Title : Pathway Flux ‘Push’ Genetic Engineering Approach in Catharanthus roseus to Enhance the Production of Antineoplastic Monoterpenoid Indole Alkaloids Vinblastine and Vincristine
Catharanthus roseus synthesizes one of the most structurally, chemically and biologically active phytomolecules monoterpenoids indole alkaloids (MIAs) with having a wide range of pharmaceutical activities. Being the sole source of antineoplastic MIAs vinblastine and vincristine C. roseus has become one of the most valued plant. The low in planta availability of these MIAs and unavailability of alternative chemical synthesis system has enhanced their demand and equally let to the exorbitant market cost. To increase the in-planta yield of these antineoplastic metabolites for the pharmaceutical and drug industry, extensive plant tissue culture-based studies were performed to provide alternative production systems. However, the strict spatiotemporal developmental regulation of MIA biosynthesis has restricted the utility of these cultures for large-scale production. To bridge this gap alternative production systems have been investigated using MIAs metabolic engineering (ME) in the homologous and heterologous systems. The availability of improved recombinant technologies along with genomics and metabolomics tools has opened the door of tremendous new potentials of ME. To encash these potentials of ME for MIAs pathway, efforts were made by expressing constitutive structure biosynthesis enzymes, transporters, and transcription factors of C. roseus MIAs biosynthesis in both homologous and heterologous systems. Therefore, we performed few studies to enhance the metabolic flux of MIA pathway towards the biosynthesis of vinblastine by overexpressing two upstream MIA pathway genes, tryptophan decarboxylase (CrTDC) and strictosidine synthase (CrSTR), at three levels of cellular organisations, (i) Callus cultures, (ii) Leaves, and (iii) whole plant levels in C. roseus. Whole plant transgenic of C. roseus was developed using Agrobacterium tumefaciens LBA1119 strain having CrTDC and CrSTR gene cassette. The results will be discussed and highlighted in Talk during Conference.