Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme V: CELL BIOLOGY AND PHYSIOLOGY Posters
comatus model instead of 'laboratory' C. cinereus one.
During analysis of enzymology of stages of development
of fruit body, we were investigating levels of enzymes
connected with melanization proces and proteolysis events.
We have been searching of also the levels of natural
protease inhibitors of various groups of proteases.
Comparison of changes in levels of protease activities and
of their inhibitors may give us new, interesting insight into
relations of various types of proteases and their natural
inhibitors, and into a role of proteolysis during
development and deliquescing of basidiocarps of genus
Coprinus mushrooms.
1112 - Characteristics of secondary metabolites from
lichen mycobionts
N. Hamada 1* , T. Tanahashi 2 & H. Miyagawa 3
1 Osaka City Institute of Public Health & Environmental
Sciences, 8-34 Tojo-cho, Tennoji, Osaka 543-0026, Japan.
- 2 Kobe Pharmaceutical University, 4-19-1 Motoyamakitamachi,
Higashinada, Kobe 658-8558, Japan. - 3 Div. of
Applied Life Science, Graduate School of Agriculture,
Kyoto University, Sakyo, Kyoto 606-8502, Japan. - E-mail:
Nobuo.Hamada@iphes.city.osaka.jp
Secondary metabolites were often obtained from colonies
of spore-derived lichen mycobionts cultured on
conventional malt-yeast extract media with 10% added
sucrose. Some substances not detected in the lichens, were
often new, and crystallized on the surface of mediumcultured
mycobiont. These substances, which differed
among the various lichen mycobionts, included
graphenone, graphisquinone, dibenzofurans, xanthones,
hybocarpone, isocoumarins and other substances. These
substances appear to be often bioactive or toxic to
photobionts. In addition to previous work identifying new
mycobiont substances, further studies are performed in
order to elucidate the biological significance of substances
produced by the lichen mycobionts and the origin of lichen
symbiosis. In the present study, we have examined the
distribution and variation in dibenzofurans, which are
common in lichen mycobionts, and distributed over many
families, e.g. Stereocaulon, Evernia, Usnea, Lecanora. On
the other hand, dibenzofurans were not found in lichens.
This biosynthetic pathway was thought to dormant in
lichenized condition, and was induced in cultured lichen
mycobiont. The structure of dibenzofurans varies with
species of lichens, and some dibenzofurans are chlorinated
derivatives. These substances appear to be toxic to an algal
partner. We tried to confirm this hypothesis in
experimental procedure. The biological significance of
these metabolites is discussed from the viewpoint of lichen
symbiosis.
1113 - T-DNA based genetic transformation of the
ectomycorrhizal fungi
M. Hanif 1* , M. Raudaskoski 1 , A.G. Pardo 2 & M. Gorfer 3
1
University of Helsinki, PL 56 viikinakari 9 00014-FIN HY,
Finland. - 2 Programa de Investigación en Interacciones
Biológicas (PIIB), Roque Saénz Peña 180, (B1876BXD)
Bernal, Argentina. -
3 Eco work lab, Vienna,
Längenfeldgasse 27, 1120, Austria. - E-mail:
hanif@mappi.helsinki.fi
The T-DNA of Agrobacterium tumefaciens can be
transferred to plants, yeasts, fungi and human cells. Using
this system, a technique was developed for transforming
ectomycorrhiza forming basidiomycetes Suillus bovinus,
Hebeloma cylindrosporum, and Paxillus involutus. The
selection marker employed was the Shble gene conferring
resistance to phleomycin under control of the
Schizophyllum commune GPD promoter and terminator.
Putative transformants were shown by PCR to contain the
GPDScP-Shble-GPDScT construct, although the fate of the
foreign DNA could not be determined. In order to improve
the system, dikaryotic mycelia of S. bovinus were
transformed with recombinant hygromycin B
phsphotransferase (hph) and enhanced green fluorescent
protein (EGFP) genes fused with a heterologous fungal
promoter and CaMV 35S terminator. Transformation
resulted in hygromycin B resistant clones, which were
mitotically stable. Putative transformants were analysed for
the presence of hph and EGFP genes by PCR and Southern
analysis which proved both multiple and single copy
integrations of the genes. Several genes encoding small
GTPases have been charcterized from S. bovinus, including
SbCdc42 SbRac1, SbRas1 and SbRas2. The introduction of
in vitro mutagenized dominant forms of these genes into S.
bovinus genome by the transformation system described
here will greatly advance our understanding of the function
of the actin cytoskeleton and small GTPases in vegetative
and symbiotic hyphae of S. bovinus.
1114 - Characterization of copper-philic mycobiont
from lichen Tremolecia atrata
K. Hara * , H. Fujii, M. Komine, H. Hattori & Y. Yamamoto
Akita Pref. Univ., 241-7 Shimoshinjo-nakano, Akita 010-
0195, Japan. - E-mail: kojiro_h@akita-pu.ac.jp
It is well known that lichens are able to accumulate high
amount of heavy metals in their thalli. To clarify the
possibility of application of lichens for bio-remediation, we
had screened lichen mycobiont cultures for coppertolerance.
As a result of the screening, a mycobiont derived
from Tremolecia atrata found to be copper-philic rather
than copper-tolerant. The copper ion level for optimum
growth in liquid medium was between 25 to 30 ppm. The
upper limit adequate for growth was around 125 ppm.
Analyses by an atomic absorption spectrophotometer
revealed an accumulation of copper ion within mycobiont
Book of Abstracts 337