrilus gracilis (Bastian, 1865) and Amphidelus lemani longicaudatus n. ssp.

     

Die Verteilung der leitenden Strukturen in der Achse vonClematis vitalba (Ranunculaceae)

The vascular pattern and its origin are described in connection with the differentiation of ground tissue in the shoot. Leaf arrangement ofClematis vitalba L. is decussate, and the vascular pattern appears rather simple at first: From internode to internode six strands—three from each leaf—alternate. About six internodes from the shoot apex, the pattern is completed by accessory strands which do not leave the axis and differentiate near the primary bark and exactly between the old strands. The formation of the acessory strands is not caused by the enlargement of the axis alone, because the balance between ground and vascular tissue is already regulated by the enlargement of the primary strands.

Zweiter Beitrag der Serie Die Sproßentwicklung vonClematis vitalba (Ranunculaceae) vgl. den ersten Beitrag:Schnettker (1976).     

Differentiation-related proteins of the broad bean rust fungus Uromyces viciae-fabae,as revealed by high resolution two-dimensional polyacrylamide gel electrophoresis

On artificial polyethylene membranes providing a thigmotropic signal, uredospores of the broad bean rust fungus Uromyces viciae-fabae differentiated a series of infection structures which in nature are necessary to invade the host tissue through the stomata. Within 24 h germ tubes, appressoria, substomatal vesicles, infection hyphae and haustorial mother cells were developed successively. Alterations in protein metabolism during infection structure differentiation of this obligate plant pathogen were analyzed in the absence of the host plant by high resolution two-dimensional polyacrylamide gel electrophoresis (2-DE) and silver staining. The norm pattern representing the 2-DE protein patterns of the whole developmental sequence of infection structures of U. viciae-fabae showed 733 spots. During infection structure differentiation 55 proteins were newly formed, altered in quantity, or disappeared. Major alterations in the protein pattern occurred during uredospore germination and when infection hyphae were formed. Uredospore germination was characterized by a decrease of acidic proteins and an increase mainly of proteins with isoelectric points ranging from weakly acidic to basic.Abbreviations 2-DE two-dimensional polyacrylamide gel electrophoresis - DAPI 4,6-diamino-phenylindol - kDa kilo Dalton - pl isoelectric point - PMSF phenylmethylsulfonyl fluoride - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis     

Organspezifische multiple Formen der Glutamatdehydrogenase in Medicago sativa

Summary The alteration of the multiple forms of NAD-dependent glutamic dehydrogenase (GDH) during the development of Medicago sativa is investigated by means of polyacrylamide electrophoresis. Seed germination is accompanied by a characteristic change of the GDH-isoenzyme pattern. Seeds contain seven isoenzymes, which gradually decrease in number during germination. At the same time a pattern of new isoenzymes becomes visible. The seed pattern is called GDH-I and the later appearing pattern GDH-II. GDH-I is characteristic for the cotyledons, whereas GDH-II is the typical pattern of the root system. Shoots produce a mixed pattern composed of the GDH-II isoenzymes as well as some GDH-I isoenzymes.These isoenzyme patterns are organ specific. No qualitative change occurs during further development of the plants and during growth in the presence of different inorganic and organic N-sources in the culture medium.All the individual isoenzymes are found predominantly in the particulate fraction. They represent stable forms which are not altered by variation of the conditions of enzyme extraction or during enzyme purification. Re-electrophoresis of the individual isoenzymes following elution from the polyacrylamide gels reveals only one specific band. The molecular weights of all the distinctive isoenzymes are identical.There is some evidence that the different isoenzymes represent conformational forms of one enzyme, and it is postulated that the GDH-I isoenzymes are correlated to a normal metabolic (or catabolic) function of the enzyme, whereas the GDH-II isoenzymes are responsible for a primarily anabolic function of glutamic dehydrogenase.     

Verteilungsmuster und Ultrastruktur des Glykogens in der Oocyte vonMusca domestica

Summary Fully grown oocytes ofMusca domestica contain large amounts of glycogen distributed in a characteristic pattern. Three cytoplasmic layers can be distinguished: 1. The periplasm which is free of carbohydrates and merely contains some lipid and protein yolk. 2. A zone of large glycogen clods. 3. Adjacent to this the central ooplasm where numerous lipid droplets and protein yolk spheres are found beside medium size glycogen clods. The glycogen areas are not surrounded by membranes, in contrast to the other yolk inclusions. Some possible interpretations of this ooplasmic pattern, which is already established during oogenesis, are discussed.     

Die Orientierung der Trichterspinne nach polarisiertem Licht

Summary The spider Agelena labyrinthica (Clerck) orients its movements by means of polarized light even if the reflection pattern of the web is not visible. If the spider is not permitted to see the overhead source of polarized light while the reflection pattern from the substratum is still visible, its orientation is not influenced by rotation of the polaroid. For this reason Agelena's orientation by means of polarized light must be based on a direct perception of the light's plane of vibration.     

Characterization of a heavy metal-tolerant endomycorrhizal fungus from the surroundings of a zinc refinery

An arbuscular mycorrhizal fungus was isolated from the rhizosphere of Agrostis capillaris growing in the contaminated surroundings of a zinc refinery in The Netherlands. After examination of the infection pattern and the spores, it was characterized as Scutellospora dipurpurescens, which was first isolated from a reclaimed coal mine area in West Virginia.     

Die räumliche Ordnung der Stoffwechselprozesse im Metazoenorganismus

Zusammenfassung 1. Es wird ein Arbeitsprogramm zur Erforschung der räumlichen Ordnung der Stoffwechselprozesse im Körper von drei repräsentativen Vertretern verschiedener Tierstämme dargestellt und mit Literaturdaten und Untersuchungsergebnissen aus dem Institut des Verfassers illustriert.2. Wegen der unterschiedlichen Enzymausstattung der verschiedenen Organe hängen bei den Metazoen die Mengenverhältnisse der im Stoffwechsel gebildeten Produkte von der Verteilung der Nährstoffe im Körper ab.3. Zur Erforschung der räumlichen Ordnung des Stoffwechsels stehen zwei Methoden zur Verfügung:a) Vergleich von Reaktionsgeschwindigkeiten bzw. Enzymaktivitäten in allen Organen eines Versuchstieres in vitro;b) Studium der Verteilung und Umwandlung radioaktiver Tracer in vivo.4. Zur Illustration der unter 3a genannten Methode wird über folgende Untersuchungen berichtet:a) Eisen- und Porphyrinstoffwechsel beiLumbricus terrestris (Delkeskamp, unpubliziert);b) Endogene Gewebsatmung beiLumbricus terrestris (Urich, unpubliziert; Abb. 1b);c) Enzyme der Glykolyse, des Pentose-phosphatweges und des Citronensäurecyclus in den Geweben vonCambarus affinis (Keller, unpubliziert; Abb. 2).

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The spatial pattern of metabolism in the metazoan organism

After absorption most food substances are converted into numerous metabolic products. The quantitative proportions of these products are controlled not only by intracellular but also by extracellular mechanisms. The extracellular regulation of metabolism may be effected by uneven distribution of metabolites within the body. The various organs of a metazoan differ in enzyme equipment and accordingly in direction of metabolism. Mechanisms which influence the distribution of metabolites among different tissues will thus modify the proportions of metabolic products. Under defined physiological conditions there is a specific spatial pattern of metabolism. This pattern may be studied (1) by comparing reaction velocities or enzyme activities in the various organs or (2) by directly observing the distribution and conversion of metabolites with the aid of radioactive tracers. Both methods support each other. The spatial pattern of metabolism is known to a certain degree only for mammals. Thus we have recently begun corresponding studies on the earthwormLumbricus terrestris, the snailHelix pomatia and the crayfishCambarus affinis. Some results of the investigations are described in this paper: (1) The synthesis of hemoglobin in the earthworm probably takes place in the chloragogenous tissue (Delkeskamp, unpubl.). (2) The endogenous respiration of the various tissues of the earthworm has been determined (Urich, unpubl.; cf. Fig. 1b). (3) The activities of some enzymes of glycolysis, pentose phosphate shunt and tricarboxylic acid cycle have been measured in the various organs of the crayfish (Keller, unpubl.; cf. Fig. 2).

     

Inhibierungserscheinungen bei der alkoholischen Gärung,I. Einfluß der Ethanolkonzentration auf die spezifische Ethanolbildungsgeschwindigkeit von Saccharomyces cerevisiae

Differential values of the specific ethanol production rate \documentclass{article}\pagestyle{empty}\begin{document}$$ v_{(t)} = \frac{1}{{x_{(t)} }} \cdot \frac{{dP}}{{dt}} $$ \end{document} can be calculated exactly from experimental batch fermentation process data by use of a nonlinear regression programme. The method used is based on the fact, that the function P = f(t) can be approximated by an exponential equation. The specific ethanol production rate is calculated then from the first differential derivation of this equation using the appropriated values of actual biomass concentration. For two strains of Saccharomyces cerevisiae a linear and nonlinear kinetic pattern, respectively, was found for product formation. This result can be explained by a simple mathematical relation according to ν=ν₀ ? a . P^b,in which the exponent becomes 1 in the case of linear kinetic pattern.     

Parasite-induced parthenogenesis in a freshwater snail: stable,persistent patterns of parasitism

Summary The role of parasites in the evolution of host reproductive modes has gained renewed interest in evolutionary ecology. It was previously argued that obligate parthenogenesis (all-female reproduction) arose in a freshwater snail, Campeloma decisum, as a consequence of severe sperm limitation caused by an unencysted trematode, Leucochloridiomorpha constantiae. In the present study, certain conditions are examined for parasitic castration to account for the maintenance of parthenogenesis: the spatial patterns of the prevalence and intensity of infection on a broad geographical scale and its relationship to host genotype; the recovery from infection after isolation from sources of infection; age-related patterns of infections; and the effects of L. constantiae on snail fecundity.In contrast to the common pattern of the aggregated distribution of parasites within host populations, many snail populations with high prevalence and intensity of infection have non-aggregated parasite distributions. Clonal genotype of the host explained little of the variation in intensity and prevalence of infection by the parasite. Female snails maintained similar prevalence and intensity of infection after isolation, and individuals accumulated parasites throughout their lifespan, both of which suggest there is no effective immune response to infection by L. constantiae. Snail fecundity is not significantly influenced by the intensity of infection. These results suggest that L. constantiae may have represented a strong selective force against males during the initial introduction of this parasite into sexual snail populations because of the persistent nature of infection.     

Leakage of electrolytes and phenols and altered activity profile of peroxidase and its isoenzymes from wheat leaves inoculated withPuccinia recondita

Second and third leaves of 25-day old wheat (Triticum aestivum L.) planta, cultivar WL-711, were inoculated with three races of the brown rust pathogen,Puccinia recondita f. sp.tritici. The host reflected a differential interaction response towards these races, viz., susceptible reaction to race 77 (reaction type 4) intermediate reaction to race 104 (reaction type 1 - 3) and resistant reaction to race 63 (reaction type 0). Post-inoculation mutual interaction brought about observable changes in peroxidase activity along with leakage of electrolytes and phenolic constituents indicating altered permeability of host tissue. Differential increase in leakage of electrolytes and phenols occurred with increase of peroxidase activity during 12 h and 24 h post-inoculation, however, during 36 h, 48 h and 72 h post-inoculation, electrolyte leakage increased continuously with corresponding increases in peroxidase activity in all three interactions, while leakage of phenols showed a differential pattern. The differential changes in isoenzymic pattern of peroxidase activity were also noted during the progressive infection process which may also be an indication of altered permeability of the host issue at the very onset of brown rust infection.     

Verhaltensmerkmale der Familie Remizidae (Beutelmeisen)

Summary Doubt has recently been expressed regarding whether the generaAuriparus andCephalopyrus belong to the Remizidae. It has, however, now been shown that all four genera in this family utilize one foot as a grasping organ. This lends support to the supposition that they belong together, as such a behaviour pattern has not been previously observed in song-birds.     

Trennung der Thylakoidbausteine einiger Athiorhodaceae durch Gelelektrophorese

Zusammenfassung Thylakoide vonRhodospirillum rubrum, Rhodopseudomonas viridis undRhodopseudomonas capsulata wurden durch Behandlung mit Phenol-Ameisensäure in makromolekulare, in der Gelelektrophorese wandernde Fraktionen aufgespalten. Dabei ergaben sich vier deutlich hervortretende Hauptfraktionen, die zum Teil noch in Unterfraktionen aufzulösen sind.BeiRhodospirillum rubrum wurden neben den Thylakoiden auch noch Rohfraktionen der cytoplasmatischen Membran und der Zellwand mit der gleichen Methode untersucht. Alle Strukturen unterschieden sich deutlich voneinander in der Zahl und Wanderungsgeschwindigkeit ihrer Banden.Aus einer Dunkelkultur vonRhodospirillum rubrum, in der durch Absenken des Sauerstoffpartialdruckes die Thylakoidmorphogenese und Pigmentsynthese induziert worden war, wurde die Gesamtmembranfraktion isoliert, durch Behandlung mit Phenol-Ameisensäure dissoziiert und gelelektrophoretisch aufgetrennt. In den Pherogrammen war deutlich von Beginn der Induktion an eine Zunahme thylakoidspezifischer Bandenmuster zu erkennen. Ein Ausplanimetrieren der Absorptionskurven ergab, daß das Wachstum der Thylakoidstrukturen exponentiell erfolgte. Unter den Bedingungen der Kultur wurde nach etwa 8 Std ein Plateau in der Ausbildung der thylakoidspezifischen Strukturen erreicht. Die Kurve der Bacteriochlorophyllsynthese nahm einen etwas anderen Verlauf. Sie war im Bereich des exponentiellen Wachstums der Thylakoidstrukturen stärker gekrümmt, bog dann aber später ebenfalls ab, so daß sie nach 8–10 Std parallel zu den Thylakoiden verlief.

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Fractionation of thylakoid-components of some athiorhodaceae by polyacrylamide-gel electrophoresis

Summary Thylakoids (chromatophores) ofRhodospirillum rubrum, Rhodopseudomonas viridis, andRhodopseudomonas capsulata were fractionated after treatment with phenol-formic acid-water (2:1:1) by gel electrophoresis in four main fractions. The pattern of maxima was different in the three species.Crude preparations of cytoplasmic membrane and cell wall ofR. rubrum differ from the thylakoids in their pattern of electrophoresis distribution.Crude total membrane fractions were isolated from cells ofR. rubrum, which was induced to synthesize bacteriochlorophyll and thylakoids.Fractionation of the membranes by the above mentioned method shows very clearly that after induction of morphogenesis the thylakoid-specific membrane units are increased exponentially.

     

Photosynthesieintensität der Stielregionen von Acetabularia mediterranea

Summary The rate of photosynthesis (¹⁴C-incorporation) of cell parts isolated from the stalk of the alga Acetabularia mediterranea is highest in parts derived from the tip region and lowest in parts from the basal region of the stalk (Table 1).Similar results are obtained when whole cells are used for photosynthesis and divided afterwards into tip region, basal region and middle region (Fig. 1, Table 2).There is a gradient of photosynthetic capacity within the stalk which shows a pattern similar to that demonstrated for the morphogenetic capacity of the different stalk regions.     

Zur Evolution des Karyotyps bei den Lepidopteren. Die Chromosomenzahlen der Noctuiden

An analysis of the haploid chromosome numbers of 97 species of the familyNoctuidae was performed. These numbers added to those formerly known, give the picture of an astonishing stability in the whole family with the exception of one genus,Orthosia, in which a wide variation was found. In 105 out of 112 species of non-Orthosia noctuids the haploid number is 31, which is thus the modal number of the family. In sharp contrast to this pattern, inOrthosia each of the 8 species investigated gives a different chromosome count, ranging from 14 to 120, and none has 1he number 31. The chromosomes are large in the speciesOrthosia gracilis, which has 14 chromosomes, smaller in the species with intermediate numbers, and smallest in the speciesO. rorida, possessing 120 chromosomes. The differences in number are therefore interpreted as mainly due to fusion and fragmentation processes, which should be facilitated by the holokinetic organisation of the Lepidoptera chromosomes. In non-Orthosia noctuids the volumes of chromosome complements differ as much as 15 in spite of the constant chromosome number. The existence of a mecanism is postulated which prevents easy fusion and fragmentation in non-Orthosia noctuids and many of the other Lepidoptera lines.     

Effekt und Risiko des Knöllchentests auf Braunfäuleresistenz bei Kartoffelsämlingen im System der Auslese in der Phytophthora-Resistenzzüchtung

The effects and risks involved with the small tuber assay in plant breeding programmes with potato seedlings for resistance to Phytophthora infestans In an assay which involved 838 potato seedlings, the relative resistance to leaf-Phytophthora (KR_G) was tested at the 4–6 leaf growth stage, and the relative tuber resistance to infection was determined on small pot-grown tubers (B_K) and, in the following 2 years, in slices from field-grown potatoes (B_s). The small tuber assay is described and its value as a measure of disease resistance, compared with the potato slice assay, discussed. Among 357 leaf-Phytophthora susceptible clones (KR_G≤ 5) were 10 clones with a good to very good tuber resistance. 18 of 204 leaf-Phytophthora highly resistant idiotypes were extremely susceptible to tuber rot. After discarding those seedlings which showed KR_G-values ≤ 5 and B_X-values ≤ 5, 208 of the remaining 241 (= 86 %) tuber rot resistance carrying seedlings were selected. 14 % of the clones which showed adequate resistance in the potato slice assay were falsely discarded according to the small tuber assay. 80 clones remained as ballast in the field trials (B_K≤ 5, B_s≤ 6.4), 160 (33 % of the idiotypes tested) had been correctly eliminated. The work-intensive small tuber assay presents a possibility by which breeding material can already be reduced in the seedling stage. In this respect there must be a pronounced genetic differentiation present in the potato population and the selection procedure carried out must not be too harsh.     

Editing of an effector gene promoter sequence impacts plant‐Phytophthora interaction

Pathogen avirulence (Avr) effectors interplay with corresponding plant resistance (R) proteins and activate robust plant immune responses. Although the expression pattern of Avr genes has been tied to their functions for a long time, it is still not clear how Avr gene expression patterns impact plant‐microbe interactions. Here, we selected PsAvr3b, which shows a typical effector gene expression pattern from a soybean root pathogen Phytophthora sojae. To modulate gene expression, we engineered PsAvr3b promoter sequences by in situ substitution with promoter sequences from Actin (constitutive expression), PsXEG1 (early expression), and PsNLP1 (later expression) using the CRISPR/Cas9. PsAvr3b driven by different promoters resulted in distinct expression levels across all the tested infection time points. Importantly, those mutants with low PsAvr3b expression successfully colonized soybean plants carrying the cognate R gene Rps3b. To dissect the difference in plant responses to the PsAvr3b expression level, we conducted RNA‐sequencing of different infection samples at 24 h postinfection and found soybean immune genes, including a few previously unknown genes that are associated with resistance. Our study highlights that fine‐tuning in Avr gene expression impacts the compatibility of plant disease and provides clues to improve crop resistance in disease control management.     

Peroxidase Activity and Isoperoxidase Pattern in Tobacco Leaves Infected with Tobacco Necrosis Virus and Other Viruses Inducing Necrotic and Non-Necrotic Alterations

The level of peroxidase activity was greatly enhanced in tobacco leaves infected by tobacco necrosis virus (TNV) and other viruses which induce necrotic symptoms (TMV, ToMV and PVY^N). The intensity was related to the age of the leaves infected: absent or neglible in mature leaves and very pronounced in young growing infected leaves. On the contrary, changes in peroxidase activity were negligible when the infection was provoked by viruses which do not produce necrotic reactions (TMV and PVY^O). Analysis of the peroxidase isoenzymes, pattern in tobacco leaves infected by TNV and other necrosis-inducing viruses revealed in all cases, a slight increase in anionic (pl 3.5–3.7) and a considerable increase in moderately anionic isoenzymes particularly the pl 4.6 isoenzyme which in TNV and PVY^N-infected leaves reached levels up to 21 and 72 times the healthy control values. A considerable increase in the cationic (pl9.3–8.8) isoenzymes and the appearance of one moderately cationic isoenzyme (pl 8.2) was also detected. In leaf extracts from-virus-infected tobacco leaves with nonnecrotic response, no, or negligible alterations on the isoenzyme pattern were detected. However, infection by a fungal parasite (Erisyphe cichoracearum), which established a fully compatible, non-necrotic, interaction with tobacco leaves, like the necrosis-inducing viruses, changed the isoperoxidase pattern. The data suggest the necrotic alterations and associated changes in the peroxidase activity and isoperoxidase pattern in virus-infected leaves are not clearly related.     

Inhibition of gene expression of T7-related phages by prophage P1

Summary The gene expression of nine phages of the T7 group was compared after infection of Escherichia coli B(P1). With the exception of phage 13a which grew normally, all of them infected E. coli B(P1) abortively. Differences were found in the efficiency of host killing which ranged from 100% for phage 13a to 37% for phage A1122. Infection by T7 prevented colony formation by about 70% of the cells but they showed filamentous growth until about 2h after infection. It was shown by SDS-polyacrylamide gel electrophoresis and autoradiography of [³⁵S]methionine-labelled phage-coded proteins that all phages except for 13a showed measurable expression only of the early genes. No correlation was observed between killing capacity and the pattern of gene expression, and the ability to hydrolyse S-adenosyl-methionine (SAM, a cofactor for the P1 restriction endonuclease) by means of a phage-coded SAMase. Mixed infection of E. coli B(P1) with 13a and T7 yielded mixed progeny indistinguishable from that observed after mixed infection of the normal host E. coli B. Genetic crosses with amber mutants of 13a and T7 showed that the 13a marker opo ⁺ (overcomes P one), required for growth on B(P1), is located in the early region, to the left of gene 1 (RNA polymerase gene).