Comparison of 454-ESTs from Huperzia serrata and Phlegmariurus carinatus reveals putative genes involved in lycopodium alkaloid biosynthesis and developmental regulation

For H. serrata, 36,763 unique putative transcripts were generated from 140,930 reads totaling over 57,028,559 base pairs; for P. carinatus, 31,812 unique putative transcripts were generated from 79,920 reads totaling over 30,498,684 base pairs. Using BLASTX searches of public databases, 16,274 (44.3%) unique putative transcripts from H. serrata and 14,070 (44.2%) from P. carinatus were assigned to at least one protein. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) orthology annotations revealed that the functions of the unique putative transcripts from these two species cover a similarly broad set of molecular functions, biological processes and biochemical pathways.In particular, a total of 20 H. serrata candidate cytochrome P450 genes, which are more abundant in leaves than in roots and might be involved in lycopodium alkaloid biosynthesis, were found based on the comparison of H. serrata and P. carinatus 454-ESTs and real-time PCR analysis. Four unique putative CYP450 transcripts (Hs01891, Hs04010, Hs13557 and Hs00093) which are the most likely to be involved in the biosynthesis of lycopodium alkaloids were selected based on a phylogenetic analysis. Approximately 115 H. serrata and 98 P. carinatus unique putative transcripts associated with the biosynthesis of triterpenoids, alkaloids and flavones/flavonoids were located in the 454-EST datasets. Transcripts related to phytohormone biosynthesis and signal transduction as well as transcription factors were also obtained. In addition, we discovered 2,729 and 1,573 potential SSR-motif microsatellite loci in the H. serrata and P. carinatus 454-ESTs, respectively.The 454-EST resource allowed for the first large-scale acquisition of ESTs from H. serrata and P. carinatus, which are representative members of the Huperziaceae family. We discovered many genes likely to be involved in the biosynthesis of bioactive compounds and transcriptional regulation as well as a large number of potential microsat