The Solanum americanum pangenome and effectoromics reveal new resistance genes against potato late blight

Late blight caused by the oomycete pathogen Phytophthora infestans continues to cause major worldwide losses in potato and tomato. Most accessions of Solanum americanum, a globally distributed, wild Solanaceae plant, are highly resistant to late blight. We generated high-quality reference genomes of four S. americanum accessions, re-sequenced 52 accessions, and we defined variation in the NLR immune receptor genes (the S. americanum NLRome). We further screened for variation in recognition of [~]315 P. infestans RXLR effectors in 52 S. americanum accessions. Using these genotypic and phenotypic data, we cloned three novel NLR-encoding genes Rpi-amr4, Rpi-amr16 and Rpi-amr17, and determined their corresponding RXLR effector genes Avramr4 (PITG_22825), Avramr16 (PITG_02860) and Avramr17 (PITG_04373) from P. infestans. These genomic resources and methodology will support efforts to convert potato into a "nonhost" of late blight and can be applied to diseases of other crops.