MPI Fungal Symposium 2019 poster: Genomic perspectives on the evolution of mating-type locus in Citrus-associated Phyllosticta species

To this date, eight Phyllosticta species are known to be associated with Citrus hosts, presenting endophytic and pathogenic lifestyles. As sexual reproduction is a key factor involved in host-interaction, it could be related to the differences in lifestyles. To evaluate this hypothesis, we characterized the mating-type locus in six Citrus-associated Phyllosticta species from whole genome assemblies. Comparisons demonstrate that mating-type genes are highly variable in their sequence content, but the genomic location and organization of mating-type locus is conserved. P. citriasiana, P. citribraziliensis and P. paracitricarpa were described as heterothallic, and P. citrichinaensis was confirmed as homothallic. In addition, P. citrichinaensis MAT1-2 idiomorph occurs in a separate location from the mating-type locus, something that was not described yet in Phyllosticta genus. Moreover, P. capitalensis and P. citrichinaensis homothallic strategies differ, which suggest they might result from independent evolutionary events. This study provides important information and perspectives for future studies on mating-type evolution in Phyllosticta genus, emphasizing the importance of studying Citrus-Phyllosticta interactions under genomic approaches.