• Admin
    UC Research Repository
    View Item 
       
    • UC Home
    • Library
    • UC Research Repository
    • College of Science
    • Science: Theses and Dissertations
    • View Item
       
    • UC Home
    • Library
    • UC Research Repository
    • College of Science
    • Science: Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of the RepositoryCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    Statistics

    View Usage Statistics

    On the metabolism of sulphur in excised roots

    Thumbnail
    View/Open
    reay_thesis.pdf (22.99Mb)
    Author
    Reay, P. F.
    Date
    1967
    Permanent Link
    http://hdl.handle.net/10092/4774
    Thesis Discipline
    Plant Physiology
    Degree Grantor
    University of Canterbury
    Degree Level
    Doctoral
    Degree Name
    Doctor of Philosophy

    The assimilation of several sulphur compounds in excised roots grown in culture was studied. To obtain sulphate deficient conditions a sulphate impurity was removed from the sugar component of the medium by ion exchange. The sulphur compounds investigated were sulphate, taurine, cysteic acid, elemental sulphur, cystine, cystamine, glutathione, homocystine and methionine. Of these possible sources of sulphur, sulphate, cystine, homocystine and methionine were utilized for growth. All four were available for the synthesis of protein cysteine and methionine. The roots responded to elemental sulphur but whether the roots assimilated the sulphur before or after oxidation to sulphate was not established. 2. The radioactive sulphur compounds present in tomato root extracts were separated after ion exchange fractionation by thin layer electrophoresis and chromatography. Thiols present in these extracts were protected from oxidation by reaction with iodoacetamide, but acetamidocysteine was later found to be unstable. 3. Among the compounds labelled by incubating tomato roots for quarter of an hour with carrier-free (³⁵S)sulphate, were glutathione, cysteine and methionine as well as protein cysteine and methionine. 4. When both sulphate and methionine were supplied to roots, exogenous methionine was incorporated preferentially into protein methionine whereas the label of sulphate, after assimilation into cysteine was incorporated preferentially into protein cysteine. Glutathione was but slightly labelled and cysteine not at all by methionine in the presence of sulphate so sulphate or a metabolite reduced the conversion of methionine into cysteine and supplied most of the sulphur for cysteine synthesis.

    Collections
    • Science: Theses and Dissertations [3440]
    Rights
    https://canterbury.libguides.com/rights/theses

    UC Research Repository
    University Library
    University of Canterbury
    Private Bag 4800
    Christchurch 8140

    Phone
    364 2987 ext 8718

    Email
    ucresearchrepository@canterbury.ac.nz

    Follow us
    FacebookTwitterYoutube

    © University of Canterbury Library
    Send Feedback | Contact Us