Objective   The transcriptomes of rose plants artificially infected by powdery mildew were obtained to identify the genes responsible for the resistance to infestation by beet armyworms.

  Method  Transcriptomes of Yanfen rose (Rosa chinensis Jacq.) before and after being infected by powdery mildew were obtained using the second-generation sequencing technology. RSEM was used to quantitatively analyze the gene expressions, DESeq2 software for the expression differences, and KOBAS for the KEGG enrichment analysis on the differentially expressed genes (DEGs). Bioinformatics of the DEGs of CYP71D susceptible of associating with triterpenoids biosynthesis was secured to study the relationship between the CYP71D and the insect resistance.

  Result   A total of 1 646 DEGs were detected by the transcriptome sequencing. Of which, 643 were enriched into 81 KEGG pathways with 31 DEGs related to terpenoid synthesis. The bioinformatics on them showed a species specificity of CYP71D subfamily. In plants, CYP71A were mainly involved in the biosynthesis of monoterpenes, while CYP71D in that of the disease and insect resistance-related secondary metabolites, such as monoterpenes, sesquiterpenes, diterpenes, and triterpenoids.

  Conclusion  The CYP71A and CYP71D subfamilies of the cytochrome P450 enzyme in the rose might relate to the synthesis of dehydro (11,12) ursolic acid lactone (DUA). It suggested a possible association of CYP71D with the formation of triterpenoids. The results provided information for the study on the relationship between the genes in host plants and infecting insects.