Cytokinin and Ethylene Control Indole Alkaloid Production at the Level of the MEP/Terpenoid Pathway inCatharanthus roseusSuspension Cells

Abstract

The Madagascar periwinkle Catharanthus roseus accumulates a number of terpenoid indole alkaloids, some of which have high therapeutic interest. The biotechnological approach with cells in vitro remains an alternative to the field culture of periwinkle for the production of such compounds. We previously reported that two phytohormones, cytokinin and ethylene, remarkably enhanced the accumulation of alkaloids in periwinkle cell suspensions. In this work, we investigated the effects of these hormones on the regulation of several genes of the indole alkaloid biosynthetic pathway. We show that cytokinin and/or ethylene greatly enhanced the expression of the geraniol 10-hydroxylase gene. When given together, these hormones also increased the expression of three genes belonging to the methyl-erythritol pathway. These results make it possible to consider elements of cytokinin and ethylene signalling pathways as tools for improving terpenoid indole alkaloid production through metabolic engineering.

Growth regulators and essential oil production

“…According to the authors this result indicates that ethrel could influence the activity of enzymes linked to the piretrin biosynthetic pathway (Haque et al 2007). In Catharanthus roseus cell suspension, Decendit et al (1993) and Papon et al (2005) observed an increase in geranyl 10-hidroxylase activity when the medium was supplied with cytokinin (zeatin). This enzyme acts in the terpene moiety of indolic alkaloids as ajmalicine, serpentine and catharantine.…”

“…GA ∅ x Activation of compounds conversion Zhang et al 2005 Catharanthus roseus CYT + x Increase of enzyme activity Decendit et al 1993;Papon et al 2005;Oudin et al 2007 Chrysanthemum cinerariaefolium ET ∅ x Enzyme activation Haque et al 2007 Cymbopogon citratus CYT + ∅ Source of hormone Craveiro et al 1989 C. citratus …”

Spatial distribution and hormonal regulation of gene products from methyl erythritol phosphate and monoterpene-secoiridoid pathways in Catharanthus roseus

“…Thus, MIAs do not accumulate in a medium containing auxin, whereas MIA production is induced at day 5 of subculture in an auxin-free medium. MIA production can be further enhanced by addition of the cytokinin zeatin (Décendit et al 1992;Chahed et al 2000;Veau et al 2000;Papon et al 2005). Methyljasmonate (MeJa) also induces the biosynthesis of MIAs in C. roseus cell suspension cultures (Gantet et al 1998) and seedlings (Aerts et al 1994) by coordinately switching on the expression of multiple genes of the MIA biosynthetic pathway, including G10H (Menke et al 1999a;Geerlings et al 2000;van der Fits and Memelink 2000;Collu et al 2001).…”

The Effect of Exogenous Phytohormones on Resistance of Wheat Calluses to <i>Tilletia caries</i> (D.C.) Tul. & C. Tul.

“…The role of cytokinins in the development of host-pathogen relationship is still far from being clear. On the one hand, cytokinins can enhance plant contraction to pathogens by its participation in the expression of some defense genes [2] and also by promoting antifungal alkaloid synthesis [19]. On the other hand, there are many data confirming negative regulation of the defense response by cytokinins.…”