Isolation of potato genes that are induced during an early stage of the hypersensitive response to Phytophthora infestans

Suppression subtractive hybridization (SSH) was used to generate a cDNA lib rary enriched for sequences induced in a late-blight-resistant potato culti var undergoing the hypersensitive response (HR), Of 100 partial cDNA sequen ces submitted to international DNA and protein data bases, 42 showed simila rity to 35 genes, of which 31 were from plants, Of these, 13 were previousl y characterized as either defense-, stress-, or senescence-associated. One sequence matched (75 to 81%) all known serine palmitoyltransferases (SPTs) at the protein level, SPT catalyzes the first committed step in the synthes is of sphingolipids, important signaling molecules involved in cell differe ntiation and apoptosis, Putative products of other genes identified here ma y play a role in programmed cell death, including protein degradation, DNA degradation, metal ion chelation, and signal transduction, cDNA-amplified f ragment length polymorphism was used to confirm differential expression of sequences isolated by SSH.