Library

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: DFG German National Licenses  (3)
  • Electronic Resource  (3)
  • 1990-1994  (2)
  • 1980-1984  (1)
  • Auxin and stem growth  (2)
  • Monooxygenases
Source
  • Articles: DFG German National Licenses  (3)
Material
  • Electronic Resource  (3)
Years
Year
  • 1
    ISSN: 1432-2048
    Keywords: Auxin and stem growth ; Epidermis and stem growth ; Pisum (stem growth) ; Phytochrome stem growth ; Stem elongation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of red (R) and far-red (FR) light on stem elongation and indole-3-acetic acid (IAA) levels was examined in dwarf and tall Pisum sativum L. seedlings. Red light reduced the extension-growth rate of etiolated seedlings by 70–90% after 3 h, and this inhibition was reversible by FR. Inhibition occurred throughout the growing zone. After 3 h of R, the level of extractable IAA in whole stem sections from the growing zone of etiolated plants either increased or showed no change. By contrast, extractable IAA from epidermal peels consistently decreased 3 h after R treatments. Decreases of 40% were observed for epidermal peels from the top 1 cm of tall plants receiving 3 h R. Brief R treatments resulted in smaller decreases in epidermal IAA levels and these decreases were not as great when FR followed R. In lightgrown plants, end-of-day FR stimulated growth during the following dark period in a photoreversible manner. The uppermost 1 cm of expanding third internodes was most responsive to the FR. Extractable IAA from epidermal peels from the upper 1 cm of third internodes increased by 30% or more 5 h after FR. When R followed the FR the increases were smaller. Levels of IAA in whole stem sections did not change and were twofold greater than in dark-grown plants. In both dark- and light-grown tall plants, IAA levels were lower in epidermal peels than in whole stem segments. These results provide evidence that IAA is compartmentalized at the tissue level within the growing stem and that phytochrome regulation of stem elongation rates may be partly based on modulating the level of IAA within the epidermis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2048
    Keywords: Auxin and stem growth ; Epidermis and stem growth ; Pisum (stem growth) ; Phytochrome stem growth ; Stem elongation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The effect of red (R) and far-red (FR) light on stem elongation and indole-3-acetic acid (IAA) levels was examined in dwarf and tallPisum sativum L. seedlings. Red light reduced the extension-growth rate of etiolated seedlings by 70–90% after 3 h, and this inhibition was reversible by FR. Inhibition occurred throughout the growing zone. After 3 h of R, the level of extractable IAA in whole stem sections from the growing zone of etiolated plants either increased or showed no change. By contrast, extractable IAA from epidermal peels consistently decreased 3 h after R treatments. Decreases of 40% were observed for epidermal peels from the top 1 cm of tall plants receiving 3 h R. Brief R treatments resulted in smaller decreases in epidermal IAA levels and these decreases were not as great when FR followed R. In lightgrown plants, end-of-day FR stimulated growth during the following dark period in a photoreversible manner. The uppermost 1 cm of expanding third internodes was most responsive to the FR. Extractable IAA from epidermal peels from the upper 1 cm of third internodes increased by 30% or more 5 h after FR. When R followed the FR the increases were smaller. Levels of IAA in whole stem sections did not change and were twofold greater than in dark-grown plants. In both dark- and light-grown tall plants, IAA levels were lower in epidermal peels than in whole stem segments. These results provide evidence that IAA is compartmentalized at the tissue level within the growing stem and that phytochrome regulation of stem elongation rates may be partly based on modulating the level of IAA within the epidermis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 44 (1980), S. 85-98 
    ISSN: 1432-0738
    Keywords: Aryl hydrocarbon hydroxylase ; Cell cultures ; Drug-metabolizing enzymes ; Glucuronyltransferase ; 3-Hydroxy-benzo(a)pyrene ; Monooxygenases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cells in culture were investigated for the expression of monooxygenase and UDP-glucuronyltransferase activities as representatives of activating and inactivating pathways of drug metabolism. Most established cell lines express monooxygenase activity that is detected by the oxygenation of polycyclic hydrocarbons and appears to be a function of cytochrome P-448-dependent enzyme forms (Wiebel et al., 1977). In the hepatoma cell line, H-4-II-E, dexamethasone is capable of increasing the level of benzo(a)pyrene-monooxygenation about 10-fold and of potentiating its induction by benz(a)anthracene. The enzyme activities elicited by dexamethasone and the polycyclic hydrocarbon did not significantly differ in their response to 7,8-benzoflavone, an inhibitor of cytochrome P-448-dependent monooxygenases. Observations on the pattern of benzo(a)pyrene metabolites formed in benz(a)anthracene-treated H-4-II-E and BHK21(C13) cells indicate that established cell cultures may contain different forms of monooxygenases of the cytochrome P-448 type. The majority of cell lines tested express UDP-glucuronyltransferase activity directed toward the substrate, 3-hydroxybenzo(a)pyrene. No clear correlation appears to exist between the presence and level of monooxygenase and glucuronyltransferase activities in the various cell lines, i.e., the cultures may express any one or both enzymes. The ratio of the two enzyme levels can be modified by selective induction. Thus, at present there is a choice of established cells in culture exhibiting widely differing ratios of activating and inactivating enzymes to analyse the metabolic pathways of selected classes of foreign compounds, such as polycyclic hydrocarbons, and to determine their toxicological significance. Further efforts are likely to yield cell lines that express the enzymic functions lacking in the cultures currently used and will be suitable to study the full spectrum of foreign compounds.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...