摘要
Scutellaria baicalensis(S.baicalensis)and Scutellaria barbata(S.barbata)are common medicinal plants of the Lamiaceae family.Both produce specific flavonoid compounds,including baicalein,scutellarein,norwogonin,and wogonin,as well as their glycosides,which exhibit antioxidant and antitumor activities.Here,we report chromosome-level genome assemblies of S.baicalensis and S.barbata with quantitative chromosomal variation(2 n=18 and 2 n=26,respectively).The divergence of S.baicalensis and S.barbata occurred far earlier than previously reported,and a whole-genome duplication(WGD)event was identified.The insertion of long terminal repeat elements after speciation might be responsible for the observed chromosomal expansion and rearrangement.Comparative genome analysis of the congeneric species revealed the species-specific evolution of chrysin and apigenin biosynthetic genes,such as the S.baicalensis-specific tandem duplication of genes encoding phenylalanine ammonia lyase and chalcone synthase,and the S.barbata-specific duplication of genes encoding 4-Co A ligase.In addition,the paralogous duplication,colinearity,and expression diversity of CYP82 D subfamily members revealed the functional divergence of genes encoding flavone hydroxylase between S.baicalensis and S.barbata.Analyzing these Scutellaria genomes reveals the common and species-specific evolution of flavone biosynthetic genes.Thus,these findings would facilitate the development of molecular breeding and studies of biosynthesis and regulation of bioactive compounds.
基金
the National Key R&D Program of China(Grant No.2019YFC1711100)
the National Natural Science Foundation of China(Grant No.31700264)
the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(CIFMS)(Grant No.2016-I2M3-016)。
