Effect of yeast elicitor and salicylic acid on the fluctuation of phytohormone contents in Ti-transformed Salvia miltiorrhiza cell cultures

When Ti transformed Salvia miltiorrhiza cells were cultured in a MS-NH4 medium (MS without ammonium nitrate, containing 30 g/L sucrose) at 25 degreesC in darkness for 18 d, the total tanshinone (cryptotanshinone and tashinone IIA) contents in cultures were 12.23 mg/L and 15.07 mg/L for yeast elicitor (4 g/L), and yeast elicitor plus 200 mumol/L salicylic acid (SA) treated cultures, respectively, whereas only trace amounts of tanshinone were detected in the control or SA treated cells. To explore the hormonal background concerning these phenomena, endogenous phytohormones were determined using ELISA kits. We found that ABA and iPAs contents in yeast elicitor plus SA treated cell cultures were increased 2.8 to 9.8-fold and 3.6 to 5.8-fold respectively, while contents of GA(1) and IAA were decreased by 13.2%-56.9% and 34.8%-74.6% respectively. This suggests that higher levels of ABA and iPAs combined with lower levels of GA(1) and IAA inhibit the growth of cells, then probably stimulate the tanshinone production.