Austropuccinia psidii isolate:MF_1 Genome sequencing. Austropuccinia psidii isolate:MF_1

Among the possible approaches to understanding the biology of phytopathogens, the extra-chromosomal genome has received special attention. Mitogenomes have a highly conserved genome in most species that can shed light on the phylogenetic relationship and evolutionary biology of pathogenic fungi. Rust fungi diseases are among the most devastating for economically important crops around the world. However, we still lack much information about their biology. Austropuccinia psidii (syn. Puccinia psidii) is rust fungi, causal agent of Myrtle rust. It is able to infect more than a hundred Myrtaceae species, causing significant loses majorly in Eucalyptus spp. around the world. Due to its importance, we aimed at sequencing and annotating the mitochondrial genome of A. psidii and then to perform a phylogenomic analysis of the scarce available mitochondrial DNA from other rust pathogens. In total, 71 genes were annotated in A. psidii. We found 34 genes encoding hypothetical proteins which represent almost 42% of all predictions in the mitochondrial genome of A. psidii. Among rust mitogenomes, A. psidii has the largest mitogenome probably due to great amount of ncORFs . From those, three ncORFs were evidenced by proteomic analysis. The orf208 had its expression evaluated by RT-PCR, that was dow-expressed during in vitro morphogenesis. This study on rust mitogenomes will give rise to new insights leading to a better understanding on the biology and pathogenicity mechanisms of myrtle rust as well as other rust pathogens.