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

QUEVEDO CV; PERASSOLO M; GIULIETTI AM; 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 pathways. The proline cycle is linked to the pentose phosphate pathway (PPP) to generate NADPH needed in the 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 accumula-tion after 6 and 10 days (68 and 179% after 6 days with A2C at 25 and 50 ìM, respectively, and 111% with T4C added at 100 ìM). Induction of the proline cycle increased the AQ content after 6 days (~40% for 50 ìM A2C and 100 ìM T4C). Whereas A2C (50 ìM) 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.