A double oxidative burst for taxol production in suspension cultures of Taxus chinensis var. mairei induced by oligosaccharide from Fusarium oxysprum

The effects of oligosaccharide from Fusarium oxysprum on secondary metabolisms in suspension cultures of Taxus chinensis var. mairei were investigated by detecting the oxidative burst (OB) signals using an Electron Paramagnetic Resonance (ESR) spectrometer. The oxidative burst signals induced by oligosaccharide gradually increased to a maximum at 4 h. Phenylalanine ammonia lyase (PAL) and polyphenol oxidase (PPO) activities were respectively 2 and 4 times higher than those of control, and large amount of phenolics were accumulated in culture medium. Two times of obvious increase in taxol production was observed, which was in accordance with the two times of elicitation of oxidative burst signals. The dependence of taxol production on the intensity of OB signals obeyed a modified Logistic curve. It was inferred that the syntheses of the side chain and nucleus of taxol were enhanced at low and high intensities of OB signals, respectively.