OBJECTIVETo study the characteristics of the growth and periplocin accumulation of the adventitious roots of Periploca sepium, and on this basis, study the effect of Ag+ and La3+ elicitors on the growth and periplocin accumulation of the adventitious roots.

METHODThe adventitious roots were sampled every four days, and the dry weight and the contents of the periplocin were measured. The curves of the growth and periplocin accumulation of the roots were plotted. The Ag+ and La3+ elicitors with different concentrations were added to the medium when the adventitious roots grew in the stable phase to study the optimal concentration which was good to synthesize the periplocin. Besides, the optimal concentration of Ag+ and La3+ elicitors was added to the different growth phases to study the effect of the elicitors on the growth and periplocin synthesis of adventitious roots.

RESULTThe characteristics of the growth of adventitious roots of P. sepium showed a typical growth S-Curve, which displayed a half-coupling relationship with the metabolism of periplocin. The optimal concentrations of Ag+ and La3+ elicitors were both 0.05 mmol L(-1). Besides, it was the best period for the Ag+ and La3+ elicitors to elicit the synthesis of periplocin when in the terminally exponential phase.

CONCLUSIONThe growth of adventitious roots and the accumulation of periplocin show a half-coupling relationship. Besides, the concentration and additive time of Ag and La3+ elicitors obviously influences the growth of adventitious roots and synthesis of periplocin.