Transcriptome-Guided Mining of Genes Involved in Crocin Biosynthesis.

is used in traditional Chinese medicine and has drawn attention as a rich source of crocin, a compound with reported activity against various cancers, depression and cardiovascular disease. However, genetic information on the crocin biosynthetic pathway of is scarce. In this study, we performed a transcriptome analysis of the leaves, green fruits, and red fruits of to identify and predict the genes that encode key enzymes responsible for crocin production, compared with . Twenty-seven putative pathway genes were specifically expressed in the fruits, consistent with the distribution of crocin in . Twenty-four of these genes were reported for the first time, and a novel gene was predicted that encodes carotenoid cleavage dioxygenase leading to crocin synthesis, in contrast to CCD2 of . In addition, 6 other candidate genes (, and ) were predicted to be involved in crocin biosynthesis following phylogenetic analysis and different gene expression profiles. Identifying the genes that encode key enzymes should help elucidate the crocin biosynthesis pathway.