Regulation of Sulfate Assimilation by Nitrogen in Arabidopsis

Using Arabidopsis, we analyzed the effect of omission of a nitrogen source and of the addition of different nitrogen-containing compounds on the extractable activity and the enzyme and mRNA accumulation of adenosine 5′-phosphosulfate reductase (APR). During 72 h without a nitrogen source, the APR activity decreased to 70% and 50% of controls in leaves and roots, respectively, while cysteine (Cys) and glutathione contents were not affected. Northern and western analysis revealed that the decrease of APR activity was correlated with decreased mRNA and enzyme levels. The reduced APR activity in roots could be fully restored within 24 h by the addition of 4 mM each of NO3 −, NH4 +, or glutamine (Gln), or 1 mM O-acetylserine (OAS). 35SO4 2− feeding showed that after addition of NH4 +, Gln, or OAS to nitrogen-starved plants, incorporation of 35S into proteins significantly increased in roots; however, glutathione and Cys labeling was higher only with Gln and OAS or with OAS alone, respectively. OAS strongly increased mRNA levels of all three APR isoforms in roots and also those of sulfite reductase, Cys synthase, and serine acetyltransferase. Our data demonstrate that sulfate reduction is regulated by nitrogen nutrition at the transcriptional level and that OAS plays a major role in this regulation.

Sulfate assimilation in higher plants. Characterization of a stable intermediate in the adenosine 5′-phosphosulfate reductase reaction

The enzyme catalysing the reduction of adenosine 5′-phosphosulfate (AdoPS) to sulfite in higher plants, AdoPS reductase, is considered to be the key enzyme of assimilatory sulfate reduction. In order to address its reaction mechanism, the APR2 isoform of this enzyme from Arabidopsis thaliana was overexpressed in Escherichia coli and purified to homogeneity. Incubation of the enzyme with [35S]AdoPS at 4 °C resulted in radioactive labelling of the protein. Analysis of APR2 tryptic peptides revealed 35SO2–3 bound to Cys248, the only Cys conserved between AdoPS and prokaryotic phosphoadenosine 5′-phosphosulfate reductases. Consistent with this result, radioactivity could be released from the protein by incubation with thiols, inorganic sulfide and sulfite. The intermediate remained stable, however, after incubation with sulfate, oxidized glutathione or AdoPS. Because truncated APR2, missing the thioredoxin-like C-terminal part, could be labelled even at 37 °C, and because this intermediate was more stable than the complete protein, we conclude that the thioredoxin-like domain was required to release the bound SO2–3 from the intermediate. Taken together, these results demonstrate for the first time the binding of 35SO2–3 from [35S]AdoPS to AdoPS reductase and its subsequent release, and thus contribute to our understanding of the molecular mechanism of AdoPS reduction in plants.

Activation of plant defense responses and sugar efflux by expression of pyruvate decarboxylase in potato leaves

When plants are infected with avirulent pathogens, a selected group of plant cells rapidly die in a process commonly called the hypersensitive response (HR). Some mutations and overexpression of some unrelated genes mimic the HR lesion and associated defense responses. In all of these situations, a genetically programmed cell death pathway is activated wherein the cell actively participates in killing itself. Here we report a developmentally and environmentally regulated HR-like cell death in potato leaves constitutively expressing bacterial pyruvate decarboxylase (PDC). Lesions first appeared on the tip of fully expanded source leaves. Lesion formation was accompanied by activation of multiple defense responses and resulted in a significant resistance toPhytophthora infestans. The transgenic plants showed a five- to 12-fold increase in leaf tissue acetaldehyde and exported two- to 10-fold higher amounts of sucrose compared to the wild-type. When plants were grown at a higher temperature, both the lesion phenotype and sucrose export were restored to wild-type situations. The reduced levels of acetaldehyde at the elevated temperature suggested that the interplay of acetaldehyde with environmental and physiological factors is the inducer of lesion development. We propose that sugar metabolism plays a crucial role in the execution of cell death programs in plants.

NO2-induced nitrate reductase activity in needles of Norway spruce (Picea abies) under laboratory and field conditions

The induction of activity of the enzyme nitrate reductase (NR, EC 1.6.6.1, 1.6.6.2) in needles of Norway spruce (Picea abies[L.] Karst.) by nitrogen dioxide (NO2) was studied under laboratory and field conditions. In fumigation chambers an increase in nitrate reductase activity (NRA) was detected 4 h after the start of the NO2 treatment. During the first 2 days with 100 µg NO2 m−3, NRA reached a constant level and did not change during the following 4 days. At the same level of NO2, NRA was lower in needles from trees grown on NPK-fertilized soil than on non-fertilized soil. After the transfer of spruce trees from fertilized soil to NPK-rich nutrient solution, NRA was transiently increased. This effect was assigned to root injuries causing nitrate transport to the shoot and subsequent induction of NRA. Neither trees on fertilized soil nor trees transferred to NPK-poor nutrient solution had increased NRA unless NO2 was provided. The NO2 gradient in the vicinity of a highway was used to test the long-term effect of elevated levels of NO2 on needle NRA of potted and field-grown spruce trees. Compared with less polluted sites, permanently increased NRAs were detected when NO2 concentrations were above 20 µg m−3. Controls of field measurements some 10 years after the introduction of catalytic converters in cars showed no significant change neither in NO2 levels nor in the decreasing NRA of spruce needles with the distance from the highway.

Light regulation of assimilatory sulphate reduction in Arabidopsis thaliana

Adenosine 5′-phosphosulphate reductase (APR) is considered to be a key enzyme of sulphate assimilation in higher plants. We analysed the diurnal fluctuations of total APR activity and protein accumulation together with the mRNA levels of three APR isoforms of Arabidopsis thaliana. The APR activity reached maximum values 4 h after light onset in both shoots and roots; the minimum activity was detected at the beginning of the night. During prolonged light, the activity remained stable and low in shoots, but followed the normal rhythm in roots. On the other hand, the activity decreased rapidly to undetectable levels within 24 h of prolonged darkness both in shoots and roots. Subsequent re-illumination restored the activity to 50% in shoots and to 20% in roots within 8 h. The mRNA levels of all three APR isoforms showed a diurnal rhythm, with a maximum at 2 h after light onset. The variation of APR2 mRNA was more prominent compared to APR1 and APR3. 35SO42– feeding experiments showed that the incorporation of 35S into reduced sulphur compounds in vivo was significantly higher in light than in the dark. A strong increase of mRNA and protein accumulation as well as enzyme activity during the last 4 h of the dark period was observed, implying that light was not the only factor involved in APR regulation. Indeed, addition of 0.5% sucrose to the nutrient solution after 38 h of darkness led to a sevenfold increase of root APR activity over 6 h. We therefore conclude that changes in sugar concentrations are also involved in APR regulation.

Estimating the uptake of traffic-derived NO2 from 15N abundance in Norway spruce needles

The 15N ratio of nitrogen oxides (NOx) emitted from vehicles, measured in the air adjacent to a highway in the Swiss Middle Land, was very high [δ15N(NO2) = +5.7‰]. This high 15N abundance was used to estimate long-term NO2 dry deposition into a forest ecosystem by measuring δ15N in the needles and the soil of potted and autochthonous spruce trees [Picea abies (L.) Karst] exposed to NO2 in a transect orthogonal to the highway. δ15N in the current-year needles of potted trees was 2.0‰ higher than that of the control after 4 months of exposure close to the highway, suggesting a 25% contribution to the N-nutrition of these needles. Needle fall into the pots was prevented by grids placed above the soil, while the continuous decomposition of needle litter below the autochthonous trees over previous years has increased δ15N values in the soil, resulting in parallel gradients of δ15N in soil and needles with distance from the highway. Estimates of NO2 uptake into needles obtained from the δ15N data were significantly correlated with the inputs calculated with a shoot gas exchange model based on a parameterisation widely used in deposition modelling. Therefore, we provide an indication of estimated N inputs to forest ecosystems via dry deposition of NO2 at the receptor level under field conditions.

Regenwind : (Gedicht)

Marianne Rein

Märchen von den vier Brüdern

Marianne Rein

Vier Gedichte

Marianne Rein

Die Liebenden : (Gedicht)

Marianne Rein

Soliman der Zweyte, oder die drey Sultaninnen : Ein Singspiel in zwey Aufzügen ; für die k. k. Hoftheater

nach dem Französischen des Herrn Favart bearbeitet von Franz Xaver Huber. Die Musik ist von Hrn. Franz Xav. Süßmayer, Kapellmeister in wirklichen Diensten der k. k. Theatral-Hof-Direktion

Na 1 Nachlass Max Horkheimer, 105 - Korrespondenzen u.a. mit Bertold Scheller und Alfred Schmidt (p. III 12, 175-380)

Briefwechsel zwischen Bertold Scheller und Max Horkheimer, 1955; Briefwechsel zwischen dem Diplom-Volkswirt Albert Schiefer und Max Horkheimer, 1957; Briefwechsel zwischen dem Bayerischer Schulbuch-Verlag und Max Horkheimer, 1954; Briefwechsel mit Beilagen zwischen der Deutschen Schlafwagen- und Speisewagen-Gesellschaft und Max Horkheimer, 1954; 1 Brief von Ludwig Benedict Schlesinger an Max Horkheimer, 1958; 1 Brief von dem Professor Alfred Schmidt an Max Horkheimer, 1957 und 1 Gutachten von Max Horkheimer, 1958; 1 Brief von Hermann Schweppenhäuser an Max Horkheimer, 1957; Briefwechsel zwischen W. Schmidt-Richberg und Max Horkheimer, 1957-1958; Briefwechsel zwischen Alfred Schmidweber und Max Horkheimer, 1956; 1 Brief von Katja Schmitz? an Max Horkheimer, 1955; Briefwechsel zwischen der Studentin Elsmarie Schmitz und Max Horkheimer, 1958; Briefwechsel zwischen dem Professor Günter Schmölders und Max Horkheimer, 1957-1958; 1 Brief an Diplom-Volkswirt Helmut Schneider von Max Horkheimer, 1955; Briefwechsel zwischen Marianne Schneider und Max Horkheimer, 1955-1956; Briefwechsel zwischen Georg von Schnitzler und Max Horkheimer, 1954; 1 Todenanzeige von Louis Schnürpel, 1956; Briefwechsel zwischen Roman Schnur und Max Horkheimer, 1955-1958; 1 Brief mit Anlagen an Günter P. Schölzel von Max Horkheimer, 1958; Briefwechsel zwischen Hans W. Schoenberg und Max Horkheimer, 1955; 1 Anzeige von Arnold Schoenberg, 1955; Briefwechsel zwischen der Studentin Annemarie Schöne und Max Horkheimer, 1956; Briefwechsel zwischen dem Professor Hans Joachim Schoeps und Max Horkheimer, 1955-1956; 1 Brief an den Professor Rudolf Schottlaender von Max Horkheimer, 1955; 1 Anzeige von Joachim Schroeter, 1955; Briefwechsel zwischen Karl Schück und Max Horkheimer, 1954; Briefwechsel zwischen Julia von der Schulenburg und Max Horkheimer, 1957; Briefwechsel zwischen dem Bankdirektor Felix W. Schulthess und Max Horkheimer, 1955; 1 Brief an den Privatdozent Walter Schulz von Max Horkheimer, 1954; Briefwechsel mit Beilagen zwischen dem Bürgermeister Wolfgang Schwabe und Max Horkheimer, 1954; Breifwechsel mit Beilagen zwischen Hans Schwalbach und Max Horkheimer, 1954; Briefwechsel mit Beilagen zwischen Poldi Schwalbach und Max Horkheimer, 1954; 1 Brief von Louis Daniel Schwallbach an Max Horkheimer, 1955; Briefwechsel zwischen Dorothea de Schweinitz und Max Horkheimer, 1958; 1 Aktennotiz von Hans Zulliger, 1956; Briefwechsel zwischen William Schwitzer und Max Horkheimer, 1954; Briefwechsel zwischen Karl von Stackelberg und Max Horkheimer, 1954; 1 Brief von Clemens Köttelwesch und Max Horkheimer, 1957; 1 Brief von dem Oberlandesgerichtspräsidenten Bruno Heusinger an Max Horkheimer, 1954; Briefwechsel zwischen dem Oberstadtdirektor Erich Walter Lotz und Max Horkheimer, 1953-1954; Briefwechsel zwischen der Stadtverwaltung Iserlohn und Max Horkheimer, 1954; Briefwechsel mit Beilagen zwischen dem Diplom Ingenieur und Oberbaurat Julius Schwalm und Max Horkheimer, 1954; 1 Brief an den Professor Herbert Plügge von Max Horkheimer, 1957; Briefwechsel zwischen den Professor und Oberlandesgerichtspräsidenten Curt Staffund Max Horkheimer, 1956-1957; 1 Brief von dem Professor B. M. Stanfield an Max Horkheimer, 1957; 1 Vermählungsanzeige von den Professor Dietrich Starck, 1956 und 1 Brief an den Professor Dietrich Starck von Max Horkheimer, 1958; Briefwechsel zwischen den Professor Werner Stark und Max Horkheimer, 1958; Briefwechsel mit Beilagen zwischen Rolf Stätter und Max Horkheimer, 1954; 1 Brief von Karl Staufen an Max Horkheimer, 1952; 1 Brief von Direktor Adolf Stauss an Max Horkheimer, 1954; Briefwechsel zwischen dem Bankier Alwin Steffan und Max Horkheimer, 1954-1957; 2 Briefe an den Professor Wolfgang Stegmüller von Max Horkheimer, 1957; Briefwechsel zwischen dem Professor und MinisterErwin Stein und Max Horkheimer, 1956-1957; 1 Brief an Lotte Steinberger von Max Horkheimer, 1954; 1 Brief von Ernst Steindorf an Max Horkheimer, ohne Jahr; Briefwechsel zwischen Helmut von den Steinen und Max Horkheimer, 1955 und 1 Brief an Helmut von den Steinen von Theodor W. Adorno, 1955; Briefwechsel zwischen den Professor Hans Erich Stier, 1958; Briefwechsel zwischen Elsbeth Stocker und Max Horkheimer, 1955; Briefwechsel zwischen Eric W. Stoetzner und Max Horkheimer, 1957-1958; Briefwechsel zwischen Gertrud Straulino und Max Horkheimer, 1957-1958; Briefwechsel zwischen den Professor Siegfried Strugger und Max Horkheimer, 1955; Briefwechsel mit Beilagen zwischen Willy Strzelewicz und Max Horkheimer, 1955-1957; Briefwechsel mit Beilagen zwischen der Studentenschaft der Universität Köln und Max Horkheimer, 1953;

Na 1 Nachlass Max Horkheimer, 510 - Korrespondenzen mit Theodor W. Adono (p. VI 2, 1 - 212)

Briefwechsel zwischen Theodor W. Adono, Gretel Adorno und Max Horkheimer, 1955-1957; 1 Brief der Gesellschaft für soziale Betriebspraxis an Theodor W. Adorno und Max Horkheimer, 30.08.1955; 1 Brief der Gesellschaft für soziale Betriebspraxis mbH in Düsseldorf an das Rationalisierungs-Kuratorium der Deutschen Wirtschaft RG Mensch und Arbeit in Frankfurt; 1 Brief von Theodor W. Adorno an Elisabeth Calvelli-Adorno, 19.08.1955; 5 Briefe zwischen Alice Maier und Theodor W. Adorno, 1955-1956; 2 Briefe von Theodor W. Adorno an Frederick Polock, 1955; 1 Brief von Theodor W. Adorno an Herrn Ritter, Dekan der Philosphischen Fakultät der Johann Wolfgang Goethe-Universität Frankfurt am Main, 24.05.1955; 1 Brief von Marianne Regensburger an Theodor W. Adorno, 1955; 1 Brief von Marianne Regensburger an Walter Abendroth, Berlin-Schöneberg, 11.05.1955; 1 Brief von Theodor W. Adorno an Herrn von Staa, 24.03.1955; 1 Brief von Theodor W. Adorno an Herrn Kux, 08.03.1955; 1 Briefentwurf von Theodor W. Adorno an Gottfried Weber, Dekan der Philosophischen Fakultät der Johann Wolfgang Goethe-Universität Frankfurt am Main, 1956; 1 Brief von Theodor W. Adorno an Renato Solmi, 04.09.1956; 1 Brief von Theodor W. Adorno an das Kuratorium der Johann Wolfgang Goethe-Universität in Frankfurt am Main, 27.03.1956;

Ms.Ff.F.Stoltze 3. 352 - Brief von Friedrich Stoltze an Gustav Kanngießer

Berichtigungen zu einem Artikel im "Beobachter", Johann Wolfgang von Goethe, Johann Gerhard Christian Thomas, Johann Jakob von Willemer, Marianne Willemer, Samuel Zirndorfer, Der Fiacre (Zeitschrift), Zensor Thomas(1848), Thomas, Redakteur der Ober-Postamts-Zeitung