Comparative Transcriptome Analysis Identified Potential Genes and Transcription Factors for Flower Coloration in Kenaf (Hibiscus cannabinus L.)

The biochemical compounds in kenaf leaves and flowers mainly consist of flavonoids, including flavonoid glycosides and floral anthocyanins. In the present study, we performed comparative transcriptome analysis using RNA-sequencing and identified putative genes involved in flower coloration in different flower developmental stages of three kenaf mutants including Baekma (white flower), Jangdae (ivory flower), and Bora (purple flower). A total of 36.1 Gb reads were generated for two kenaf accessions and 38,601 representative transcripts with an average length of 1350 bp were yielded, of which 33,057 (85.64%) were annotated against two databases. Expression profiling of the transcripts identified 1044 and 472 differentially expressed genes (DEGs) among three mutants in the young bud and full bloom stages, respectively. KEGG enrichment analysis of these DEGs revealed that the representative pathway was "biosynthesis of secondary metabolites", including phenylpropanoid biosynthesis and flavonoid biosynthesis. Consequently, we investigated genes related to the phenylpropanoid pathway, which included 45 DEGs from a total of 1358. Our results provide useful information for understanding gene functions of flower coloration in kenaf, which will be useful in further studies.