New Strategies Towards Durable Late Blight Resistance in Potato

Late blight caused by the oomycete pathogen Phytophthora infestans is the most devastating disease of potato. So far, potato resistance breeding has mainly relied on resistance (R) genes that encode an intracellular nucleotide-binding site, Leucine-rich repeat (NLR) receptors. More than 20 NLR genes have been cloned to date, however, they have become ineffective rather quickly. Recent studies have shown that resistance to late blight in wild Solanum species is not only dependent on this type of R gene. Additional types of plant genes, such as pattern recognition immune receptors (PRR) and defense-responsive genes can also contribute to resistance potentially in a more durable way. Thus, it is wise to source those additional types of genes as well and not rely only on NLR genes. The release of potato genome sequences and the development of technologies, such as resistance gene enrichment sequencing (RenSeq) and effectoromics, are speeding up the identification and cloning of such potato genes. The potential for potato breeding with more durable resistance to late blight, by employing multiple molecular strategies is discussed.