In Vivo Gloriosa Superba and Colchicum Autumnale Multi-Tissues Transcriptome Analysis for Colchicine Pathway and Rhizome Development Candidate Genes Identification

Background: The continued emergence of side-effects caused by synthetic drugs underscores the need for plant-based drugs in human medicine. Medicinal rhizomatous crops are “the goldmine for modern drugs”, and include such species as Gloriosa superba L., and Colchicum autumnale L., the producer of colchicine, a plant-based medicine. The natural isomer of bioactive colchicine is used to effectively treat major diseases such as cancer, cardiovascular disease, and gout. The medicinal properties of colchicine are well characterized, however, almost nothing is known about its biosynthetic mechanism and colchicine pathway has not been elucidated that are significant barriers in biomanufacturing of biomedicine. The comparative transcriptomes study of G. superba and C. autumnale can serve as sequence resource and synthetic biology toolbox components for identifying biomedicine pathway and rhizome development genes, which could aid colchicine pathway metabolic engineering or synthetic biotechnology to improve colchicine biomanufacturing. Result: Predominantly colchicine synthesizing two monocots such as G. superba and C. autumnale transcriptomes were used to identify putative protein involved in the colchicine biosynthetic pathway and rhizome development along with transcription factors. Mining of the transcriptomes using Blast2GO, 20 and 29 candidate genes [3 and 1 candidate N-methyltransferase (NMT); 10 and 16 candidate 3-O-methyltransferase (3-OMT); cytochrome P450s, a class that could catalyze several steps in the pathway namely, 2 and 5 candidate CYP96T1, 1 and 4 candidate CYP82E10; 4 and 3 candidate N-acetyltransferase (NAT)] were identified in colchicine pathway for G. superba and C. autumnale, respectively. Similarly, 19 and 15 candidate rhizome developmental genes [2 and 1 candidate GIGANTEA (GI), 5 and 4 candidate CONSTANS (CO), 2 and 1 candidate Phytochrome B (PHYB), 2 and 5 candidate Sucrose Synthase (SuSy), 5 and 2 candidate Flowering Locus T (FT), and 3 and 2 candidate REVOLUTA (REV)] were identified in G. superba and C. autumnale, respectively. While 16 and 12 transcription factors in rhizome development and regulating secondary metabolic pathways in rhizomes [3 and 1 candidate MADS-box, 6 and 2 candidate AP2-EREBP, 2 and 2 candidate bHLH, 1 and 2 candidate MYB, 2 and 2 candidate NAC, and 2 and 3 WRKY] were screened in G. superba and C. autumnale, respectively. These genes could represent potential leads for metabolic engineering of G. superba or synthetic biotechnology of colchicine metabolism for enhanced colchicine and biorhizome biomass in biomanufacturing. Conclusion: The study of G. superba and C. autumnale genes predicated to encode colchicine pathway enzymes are highly significant for fundamental information on plant-based biomedicine biosynthesis, which could facilitate engineered production in biorhizomes, a potentially important area of synthetic biotechnology. Additionally, increasing our understanding of rhizome genomics could improve colchicine production in G. superba, and generate important knowledge that could be applied to many other medicinal plant species, and could allow engineered production of additional biomedicines in biorhizomes, a potentially important area of expansion for synthetic biotechnology to solve overarching biomanufacturing challenges.