ARS | Publication request: Comparative analysis of three Magnaporthaceae mitochondrial genomes reveals group I introns in the soil-inhabiting pathogens

Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: October 31, 2012
Publication Date: N/A

Technical Abstract: A comparison of the mitochrondrial genomes of two soilborne grass pathogens, M. poae of turfgrass and Gaemannomyces graminis var. triciti (Ggt) of wheat, was made to the foliar rice blast pathogen, Magnaporthe oryzae. We sought to extend observations from nuclear-coded genes that the soilborne pathogens were more closely related than either was to M. oryzae. The mitochondrial genome of M. oryzae was 34.9 kb, whereas the draft genomes of M. poae and Ggt were 138.5 kb and 153.5 kb, respectively. All three genomes encoded a core set of thirteen genes, including subunits of cytochrome c oxidase, NADH dehydrogenase and ATPase, along with tRNAs, and rn1 (LSU) and rns (SSU) ribosomal RNAs. The mitochondrial genomes of M. poae and Ggt harbored LAGLIDADG or GIY-YIG endonuclease-class introns in at least seven genes each. The mitochondrial LSU and SSU genes of M. poae and Ggt also contained group I introns, in accord with previous observations of M. Tan. Our findings support nuclear genome comparative analysis showing that the two soilborne pathogens are close relatives. Progress in intron identification and phylogeny will be reported.