Comparative analysis using the draft genome sequence of California poppy (Eschscholzia californica) for exploring the candidate genes involved in benzylisoquinoline alkaloid biosynthesis

Genome characterization of California poppy (Eschscholzia californica cv. "Hitoezaki"), which produces pharmaceutically important benzylisoquinoline alkaloids (BIAs), was carried out using the draft genome sequence. The numbers of tRNA and rRNA genes were close to those of the other plant species tested, whereas the frequency of repetitive sequences was distinct from those species. Comparison of the predicted genes with those of Amborella trichopoda, Nelumbo nucifera, Solanum lycopersicum, and Arabidopsis thaliana, and analyses of gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway indicated that the enzyme genes involved in BIA biosynthesis were highly enriched in the California poppy genome. Further comparative analysis using the genome information of Papaver somniferum and Aquilegia coerulea, both BIA-producing plants, revealed that many genes encoding BIA biosynthetic enzymes, transcription factors, transporters, and candidate proteins, possibly related to BIA biosynthesis, were specifically distributed in these plant species.