© Benaki Phytopathological Institute
Abstracts - 16th Hellenic Phytopathological Congress
15
host resistance. The exact nature, of these
compounds in
V. dahliae
, however, remains
unknown. In
Aspergillus,
the global regulator
of secondarymetabolism
laeA
encodes a nu-
clear protein that is required for the expres-
sion of secondary metabolite genes, while
its presence is considered indispensable for
mycotoxin, antibiotic and mycelial pigment
biosynthesis. BLAST analysis of the
V. dahli-
ae
genome with the
laeA
gene of
A. nidulans
led to the discovery of a homologous gene
that was named
VdlaeA. VdlaeA
was delet-
ed in
V. dahliae
in order to clarify whether
products of secondary metabolism play any
role in the virulence and physiology of this
fungus. Pathogenicity experiments in the
greenhouse revealed that the transformed
ΔVdlaeA
strains resulted in significantly re-
duced disease levels in eggplants, toma-
toes and
Arabidopsis thaliana
hosts.
ΔVdlaeA
strains also showed alteration in the rates
and morphology of germinating conidia, in
mycelial development, and in microsclerotia
formation. The study of the regulatory gene
VdlaeA
may contribute to a broader under-
standing of the molecular mechanisms by
which secondary metabolites are produced,
and more specifically to the investigation of
its role in
V. dahliae
virulence.
Molecular identification of and ochratoxin Α production by
Aspergillus
Section
Nigri
isolates from vineyards in Cyprus
Ι.S. P
ANTELIDES
, Ε. A
RISTEIDOU
, D. T
SALTAS
and Ν. I
OANNOU
Department of Agricultural Sciences, Biotechnology and Food Science, Cyprus
University of Technology, 3603 Limassol, Cyprus
calmodulin
gene. The PCR products were se-
quenced and the sequences obtained were
compared to those in the NCBI database. It
was found that 148 isolates were identified
as
A. tubingensis
(92%), 12 as
A. niger
(7.4%)
and 1 as
A. carbonarius
(0.6%)
.
Liquid chro-
matography analysis revealed that 17 of the
161 isolates were toxigenic; 16 of the
A. tub-
ingensis
(1.3 pg/mg-1.96 ng/mg) and the
A.
carbonarius
(1.43-1.68 ng/mg). This study
confirmed the infection of Cyprus vineyards
with black aspergilli and showed
A. tubin-
gensis
to be the predominant species. More-
over, 10.8% of these isolates were toxigenic
.
The population synthesis seems to be differ-
ent compared to other Mediterranean coun-
tries as only a single isolate was identified as
A. carbonarius
.
The aim of this study was to investigate the
infection of Cyprus vineyards with black
aspergilli (A
spergillus
section
Nigri
), the mo-
lecular identification and the evaluation of
ochratoxin A (OTA) production of the iso-
lated aspergilli. The mycotoxin ΟΤΑ is con-
sidered to be nephrotoxic, teratogenic,
immunosuppressive, carcinogenic and neu-
rotoxic. Initially, black aspergilli were isolat-
ed from grapes of the varieties ‘Marathef-
tiko’ and ‘Cabernet Sauvignon’ during 2010,
that originated from four areas of the Limas-
sol district, one of the main wine-produc-
ing regions of Cyprus. In total 161 isolates
(18%) were selected based on the macro-
scopic characteristics of black aspergilla.
DNA from each isolate was used in PCR reac-
tions with primers that amplified part of the
Genetic and molecular characterization and evaluation of Greek non-
toxigenic isolations of the fungi
Aspergillus
as potential biocontrol agents
against aflatoxins
M. G
EORGIADOU
1
, S.P. A
GORITSIS
2
, Κ. V
ICHOU
2
, G. V
ARDOUNIOTIS
2
, S. Y
ANNIOTIS
1
, Ε. P
APLOMATAS
2
,
P.J. C
OTTY
3
and D.I. T
SITSIGIANNIS
2
1
Agricultural University of Athens, Department of Food Science & Technology, Labo-
ratory of Food Engineering, 75 Iera Odos Str., GR-118 55 Athens, Greece.
2
Agricultural
