Seasonal Variations of Rosmarinic Acid and Its Glucoside and Expression of Genes Related to Their Biosynthesis in Two Medicinal and Aromatic Species of subg. .

Kar. and B.T. Drew are medicinal and aromatic plants belonging to the subgenus and used as herbal medicines in Asia. Derivatives of caffeic acid, mainly rosmarinic acid (RA), are the major phenolic compounds identified in these plants. Understanding the factors and molecular mechanisms regulating the accumulation of pharmacologically and ecologically relevant phenolic metabolites is essential for future biotechnological and medical applications. Up to date, no studies of phenylpropanoid biosynthetic pathway at the transcriptional level has been performed in the subgenus. Using a combined qRT-PCR transcriptional activity analysis with LC-MS based metabolic profiling of roots and leaves at the beginning, in the middle and at the end of vegetation season, we have identified the following gene candidates with properties correlating to phenolic acid biosynthesis in and : , , , , , , and . A comparison of phenolic acid profiles with gene transcript levels revealed the transcriptional regulation of RA biosynthesis in the roots but not the leaves of the studied species. Additionally, and were identified as rate-limiting steps regulating phenylpropanoid biosynthesis on a transcription level. In the future, this will facilitate the gene-based metabolic enhancement of phenolic compounds production in these promising medicinal herbs.