Book of Abstracts - Geyseco

FESPB 2010 - XVII Congress of the Federation of European Societies of Plant Biology
sea. We observed a differential distribution of species in the field.
As initial hypotheses, we suggested the probable influence of
water stress (caused by drought and/or salinity) and competition
in such distribution. In order to test the effects of each environmental
variable, we combined field observations with several
greenhouse experiments of water stress and competition, with
the analysis of different morphological, physiological and biochemical
parameters, including stress markers (free proline and
polyamines). Overall discussion revealed that the differential distribution
of grass species is due to complex interactions among
biotic and abiotic factors: K. glauca is not able to compete with
H. lanatus and D. glomerata under its physiological optimum.
But the increase of stress along bioclimatic gradient gradually
buffers the effects of competition, so that all species can coexist
in the driest coastal locations. Water deficit balances competitive
abilities of the species. Finally, the presence of K. glauca seems
to improve the adequation of the other two species to salinity
through niche divergence and/or the establishment of positive
interactions. Biotic and abiotic stress interactions are shown as
sources of biodiversity and stability.
P01-128: EFFECT OF SHORT-TERM SALINIZATION
AND DROUGHT ON THE RATE OF PLANT GROWTH
AND WATER TRANSPORT IN SHOOTS AND ROOTS
Budagovskaya, N.*
Institute of Plant Physiology
*Corresponding author, e-mail: postnabu@mail.ru
Rapid (min) and slower (h) growth response reactions of leaves
and stems of oat, barley, wheat, rice and buckwheat plants on
increase and decrease in NaCl concentration and drought at the
root zone have been studied using a highly sensitive method -
laser interference auxanometry. Addition of NaCl in increased
concentration to the root zone of plants caused a two phase response
reaction of leaves: decrease and the following increase in
their growth rate in each phase. Duration of the 1st phase was
shorter than that of the 2nd. Growth rate of leaves was restored
by the end of the 2nd phase (in few h after addition of NaCl). The
1st phase may be related to rapid adaptive reactions and changes
in leaf turgor, the 2nd – to slower adaptive processes –de novo
synthesis of protectors. Introduction of NaCl in high concentration
caused stoppage in leaf and stem growth and shrinking of
their tissues as result of dehydration. Reversal of water transport
in roots under salinization has been demonstrated. Washing the
roots of NaCl rapidly restored the turgor of leaves and increased
their growth rate. Under drought conditions the growth rate of
shoots decreased rapidly. Shrinking of leaf and stem tissues was
observed after the stoppage of shoot growth under drought as
well as at high level of salinization. The data obtained provide
information on dynamics of response reactions of shoots and
roots on increase and decrease of NaCl concentration, drought
and watering.
P01-129: DEPTH-DEPENDENT RESPONSE TO LIGHT
OF THE SEAGRASS POSIDONIA OCEANICA (L.) DELI-
LE
Ortolà, A.G. - Moliner, M. - Rodilla, M. - Ballester, I.
Universitat Politècnica de València
Posidonia oceanica is a seagrass endemic to the Mediterranean
Sea which is considered highly sensitive to reductions in light
availability, where small decreases can cause significant declines
in growth and depth distribution. The objetive of this study was
to characterize in Posidonia oceanica plants the effect of light
attenuation depth- dependent on whole plant carbon distribution,
using the activity of sucrose synthase (EC 2.4.1.13) as a general
indicator of the degree of metabolic activity. Posidonia plants
were collected at the Denia coast (Alacant, Spain) in depths of
3, 6 and 9 metres. The plants were divided into leaves, rhizomes
and roots for analysis. The increment in light attenuation within
the water column induces an increase in leaf length, a reduction
in shoot density and chlorophyll content, and a change in the
distribution pattern of carbohydrates. Soluble carbohydrates and
sucrose accumulate in below-ground tissues and their levels decreases
with the light attenuation. Starch is accumulated in the
leaves of plants growing in the deeper meadow. Sucrose synthase
(SS) activity decreases in leaves under reduced light conditions
but does not change in below-ground tissues. The results presented
show that under sub-optimal light conditions Posidonia
oceanica adjusts their carbon-budget to maintain growth and metabolic
processes.
P01-130: SULPHUR METABOLITES OF DURUM WHEAT
SEEDLINGS GROWN UNDER SALT STRESS
Nacca, F.* - Parisi, D. - Massaro, G. - Annunziata, M.G. - Carillo,
P. Fuggi, A.
Dipartimento di Scienze della Vita, Seconda Università di Napoli,
Caserta
*Corresponding author, e-mail: amodio.fuggi@unina2.it
Keywords: Glutathione, sulphur nutrition, salt stress, Triticum
durum Desf. cv. Ofanto.
Salt stress can strongly limit growth and productivity of crop
plants, mainly because of the oxidative stress caused by the increased
release of Reactive Oxygen Species (ROS). To prevent
or repair the oxidative damages, plant cells activate a complex
defence system involving enzymes and low molecular compounds
like glutathione, the major thiol metabolite occurring in
plants. Glutathione has key roles in sulphur metabolism, being
involved in the maintenance of the cellular redox state, detoxification
of xenobiotics, synthesis of phytochelatins, as well as in
regulation of sulphur allocation. Even if its role in the control of
sulphate assimilation has been demonstrated, minor information
are available in relation with salt stress. Here the effect of sulphur
nutrition on the levels of glutathione and its precursors has been
determined in leaves and roots of durum wheat (Triticum durum
Desf. cv ofanto) grown in hydroponics in Hoagland medium
containing different sulphate concentrations and kept in a growth
chamber under controlled conditions. Sulphur compounds were
determined as bimane-derivatives, separated in reverse phase
HPLC and quantified fluorimetrically. The findings evidenced
that, salt treatment decreased the tissue levels of glutathione and
cysteine, in the leaves and increased their content in the roots.
Financial support was obtained by “Seconda Università degli
Studi di Napoli”, “Ministero dell’Università e della Ricerca”
(PRIN 2006077008_005; 2008S9T3KK_003), “Regione Campania”.
P01-131: BIOCHEMICAL MECHANISM OF METHYU-
RE EFFECT IN CORN SEEDLING ROOTS UNDER SALT
STRESS CONDITIONS
Palladina, T. – Ribchenko, I. – Konturska, O.
M.G. Kholodny Institute of Botany National Academy of Science
of Ukraine
Salinity is the hard negative factor for plant organisms prevented
agriculture in many regions. This actual problem can be resolved
by plant salt tolerance increasing. Its main stream is consisted
in salt tolerant transgenic forms creation. However there
is another way with adaptogenic preparations using. Early we
have demonstrated preference of nontoxic synthetic preparation
Methyure permitted to breed corn on salinized fields. In
experiments on corn seedlings exposed at 0.1M NaCl presence
is was find that seed soaking in 10-7M Methyure prevented
salt stress display. This treatment normalized peroxidation process
and homeostasis. Besides Methyure influenced transport
processes in root cell membranes by lipid content stabilization
which restricted their permeability and by activation of H+pumps
and Na+-Н+-antiporters in plasmalema and tonoplast.
Thus Methyure adaptation effect under salt stress conditions
can be explained mainly by Na+ removing from cytoplasm.