GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    ISSN: 1573-5028
    Keywords: copper detoxification ; metallothionein ; metal tolerance ; pea ; Pisum sativum ; PsMT A
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The PsMT A gene from pea (Pisum sativum) shares similarity with metallothionein (MT) genes and related sequences have also been isolated from a number of other higher-plant species. The proteins encoded by these genes have not yet been purified from plants and their functions remain unclear although, by analogy to MT, roles in the metabolism and detoxification of metal ions have been proposed. By contrast, correlation between transcript abundance and Fe availability has led to an alternative proposal that these genes are involved in mechanisms of Fe efficiency. Phenotypic effects of constitutive PsMT A expression were examined in Escherichia coli and Arabidopsis thaliana. Copper accumulation by E. coli cells expressing recombinant PsMTA protein was approximately 8-fold greater than in control cells. No significant effects on the accumulation of Zn or Cd were detected. In segregating A. thaliana progeny, derived from a transgenic F1 parent containing the PsMT A gene under the control of a CaMV 35S promoter, 75% of individuals accumulated more Cu (several-fold in some plants) than untransformed, control plants. These data suggest that PsMTA protein binds Cu in planta and that uncoupled (constitutive) expression of the PsMT A gene causes enhanced Cu accumulation. Roots of P. sativum plants grown under conditions of low Fe availability showed elevated activity of root surface Fe(III) reductase and accumulated more Cu than roots of plants grown in an Fe-supplemented solution. Changes in the expression of MT-like genes, coincident with changes in Fe availability, are consistent with a role in Cu homoeostasis.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-5028
    Keywords: metallothionein ; PsMT A ; roots ; reporter gene ; senescence ; trace metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Upstream sequences (including the first seven codons) of a metallothionein (MT)-like gene from pea, PsMT A, were fused to GUS and introduced into Arabidopsis. High-level GUS expression was detected in the roots of plants grown on MS medium, except in regions proximal to the root apex. There was precise delineation of the root-shoot boundary. In soil-grown plants there was low GUS expression and this was absent from the more mature regions of the roots. In the aerial tissues of soil-grown plants, GUS expression was restricted to hydathodes, stipules, expanding cotyledons and the following senescent tissues: leaves, cotyledons, petals, sepals, filaments, stigmas, nectaries and siliques. A 298 bp region was shown to be required for GUS expression in roots but not for expression in vegetative aerial tissues of plants grown on MS medium. This region contains predicted ethylene-responsive elements (EREs) but similar patterns of GUS expression were detected in etr1 seedlings. GUS expression was significantly higher in roots exposed to 500 nM copper, but this increase was small in proportion to expression in roots exposed to 50 nM copper.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...