Department of Entomology and Plant Pathology, NC State University, Raleigh, NC, USA.
Functional Genomics Program, NC State University, Raleigh, NC, USA.
Nat Commun. 2024 Aug 5;15(1):6488. doi: 10.1038/s41467-024-50749-4.
Phytophthora infestans is a major oomycete plant pathogen, responsible for potato late blight, which led to the Irish Potato Famine from 1845-1852. Since then, potatoes resistant to this disease have been bred and deployed worldwide. Their resistance (R) genes recognize pathogen effectors responsible for virulence and then induce a plant response stopping disease progression. However, most deployed R genes are quickly overcome by the pathogen. We use targeted sequencing of effector and R genes on herbarium specimens to examine the joint evolution in both P. infestans and potato from 1845-1954. Currently relevant effectors are historically present in P. infestans, but with alternative alleles compared to modern reference genomes. The historic FAM-1 lineage has the virulent Avr1 allele and the ability to break the R1 resistance gene before breeders deployed it in potato. The FAM-1 lineage is diploid, but later, triploid US-1 lineages appear. We show that pathogen virulence genes and host resistance genes have undergone significant changes since the Famine, from both natural and artificial selection.
疫霉（Phytophthora infestans）是一种主要的卵菌植物病原体，可引发马铃薯晚疫病，导致 1845 年至 1852 年的爱尔兰马铃薯饥荒。此后，全球范围内培育并部署了对这种疾病具有抗性的马铃薯。这些马铃薯的抗性（R）基因可以识别导致毒性的病原体效应物，然后诱导植物产生阻止疾病进展的反应。然而，大多数已部署的 R 基因很快就被病原体克服了。我们使用针对 1845 年至 1954 年标本中的效应物和 R 基因进行靶向测序，以研究疫霉和马铃薯的共同进化。目前相关的效应物在历史上存在于疫霉中，但与现代参考基因组相比，存在替代等位基因。历史上的 FAM-1 谱系具有毒性 Avr1 等位基因，并且在育种者将其部署在马铃薯中之前，具有打破 R1 抗性基因的能力。FAM-1 谱系是二倍体，但后来出现了三倍体 US-1 谱系。我们表明，自饥荒以来，病原体毒力基因和宿主抗性基因已经发生了重大变化，这是自然选择和人工选择的结果。
