Squalestatin-induced production of taxol and baccatin in cell suspension culture of yew (Taxus baccata L.)

Various elicitors have already been reported to enhance the production of taxol and related taxanes. In this study, effects of a fungal metabolite, squalestatin, on production of taxol and baccatin III were studied. Expressions of 4 key involved genes, ts, dbat, bapt, and dbtnbt, in suspension cultures of Taxus baccata were also detected using qPCR. Results showed that application of squalestatin significantly increased taxol and baccatin III yields. Increased expressions of the genes were in accordance with measures of taxol and baccatin accumulations in cells and medium. Production of H2O2 has significant positive correlations with both gene expression and taxanes, indicating that the increase in H2O2 might be involved in the upregulation of the taxane production in yew under squalestatin treatment. Our results suggest that H2O2 is a key signaling component in the stimulation of taxane production in T. baccata cells induced by squalestatin

Stimulatory effect of methyl jasmonate and squalestatin on phenolic metabolism through induction of LOX activity in cell suspension culture of yew

Cell suspension cultures of Taxus baccata were treated with 2 elicitor compounds, methyl jasmonate (MeJA) and squalestatin (S), individually and in combination for 7 days to determine if they mediated the enhancement of biosynthesis of endogenous jasmonate through induction of lipoxygenase (LOX) activity. Total phenolic compounds, total flavonoids, total antioxidants, phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), and LOX activities in 5-month-old yew cell cultures were studied. Our results showed that MeJA and S could stimulate production of phenol derivatives in cell suspension cultures of T. baccata. In parallel to the induction of phenolic production in elicited cells, results showed that activities of PAL and PPO enzymes and total antioxidants significantly increased in Taxus cells in response to MeJA and S. Maximal activities of lipoxygenase were obtained 48 h after treatment with MeJA (100 mu M), S (0.1 mu M), and the combination of the 2 elicitors. Results showed that MeJA and S are effective elicitors for increasing phenolic production in Taxus cell suspension cultures, likely through increasing LOX activity followed by an increase in endogenous jasmonate