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

Abstract

Salvia abrotanoides Kar. and Salvia yangii B.T. Drew are medicinal and aromatic plants belonging to the subgenus Perovskia 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 Perovskia 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 S. abrotanoides and S. yangii: PAL, C4H, 4CL, TAT, HPPR, RAS1, RAS2 and Cyp98A14. 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, RAS1 and Cyp98A14 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.

The Influence of Methyl Jasmonate on Expression Patterns of Rosmarinic Acid Biosynthesis Genes, and Phenolic Compounds in Different Species of Salvia subg. Perovskia Kar L.

“…Our results imply that MeJA treatments may increase the amount of RA in various Salvia species, which in turn has an effect on the gene expression patterns of genes implicated in RA synthesis. On the other hand, our findings support those of earlier research [ 47 , 48 , 49 , 56 ] and suggest that Salvia plants’ RA levels vary depending on their genotype and dose. It has been reported that the treatments with 100–150 µM MeJA result in the accumulation of high levels of RA in Lamiaceae families [ 50 , 57 ].…”

“…Following the manufacturer’s instructions [ 20 ], total RNA was extracted from uniform young leaves of Salvia species, and cDNA was synthesized using the cDNA Synthesis Kit. As described before [ 56 ], we used gene-specific primers and the actin gene (as a housekeeping gene) to determine how varying amounts of MeJA affected the mRNA transcript levels of PAL , 4CL , and RAS ( Table 1 ). The fold-change (2 −ΔΔCt ) approach, which has been described earlier [ 90 ], was used for this investigation.…”

Comparative Transcriptomic Analysis of two Asian Medicinal and Aromatic Species of Salvia subg. Perovskia – a Contribution Towards Molecular Background of Abietane-type Diterpenoid Biosynthesis

“…Among various secondary metabolic pathways, only phenylpropanoid biosynthesis was pointed out by the analysis, showing signi cantly different transcriptional levels of six genes, including 4-coumaryl-CoA ligase (4CL). The phenylpropanoid pathway in S. abrotanoides and S. yangii was already analysed by us earlier [25]. The diterpenoid pathway was not enriched in present analysis, which may be explained in two ways.…”

“…S. abrotanoides and S. yangii display a wide array of bioactive natural compounds belonging to different chemical classes [5]. Apart from essential oil constituents [18][19][20][21] and phenolic compounds [1,[22][23][24][25], they produce also a wide range of abietane-type diterpenoids. Aerial parts of S. abrotanoides and S. yangii contain carnosic acid, rosmanol and their derivatives [26][27][28].…”

Comparative transcriptomics of two Salvia subg. Perovskia species contribute towards molecular background of abietane-type diterpenoid biosynthesis

“…S. abrotanoides and S. yangii display a wide array of bioactive natural compounds belonging to different chemical classes 5 . Apart from essential oil constituents 18 – 21 and phenolic compounds 1 , 22 – 25 , they produce also a wide range of abietane-type diterpenoids. Aerial parts of S. abrotanoides and S. yangii contain carnosic acid, rosmanol and their derivatives 26 – 28 .…”