Potato late blight as a model of pathogen-host plant coevolution

A striking progress in molecular genetic studies of Phytophthora infestans and the genes for resistance to this pathogen in cultivated and wild Solanum species made potato late blight an instructive experimental model of “arms race” — rapid coevolution of the pathogen, oomycete P. infestans , and Solanum host plants. Mechanisms of this coevolution are discussed in the context of new information on the origin of past and present forms of P. infestans and cultivated potato. The focus of the lecture is on the functional organization of the genes for pathogen virulence and the race-specific genes for plant resistance as well as on the molecular interactions of the products of these genes: pathogen RxLR effectors and plant CC-NB-LRR receptor kinases. New knowledge on the molecular mechanisms of interaction between P. infestans and potato will promote breeding for durable resistance to late blight, especially with new technologies of effectoromics introduced to detect promising resistance genes in Solanum genetic collections, to characterize these genes and to promote their deployment in breeding process.