The complete genome of lettuce reveals centromere landscape and empowers breeding

Abstract

Lettuce (Lactuca sativa L.) is a globally grown vegetable crop as the most popular salad ingredient. Lettuce breeding is crucial to enhancing yield, nutrition and disease resistance, but impeded by lacking a high-quality genome resource. In addition, the released genomes remain fragmented (with hundreds of gaps) and incomplete with omitting pivotal centromeres and telomeres. Here, we report a 2.59 Gb complete telomere-to-telomere (T2T) genome assembly for lettuce. T2T genome analysis revealed the unique genetic and epigenetic architectures of centromere repeats dominated by retrotransposons and satellites. The complete genome and annotation facilitate the identification of candidate disease resistance (NLR) genes induced during grey mold infection. The genomic resources, and biological insights into genetic and epigenetic landscape of centromeres not only advance lettuce research and breeding, but also propel the biology and evolution of centromeres across plant kingdom.