The oomycete phytophthora infestans, the irish potato famine pathogen

Abstract

The oomycete Phytophthora infestans is a filamentous plant pathogen that causes the late blight disease in potato worldwide. It has been a favorite subject of study since the Great Irish Famine in the 1840s and is considered to be a model species for oomycetes. Its genome of over 240 Mb has a remarkable organization with gene dense regions interspersed with gene poor regions, the latter harboring genes involved in host specificity and virulence. These genes are key players in the arms race with the host. They can easily mutate to avoid recognition by immune receptors and their abundance shows that P. infestans possesses an impressive arsenal of weapons for attacking potato and is likely hard to beat.