Enhancement of anthraquinone production in Morinda citrifolia cell suspension cultures after treatment with azetidine-2-carboxylic acid and thiazolidine-4-carboxylic acid

QUEVEDO, C.; PERASSOLO, M; GIULIETTI A M; RODRIGUEZ TALOU, J

Barcelona

Congreso; 14th European Congress on Biotechnology,; 2009

European Federation of Biotechnology

Plant cell suspension cultures are attractive alternatives for large scale production of plant-derived natural products, in particular of secondary metabolites. Morinda citrifolia is a member of Rubiaceae family that produces anthraquinones (AQs), anthracene derivatives which exhibit biological interesting properties. The basal compound, anthraquinone (9,10-dioxoanthracene), can be substituted in various ways, resulting in a great diversity of structures. Different metabolic routes are involved in AQs synthesis: shikimate pathway produces chorismic acid, which is then converted into isochorismic acid by the enzyme isochorismate synthase. The reaction of this compound with _-ketoglutaric acid generates osuccinylbenzoic acid, the precursor of A and B rings of the AQs structure. C ring is derived from an isoprene unit produced by the 2-C-methyl-D-erythritol-4-phosphate pathway. The proline cycle was proposed to be linked to the pentose phosphate pathway (PPP), as the first one generates two NADP+ which are cofactors of the two first enzymes in the PPP. The PPP produces erithrose-4- phosphate, which is substrate of the shikimate pathway. The aim of this work was to study a possible link between proline cycle and AQs production and to evaluate this link as a possible strategy for AQs accumulation. M. citrifolia cell suspension cultures were treated with azetidine-2-carboxylic acid (A2C; 25 and 50_M) and thiazolidine-4-carboxylic acid (T4C; 100 and 200_M), two proline analogs. All treatments except from A2C 25_M showed a higher AQs content (P < 0.05) compared to the control line, while only T4C 200_M treatment increased total phenolics (TP) content after a six-day culture. After ten days of culture, both T4C treatments enhanced AQs and TP production compared to control. Accumulation of proline was significantly increased by all treatments after ten days  of culture (P < 0.01). These findings could be correlated with PPP stimulation. doi:10.1016/j.nbt.2009.06.807 doi:10.1016/j.nbt.2009.06.807