Special issue december 2015 - page 34

© Benaki Phytopathological Institute
Hellenic Plant Protection Journal - Special Issue 32
In tomato cultivation biotic stresses result in
lower production and product quality. The
GST isoenzymes participate in the antiox-
idative defence mechanism of plants con-
tributing to resistance against biotic stress
factors. The basic aim of our study was the
formation of transgenic lines overexpressing
the gmgstu4 gene using the CLX3731 toma-
to hybrid and to study their response to bac-
terial speck disease. For the genetic transfor-
mation, cotyledons of 12-15 days old were
cocultivated with transformed Agrobacteri-
um tumefaciens and subsequently grown on
MS R medium (0.1 mg/L ΙΑΑ, 0.5 mg/L Ζ, 250
mg/L Cf και 100 mg/L Km). PCR and RT-PCR
were conducted to verify the the presence
of the transgene in the lines (Β3 και Β7), and
to study transgene expression, respectively.
To examine resistance, in vivo transgenic and
wild type plants of 4-6 weeks old were in-
fected with the bacterium P. syringae pv. to-
mato. The response of the transgenic plants
to infection was evaluated 5 days later. The
transgenic lines showed 1.5 times fewer in-
fected leaves and 6.4 times fewer necrotic
lesions per plant, 1.7 times less electrolyte
leakage and 3.7 times more glutathione per-
oxidase enzymatic activity when compared
with the wild type plants. The study of the
gstu4 gene in genetically modified tomato
plants may suggest new ways to engineer
resistance against biotic stress factors.
First report of a “C andidatus phytoplasma solani” related strain infecting
two accessions of jimsonweed ( Datura stramonium) in Greece
L. L OTOS1, J.T. TSIALTAS2, V.I. M ALIOGKA1 , N. KALOUMENOS2 , I. G. ELEFTHEROHORINOS 2 and N.I.
K ATIS1
1Aristotle University of Thessaloniki, Faculty of Agriculture, Forestry and Natural
Environment, School of Agriculture, Laboratory of Plant Pathology, GR-541 24
Thessaloniki, Greece. 2Aristotle University of Thessaloniki, Faculty of Agriculture,
Forestry and Natural Environment, Faculty of Agriculture, Laboratory of Agronomy,
GR-541 24 Thessaloniki, Greece
Datura stramonium is a common weed in
spring crops in Greece and worldwide, which
includes two accessions (D. stramonium f.
stramonium, D. stramonium f. tatula). During a
field trial conducted at the Aristotle Universi-
ty Farm, where the two accessions were eval-
uated for growth rate and alkaloid content,
phytoplasma-like symptoms were observed.
Plant samples were taken and tested with
a generic nested-PCR targeting the high-
ly conserved 16S rRNA gene of the phyto-
plasma genome. The ~1200 bp amplicon ob-
tained only from the symptomatic plants of
both Datura accessions was sequenced and
compared with the NCBI database isolates,
using the BLASTn algorithm. Both isolates
(acc. no. HE598778 and HE598779 for D. stra-
monium f. stramonium and D. stramonium f.
tatula, respectively) exhibited 99% similarity
with the “Ca. Phytoplasma solani” reference
strain (AF248959). Infected plants of D. stra-
monium f. stramonium and D. stramonium f.
tatula showed 49-69% and 38% reduction of
the above-ground fresh weight, respective-
ly, as compared with the healthy ones. These
findings suggest that the phytoplasma is an
important pathogen of jimsonweed, which
reduces its vigour and makes this weed spe-
cies a good host-reservoir for this disease.
This is, to our knowledge, the first report of
a “Ca. Phytoplasma solani” related disease in
jimsonweed found in Greece.
Pseudomonas cichorii is the causal agent of tomato pith necrosis in Crete
E.A. TRANTAS, P.F. SARRIS*, M.G. PENTARI, E.E. M PALANTINAKI, F.N. VERVERIDIS and D.E. G OUMAS
Technological Educational Institute of Crete, School of Agricultural Technology,
Department of Plant Sciences, P.O.Box 1939, GR-710 04 Heraklion, Crete, Greece.