ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    How technology can reduce our impact on the Earth (2003)
    [s.l.] : Nature Publishing Group
    Nature 423 (2003), S. 115-115 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Sir William E. Rees, in his Concepts essay ”A blot on the land“ (Nature 421, 898; 2003), uses the ecological-footprint concept to argue that the 'carrying capacity' of the Earth has been exceeded because of technological ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/423115a
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Cell signalling Control of free calcium in plant cell nuclei (2000)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 405 (2000), S. 754-755 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Free calcium ions stimulate a huge variety of processes inside the cell, eliciting specific responses that depend on their spatio-temporal concentrations. Here we investigate how these changes in calcium concentration are triggered in the cytosol and nucleus of plant cells, and find that ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/35015671
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Abscisic-acid-induced turion formation in Spirodela polyrrhiza L. IV. Comparative ion flux characteristics of the turion and the vegetative frond and the effect of ABA during early turion development (1984)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 7 (1984), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Using the method of compartmental analysis, the ion fluxes and compartment concentrations of Ca2+, K+ and Cl- have been compared in the untreated vegetative frond and the abscisic acid (ABA) induced turion of Spirodela polyrrhiza. The ABA-induced turion is characterized by reduced Ca2+ exchange across the tonoplast and low vacuolar Ca2+ concentration relative to the vegetative frond. In addition the turion exhibits a higher plasmalemma flux with a correspondingly high Ca2+ concentration in the cytoplasm. The concentration of K+ and Cl- is much lower in the cytoplasm of the ABA-induced turion than in the vegetative frond with the influx/efflux ratio at both the plasmalemma and the tonoplast being less than 1, a finding exhibited also in dormant storage tissue.Treatment of vegetative fronds with ABA for 18 h resulted in a reduced K+ plasmalemma efflux relative to untreated vegetative fronds and a concomitant increase in the cytoplasmic concentration. There was no rapid effect of ABA on Ca2+, K+ or Cl- fluxes through either membrane. These results are consistent with the notion that drastic changes in ion fluxes and concentrations in the turion are a secondary consequence of ABA-induced development, possibly due to prior regulation by ABA of enzymes inherent to processes involved in membrane transport.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/1365-3040.ep11616215
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Abscisic-acid-induced turion formation in Spirodela polyrrhiza L. II. Ultrastructure of the turion; a stereological analysis (1983)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 6 (1983), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract The ultrastructural features of the abscisic-acid-induced turion of Spirodela polyrrhiza are briefly described and a comparison between turion and vegetative frond tissue was made by stereological analysis. The turion is characterized by its small size, reniform shape, and dark-brown coloration; the mesophyll is undifferentiated and totally lacking the substantial acrenchyma development found in the vegetative frond. The turion cells have a smaller vacuole and a denser cytoplasm than the cells of the vegetative frond. Stereological analysis showed that the tissues differed quantitatively only in three main respects: air space formation, vacuolation, and starch and cell wall material accumulation. During development, it is suggested that the cells of the turion, while reaching the same final size as the vegetative frond cells, accumulate numerous starch grains, thick cell walls, and large deposits of tannins and anthocyanin pigment at the expense of the vacuolar expansion characteristic of the normal maturity programme. Certain features of the turion ultrastructure indicate a differential cell sensitivity to ABA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/1365-3040.ep11588143
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Abscisic-acid-induced turion formation in Spirodela polyrrhiza L III. Specific changes in protein synthesis and translatable RNA during turion development (1984)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 7 (1984), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract The developmental process leading to the formation of the abscisic acid (ABA) induced turion of Spirodela polyrrhiza was accompanied by a repression of nucleic acid and protein synthesis. DNA synthesis in the developing lurion (induced by 10−4mol m−3 ABA) was inhibited within 3h of ABA addition, followed by a repression of protein synthesis after 24 h, while RNA synthesis was not inhibited until 3 d. The inhibitory effect of ABA on protein synthesis was found to be selective and the synthesis of several novel proteins appeared to be induced. These effects were specific to ABA-sensitive tissue.The relationship between the changes in the protein and mRNA profiles during the development of the turion was investigated. The rapid general inhibition of protein synthesis at early stages of lurion formation could not be accounted for by the level of translatable mRNA, indicating an effect of ABA at the translational level. The specific alteration to the pattern of in vivo labelled proteins could have resulted, however, from control of the level of specific mRNAs for those particular proteins. Only after 3 d in ABA, when the developing primordium is committed to the turion developmental pathway, is there a total inhibition in the production of mRNA leading to the shutdown of all primary processes and the onset of the irreversible events leading to the dormant state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-3040.1984.tb01565.x
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Abscisic-acid-induced turion formation in Spirodela polyrrhiza L. I. Production and development of the turion (1983)
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 6 (1983), S. 0 
    Details
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract The production, growth, and development of the abscisic-acid-induced turion (a small dormant bud) of Spirodela polyrrhiza were investigated. Addition of ABA to a culture of S. polyrrhiza resulted in growth inhibition at concentrations as low as 10−6molm−3, growth being completely arrested at 10−2 mol m. Over a single order of magnitude range around I0−4molm−3, ABA also induced the production of turions. The range of turion-producing concentrations of ABA was found to be much narrower than previously reported, turion production having a clearly defined threshold, optimum, and upper limit. The possibility that growth inhibition and turion formation are integrally linked aspects of a single response is discussed. Only primordia ≤0.7 mm long at the time of ABA addition could be induced to develop into turions and the events leading to turion formation were found to be reversible up to 72 h in ABA. It is concluded that in terms of turion formation there is a sensitivity window to abscisic acid lasting some 4–20h in the normal developmental life of frond cells. Providing cells experience the appropriate signal in this sensitivity window they initiate a new programme which eventually leads to turion formation. Microscopical analysis showed that the cells within this sensitivity window were still actively dividing. It is suggested that the developmental switch-over to rapid cell expansion and separation marks the end of this ABA sensitivity window.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/1365-3040.ep11588135
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Transgenic plant aequorin reports the effects of touch and cold-shock and elicitors on cytoplasmic calcium (1991)
    [s.l.] : Nature Publishing Group
    Nature 352 (1991), S. 524-526 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The apoaequorin-coding region from complementary DNA clone pAEQl (ref. 7) was fused to the cauliflower mosaic virus (CMV) 35S promoter8 and transferred to Nicotiana plum-baginifolia using the Agrobacterium tumefaciens pBIN19 binary vector system9 to provide constitutive expression (Fig. la). ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/352524a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Plant cyclic AMP comes in from the cold (1997)
    [s.l.] : Macmillan Magazines Ltd.
    Nature 390 (1997), S. 657-658 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Whether or not plant cells contain the growth factor cyclic AMP has been a source of controversy for over 25 years. Now, characterization of an enzyme that produces cAMP and mediates the action of the plant hormone auxin marks a decisive defeat for the majority view. Cyclic AMP is a key ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/37720
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Calcium in gravitropism. A re-examination (1997)
    Springer
    Planta 203 (1997), S. S85 
    Details
    ISSN: 1432-2048
    Keywords: Key words: Calcium ; Calmodulin ; Gravitropism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. For more than a decade it has been assumed that there is a strong relationship between Ca2+ and gravitropism. There is evidence to suggest that the movement of Ca2+ in the wall might regulate extension growth and that free intracellular Ca2+ might mediate signalling in statocytes. However, it is unlikely that changes in either wall Ca2+ or the concentration of free intracellular calcium, [Ca2+]i, act independently of each other. This results in ambiguity in both experimentation and interpretation of experimental information. It is also uncertain that the observed redistributions of wall Ca2+ are sufficient to induce bending and there is at present no direct evidence from measurement or imaging that changes in [Ca2+]i initiate or transduce gravitropic signals. The evidence relating Ca2+ to gravitropism is therefore substantial but still circumstantial. The involvement of free intracellular Ca2+ might best be tested using the new technologies of transgenic aequorin targeted to columella cells and thus resolve this important question. New information which relates control or orientation of tip-growing cells, such as pollen tubes, to cytosolic Ca2+ manipulation is presented. This information may be directly applicable to a gravitropic model system studied for many years, the Chara rhizoid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00008120
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Distribution of calmodulin protein and mRNA in growing pollen tubes (1998)
    Springer
    Sexual plant reproduction 11 (1998), S. 131-139 
    Details
    ISSN: 1432-2145
    Keywords: Key words Calmodulin ; mRNA ; Calcium ; Pollen tube ; Agapanthus umbellatus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  Pollen tube growth is a vital process for angiosperm fertilisation and is dependent on the presence of a tip-focused gradient of cytosolic free calcium ([Ca2+]c). In order to clarify some of the target molecules which convey the Ca2+ signal information, we investigated calmodulin distribution during tube growth. Fluorescently labelled calmodulin was pressure microinjected into pollen tubes and its distribution monitored by confocal microscopy. Calmodulin distributes evenly throughout the cell, but some of its binding sites form a V-shaped collar behind the apical region. This specific association dissipates upon growth arrest, and suggests an interaction of calmodulin with cytoskeletal-bound target proteins. The distribution of calmodulin mRNA was also analysed by microinjection of fluorescently labelled mRNA. No specific pattern was observed, with an even localisation in the body of tube and a lower concentration in the cell apex. Studies with localised application of inhibitors/activators indicate that calmodulin plays a crucial role in tip elongation but does not direct tube orientation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004970050130
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...