Genomic insights into the adaptive evolution of the memorial rose (Rosa lucieae; Rosaceae) in saline environments

Abstract

Rosa lucieae (syn. Rosa wichurana or R. wichuraiana; Rosaceae) is one of the major wild progenitors of modern rose cultivars. In breeding roses, R. lucieae has contributed not only to white blooms and shiny leaves, but most of all, to succeed in various harsh conditions and high resistance to diseases and pests. The wild R. lucieae inhabits littoral sand banks or rocks, where drought stress and high salinity inhibit plant growth. In this study, we assembled the chromosome-level genome sequence of a wild accession of R. lucieae and identified potential genes that may responsible for the evolution of salt tolerance. Within the 544.7 Mb-long genome of R. lucieae, recent duplications and divergence of the genes responsible to stress tolerance were identified, including stress response, signaling, homeostasis, and detoxification. Additionally, the gene family evolution analyses elucidated rapid evolution of stress tolerant functions in R. lucieae. The first high-quality genome assembly of wild R. lucieae contributes significantly to our understanding of the genomic evolution and adaptive mechanism of R. lucieae, which promises the enhancement of our efforts in rose breeding programs.