Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    ISSN: 1573-5044
    Keywords: Ipomoea ; morning glory ; cell culture ; acid phosphatases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Two acid phosphatases isolated from culturedIpomoea (moring glory) cells were separated by column chromatography on DEAE-cellulose. The two acid phosphatases have different pH optima (pH 4.8–5.0 and 6.0) and do not require the presence of divalent ions. The enzymes possess high activity toward pyrophosphate,p-nitrophenylphosphate, nucleoside di- and triphosphates, and much less activity toward nucleoside monophosphates and sugar esters. The two phosphatases differ from each other in Michaelis constants, in the degree of inhibition by arsenate, fluoride and phosphate and have quantitative differences of substrate specificity. In addition, they also differ in their response to various ions.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-5044
    Keywords: polypropylene membrane ; protoplast ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A method of using a buoyant polypropylene membrane floated on liquid medium to culture asparagus cells and protoplasts was examined. Compared with direct culture in lquid medium the method using a polypropylene membrane was found to be superior for small-volume culture of cells at low density as well as for the culture of protoplasts.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-5044
    Keywords: anthraquinone production ; cell culture ; Galium vernum ; polymeric adsorbents ; secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Anthraquinones produced by suspension cultures of Galium vernum are completely retained intracellularly. Surprisingly, in the presence of some polymeric adsorbents anthraquinones are partially released into the culture medium. The secretion and in situ removal stimulates anthraquinone production in cell cultures of Galium vernum. Best results were obtained with Wofatit ES and Amberlite XAD-2.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-5044
    Keywords: sweet potato ; amylase ; electrophoretic forms ; sucrose ; glucose ; maltose ; starch ; cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Cell cultures of sweet potato grown in media containing sucrose, glucose, maltose, or starch secreted amylase into the growth medium. The growth rate of cells was not appreciably affected by the carbon source employed for growth, although cells grown on sucrose had a slightly longer lag period before exponential growth occurred. Amylase levels inside the cells were not affected by carbon source, but the amount of amylase released into the medium was drastically affected. Maltose-grown cells released the most amylase while sucrose-grown cells released the least. Cells grown in the light released about twice as much amylase as cells grown in the dark when grown on glucose, maltose, or starch. Three amylase electrophoretic forms were found in the storage root tissue from which all cultures were derived. Cells grown in culture exhibited either two or three amylase forms, depending on the carbon source. The slowest migrating root amylase was found only in cells grown on starch. The root amylase having intermediate mobility was present in all cultures, as was a form having higher mobility than the most mobile root form. The fastest migrating electrophoretic form from the root was not present in any of the cells.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-5044
    Keywords: berberine ; callus ; cell culture ; Coscinium fenestratum ; Menispermaceae ; suspension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Callus and cell suspension cultures of Coscinium fenestratum were established from sterile petiole segments on Murashige & Skoog (MS) medium, supplemented with 2,4-dichlorophenoxy acetic acid (2,4-D) and benzyl amino purine (BAP). The cells in the culture produced berberine as the major compound. NAA stimulated the product synthesis over 2,4-D. Presence of light inhibited the growth and enhanced the berberine synthesis.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1573-5044
    Keywords: axillary bud culture ; cell culture ; peroxidase isoenzymes ; viniferin synthesis ; Vitis vinifera ; (Vitis vinifera x Vitis rupestris) x Vitis riparia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A zymographic screening of peroxidases (EC 1.11.1.7) capable of oxidizing 4-hydroxystilbene was carried out by means of the peroxidase-catalyzed oxidative coupling of 4-hydroxystilbene and 4-aminoantipyrine. This screening reveals that only a few isoperoxidases are active in oxidizing 4-hydroxystilbene to viniferin-type compounds in in vitro cultures of grapevine. Unlike total peroxidase activity measured with 4-methoxy-α-naphthol, the levels of total peroxidase activity measured using 4-hydroxystilbene are related to disease resistance against downy mildew in axillary bud cultures of Vitis vinifera and (Vitis vinifera x Vitis rupestris) x Vitis riparia. From this observation, and using the above zymographic assay, it was found that a 4-hydroxystilbene-oxidizing isoperoxidase was overexpressed in both leaves and stems of the hybrid in relation to the increase in disease resistance of this species. These results suggest that constitutive 4-hydroxystilbene-oxidizing isoperoxidases may participate through their role in viniferin synthesis in the constitutive resistance mechanism that grapevines show against downy mildew.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-5044
    Keywords: cell culture ; root culture ; rooting ; sodium chloride ; Solanum tubersom L.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Salt sensitivities of six potato cultivars using six levels of sodium chloride (0.0 to 0.25M) were studied in a greenhouse. Responses of these cultivars were also determined in tissue culture by studying rooting of stem segments, increase in length of cultured roots and inhibition of growth of cell suspension cultures using similar salt concentrations. Responses of cultured stem segments and cell suspensions differed from those expressed by whole plants. A close similarity was observed between the salt stress response of whole plants and of cultured roots. The latter technique may provide a preliminary screening method for assessing salt tolerance in potato genotypes.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-5044
    Keywords: cell culture ; hormones ; sex differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The endogenous levels of abscisic acid (ABA), indoleacetic acid (IAA) and of three cytokinins (transzeatin riboside, tZR; isopentenyladenosine, IPA; dihydrozeatin riboside, DHZR) were assayed in suspension cell cultures of male and female plants of asparagus by an immunological method. Assays were carried out on two different materials: - suspension cells of nine different genotypes (four males and five females), cultured in a growth regulator-free medium; - suspension cells of both male and female plants of a hybrid cultured in five different media. In the first series of assays, significant difference in ABA and cytokinins were found between the nine genotypes but not between the suspension cells of male and female plants even when they belonged to the same hybrid. In the second series, we found highly significant differences in tZR and DHZR levels between cell suspensions cultured in different liquid media; the levels of these endogenous growth regulators were positively correlated with the amount of sucrose in the medium. In comparison with flowers and spears of asparagus, assayed in a previous work (Marziani et al. 1990) suspension cells contained a higher cytokinin level (about 5 fold) and a greatly reduced abscisic acid content (about 175 fold).
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-5044
    Keywords: cell culture ; karyotype instability ; rDNA ; repetitive DNA ; retroelement ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A rapidly growingTriticum aestivum L. (wheat) derived long term suspension culture (named TaKB1), that is probably not regenerable, was analysed for karyotype rearrangements, stability and changes in repetitive DNA. The cell line has an average chromosome number of 21 and the DNA amount of unreplicated cells of TaKB1 measured by flow cytometry is about 30% lower than an unreplicated (1C) bread wheat genome.In situ hybridization of a repetitive DNA sequence (pSc119.2), which occurs as tandemly repeated blocks (heterochromatin) in wheat, shows that chromosomes from the TakB1 line have fewer and weaker subtelomeric locations of the sequence than wheat, suggesting deletions of distal chromosome segments and a reduction in the sites and copy number of the sequence. Thein situ hybridization pattern and chromosome morphology allowed 27 chromosome types to be identified in the cell line. No two analysed cells contained the same chromosome complement, although some chromosome types were present in every cell. Using Southern hybridization the structure and copy number of a retroelement (Wis-2) and its flanking sequence was shown to be the same in the TaKB1 cell line and wheat. Anin situ analysis of rDNA in the TaKB1 cell line (using the probe pTa71) showed a reduction in number of sites and rRNA genes in each cell from that in wheat. Interphase cells of the cell line showed dispersed signal throughout the nucleolus with no evidence for clusters of condensed and inactive rRNA genes.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-5044
    Keywords: acid phosphatase ; α-amylase ; cell culture ; enzyme inactivation ; fungal elicitor ; β-glucosidase ; pectinase ; peroxidases ; Picea abies ; Rhizosphaera kalkhoffii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Extracellular peroxidases of suspension cultures of spruce (Picea abies) (L.) (Karst) become inactivated when the cell suspension is elicited with a cell wall preparation of the spruce pathogenic fungus Rhizosphaera kalkhoffii. In contrast, cellular peroxidases are induced under these conditions. Both changes of activity are reflected in the isoenzyme profiles. Inactivation of the extracellular peroxidases is caused by an effector, arising from the cells after contact with the elicitor. Formation of the effector is limited to the beginning of elicitation, showing maximal activity at this period of time. Subsequently it becomes increasingly ineffective, probably due to inactivation. The effector is able to also inactivate commercial (horseradish) peroxidase. Inactivation was not the result of the action of a protease present in the medium. The elicitor exerts two different effects on the spruce cell suspension culture. It induces synthesis of enzymes correlated with lignin synthesis and an accumulation of lignin-like material. It also induces secretion of the negative effector which inactivates extracellular peroxidases. The elicitor-induced inactivation is not specific for peroxidases. Other extracellular enzymes, β-glucosidase and acid phosphatase (secreted by the cells into the medium) and α-amylase and pectinase (from Aspergillus strains) are also inactivated.
    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...