Gene duplication and adaptive evolution of the CHS-like genes within the genus Rheum (Polygonaceae)

► Radiative speciation of Rheum lineage had been driven by uplifting of Qinghai-Tibetan Plateau. ► CHS-like genes underwent duplication and functional divergence within the Rheum lineage. ► The adaptive evolution of CHS-like genes contributed Rheum to occupy the extreme habitats.