Book of Abstracts - Geyseco

P - Posters
Ahrazem, O.* - Gómez-Gómez, L. - Rubio Moraga, A. - Trapero-
Mozos, A.
E.T.S.I.Agrónomos, Universidad de Castilla-La Mancha
*Corresponding author, e-mail: oussama.ahrazem@uclm.es
Pathogenesis-related proteins are produced as part of the active
defences used to prevent attacks from microbial pathogens. In
this study, a full length cDNA encoding the CsPR10 protein was
identified in fresh saffron stigmas (Crocus sativus). The deduced
amino acid sequence from the nucleotide sequence of the coding
region showed its homology with PR10 proteins. The clone expressed
as a protein in fusion with a GST tag had a 47 kDa protein
in E. coli. CsPR10 had ribonuclease activity with features
common to class II-type ribonuclease; its specific activity was
quantified and found to be a 68.8 U mg-1 protein. CsPR10 inhibited
F. oxysporum growth and its antifungal potency toward
this fungus was reflected in the IC50 value of 8.3 μM. RT-
PCR analysis revealed of CsPR10 the presence of high transcript
levels in anther and tepal tissues, and low levels in stigmas and
roots, whereas no signal was detected in leaves. This protein
seems to be involved in the active defence response through activation
of the jasmonic acid pathway.
P17-018: IDENTIFICATION OF NBS-LRR CANDIDATE
RESISTANCE GENES IN WILD STRAWBERRY (FRAGA-
RIA VESCA) EXPRESSED DURING INFECTION WITH
PHYTOPHTHORA CACTORUM
Martinussen, I.* - Elameen, A. - Chen, X. - Klemsdal, S. - Brurberg,
M. B.
Norwegian Institute for Agricultural and Environmental Research
*Corresponding author, e-mail: inger.martinussen@bioforsk.no
Strawberry producers experience serious economical losses due
to the development of diseases caused by fungal or oomycete pathogens.
Phytophthora cactorum causes crown rot in strawberry
which is characterized by a sudden wilt of the younger leaves
and further collapse of the entire plant within a few days. In the
past, the most efficient method of preventing disease in crop
plants was through breeding for resistance using classical genetic
approaches. However, breeding for a single disease resistance
trait can take years and pathogens rapidly evolve mechanisms to
overcome single resistance traits. In order to improve the ability
to control and combat plant diseases, detailed insight in the molecular
mechanisms of disease development is required. NBSprofiling
is a powerful method developed to identify plant resistance
(R) genes. The technique is based on amplification of DNA
fragments, or as in this case c-DNA fragments, using adaptors
and primers designed to anneal to the conserved regions in the
P-loop and the kinase-2 motif in the NBS region of the R genes.
Here we present a time course study on the expression of putative
NBS-LRR genes from 0 to 8 days after infection with P. cactorum.
Several new NBS resistance genes have been identified.
P17-019: SPATIAL VARIATION OF REACTIVE OXYGEN
SPECIES AND ANTIOXIDANT ENZYMES IN STEMS
OF TWO CAPSICUM ANNUUM VARIETIES INFECTED
WITH PHYTOPHTHORA CAPSICI.
Candela, M. 1 - Requena, M. E. 1 - Gonzalez-Ramiro, L. 1 -
Egea-Gilabert, C. 2
1
University of Murcia
2
University Politechnic, Cartagena
*Corresponding author, e-mail: mcandela@um.es
The response to the pathogenic oomycete, Phytophthora capsici,
in plants of two varieties of pepper (Capsicum annuum L.),
(SCM) resistant and (CW) sensible, was studied. Both varieties
development a hypersensitive reaction and a potent signal associated
with significant accumulation of reactive oxygen species
(ROS) as superoxide anions (O2.-) and hydrogen peroxide
(H2O2), and an interesting variation of antioxidant enzymes
through stem. Both ROS increased much more in SCM stem
tissue, whereas in CW, ROS generation was noticed lesser, and
only in very few stem zones near inoculation. At similar level
with these compounds, changes of lipid peroxidation, solutes
leakage and the activity of the enzymes superoxide dismutase,
ascorbate peroxidase, glutathione reductase, catalase, and oxidized,
reduced and total glutathione were largely changed. The
effects of inhibitors of endogenous Cu/Zn superoxide dismutase
(Diethyldithio carbamate) and catalase (3-amino-1,2,4-triazole
and salicylic acid) were also examined. Yields of ROS in the presence
of the inhibitors diphenylene iodonium and hydroxamic
acid suggest that ROS were generated in both host responses by
more than one mechanism and which are in direct relation with
resistant to pathogen.
This work has been partly supported by the Project BFU2004-
4707-CO2-01 from CICYT, Spain
P17-020: CHEMICAL GENETICS - IDENTIFICATION OF
NEW MICROBIAL ELICITORS OF PLANT DEFENSE
Steinhauser, C.* - Fekete, A. - Schmitt-Kopplin, P. - Vlot, C. -
Durner, J. - Von Rad, U.
Helmholtz Center Munich
*Corresponding author, e-mail: clara.steinhauser@helmholtzmuenchen.de
Defined bacterial or fungal surface molecules, called elicitors,
induce a defense response in plants against disease. We aimed
to identify new biological elicitors for defense from a library of
1150 bacterial extracts (provided by the German company Sourcon
Padena). The extracts were screened in Arabidopsis thaliana
cell suspension cultures with fluorescent dyes to specifically monitor
the induction of two early plant defense signals, nitric oxide
(NO) and reactive oxygen species. Furthermore, activation of
genes related to inducible disease resistance signaling pathways
was used as an indicator for defense on a genetic level. To this
end, transgenic A. thaliana cell suspension cultures carrying
promoter-GFP-constructs were used. Activation of salicylic
acid-related signaling (systemic acquired resistance) was monitored
with PR1::GFP and PR5::GFP construct, whereas jasmonic
acid/ethylene-dependent signaling was monitored by using
PDF1.2::GFP. As a result of the screening two bacterial extracts
were identified that show strong NO and PR-gene induction in
vitro. Subsequent studies with A. thaliana plants showed that the
extracts induced lesions in vivo that are reminiscent of a Hypersensitive
Response (HR) defense reaction. We are currently
deploying various liquid chromatography approaches (HPLC
and UPLC) combined with high resolution mass spectrometry
(FTICR-MS) to isolate the active compounds, or elicitors, from
the defense-inducing bacterial extracts.
P17-021: SULFUR SUPPLY INFLUENCES THE UP-RE-
GULATION OF TOBACCO GENES ENCODING KEY
ENZYMES OF CYSTEINE AND GLUTATHIONE BIOS-
YNTHESIS FOLLOWING TMV INOCULATION
Gullner, G. 1 * - Künstler, A. 1 - Király, L. 1 - Müller M 2 - Zechmann B 2
1 Plant Protection Institute, Hungarian Academy of Sciences
2 (Institute of Plant Sciences, University of Graz)
*Corresponding author, e-mail: ggull@nki.hu
Atmospheric sulfur depositions were strongly reduced in the
1980s so that soil sulfur deficiency became a nutrient disorder
and some fungal infections became increasingly obvious. In
agronomic field experiments a new form of disease resistance,
the sulfur-induced resistance (SIR) was described. Sulfur is essential
for the biosynthesis of cysteine (CYS), methionine and
the tripeptide glutathione (GSH) in plants. GSH and other sulfur
compounds play important roles in plant defense reactions
against microbial pathogens. However, very little is known about
the importance of CYS and GSH biosynthetic pathways in the
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