1. Inter-genome comparison of the Quorn fungus <italic>Fusarium venenatum</italic> and the closely related plant infecting pathogen <italic>Fusarium graminearum</italic>.
- Author
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King, Robert, Brown, Neil Andrew, Urban, Martin, and Hammond-Kosack, Kim E.
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FUSARIUM , *GENOMES , *PHYTOPATHOGENIC microorganisms , *METABOLITES , *MITOCHONDRIAL DNA , *HYDROLASES - Abstract
Background: The soil dwelling saprotrophic non-pathogenic fungus
Fusarium venenatum , routinely used in the commercial fermentation industry, is phylogenetically closely related to the globally important cereal and non-cereal infecting pathogenF. graminearum . This study aimed to sequence, assemble and annotate theF. venenatum (strain A3/5) genome, and compare this genome withF. graminearum . Results: Using shotgun sequencing, a 38,660,329 bpF. venenatum genome was assembled into four chromosomes, and a 78,618 bp mitochondrial genome. In comparison toF. graminearum , the predicted gene count of 13,946 was slightly lower. TheF. venenatum centromeres were found to be 25% smaller compared toF. graminearum . Chromosome length was 2.8% greater inF. venenatum, primarily due to an increased abundance of repetitive elements and transposons, but not transposon diversity. On chromosome 3 a major sequence rearrangement was found, but its overall gene content was relatively unchanged. Unlike homothallicF. graminearum , heterothallicF. venenatum possessed theMAT1–1 type locus, but lacked theMAT1–2 locus. TheF. venenatum genome has the type A trichothecene mycotoxinTRI5 cluster, whereasF. graminearum has type B. From theF. venenatum gene set, 786 predicted proteins were species-specific versus NCBI. The annotatedF. venenatum genome was predicted to possess more genes coding for hydrolytic enzymes and species- specific genes involved in the breakdown of polysaccharides thanF. graminearum . Comparison of the two genomes reduced the previously definedF. graminearum- specific gene set from 741 to 692 genes. A comparison of theF. graminearum versusF. venenatum proteomes identified 15 putative secondary metabolite gene clusters (SMC), 109 secreted proteins and 38 candidate effectors not found inF. venenatum . Five of the 15F. graminearum-specific SMCs that were either absent or highly divergent in theF. venenatum genome showed increased in planta expression. In addition, two predictedF. graminearum transcription factors previously shown to be required for fungal virulence on wheat plants were absent or exhibited high sequence divergence. Conclusions: This study identifies differences between theF. venenatum andF. graminearum genomes that may contribute to contrasting lifestyles, and highlights the repertoire ofF. graminearum -specific candidate genes and SMCs potentially required for pathogenesis. [ABSTRACT FROM AUTHOR]- Published
- 2018
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