EFS12- Book of abstracts - Contact

SESSION 1: FUSARIUM – GENETICS, GENOMICS AND SYSTEMS BIOLOGY
EBR1, a master regulator shaping the transcriptional
landscape of Fusarium graminearum
Z. Chunzhao 1,2,3,4 , C. Waalwijk 1,2 , P. J. G. M. de Wit 2,5 , D. Tang 3 , T. van der
Lee 1,2
1 Plant Research International, P.O. Box 6708 PB, Wageningen, The Netherlands; 2 Graduate School
Experimental Plant Sciences, Wageningen, The Netherlands; 3 State Key Laboratory of Plant Cell and
Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of
Sciences, Beijing 100101, China; 4 Graduate University of Chinese Academy of Sciences, Beijing
100049, China; 5 Wageningen University, Laboratory of Phytopathology, P.O. Box 6708 PB,
Wageningen, The Netherlands
E-mail: theo.vanderlee@wur.nl
Mycotoxins are secondary metabolites that are produced by fungi. The expression
of genes involved in the production of secondary metabolites is often repressed
under nutrient-rich conditions, when the available resources seem to be primarily
used to promote fungal growth. When confronted with stress conditions, fungi can
significantly increase the production of secondary metabolites. The relationship
between primary and secondary metabolism, and the components that regulate
the switch between both life-forms in Fusarium graminearum was studied.
Previously, we have identified that a gene knock-out of ebr1 results in pleiotropic
effects, including reduced pathogenicity, reduced radial growth, enhanced hyphal
branching and overproduction of pigment. EBR1 (Enhanced Branching 1)
encodes a Gal4-like Zn2Cys6 transcription factor, which is constitutively
expressed. RNA-seq analyses of the wild-type and Δebr1 demonstrated that this
gene is a master regulator involved in the switch between primary and secondary
metabolism. The regulation of secondary metabolism in the wild type and the ebr1
knock-out mutant has been studied at different developmental stages and under
various growth conditions. We compared the expression of genes that hallmark
primary metabolism such as the ribosomal genes, to the expression of genes
implicated in the production of secondary metabolites such as polyketide
synthases and non-ribosomal peptide synthetases. Whereas the wild-type strain
produces limited amounts of secondary metabolites under nutrient-rich conditions,
a significant increase in the expression of genes implicated in the production of
secondary metabolites was observed in the knock-out strain Δebr1. These results
may provide new targets to reduce the production of secondary metabolites and
the identification of new fungicides that may reduce the amount of mycotoxins.
Keywords: transcription, RNA-Seq, regulation, secondary metabolism
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