Genome-Wide Comparison and Functional Characterization of Gene Family Associated with Shikonin Biosynthesis in .

3-hydroxy-3-methylglutaryl-CoA reductase (HMGR), as the rate-limiting enzyme in the mevalonate pathway, is essential for the biosynthesis of shikonin in . However, in the absence of sufficient data, the principles of a genome-wide in-depth evolutionary exploration of family members in plants, as well as key members related to shikonin biosynthesis, remain unidentified. In this study, 124 s were identified and characterized from 36 representative plants, including . Vascular plants were found to have more HMGR family genes than nonvascular plants. The phylogenetic tree revealed that during lineage and species diversification, the s evolved independently and intronless s emerged from multi-intron in land plants. Among them, and had the most gene duplications, with 11 most likely expanded through WGD/segmental and tandem duplications. In seedling roots and M9 cultured cells/hairy roots, where shikonin biosynthesis occurs, and were expressed significantly more than other genes. The enzymatic activities of LerHMGR1 and LerHMGR2 further supported their roles in catalyzing the conversion of HMG-CoA to mevalonate. Our findings provide insight into the molecular evolutionary properties and function of the family in plants and a basis for the genetic improvement of efficiently produced secondary metabolites in .