The first draft genome of Picrorhiza kurrooa, an endangered medicinal herb from Himalaya

Background: Picrorhiza kurrooa is an endangered medicinal herb, which is distributed across the Himalayan region at an altitude between 3,000-5,000 m above mean sea level. The medicinal properties of P. kurrooa are attributed to monoterpenoid picrosides which are present in leaf, rhizome and root of the plant. However, no genomic information is currently available for P. kurrooa which limits our understanding about this plant, on its molecular systems and associated responses.Results: The present study is the first ever attempt to assemble the draft genome of P. kurrooa, while handling 227 Gb of raw data generated by Illumina and PacBio RS II sequencing platforms. The final assembled haploid genome has a size of ~1.7 Gb with 12,924 scaffolds and N50 of 129.6 Kb. About 76% of the genome is enriched for complex repeats like retrotransposons. This study also provides an efficient approach for assembling complex genomes while dealing with repeats when regular assemblers fail to progress further due to repeats. Multiple assembly quality validations confirmed high reliability of the assembly. The genome has GC content of 37.89%. Annotation revealed 24,798 protein coding and 9,789 non-coding genes. Large number of genes were found existing in multicopy. A total of 710 miRNAs were discovered in the genome, many of which were found responsible for molecular response against temperature changes.Conclusion: The information arising from this study has been provided as a dedicated interactive database for P.kurrooa genome at https://scbb.ihbt.res.in/Picro-db/. The availability of this draft genome sequence will facilitate the discovery of molecular biology and systems of P.kurrooa as well as will aid in genetic improvement and conservation of P. kurrooa, an endangered species rapidly approaching extinction.