Oomycetes are single celled pathogens of plants; the most widely-known representative of this class is the potato blight pathogen, Phytophthora infestans, which was responsible for the Irish potato famine in the 18th century.
In this issue of Genome Biology, C. Robin Buell and colleagues present the genome and transcriptome of the related plant pathogenic oomycete, Pythium ultimum – a blight pathogen of many ornamental and crop species that is less host-specific than some of its oomycete cousins.
Buell and colleagues compared the genome and transcriptome sequence of P. ultimum with that of P. infestans, the genome sequence of which was recently published in Nature and highlighted in Genome Biology here. Buell and colleagues found that the P. ultimum genome has a very different repertoire of genes involved in pathogenicity compared with P. infestans, including very few Crinkler (cytoplasmic effector proteins) protein-encoding genes, which are abundant in related oomycetes and previously thought to be essential for pathogenicity.
The genome sequence of P. ultimum will increase our understanding of the mechanisms of pathogeniticty in this agriculturally important family of crop pathogens.
You can read the article by Buell and colleagues here.