Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme V: CELL BIOLOGY AND PHYSIOLOGY Posters
adjusted to 2 × 10 7 ufc mL - 1 and 50 mL inoculated into
Petri dishes with 8% water agar; six superficially
disinfected (NaOCl) AMF spores/plate were then placed on
the medium and incubated in the dark, at room temperature
(28 °C). Experiments combining PGPR and AMF, with
five replicates, were performed and evaluated at the 21th
and 28th days. The PGPR promoted different effects on
germination and mycelial growth of the AMF. Spore
germination of G. albida was stimulated by RAB9 and
GN212 and the mycelial growth stimulated by the latter,
but inhibited by the other bacterial strains. Neither the
incubation period nor the PGPR affected germination of S.
heterogama. However, the mycelial growth was stimulated
since the 21th day by GN1212, and later by the other
bacteria. Germination of G. etunicatum was stimulated by
the PGPR, but at the 28th day did not differ from the
control, while mycelial growth was benefited by ENF10
and C210. In general, among the AMF, higher germination
and mycelial formation were obtained with G. albida.
Financial support: CAPES and CNPq.
1180 - Effects of photosynthetically active radiation
(PAR) and carbohydrate source on UV-B induced
parietin synthesis in Xanthoria parietina
K.A. Solhaug * & Y. Gauslaa
Department of Biology and Nature Conservation,
Agricultural University of Norway, P.O. Box 5014, NO-
1432 Ås, Norway. - E-mail: knut.solhaug@ibn.nlh.no
Lichen secondary compunds can be removed by rinsing in
100% acetone without affecting thalli viability. Acetonerinsed
parietin-free Xanthoria parietina thalli were
cultivated in two growth chamber experiments. Thalli were
soaked in water or carbohydrate solution once a day during
both seven days experimental periods. In the first
experiment a factorial design with ±UV-B (0.75 Wm-2),
±PAR (200 µmol photons m-2s-1) and 0, 2 or 5 g ribitol
per liter water was used. No resynthesis of parietin took
place in the abcence of UV-B. For thalli exposed to UV-B
both PAR and ribitol contributed to the parietin resynthesis.
Thalli exposed to PAR and the highest concentration of
ribitol resynthesized more than 20% of the original content
during the seven days experimental period. In the second
experiment thalli were exposed to UV-B in the dark and
moistened with various carbohydrate solutions. Thalli
moistened with ribitol or sucrose resynthesized about 14%
of their original parietin content, those moistened with
mannitol or glucose resynthesized about 8%, while
moistening with sorbitol or water resulted in resynthesis of
2-4% parietin only. The results are discussed in relation to
the role the different carbohydrates may play in the lichen
symbiosis e.g. that ribitol is the carbohydrate that the
photobiont Trebouxia export to the fungal partner in the
lichen X. parietina.
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Book of Abstracts
1181 - Eucalypt wood pretreatment with Phanerochaete
crassa and Peniophora lycii decreased pitch content
after laboratory kraft cooking
M. Speranza 1* , A. Gutíerrez 2 , J.C. del Río 2 , J. Romero 3 ,
A.T. Martínez 1 & M.J. Martínez 1
1 Centro de Investigaciones Biológicas, CSIC, Velázquez
144, E-28006 Madrid, Spain. - 2 Instituto de Recursos
Naturales y Agrobiología de Sevilla, P.O. Box 1052, E-
41080 Sevilla, Spain. - 3 Centro de Investigación y
Tecnología (ENCE), Cra. Campañó s/n, E-36157
Pontevedra, Spain. - E-mail: marielas@cib.csic.es
During last years eucalypt wood treatment with
basidiomycetes is being studied as an alternative to
traditional methods for pitch control. In this way,
Phanerochaete crassa and Peniophora lycii, isolated from
the Uruguay forestry, have been selected by their ability to
remove both sterols, which are responsible for pitch
deposition, and lignin from eucalypt wood. Here we
confirm the effectiveness of Eucalyptus globulus wood
pretreatment with these two fungi to reduce the amount of
free and esterified sterols from pulp and black liquors after
laboratory kraft pulping, and the distribution of lignin and
free sterols in the pretreated wood is analyzed. P. lycii and
P. crassa decreased lignin content after two weeks of
industrial chips treatment (24 and 16% respectively). An
extensive alteration of lignin was observed by confocal
laser scanning microscopy of wood sections. Filipin
staining (a selective method to localize free sterols) showed
that most of sitosterol was degraded after wood
pretreatment, although some deposits remained in the
lumen of parenchymatic cells. Chemical analysis after
laboratory kraft cooking showed that both fungi decreased
the content of free sterols (32 and 31%, respectively) and
sterol esters (39 and 45%, respectively) in brown kraft
pulps, and the free sterol content in black liquors (87 and
73%, respectively). The optical and papermaking
properties of the bio-pulps obtained are being analyzed.
1182 - A gene cluster associated with production of
insecticidal loline alkaloids in the fungal endophyte
Neotyphodium uncinatum
M.J. Spiering 1* , H.H. Wilkinson 2 , C.D. Moon 1 , J.D.
Blankenship 1 & C.L. Schardl 1
1 University of Kentucky, Lexington, Kentucky 40546,
U.S.A. - 2 Texas A&M University, College Station, Texas
77843, U.S.A.
Grass plants can acquire chemical defenses against insect
and vertebrate herbivores by living in symbiosis with
fungal endophytes of the genus Epichloë (anamorphs,
Neotyphodium). In several Epichloë/Neotyphodium - grass
associations, insecticidal 1-aminopyrrolizidine (loline)
alkaloids are produced, which hold promise as natural plant
protectants. The objective of this study was to identify the
genes involved in loline production. N. uncinatum can