Synergistic and additive influence of cyclodextrins and methyl jasmonate on the expression of the terpenoid indole alkaloid pathway genes and metabolites in Catharanthus roseus cell cultures

In the present work, we study the relationship between the production of indole alkaloids and the transcript profiles of several genes involved in their biosynthesis in Catharanthus roseus cell cultures elicited with 50 mM cyclodextrins (CDs) and/or 100 A mu M methyl jasmonate (MJ) for 8 days. Gene expression and indole alkaloid production were significantly enhanced by CDs treatment while MJ induced alkaloid synthesis to a lesser extent and had almost no effect on gene expression. The combined treatment with both the elicitors pointed to synergistic effect on gene transcript accumulation, which resulted in a 6,071.42 and 8,100 % enhancement of ajmalicine and catharanthine productivity, respectively, compared with non-treated cells at day 8. This increase in alkaloid production under the combined influence of CDs and MJ was 329.66 and 595.07 % for ajmalicine and 202.5 and 291.36 % more for catharanthine in compared with elicitation with CDs or MJ alone. Interestingly the over-synthesized alkaloids readily secreted into the culture medium, thereby avoiding the possibility of retro-inhibition and cytotoxicity due to their accumulation in cells.