Complete genome of the Medicago anthracnose fungus, Colletotrichum destructivum, reveals a mini-chromosome-like region within a core chromosome.
Colletotrichum is a large genus of fungal phytopathogens that cause major economic losses on a wide range of crop plants throughout the world. These pathogenes vary widely in their host specificity and may have either broad or narrow host ranges. Here, we report the first complete genome of the alfalfa (Medicago sativa) pathogen, Colletotrichum destructivum, which will facilitate the genomic analysis of host adaptation and comparison with other members of the Destructivum clade. We identified a specific 1.2Mb region within chromosome 1 displaying all the hallmarks of fungal accessory chromosomes, which may have arisen through the integration of a mini-chromosome into a core chromosome and possibly linked with the pathogenicity of this fungus. We show this region is also a focus for chromosomal rearrangements, which may contribute to generating genetic diversity for adaptive evolution. Finally, we report infection by this fungus of the model legume, Medicago truncatula, providing a novel pathosystem for studying fungal-plant interactions. Overall design: Colletotrichum destructivum LARS709 (Cd709) was grown in vitro (in PDB) or inoculated on Medicago sativa for 48h or 72h.