Transcriptome Assembly of Two Fern Species Identifies Enzymes Required for Two Upstream Pathways of Phytoecdysteroids

species produce a high amount of phytoecdysteroids (PEs), which are widely used in traditional medicine in the Pacific islands. The PEs in two different species, (MP) and (MS), were examined using high-performance liquid chromatography (HPLC). In particular, MS produces a high amount of 20-hydroxyecdysone, which is the main active compound in PEs. To identify genes for PE biosynthesis, we generated reference transcriptomes from sterile frond tissues using the NovaSeq 6000 system. De novo transcriptome assembly after deleting contaminants resulted in 57,252 and 54,618 clean transcripts for MP and MS, respectively. The clean transcripts for each species were annotated according to gene ontology terms, UniProt pathways, and the clusters of the orthologous group protein database using the MEGAN6 and Sma3s programs. In total, 1852 and 1980 transcription factors were identified for MP and MS, respectively. We obtained transcripts encoding for 38 and 32 enzymes for MP and MS, respectively, potentially involved in mevalonate and sterol biosynthetic pathways, which produce precursors for PE biosynthesis. Phylogenetic analyses revealed many redundant and unique enzymes between the two species. Overall, this study provides two reference transcriptomes that might be useful for further studies regarding PE biosynthesis in species.