Enhancement of anthraquinone production in Morinda citrifolia cell suspension cultures after stimulation of the proline cycle with two proline analogs

QUEVEDO, C.V.; PERASSOLO, M.; GIULIETTI, A.M.; RODRÍGUEZ TALOU, J.

BIOTECHNOLOGY LETTERS

SPRINGER

Año: 2012 vol. 34 p. 571 - 575

0141-5492

Synthesis of anthraquinones (AQs)involves the shikimate and 2-C-methyl-D-erythritol-4-phosphate (MEP) pathways, among others. The proline cycle is linked to the pentose phosphate pathway (PPP) to generate the NADPH needed in the first enzymatic steps of this pathway. The effect of two proline analogs, azetidine-2-carboxylic acid (A2C) and thiazolidine-4-carboxylic acid (T4C), were evaluated in Morinda citrifolia suspension cultures. Both analogs gave higher proline accumulation after 6 and 10 days(68 and 179% after 6 days of culture with A2C added at a final concentration of 25 and 50 µM, respectively, and 111% with T4C added at 100 µM). Induction of the proline cycle increased AQ content after 6 days around 40% for 50 µM A2C and 100 µM T4C). Whereas A2C (50 μM) increased only AQ production, T4C also enhanced total phenolics. However, no induction of the PPP was observed with any of the treatments. This pathway, therefore does not limit the supply of carbon skeletons to secondary metabolic pathways.