Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The effect of exogenously applied galactose on the cell wall polysaccharide synthesis and UDP-sugar levels in oat (Avena sativa L. cv. Victory I) coleoptile segments was studied to clarify the mechanism of inhibition of IAA-induced cell elongation by galactose, and the following results were obtained: (1) The inhibition of IAA-induced cell elongation by galactose became apparent after a 2 h-lag, while the lag was shortened to 1 h when galactose was added to the segments after more than 1 h of IAA application. (2) Galactose inhibited the [14C]-glucose incorporation into cellulosic and non-cellulosic fractions of the cell wall and the increase in net polysaccharide content in the fractions during long-term incubation. (3) The dominant sugar nucleotide in oat coleoptiles was UDP-glucose (2.1 nmol segment−1). Galactose application caused a remarkable decrease in the UDP-glucose level, accompanying a strong accumulation of galactose-1-phosphate and UDP-galactose. (4) Galactose-1-phosphate competitively inhibited the UTP: a-d-glucose-1-phosphate uridylyltransferase (EC 2.7.7.9) activity of the crude enzyme preparation from oat coleoptiles. From these results we conclude that galactose inhibits the IAA-induced cell elongation by inhibiting the formation of UDP-glucose, which is a key intermediate of cell wall polysaccharide synthesis.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 61 (1984), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Auxin-induced cell elongation in oat coleoptile segments was inhibited by galactose; removal of galactose restored growth. Galactose did not appear to affect the following factors which modify cell elongation: auxin uptake, auxin metabolism, osmotic concentration of cell sap, uptake of tritium-labeled water, auxin-induced wall loosening as measured by a decrease in the minimum stress-relaxation time and auxininduced glucan degradation. Galactose markedly prevented incorporation of [14C]-glucose into cellulosic and non-cellulosic fractions of the cell wall. It was concluded that galactose inhibited auxin-induced long-term elongation of oat coleoptile segments by interfering with cell wall synthesis.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 51 (1981), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: An exo-β-(1β3)-glucanase derived from Selerotinia libertiana induced growth of Avena sativa coleoptiles and degraded hemicelluloses and β-(1→4):(1→3) mixed linked glucan. However, neither endo-β-(1→4)- nor endo-β-(1→3)-glucanase activity could be detected in the enzyme preparation. Nojirimycin inhibited the glucan degradation caused by the enzyme but glucono-1,5-lactone did not. Another exo-β-(1→3)-glucanase derived from Basidiomycete QM 806 did not induce coleoptile growth and did not degrade the glucan. Growth-inducing properties of exo-β-(1→3)-glucanases are discussed.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Physiologia plantarum 25 (1971), S. 0 
    ISSN: 1399-3054
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Changes in the cell wall properties of Avena coleoptile segments were studied under various conditions by stress-relaxation analysis. Rheological models consisting of four or an infinite number of Maxwell viscoelastic components were used. The stress-relaxation parameters of these models, t1, to, T, Gi and stress/strain ratio, were determined. The following results were obtained.1. The 1/T1 increased and stress/strain ratio decreased with the age of the coleoptiles. Decapitation caused a decrease in l/t1.2. Auxin increased I/T1 but decreased to and stress/strain ratio within 5 minutes after application.3. Treatment with a fungal β-l,3-glucanase increased 1/T1 both in living and methanol-killed, pronase-treated coleoptiles. Cellulase did not cause the changes observed in the parameters of the isolated cell wall of the coleoptile segments. This held true for all treatments (with and without auxin, killed and pronase-treated).The results obtained suggest that auxin primarily causes a partial degradation of the non-cellulosic physaccharide components of the cell wall.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 117 (2002), S. 2359-2367 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Using molecular dynamics simulations, we study dynamics of a model polymer melt composed of short chains with bead number N=10 in supercooled states. In quiescent conditions, the stress relaxation function G(t) is calculated, which exhibits a stretched exponential relaxation on the time scale of the α relaxation time τα and ultimately follows the Rouse dynamics characterized by the time τR∼N2τα. After application of shear γ(overdot), transient stress growth σxy(t)/γ(overdot) first obeys the linear growth ∫0tdt′G(t′) for strain less than 0.1 but saturates into a non-Newtonian viscosity for larger strain. In steady states, shear thinning and elongation of chains into ellipsoidal shapes take place for shear γ(overdot) larger than τR−1. In such strong shear, we find that the chains undergo random tumbling motion taking stretched and compact shapes alternatively. We examine the validity of the stress–optical relation between the anisotropic parts of the stress tensor and the dielectric tensor, which are violated in transient states due to the presence of a large glassy component of the stress. We furthermore introduce time-correlation functions in shear to calculate the shear-dependent relaxation times, τα(T,γ(overdot)) and τR(T,γ(overdot)), which decrease nonlinearly as functions of γ(overdot) in the shear-thinning regime. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 1020-1022 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It is shown that the magnetoelastic anisotropy energies of the transition metal-noble metal multilayers which have fcc [111] perfectly flat interfaces can be expressed with biaxial moduli, magnetostrictions, and lattice mismatch. The calculated magnetoelastic anisotropy energies are larger than the shape anisotropy energy of Ni and large enough for the effective uniaxial magnetic anisotropy energies to be positive. For films with a large interfacial roughness, we have found the strain-induced magnetic anisotropy reduced considerably.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1520-5827
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-4854
    Keywords: woodceramics ; porous carbon ; electromagnetic shielding ; wastepaper
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Woodceramics are new porous carbon materials, which are made by impregnating woody materials with phenol resin and then thermoformed in a vacuum furnace and these have been shown to have electromagnetic shielding properties. In the recycling of wastepaper, ways of using the wastepaper other than for paper pulp are needed to be developed. In this study, we made Woodceramics from handbill advertisement paper and telephone directory paper, and measured their electromagnetic shielding properties in order to find new uses for wastepaper. The results showed that the Woodceramics made from wastepaper had an electric shielding effectiveness of 30 dB for 100 MHz and 40 to 43 dB for 300 MHz or higher, and had a magnetic shielding effectiveness of 30 dB for 100 MHz and 37 dB for about 400 MHz. An electric equivalent circuit of the pore model in the Woodceramics is introduced. In addition, it is proposed that the excellent electromagnetic shielding effectiveness of the Woodceramics is caused by dielectric loss.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1432-2048
    Keywords: Acid growth ; Auxin ; Fusicoccin ; Galactose ; Proton excretion ; Vigna epicotyl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We investigated the effect of galactose on IAA-induced elongation and proton excretion in azuki bean (Vigna angularis Ohwi et Ohashi) segments in order to confirm whether or not protons were involved in auxin-induced growth. Galactose inhibited the IAA-induced decrease in the solution pH but had no inhibitory effect on IAA-induced growth in segments of azuki bean epicotyls. On the other hand, galactose inhibited both IAA-induced growth and proton excretion in oat (Avena sativa L.) coleoptile segments. From these results it is unlikely that IAA-induced growth is mediated by proton excretion at least in azuki bean epicotyls.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A bacterium that assimilates (S)-3-chloro-1,2-propanediol [monochlorohydrin (MCH)] was isolated from soil by enrichment culture. The bacterium was identified as Pseudomonas sp. by taxonomic studies. The strain grew in a medium containing racemic MCH as a source of carbon and degraded (S)-MCH stereoselectively, liberating chloride ions. The residual isomer was the (R)-form [99.5% enantiomeric excess (ee)], which was obtained from the racemate in a final yield of 36% by using this strain. Subsequently, highly optically active (R)-glycidol (GLD) (99.3% ee) was prepared from the (R)-MCH obtained by reaction in alkaline solution. The cell-free extracts of the cells had both dehalogenating and epoxide-opening activities, which converted various halohydrins to the corresponding epoxides and epoxides to the corresponding diols, respectively.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...