Book of Abstracts - Geyseco

P - Posters
the inflorescence. As a typical member of Asteraceae, gerbera tissues
are rich in two glucosidic lactones gerberin and parasorboside,
and many other secondary metabolites, which are important
for the plants to protect against microbial attack and insect herbivores.
During the recent years, high throughput genetic methods,
such as EST sequencing and microarrays, have been adopted for
identification of hundreds of candidate genes affecting gerbera
flower development or secondary metabolism. In this highly heterozygous
species, the functional studies need to be conducted
through reverse genetic methods by producing transgenic lines.
To facilitate these studies, our aim is to adapt virus-induced gene
silencing (VIGS) method for gerbera. Tobacco rattle virus (TRV)
has a very broad host range including gerbera. VIGS vectors
based on TRV have been powerful in inducing gene silencing
in many important plant species. Our initial studies show that
the TRV-based vectors induce gene silencing also in gerbera leaf
and flower tissues. Screening of 21 different gerbera genotypes
showed large differences in VIGS response. Out of these varieties,
6 most sensitive gerbera genotypes were selected for further
studies. Among different inoculation methods, vacuum inoculation
induced most intensive silencing on gerbera leaf tissues, and
stem wound scratching was more practical for inducing gene silencing
on flowers. The silencing of gerbera phytoene desaturase
gene (GPDS) and gerbera chalcone synthase (GCHS) gene induced
typical gene knock-out symptoms on host gerbera plants.
P17-035: CA2+-PUMPING ATPASE IN THE PERIBACTE-
ROID MEMBRANE OF BROAD BEAN ROOT NODULES:
SUBSTRATE SPECIFICITY AND EFFECTS OF PH AND
CALMODULIN
Krylova V*
K.A.Timiryazev Institute of Plant Physiolgy Russian Academy of
Sciences
*Corresponding author, e-mail: KrylovaVV@list.ru
Ca2+-pumping ATPase in the peribacteroid membrane of broad
bean root nodules:substrate specificity and effects of pH and calmodulin
( K.A.Timiryazev Institute of Plant Physiolgy Russian
Academy of Sciences ) It is well known that the processes of ion
transport through the peribacteroid membrane (PBM) of symbiosomes
play an important role in the regulation of nitrogen fixing
plant root-rhizobium symbiosis in legumes in the course of the
interaction between pro- and eukaryotic cells in root nodules.
Previously, we had shown that symbiosomes from yellow lupine
and broad bean root nodules behave as Ca-storing compartments
in infected cells and such a behavior is in part due to an active
transport of Ca2+ through the PBM as a result of functioning of
ATP-driven Ca2+-pump in this membrane. Here, some biochemical
characteristics of the Ca2+-pumping ATPase in the PBM of
broad bean root nodules were studied by monitoring the decrease
in the external calcium concentration caused by ATP-dependent
Ca2+ uptake by both isolated symbiosomes and the PBM vesicles
with a metallochromic Ca2+-indicator arsenazo III. The rate
of this process was shown to achieve a maximal value at pH 7.2
and to decline about six-fold at extreme chosen pH values (pH
6.0 and 8. 0). It was established that, although a predominant
substrate for the Ca2+-ATPase is ATP, this enzyme is capable
of utilizing other nucleotide triphosphates as well, such as ITP,
GTP, UTP and CTP, as energy donors for providing Ca2+ translocation
through the PBM. An efficiency of all these substrates
was found to decline in the following series: ATP > ITP > GTP
> UTP > CTP. An apparent Km of the Ca2+-ATPase for MgATP
was shown to be in the range of 0.1 – 0. 2 mM. In the
reaction medium not containing exogenous calcium, the rate of
ATP-dependent Ca2+-pumping appeared to be markedly stimulated
by exogenous calmodulin, a well-known Ca2+-sensor in
animal and plant cells, from bovine brain achieving a maximal
incre-ase of about two-fold at moderately high concentrations of
the given protein. The results obtain-ned allow us to conclude
that the characteristics revealed
of the PBM Ca2+-ATPase under study share with those inherent
in IIB type Ca2+-ATPases functioning in other plant cell membranes.
P17-036: ANALYSIS OF MICROTUBULE AND ACTIN
FILAMENTS DYNAMIC OF THE PINUS SYLVESTRIS
ROOTS TO INFECTION BY P, S AND F GROUPS OF HE-
TEROBASIDION ANNOSUM
Zadworny, M. * 1 - Guzicka, M. 1 - Lakomy, P. 1 - Samardakiewicz, S. 2 -
Smolinski, D.J. 3 - Mucha, J. 1
1
Institute of Dendrology, Polish Academy of Sciences
2
Adam Mickiewicz University, Poznan, Poland
3
Nicolaus Copernicus University, Torun, Poland
*Corresponding author, e-mail: zadworny@man.poznan.pl
Cytoskeleton dynamic plays a crucial role in pathogen recognition
and defence response during initial steps of interaction between
invader and host in the plant cell. Extend of the response
is linked to the host specialization and resistance status. The aim
of our study was to characterize the cytoskeleton arrangement
of Pinus sylvestris root cortex cell in reactions to infection by P,
S and F intersterility group of Heterobasidion annosum and to
enhance by this our knowledge about pathogen specialization.
The cytoskeleton was visualized using immunofluorescence technique
on Steedman‘s wax sections. P. sylvestris inoculation
with non-adapted Fand S groupsfungal strains resulted in more
intensive depolymerizationof host microtubule during early stages
of interaction than was observed after inoculation with welladapted
P group. In S and F groups abnormal arrangements and
deposition of the polymerized tubulin aggregates was seen. The
analysis also showed polarisation of hostmicrofilaments towards
the site of attempted penetration by specificfungal strains. Application
of the cytoskeleton inhibitors enhanced fungal entry in the
non-host cells. It suggests that cytoskeleton of P. sylvestris cell
play a crucial role in restricting access by P, S and F intersterility
groups of H. annosum showing different host preferences.
The research has been supported by the Ministry of Science and
Higher Education (project no. NN 309377733).
P17-037: PRE-EXPOSURE OF ARABIDOPSIS TO CD2+
DOES NOT AMELIORATE THE PLANT RESPONSE TO
THE INFECTION CAUSED BY BOTRYTIS CINEREA.
Cabot, C.* - Gallego, B. - Martos, M. - Sibole, J.V. - Barceló,
J. - oschenrieder, C.
Universitat Autònoma de Barcelona
*Corresponding author, e-mail: ccabot@uib.es
Plants aresimultaneously exposed to multiple stresses in nature.
Different studies have shown that a stress exposure can prime
the plant response to forthcoming unfavorable conditions, which
are mediated by a cross-talk among multiple hormone signalling
pathways. The interaction between jasmonic (JA) and salicilic
(SA) acid has been studied using biotic stresses caused by a combination
of biotrophic and necrotrophic organisms. While at very
low phytohormone concentrations synergistic responses were reported,
high SA concentration was found to suppress JA-induced
gene expression. Little information is available on these phytohormone
interactions in the combined response to biotic and
abiotic stresses. In Arabidopsis, the JA-signalling pathway was
found to participate in the plant response to Cd2+ and infections
caused by the nectrofic pathogenic fungus Botrytis cinerea. In
this work five week-old Arabidopsis thaliana Col 0 plants individually
cultured in aereated 25% Hoagland solution were sumitted
to the following treatments: 1,5 mM Na4SiO4; 1 μM CdCl2; 10
μM CdCl2; 1,5 mM Na4SiO4 + 1 μM CdCl2; 1,5 mM Na4SiO4
+ 10 μM CdCl2. After 48 h, half of the plants of each treatment
were inoculated with Botrytis cinerea. Different physiological
parameters and gene expression of different markers for the
ethylene, JA and SA gene signalling pathways were analyzed at
different times. Only plants pre-exposed to Si showed an ame-
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