ARS | Publication request: Intraspecific comparison and annotation of two complete mitochondrial genome sequences from the plant pathogenic fungus Mycosphaerella graminicola

Submitted to: International Septoria Stagonospora Workshop
Publication Type: Abstract Only
Publication Acceptance Date: July 26, 2008
Publication Date: August 18, 2008
Citation: Torriani, S.F., Goodwin, S.B., Kema, G.J., Pangilinan, J.L., Mcdonald, B.A. 2008. Intraspecific comparison and annotation of two complete mitochondrial genome sequences from the plant pathogenic fungus Mycosphaerella graminicola. International Septoria Stagonospora Workshop. Available at: http://www.path.ethz.ch/news/conferences/Mycosphaerella_Ascona_2007/00021_posterabstract.pdf

Technical Abstract: The mitochondrial genomes of two isolates of the wheat pathogen Mycosphaerella graminicola were sequenced completely and compared to identify polymorphic regions. This organism is of interest because it is phylogenetically distant from other fungi with sequenced mitochondrial genomes and it has shown discordant patterns of nuclear and mitochondrial diversity. The mitochondrial genome of M. graminicola (EU090238) is a circular molecule of approximately 43,960 bp containing the typical genes coding for 14 proteins related to oxidative phosphorylation, one RNA polymerase, two rRNA genes and a set of 27 tRNAs. The mitochondrial DNA of M. graminicola lacks the gene encoding the putative ribosomal protein (rps5-like), commonly found in fungal mitochondrial genomes. Most of the tRNA genes were clustered with a gene order conserved with many other ascomycetes. A sample of thirty-five additional strains representing the known global mt diversity was partially sequenced to measure overall mitochondrial variability within the species. Little variation was found, confirming previous RFLP-based findings of low mitochondrial diversity and isolates of M. graminicola adapted to durum wheat had unique RFLP and SNP haplotypes. The mitochondrial sequence of M. graminicola is the first reported from the family Mycosphaerellaceae or the order Capnodiales. The sequence also provides a tool to better understand the development of fungicide resistance and the conflicting pattern of high nuclear and low mitochondrial diversity in global populations of this fungus.