GLORIA

GEOMAR Library Ocean Research Information Access

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
Filter
  • Articles  (5)
  • Articles: DFG German National Licenses  (5)
  • Abscisic acid  (2)
  • root length  (2)
  • Dinoflagellates
  • Springer  (5)
  • American Institute of Physics (AIP)
  • 2000-2004
  • 1995-1999  (2)
  • 1990-1994  (3)
  • 1960-1964
  • Biology  (3)
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition  (2)
  • Geosciences  (1)
  • Physics
Document type
  • Articles  (5)
Source
  • Articles: DFG German National Licenses  (5)
Keywords
Publisher
  • Springer  (5)
  • American Institute of Physics (AIP)
Years
  • 2000-2004
  • 1995-1999  (2)
  • 1990-1994  (3)
  • 1960-1964
Year
Topic
  • Biology  (3)
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition  (2)
  • Geosciences  (1)
  • Physics
  • 1
    Electronic Resource
    Electronic Resource
    Cell-specific density of symbiotic dinoflagellates in tropical anthozoans (1998)
    Springer
    Coral reefs 17 (1998), S. 329-337 
    Details
    ISSN: 1432-0975
    Keywords: Key words Coral ; Sea anemone ; Dinoflagellates ; Symbiosis ; Eutrophication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract  Symbiotic dinoflagellates are abundant in the endoderm cells of tropical marine anthozoans, but the cell-specific density (CSD) of symbionts has not yet been investigated. In this study we used mechanical and enzymatic methods of maceration, and staining with substrate-specific fluorochromes, to observe a large number of individual host cells from 33 species of tropical anthozoans collected in Florida, Hawaii and Jamaica or cultured in Monaco. In the majority of species, most of the host cells contained a single algal cell (singlet). Host cells with two or more (up to six) algae were much less abundant. The average CSD for the 33 species was 1.54±0.30 (range 1.11 to 2.19). Singlets arranged in a monolayer can account for the areal density of algae observed in many anthozoans. The dinoflagellates occupy most of the interior of macerated host cells, leaving the host cytoplasm and cell membrane as a thin outer layer, often unresolvable by light microscopy. This spatial arrangement may favor diffusion and transport of CO2, bicarbonate ions, and nutrients from the environment to the algae. The effect of nutrient enrichment on CSD was determined by exposing eleven species to chronically elevated levels of ammonium-N. After four weeks all species exhibited a dramatic increase in algal mitotic index and CSD. The potential consequences of environmentally induced increases in CSD in tropical anthozoans are discussed in terms of the decreased cell-specific photosynthesis (CO2 limitation) and decreased rates of calcification observed in other studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003380050133
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Regulation of the abscisic acid-responsive gene rab28 in maize viviparous mutants (1991)
    Springer
    Molecular genetics and genomics 230 (1991), S. 394-400 
    Details
    ISSN: 1617-4623
    Keywords: Maize rab gene ; Abscisic acid ; Water-stress ; viviparous mutants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We have isolated a new maize gene, rab 28, that responds to abscisic acid (ABA) treatment. This gene has been characterized by determining the sequence of the cDNA and corresponding genomic copy, and by mapping the start site of its transcript. The rab 28 gene encodes a protein of predicted molecular weight 27713 Da which shows strong homology with the Lea D-34 protein identified in cotton. The proximal promoter region contains the conserved ABA-response element, CACGTGG, reported in other plant genes to be responsible for ABA induction. rab 28 mRNA has been identified as ABA-inducible in embryos and young leaves. It is also induced by water-stress in leaves of wild-type plants. Regulation of the rab 28 gene was studied in maize viviparous mutants. The results obtained with the ABA-insensitive vp1 mutant show that rab 28 transcripts do not accumulate to a significant level during embryogenesis. Surprisingly, induction of rab 28 mRNA can be achieved in young embryos by exogenous ABA treatment. Moreover, water-stressed or ABA-treated seedlings of vp1 contain significant levels of rab 28 mRNA which is not detectable in well-watered seedlings. Regulation of the rab 28 gene in excised young embryos of ABA-deficient vp2 mutants, in which influences of the maternal environment are absent, closely resembles that found in non-mutant excised young embryos. The significance of these results is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00280296
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Two different Em-like genes are expressed in Arabidopsis thaliana seeds during maturation (1993)
    Springer
    Molecular genetics and genomics 238 (1993), S. 409-418 
    Details
    ISSN: 1617-4623
    Keywords: Dry seed ; Em-like genes ; Arabidopsis thaliana ; Abscisic acid ; Responsive genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Using a radish cDNA probe, we have isolated and characterized two genomic clones from Arabidopsis thaliana (GEA1 and GEA6) encoding two different proteins that are homologous to the “Early methionine-labelled” (Em) protein of wheat. GEA1 differs from GEA6 and Em clones of wheat in that a sequence coding for 20 amino acid residues is tandemly repeated 4 times. These two genomic clones correspond to two genes named AtEm1 and AtEm6. Sequencing of several cDNA clones showed that both genes are expressed. The transcription start site was determined for both genes by RNase mapping. The site of polyadenylation is variable and there is no obvious consensus sequence for polyadenylation at the 3′ ends of the genes. mRNA corresponding to GEA6 is present only in nearly dry and dry seeds, whereas that corresponding to GEA1 appears in immature seeds and is maximum in dry seeds. No expression of either gene could be detected in leaf, stem, or floral buds. Expression of both genes could be detected in immature seeds when the siliques were incubated with abscisic acid (ABA), demonstrating that both genes are ABA responsive. However, examination of the 5′ upstream region does not reveal any extensive homology, suggesting that regulation of the two genes differs. In situ hybridization with a GEA1 probe demonstrated that the expression of this gene is essentially located in the provascular tissues of the cotyledons and axis of the dry seed as well as in the epiderm and outer layers of the cortex in the embryo axis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00292000
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Evaluation of parameters describing the root system architecture of field grown maize plants (Zea mays L.) (1994)
    Springer
    Plant and soil 164 (1994), S. 155-167 
    Details
    ISSN: 1573-5036
    Keywords: axile roots ; maize ; nodal roots ; root length ; root system ; seminal roots ; Zea mays L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The objective of this work was to study elongation curves of maize axile roots throughout their elongation period under field conditions. Relationships between their elongation rate and the extension rate of their branched region were also studied. Maize, early-maturing cultivar Dea, was grown on a deep, barrier-free clay loam (depth 1.80m). Trenches were dug during four periods until after silking and axile roots were excavated. Parameters measured were total length and the lengths of basal and apical unbranched zones. The rank of the bearing phytomer and general data about the carrying plant were also recorded. Results showed that axile roots from lower phytomers had similar elongation rates irrespective of the rank of the carrying phytomer. This elongation rate declined with root age. A monomolecular elongation model was fitted to the experimental data. Elongation was much slower in roots from upper phytomers. A rough linear relationship was found between the elongation rate of axile roots and the length of the apical unbranched zone. This result suggests that laterals appeared on a root segment a constant time after it was formed. Possible mechanisms with may account for the declining elongation rate with root age (increasing distance from aerial parts or adverse environmental conditions in deep soil layers) and variability between individual roots are also discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00010067
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Geometrical properties of simulated maize root systems: consequences for length density and intersection density (1998)
    Springer
    Plant and soil 200 (1998), S. 157-167 
    Details
    ISSN: 1573-5036
    Keywords: maize ; model ; root architecture ; root intersection ; root length ; stochastic geometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The spatial distribution of root length density (RLD) is important because it affects water and nutrient uptake. It is difficult to obtain reliable estimates of RLD because root systems are very variable and heterogeneous. We identified systematic trends, clustering, and anisotropy as geometrical properties of root systems, and studied their consequences for the sampling and observation of roots. We determined the degree of clustering by comparing the coefficient of variation of a simulated root system with that of a Boolean model. We also present an alternative theoretical derivation of the relation between RLD and root intersection density (RID) based on the theory of random processes of fibres. We show how systematic trends, clustering and anisotropy affect the theoretical relation between RLD and RID, and the consequences this has for measurement of RID in the field. We simulated the root systems of one hundred maize crops grown for a thermal time of 600 K d, and analysed the distribution of RLD and root intersection density RID on regular grids of locations throughout the simulated root systems. Systematic trends were most important in the surface layers, decreasing with depth. Clustering and anisotropy both increased with depth. Roots at depth had a bimodal distribution of root orientation, causing changes in the ratio of RLD/RID. The close proximity of the emerging lateral roots and the parent axis caused clustering which increased the coefficient of variation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004382531671
    Location Call Number Limitation 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...