Book of Abstracts - Geyseco

P - Posters
variety 16x36, but not in those of variety Cateto. Our results suggest
that Al-induced inhibition of root elongation has two components.
A reversible inhibition probably linked to Al binding to
pectin fraction in the cell wall and an irreversible component that
may operate at the level of BFA-induced inhibition of root elongation.
The Al-induced amelioration of BFA-induced inhibition
of root elongation suggests that Al could act as an activator of
G-protein-mediated signaling.
Acknowledgement: Supported by Spanish GovernmenBt
FU2007-60332/BFI
P07-009: FUNCTIONAL ANALYSIS OF METALLOTHIO-
NEIN GENES IN GENUS SILENE
Hudzieczek, V.* - Nevrtalova, E. - Hobza, R. - Vyskot, B.
Institute of Biophysics, v.v.i., ASCR
*Corresponding author e-mail: hudzieczek@ibp.cz
Metallothioneins are one of the most important genes in heavy
metal resistance and homeostasis. These genes code low molecular,
cysteine-rich proteins acting as metal binding chelators in
heavy metal detoxification. It has passed more than seventy years
since it was reported that closely related species Silene vulgaris
and S. dioica can sustain high concentrations of copper in soil.
On the other hand, still is little known about the molecular mechanisms
of this phenomenon in genus Silene. We have cloned
and characterized metallothionein3 gene (MT3) from different
ecotypes growing on copper-polluted soils (mainly from Špania
Dolina copper mines, Slovakia). Here we manifest that Silene
MT3 gene is - based on complementation assays in copper sensitive
mutant yeast strain - associated with heavy metal resistance.
The work was supported by the Grant Agency of AS CR grant
nos. M200040905 and KJB600040901.
P07-010: THE CONTRIBUTION OF CAX TRANSPOR-
TERS IN HEAVY METALS TOLERANCE OF CUCUM-
BER PLANTS
Papierniak, A.* - Migocka, M. - Klobus, G.
Wroclaw University, Faculty of Biological Science, Department
of Plant Physiology
*Corresponding author e-mail: anna.papierniak@gmail.com
Plant possess a wide range of heavy metal transporters engaged
in the various ions homeostasis. They include the proteins of
CAX (CAation eXchangers) family, which are likely to be involved
in the active sequestration of metals in the plant vacuole.
Indeed, our preliminary studies clearly indicate that the vacuole
membranes isolated from cucumber roots accumulate Cd, Mn
and Ni via H + /Me antiport. We have assumed that proteins of
CAX family could mediate that process. Therefore we screened
the cucumber genome in search for the genes encoding CAX
transporters and sequenced 6 orthologs of Arabidopsis typical
CAX1-6 genes. Following this, we performed a wide analysis of
the expression pattern of each CsCAX gene in both, inflorescence
and florescence organs and in response to heavy metals stress. All
CsCAX transcripts were clearly detectable in all tissues of both
7-day-old seedlings and 2- and 6-week-old plants with the exception
of CAX3, which was not expressed in the roots of seedlings.
However, in the 2 week-old plants shoots and leaves the levels
of CAX3 RNA significantly increased after Mn 2+ , Pb 2+ , Cd 2+ and
Ni2+ treatment. According to this, the CAX2 expression was also
enhanced by metals in roots, shoots and leaves of seedlings and
older plants. Our findings suggest that of all the CsCAX transporters
in cucumber, CAX2 and CAX3 may increase the metal
transport properties of tonoplast membrane in all plant tissues,
and thus determine cucumber tolerance to heavy metals stress.
Moreover, these studies provide a profound insight in the potential
function of CAXs in the distribution of various metals among
different cell tissues. The results also provide a basis for futher
functional studies of CAX genes in cucumber.
P07-011: CHARACTERIZATION OF METALLOTHIO-
NEIN OF TYPE 3 GENE AND ITS ROLE IN HEAVY-
METAL TOLERANCE AND ACCUMULATION IN THE
GENUS SILENE
Nevrtalova, E. 1 * - Vojtech, H. 2 - Roman, H. 2 - Boris, V. 2
1
Institute of Biophysics ASCR
2
Department of Plant Developmental Genetics, Institute of Biophysics,
ASCR, Brno Czech Republic
*Corresponding author e-mail: nevrtalova@ibp.cz
Metallothioneins (MTs) are a small Cys – rich cytoplasmatic proteins
with capacity to chelate different metal ions. Although it is
known that MTs play a general role in metal homeostasis, recent
data show that they participate mainly in copper tolerance and accumulation.
We have isolated a MT3 gene in heavy metal tolerant
plants Silene vulgaris and S. dioica. Molecular analysis indicates
different levels of expression induction of MT3 gene in some populations
of S. dioica and S. vulgaris species. To study the mode
of regulation of MT3 gene we also analyzed flanking regulatory
regions of the gene and we found an insertion of retroelement
into the promoter sequence. We conclude that the activation of
gene expression via the retrotransposon activation in stress conditions
(a high copper concentration in medium) could play a role
in the copper homeostasis in different Silene species.
Key words: metallothioneins, heavy metal resistance and accumulation,
copper, Silene vulgaris
Acknowledgements: The work was supported by AS CR grant
M200040905 and GACR 20409H002.
P07-012: A MUTANT SCREEN FOR REVERTANTS OF
H2O2-INDUCED CELL DEATH IN ARABIDOPSIS THA-
LIANA
Hoeberichts, F.* - Mühlenbock, P. - Vandorpe, M. - Van Breusegem,
F.
VIB Department of Plant Systems Biology, Ghent University
*Corresponding author e-mail: frhoe@psb.vib-ugent.be
Photorespiration is the most important source of H 2
O 2
production
in leaves in the light. This proces is initiated from the Calvin
cycle, when oxygenation of ribulose-1,5-biphosphate by Rubisco
is favoured over carboxylation. Oxygenation occurs at high
rates in the leaves of C3 plants and increases during adverse environmental
conditions that limit CO 2
availability and/or increase
light influx, such as drought or high light. H 2
O 2
is released during
the peroxisomal conversion of glycolate to glyoxylate, and
catalases are the principal H 2
O 2
-scavenging enzymes present in
the peroxisomes. Perturbation of catalase activity results in the
accumulation of photorespiratory H 2
O 2
, and studies using catalase-deficient
plants have revealed that photorespiratory H 2
O 2
triggers
extensive transcriptional reprogramming, bleaching of the
leaves, and cell death. In order to isolate mutants disturbed in
their response to photorespiratory H 2
O 2
, we screened an EMSmutagenised
population of the Arabidopsis thaliana catalasedeficient
T-DNA insertion line cat2-2. The obtained revertants all
display a reduction in the cell death phenotype and are expected
to carry mutations in genes involved in photorespiration and/
or H 2
O 2
-dependent cell death pathways. Results relating to the
phenotypic, biochemical and molecular characterisation of the
obtained revertants will be presented.
P07-013: MODULATION OF PLASMA MEMBRANE H+-
ATPASE UNDER HEAVY METALS.
Janicka-Russak, M.* - Klobus, G.
Wroclaw University, Institute of Plant Biology
*Corresponding author e-mail: russak@biol.uni.wroc.pl
Plasma membrane functions are rapidly altered by heavy metals
present in the environment at high concentrations. The first
diagnostic symptom of membrane damage by heavy metals is an
increase in its permeability with a subsequent disturbance in the
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