Elicitor-induced rosmarinic acid accumulation and secondary metabolism enzyme activities in Salvia miltiorrhiza hairy roots

This work is to examine the rosmarinic acid (RA) accumulation and related secondary metabolism enzyme activities of Salvia miltiorrhiza Bunge (Lamiacae) hairy roots in response to a biotic elicitor, yeast extract (YE) and an abiotic elicitor, Ag+. RA accumulation as well as total phenolic content of the hairy roots was increased by both elicitors, but more significantly by YE. Preceding the elicitor-induced RA accumulation, there was a notable rise in the tyrosine aminotransferase (TAT) activity but a rapid drop in the phenylalanine ammonia-lyase (PAL) activity of roots. All elicitor effects were dependent on the elicitor dose, maximized with YE at 200 mg/L and Ag+ at 15 μM. The results showed that the elicitor-induced biosynthesis of RA and phenolic compounds in the S. miltiorrhiza hairy roots was correlated with the TAT but not the PAL activity.