Methyl jasmonate dramatically enhances the accumulation of phenolic acids in Salvia miltiorrhiza hairy root cultures

The aim of this work was to examine rosmarinic acid and its derivative lithospermic acid B accumulation, as well as related gene transcript and metabolite profiling in Salvia miltiorrhiza Bunge (Lamiacae) hairy root cultures, in response to methyl jasmonate (0.1 mM). Results showed methyl jasmonate dramatically enhanced both rosmarinic acid and lithospermic acid B accumulation, from approximately 3.25 to 6.02%, and 2.94 to 19.3% of dry weight, respectively. Meantime, several rosmarinic acid biosynthetic gene transcripts were coordinately induced, with phenylalanine ammonia-lyase, cinnamic acid 4-hydroxylase, tyrosine aminotransferase, 4-hydroxyphenylpyruvate reductase and 4-hydroxyphenylpyruvate dioxygenase transcripts displaying the most rapid and substantial increases. Liquid chromatographic-tandem mass spectrometry was used to characterize the profile of metabolites involved in rosmarinic acid biosynthesis pathway, in both control and elicited-treated hairy root cultures. Further canonical correlation analysis constructed a gene-to-metabolite network, locating possible gene candidates which would directly link to phenolic acids (rosmarinic acid and lithospermic acid B) production, and thereby, would help to prompt the possibility of a key gene-based metabolic engineering for the synthesis of active pharmaceutical compounds in S. miltiorrhiza.