Temporal gene expression profiling suggests stage-specific regulation of apocarotenoid biosynthesis genes during stigma development in Crocus sativus L.

Saffron (Crocus sativus L.) is a sterile triploid medicinal plant and is the world's most expensive cultivated herb. Its dried red stigmas accumulate important carotenoids, which produce apocarotenoids after oxidative cleavage. Saffron produces important apocarotenoids, crocin, picrocrocin and safranal, that provide color, flavor and aroma to it. To understand the expression pattern and stage specificity of apocarotenoid biosynthesis genes, we performed RNA sequencing at six different stages of stigma development (yellow, orange, red, two days before anthesis, at the day of anthesis and two days after anthesis) using Illumina platform. Differential expression analysis revealed preferential/specific expression of many genes at the different stages of stigma development. Functional annotation identified many genes encoding enzymes involved in different steps of apocarotenoid biosynthesis pathways expressed preferentially at red and later stages of stigma development. In addition, gene ontology enrichment analysis revealed several genes involved in primary/secondary metabolic processes and reproductive development pathways, exhibiting higher transcript abundance at the later stages of stigma development. Overall, the data and results presented in this study can serve as a rich resource for understanding the apocarotenoid biosynthesis in C. sativus during stigma development.

Supplementary information: The online version contains supplementary material available at 10.1007/s12298-025-01621-2.