Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme V: CELL BIOLOGY AND PHYSIOLOGY Posters
the method of modern confocal lasermicroscopy (CLSM) -
a novel method in lichenology - is presented.
1089 - Phosphate transporter expression in the soybean
AM symbiosis
J.D.W. Dearnaley 1 , B.A. Learmonth 1 & D.S. Bougoure 2*
1 The University of Southern Queensland, West Street,
Toowoomba, 4350, Australia. - 2 The University of Western
Sydney, Locked Bag 1797, Penrith, Australia.
We are currently studying genes that are potentially
involved in the process of phosphate uptake in the
arbuscular mycorrhizal (AM) symbiosis of soybean. We
have extracted mRNA from AM colonised and uncolonised
soybean roots using biotinylated poly-T probes and
streptavidin-coated magnetic particles. Total mRNA
extracted by this method was reverse-transcribed into
cDNA with poly-T primer and reverse transcriptase. cDNA
was next PCR-amplified with primers for a previously
published soybean root phosphate transporter gene and
amplified sequences were visualized on silver-stained
acrylamide gels. In situ hybridization studies were carried
out to localise the phosphate transporter in root tissues.
Root cryosections were probed with a fluorosceinconjugated
antisense probe and bound targets were
visualized either via alkaline phosphatase labeling or with
an antifluoroscein texas-red antibody. Results of these
investigations are presented here.
1090 - Profiling differences in metabolic activity
between isolates of Penicillium camemberti using
dielectric spectroscopy (impedimetric measurements)
M. Decker * & P.V. Nielsen
Technical University of Denmark, BioCentrum-DTU,
Building 221, Technical Univeristy of Denmark, DK-2800,
Kgs. Lyngby, Denmark. - E-mail: mad@biocentrum.dtu.dk
In this work we characterise Penicillium camemberti starter
cultures in order to predict the quality of white mould
cheeses. Impedimetric changes in the first 100 hours after
inoculation are detected using a Bactometer at a 1 kHz
frequency. At this low frequency, the capacitance and
conductance changes in the medium are measured, thereby
indirectly measuring the metabolic activity of the fungi
growing in the medium. Traditional impedimetric methods
are used for detecting lag phase and growth rate. In the
present work we try to use all impedimetric changes in the
first 100 hours as a profile of the each isolate and
subsequently treat the data using chemometric methods. As
the metabolic activity of fungi depends strongly on the
environmental conditions, this study is done using a cheese
medium developed in our laboratory.
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Book of Abstracts
1091 - Intracellular enzymatic activity of the mycelium
of Pleurotus spp. grown on media containing 2-deoxy-
D-glucose
G. Díaz-Godínez * & C. Sánchez
Universidad Autónoma de Tlaxcala, Apartado Postal 129,
Tlaxcala, Tlax. C.P. 90000, Mexico. - E-mail:
gdg@cci.uatx.mx
The strain selection of edible mushrooms has often been
done by trial and error because there appear to be no clear
correlation between mycelial growth rates evaluated on
Petri dishes at laboratory level and productivity under
production plant conditions. It has recently been found that
the tolerance of some P. ostreatus strains to 2-deoxy-Dglucose
(DG) at laboratory level, is correlated with
improved yield of these strains at mushroom production
level. In this work, the effect of DG on the intracellular
activity of laccases (L), proteases (P), &beta-1,3glucanases
(G) and endoglucanases (E) of the mycelium of
strains of Pleurotus was evaluated. Six strains of P.
ostreatus; 201216, 32783, 58052, 38537, 201218 from
ATCC, and 3526 from NRRL, and two strains of P.
pulmonarius; PPL27 and PPL34 from the Chinese
University of Hong Kong Collection were studied. The
strains were grown on a starch-based media with 0.01%
(SDG) and without addition of DG (S) at 25 °C for 7 days.
On S, all the strains presented L, P, G and E activity.
However, on SDG, the strains 201216, 32783, 58052,
38537 (previously reported as sensitive to DG) did not
present any enzymatic activity. On SDG, the strains
201218, 3526, PPL27 and PPL34 (previously reported as
tolerant to DG) presented higher P, G and E activity than
those presented on S. It suggests that the DG tolerant
strains are derepressed for producing L, P, G and E, which
could be importantly related to the mushroom productivity.
1092 - Twin arbuscules in Linum usitatissimum L.
S. Dickson 1* , P. Schweiger 2 , F.A Smith 1 , B. Söderström 3 &
S.E. Smith 1
1 The University of Adelaide, Waite Campus, PMB 1, Glen
Osmond, South Australia 5064, Australia. - 2 Institute of
Ecology and Conservation Biology, Vienna University, A-
1090 Vienna, Austria. - 3 Department of Microbial Ecology,
Ecology Building, Lund University, S-223 62 Lund,
Sweden. - E-mail: sandy.dickson@adelaide.edu.au
The 'twin' arbuscule development of Arum-type
mycorrhizal colonization in Linum usitatissimum L. were
investigated using a time-course study to show formation
and senescence of the structures. Roots were freezesectioned
longitudinally, mycorrhizal structures were
visualized using 1) nitroblue tetrazolium as a vital stain to
indicate metabolic activity of arbuscules and intercellular
hyphae and 2) acid fuchsin counterstaining. Arbuscules
occur in pairs in adjacent cortical cells arising from a
single, radial intercellular hypha. These 'twin' structures
often appeared to be at different stages of metabolic
development. Arbuscules and their relationship to