The parsley genome assembly and DNA methylome shed light on apigenin biosynthesis in the Apiaceae

Parsley [Petroselinum crispum (Mill.)] is a medicinal and edible vegetable of the Apiaceae family that is rich in apigenin. The Apiaceae family is well known for its diverse secondary metabolites. As a high-quality reference genome is lacking for parsley, the evolution and apigenin biosynthesis in Apiaceae have remained unexplored. Here, we report the chromosome-level genome sequence of parsley, consisting of 1.85 Gb that mainly arose from the expansion of long terminal repeats. Whole-genome bisulfite sequencing revealed a significantly higher number of hypermethylated differentially expressed genes in leaf blades and petioles than in root tissues. Moreover, we identified and characterized chalcone isomerase (CHI) genes, encoding key enzymes involved in apigenin biosynthesis in parsley. We also established that the APETALA2 family transcription factor Pcrispum_6.2855 (PcAP2) binds to the (Pcrispum_11.4764) PcCHI promoter and promotes apigenin accumulation. In conclusion, our work presents a multiomics data resource for understanding apigenin biosynthesis and its transcriptional regulation in parsley, in addition to shedding light on the evolution of parsley within the Apiaceae.