Book of Abstracts (PDF) - International Mycological Association

IMC7 Main Congress Theme V: CELL BIOLOGY AND PHYSIOLOGY Posters
These findings confirm our previous observations of
mycorrhizas under heavy metal stress.
1160 - Metabolism in ectomycorrhizal preinfection:
Expression of malate synthase and acetylCoA
acetyltransferase genes from Laccaria bicolor
G.K. Podila 1* , S. Balasubramanian 2 & S.T. Hiremath 3
1 University of Alabama, Dept. of Biological Sciences,
Huntsville, AL 35899, U.S.A. - 2 Michigan Tech University,
Dept. of Biological Sciences, Houghton, MI 49931, U.S.A. -
3 USDA-NEFES, 359 Main Road, Delaware, OH 43015,
U.S.A. - E-mail: podilag@email.uah.edu
The ectomycorrhizas are beneficial fungal associations
with temperate tree roots. Ectomycorrhizal fungi improve
survivability, pathogen resistance, drought tolerance and
provide mobilized mineral nutrient in exchange for fixed
carbon from the plant. Molecular level analysis suggests
that, in response to the perception of the plant root, there is
a directional shift in fungal cell physiology as early as four
hours into the interaction. During the interaction between
Laccaria bicolor and Pinus resinosa, we have observed the
upregulation of metabolic genes such as Lb-MS coding for
a malate synthase and Lb-AAT that codes for an acetylCoA
acetyltransferase. The former, one of the two unique
enzymes of the glyoxylate pathway and the latter the
terminal thiolase of beta oxidation of fatty acids. The
expression of these two genes in conjunction with others
(LB-AUT7) suggests that recycling of cell contents and
breakdown of reserve food and channeling towards growth
occur early in the preinfection stage of the symbiosis.
Regulation of Lb-MS and Lb-AAT under interaction
conditions and under alternate carbon sources have been
studied. Lb-MS has been analyzed at the protein level and
gene structure of Lb-AATg has been elucidated. We
present our findings on these two metabolic genes and their
significance in the symbiosis via the agency of the
peroxisome.
1161 - Pre-infection and nutrient starvation expression
profiling of interaction related ESTs from the
ectomycorrhizal fungus Laccaria bicolor
G.K. Podila 1* , M.J. Hymes 2 & J.H. Brand 2
1 University of Alabama, Dept. of Biological Sciences,
Huntsville, AL 35899, U.S.A. - 2 Michigan Tech University,
Dept. of Biological Sciences, Houghton, MI 49931, U.S.A. -
E-mail: podilag@email.uah.edu
In this study, a 384 member macroarray was created
consisting of 340 ESTs derived from mRNA of Laccaria
bicolor during early interaction with Pinus resinosa. The
macroarray also contained several positive and negative
controls as internal standards and to confirm
reproducibility and reduce experiment-to-experiment
variability. This array was used to study multiple factors of
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Book of Abstracts
interaction, including expression patterns at various time
points of early interaction (