Book of Abstracts - Geyseco

P - Posters
(from 0.5 to 4 g/MJ). Maximum quantum efficiency of PSII (Fv/
Fm) and photochemical quenching of PSII (phiPS2) of the last
ligulae leaf were measured during the cycle. Variations of Fv/
Fm and PhiPS2 can in some extent explain the RUE variations
observed.
P01-082: UPTAKE AND TRANSLOCATION OF HEAVY
METALS IN RAPHANUS SATIVUS : A COMPARISON OF
TWO GROWING SYSTEMS
Di Salvatore, M.* - Carafa, A.M. - Aprile, G.G. - Carratù, G.
DIARBOPAVE - Università degli Studi di Napoli Federico II
*Corresponding author, e-mail: mdisalva@unina.it
In this study we compare the heavy metals effect on radish plants
grown in soil and in hydroponic culture to check whether the
plant response to heavy metals (Cd, Cu, Ni and Zn) is affected
by the cultural system. In hydroponics all nutrient elements are
fully available to the plant, while in soil only a fraction of the total
nutrients are available. In order to obtain comparable nutrient
availability in both cultural systems, we prepared artificial soils
where the available fraction of each element was the same as
in the hydroponic nutrient solution. In both growing substrates
the heavy metals were given together. The following parameters
were monitored: 1) germination percentage 2) biomass production
3) heavy metals quantity in the shoot. In both growth substrates,
soil and hydroponic culture, the seed germination percentage
(> 90%) was not affected by heavy metals. With no heavy
metals added, biomass production of plants grown in soil or in
hydroponics was not statistically different. In hydroponics, the
addition of heavy metals resulted in a reduction of radish growth
while in soil, the differences between the biomass of the controls
and the respective treatments was in no case statistically significant.
At the same available concentration of heavy metals in both
substrates, radish plants grown in hydroponics absorb higher
concentrations of heavy metals in comparison with plants grown
in soil. These results suggest that when studying the absorption
and translocation of metals in vegetables, it is not possible to
compare the concentration of heavy metals in a hydroponic solution
with the heavy metals concentrations chemically extracted
from a soil.
P01-083: POTENTIAL REDOX IN POTATO (SOLANUM
TUBEROSUM) UPON WATER DEFICIENCY
D.Boguszewska* - M.Grudkowska - B.Zagdanska
Plant Breeding and Acclimatization Institute
*Corresponding author, e-mail: dominika@boguszewska.net
Drought is one of the major abiotic stresses affecting plant
growth, development and productivity. Plants exposed to water
deficiency undergo changes in their metabolism in order to cope
with the unfavourable environmental conditions. One of the biochemical
consequences occurring under dehydration of plants is
the production of reactive oxygen species (ROS). Mechanisms
that minimize oxidant concentrations and maintain the internal
reducing environment ranged from reducing molecules such as
glutathione and ascorbate to many enzymes such as superoxide
dismutase, catalase and other peroxidases, that further reduce
ROS to water. Mechanisms that initiate the production of ROS
are central to understanding not only the stress physiology but
the pattern of plant growth as well.
Therefore, the question arises whether ROS-scavenging mechanisms
of plants including activity and pattern of superoxide dismutase,
peroxidase and catalase (EC 1.11.1.6) are changed under
soil drought applying in tuberisation phase of potato development.
Experiments were carried out on 2 potato cultivars: Cekin
and Tajfun differing in dehydratation tolerance. Analytic electrophoresis
of tuber extracts under non-denaturating conditions (native
PAGE) was performed according to Laemmli (1972).
The proteins subjected to SDS-PAGE were transferred electrophoretically
to a nylon membrane. The membrane blot was incubated
with anti-cAPX antibodies or anti-Gluthatione reductase.
The obtained results clearly indicate that soil drought induced the
new bands of peroxidase and superoxide dismutase activities in
leaves and tubers. However, the observed induction of antioxidant
responses seems to be genotype dependent.
The proteome analysis of potato tubers during drought has been
initiated. The knowledge of potato stress-related proteins could
help to understand the molecular basis of potato drought tolerance
P01-084: CHANGES IN HYDROGEN PEROXIDE PRO-
DUCTION AND THE CONTENTS OF ASCORBATE AND
GLUTATHIONE IN ROOTS OF TWO WHEAT CULTI-
VARS DURING EXPOSURE TO WATER STRESS
Koenigshofer, H.* - Loeppert, H.
University of Natural Resources and Applied Life Sciences
BOKU
*Corresponding author, e-mail: helga.koenigshofer@boku.ac.at
Drought like other stress conditions frequently enhances the level
of reactive oxygen species (ROS) in plants. In green leaves an
excess of ROS during water deficit is mainly the result of increased
photorespiratory activity upon drought-related stomata
closure. However, less is known about the role of ROS in roots
under drought stress. Therefore, in the present study we have
monitored the contents of hydrogen peroxide (H 2
O 2
) and the major
water-soluble antioxidants ascorbate and glutathione during
water-stress conditions in roots of two wheat cultivars differing
in drought tolerance. The level of H 2
O 2
in the unstressed roots
of both cultivars did not change significantly during the daily
light-dark cycle. Deprivation of water did not affect the level
of H 2
O 2
in the roots of the drought-sensitive cultivar (Triticum
aestivum L. cv. Manhattan). In contrast, the drought-tolerant cultivar
(Triticum aestivum L. cv. Josef) showed a transient increase
in H2O2 in response to water deficit. Since the relative water
content (RWC) of the roots decreased in “Manhattan” but not in
“Josef” after prolonged exposure to drought, the H 2
O 2
increase in
the roots of “Josef” might act as a signal triggering adaptive processes
which allow to maintain a high water status. In the course
of exposure to water stress the concentration of ascorbate increased
markedly in the roots of both cultivars indicating that this
antioxidant substantially contributes to the control of the H 2
O 2
level in the roots.
P01-085: PLANT CELL WALLS, TOXIC METALS AND
THE ENVIRONMENT
Vatehová, Z. 1 * - Malovíková, A. 2 - Kollárová, K. 2 - Lišková, D. 2
1
Department of Plant Physiology, Faculty of Natural Sciences,
Comenius University
2
Institute of Chemistry, Slovak Academy of Sciences
*Corresponding author, e-mail: zuzana.vatehova@savba.sk
The plant cell wall is a dynamic extracellular structure with characteristics
depending on the species, developmental stage of
the plant/cell cycle, type of the tissue, and growth conditions.
It provides cells with structural support and protection, and also
acts as a filtering/immobilization mechanism limiting the entry
of molecules that may be toxic to the cell. The aim of our work
is to identify cell wall structure/components and mechanism or
mechanisms coupled with the cell wall which could be responsible
for plant tolerance and/or sensitivity to toxic metals. For
cell wall isolation we selected two clones of Zea mays, tolerant
and sensitive. The seeds were germinated for 72 hours at 25 oC,
70% humidity in the dark. Uniform seedlings were selected and
cultivated 10 days in solutions containing various concentrations
of Cd(NO 3
) 2
(10 -5 , 5x10 -5 and 10 -4 M) at 25 oC, 70% humidity, in
light conditions (130-140 μmol m -2 s -1 , 16 -h photoperiod). Single
cell wall components were extracted by chemical procedures
from aboveground plant parts and roots. Growth parameters
(elongation and fresh/dry mass of aboveground plant parts and
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