Abstract
Late blight caused by Phytophthora infestans greatly constrains potato production. Many Resistance (R) genes were cloned from wild Solanum species and/or introduced into potato cultivars by breeding. However, individual R genes have been overcome by P. infestans evolution; durable resistance remains elusive. We positionally cloned a new R gene, Rpi-amr1, from Solanum americanum, that encodes an NRC helper-dependent CC-NLR protein. Rpi-amr1 confers resistance in potato to all 19 P. infestans isolates tested. Using association genomics and long-read RenSeq, we defined eight additional Rpi-amr1 alleles from different S. americanum and related species. Despite only ∼90% identity between Rpi-amr1 proteins, all confer late blight resistance but differentially recognize Avramr1 orthologs and paralogs. We propose that Rpi-amr1 gene family diversity facilitates detection of diverse paralogs and alleles of the recognized effector, enabling broad-spectrum and durable resistance against P. infestans.
Competing Interest Statement
KW, HSK, FGJ and JDGJ are named inventors on a patent application (PCT/US2017/066691) pertaining to Rpi-amr1 that was filed by the 2Blades Foundation on behalf of the Sainsbury Laboratory.
Footnotes
We updated information about NRC knockout N. benthamiana lines (New Figuer S3, and updated Figure 4) and included co-authors for their contribution.