De novo genome assembly of the soil-borne fungus and tomato pathogen Pyrenochaeta lycopersici.
BACKGROUND
Pyrenochaeta lycopersici is a soil-dwelling ascomycete pathogen that causes corky root rot disease in tomato (Solanum lycopersicum) and other Solanaceous crops, reducing fruit yields by up to 75%. Fungal pathogens that infect roots receive less attention than those infecting the aerial parts of crops despite their significant impact on plant growth and fruit production.


RESULTS
We assembled a 54.9Mb P. lycopersici draft genome sequence based on Illumina short reads, and annotated approximately 17,000 genes. The P. lycopersici genome is closely related to hemibiotrophs and necrotrophs, in agreement with the phenotypic characteristics of the fungus and its lifestyle. Several gene families related to host-pathogen interactions are strongly represented, including those responsible for nutrient absorption, the detoxification of fungicides and plant cell wall degradation, the latter confirming that much of the genome is devoted to the pathogenic activity of the fungus. We did not find a MAT gene, which is consistent with the classification of P. lycopersici as an imperfect fungus, but we observed a significant expansion of the gene families associated with heterokaryon incompatibility (HI).


CONCLUSIONS
The P. lycopersici draft genome sequence provided insight into the molecular and genetic basis of the fungal lifestyle, characterizing previously unknown pathogenic behaviors and defining strategies that allow this asexual fungus to increase genetic diversity and to acquire new pathogenic traits.
Maria
M
Aragona
Andrea
A
Minio
Alberto
A
Ferrarini
Maria Teresa
MT
Valente
Paolo
P
Bagnaresi
Luigi
L
Orrù
Paola
P
Tononi
Gianpiero
G
Zamperin
Alessandro
A
Infantino
Giampiero
G
Valè
Luigi
L
Cattivelli
Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie, 15, 37134 Verona, Italy. massimo.delledonne@univr.it.
Massimo
M
Delledonne
D001203:Ascomycota / Q000235:genetics*; D016681:Genome, Fungal; D018551:Solanum lycopersicum / Q000382:microbiology*; D012988:Soil Microbiology