EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
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SESSION 3: PATHOGENESIS – EPIDEMIOLOGY AND POPULATION<br />
GENETICS<br />
P43 - Heterochromatin protein 1 (Hep1) deletion in F.<br />
graminearum causes hypervirulence on wheat heads.<br />
S. Boedi 1 , M. Imer 2 , U. Güldener 3 , T. Nussbaumer 3 , K. Kugler 3 , M. Sulyok 2 , V.<br />
Preiser 2 , G. Siegwart 2 , E. Sam 2 , M. Lemmens 2 , H. Bürstmayr 2 , R. Krska 2 , K.<br />
Brunner 2 , J. Strauss 1<br />
1 Department <strong>of</strong> Applied Genetics and Cell Biology, University <strong>of</strong> Natural Resources and Life Sciences<br />
Vienna, University and Research Center Tulln (UFT), Konrad Lorenz Strasse 24, A-3430 Tulln,<br />
Austria; 2 Department for Agrobiotechnology (IFA-Tulln), University <strong>of</strong> Natural Resources and Life<br />
Sciences Vienna, Konrad Lorenz Strasse 20, 3430 Tulln, Austria; 3 Helmholtz Zentrum München,<br />
Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH), Ingolstädter Landstr. 1, 85764<br />
Neuherberg<br />
E-mail: stefan.boedi@boku.ac.at<br />
Chromatin modifications and formation <strong>of</strong> facultative heterochromatin have been<br />
shown to be involved in the regulation <strong>of</strong> secondary metabolism gene clusters in<br />
the fungal model organism Aspergillus nidulans. Based on that work we deleted<br />
the heterochromatin protein-1 homologue, Hep1, in F. graminearum Ph-1<br />
background and measured its impact on histone H3K9 methylation by ChIP<br />
analysis, confirming its functionality. We investigated the effect <strong>of</strong> Hep1 deletion<br />
on the ability <strong>of</strong> F. graminearum to infect wheat heads <strong>of</strong> the susceptible cultivar<br />
Remus and found the hep1 mutant to be hypervirulent with a ~2 fold increased<br />
infection rate. These findings correlated with an increased production <strong>of</strong> the<br />
trichothecene deoxynivalenol (DON) during pathogenic growth on living wheat<br />
heads. Interestingly the hep1 mutant produced less DON than the Ph-1 wildtype<br />
on axenic minimal medium and the produced DON amounts on dead wheat<br />
heads, which served as non- response control, were much smaller than the<br />
produced amounts on living wheat heads. This indicates that the plant response<br />
system plays a crucial role in the activation <strong>of</strong> this secondary metabolite cluster as<br />
well as that a crosstalk between heterochromatin status and pathogenicity exists.<br />
Our aim in this study is to understand the molecular basis <strong>of</strong> the hypervirulence<br />
caused by hep1 deletion as well as to investigate the effect <strong>of</strong> the plant response<br />
on F. graminearum by determination <strong>of</strong> the transcriptome levels <strong>of</strong> the hep1<br />
deletion versus the Ph-1 wildtype strain on alive and dead (non-responding)<br />
wheat heads using RNA-seq methodology. Preliminary results show that the plant<br />
response has a huge systemic impact on F. graminearum transcript levels what<br />
will be further investigated. The RNA-seq analysis <strong>of</strong> the complex infection<br />
samples will also mark plant genes differentially responding to the hep1 mutant.<br />
Keywords: Fusarium graminearum infection <strong>of</strong> wheat, heterochromatin protein 1,<br />
secondary metabolism, RNA-seq<br />
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