Systematic Identification and Analysis of OSC Gene Family of Rosa rugosa Thunb

The oxidosqualene cyclase family of Rosa rugosa (RrOSC) provides a starting point for the triterpenoid pathway, which contributes to the medicinal value of the extraction of tissues of Rosa rugosa. However, the structure and function of key RrOSCs of active triterpenoids remain ambiguous. In this study, a total of 18 RrOSC members with conservative gene structures and motifs were identified based on the genome of Rosa rugosa. The RrOSCs were located on three chromosomes including two gene clusters that derived from gene replication. The phylogenetic relationship divided RrOSCs into six groups, and the RrOSCs of GI and GIV that were represented by lupeol or α-amyrin were identified as likely to include candidate genes for producing active triterpenoids. Considering the high expression or specific-tissue expression of the candidates, RrOSC1, RrOSC10, RrOSC12, and RrOSC18 were considered the key genes. RrOSC12 was identified in vitro as lupeol synthase. The results provided fundamental information and candidate genes for further illustration of the triterpenoid pathway involved in the pharmacological activities of Rosa rugosa.