Integrated Transcriptomics and Metabolomics Studies Reveal Steroid Biosynthesis Pathway and BCL2 Inhibitory Diazo-Progesterone of Drimia indica for Conservation and Sustainable Utilization.

Background: This study is the first report on the sequence of the transcriptome of Drimia indica, a non-model plant with medicinal properties found in a forest tribal belt, using the Illumina NovaSeq platform. The primary objectives of this study were to elucidate the gene expression profiles in different tissues, identify key regulatory genes and pathways involved in secondary metabolite biosynthesis, and explore the plant's potential pharmacological properties.

Methods: The study generated 670087 unigenes from both leaves and roots and identified putative homologs of annotated sequences against UniProt/Swiss-Prot and KEGG databases. The functional annotation of the identified unigenes revealed the secondary metabolite biosynthetic process as the most prominent pathway, with gene enrichment analysis predominantly accounting for secondary metabolite pathways, such as terpenoid, steroid, flavonoid, alkaloid, selenocompound, and cortisol synthesis. The study also identified regulatory genes NAC, Bhlh, WRKY, and C2H2 on the transcriptome dataset.

Results: The functionally annotated unigenes suggested phytocompounds in Drimia indica to have multi-potent properties, such as anti-cancer, anti-inflammatory, and anti-diabetic activities, which has been further validated by GC-MS-based metabolite profiling. Notably, we have identified two novel molecules, di-azo progesterone and 4H-pyran-4-one 2,3-dihydro-3,5-dihydroxy- 6-methyl, with potential BCL2 inhibitory anticancer properties, supported by stable binding interactions observed in molecular docking and dynamics simulations. Additionally, an abundance of mono-nucleotide SSR markers has been identified, useful for genetic diversity studies.

Conclusion: This study provides a foundational understanding of the molecular mechanisms in Drimia indica, highlighting its potential as a source for novel therapeutic agents and contributing valuable insights for future pharmacological and agricultural applications. However, further in vivo studies are warranted to confirm these findings and validate their pharmacological efficacy and therapeutic potential. The SSR markers identified also offer valuable tools for molecular genetics, plant breeding, and sustainable drug development.