Evolution and chemical diversity of the volatile compounds in Salvia species.

INTRODUCTION: The plant essential oils are composed of volatile compounds and have significant value in preventing and treating neurological diseases, anxiety, depression, among others. The genus Salvia has been shown to be an important medicinal resource, especially the aerial parts of genus Salvia, which are rich in volatile compounds; however, the chemical diversity and distribution patterns of volatile compounds in Salvia species are still unknown. OBJECTIVE: The work is performed to analyse the chemical diversity and distribution patterns of volatile compounds in genus Salvia. METHODS: The genomic single nucleotide polymorphisms (SNPs) combined with gas chromatography-mass spectrometry (GC-MS) were used to explore the evolution and chemical diversity of Salvia volatile compounds. Initially, the genetic relationship of genus Salvia was revealed by phylogenetic tree that was constructed based on SNPs. And then, GC-MS was applied to explore the chemical diversity of volatile compounds. RESULTS: The results indicated that the volatile compounds were mainly monoterpenoids, sesquiterpenoids, and aliphatic compounds. The genomic SNPs divided species involved in this work into four branches. The volatile compounds in the first and second branches were mainly sesquiterpenoids and monoterpenoids, respectively. Species in the third branch contained more aliphatic compounds and sesquiterpenoids. And those in the fourth branch were also rich in monoterpenoids but had relatively simple chemical compositions. CONCLUSION: This study offered new insights into the phylogenetic relationships besides chemistry diversity and distribution pattern of volatile compounds of genus Salvia, providing theoretical guidance for the investigations and development of secondary metabolites.

Metabolomic and antioxidant analyses of Salvia miltiorrhiza Bunge and Salvia prattii Hemsl. seeds.

Salvia miltiorrhiza and Salvia prattii seeds are rich in metabolites that are beneficial to human health and can be utilised as nutritional supplements. In this study, UPLC-MS and GC-MS based on extensively focused metabolomics were used to compare the seed metabolomics of the two species. LC-MS detected 118 metabolites, primarily Lipids and phenylpropanoids. GC- MS detected a total of 188 metabolites, mainly organic acids and their derivatives, of which Salvia prattii seeds contain high levels of nutrients. In addition, we experimentally determined antioxidant activity of two Salvia species, and the results showed that the antioxidant activity of Salvia prattii seeds was about twice as high as that of Salvia miltiorrhiza seeds. We used WGCNA to group the metabolites, and found the central metabolites in the focal modules including flavonoids and terpenoids. Our study contributes valuable knowledge for future research on the chemical makeup of Salvia prattii seeds.

Unveiling the spatial distribution and molecular mechanisms of terpenoid biosynthesis in Salvia miltiorrhiza and S. grandifolia using multi-omics and DESI-MSI.

Salvia miltiorrhiza and S. grandifolia are rich in diterpenoids and have therapeutic effects on cardiovascular diseases. In this study, the spatial distribution of diterpenoids in both species was analyzed by a combination of metabolomics and mass spectrometry imaging techniques. The results indicated that diterpenoids in S. miltiorrhiza were mainly abietane-type norditerpenoid quinones with a furan or dihydrofuran D-ring and were mainly distributed in the periderm of the roots, e.g. cryptotanshinone and tanshinone IIA. The compounds in S. grandifolia were mainly phenolic abietane-type tricyclic diterpenoids with six- or seven-membered C-rings, and were widely distributed in the periderm, phloem, and xylem of the roots, e.g. 11-hydroxy-sugiol, 11,20-dihydroxy-sugiol, and 11,20-dihydroxy-ferruginol. In addition, the leaves of S. grandifolia were rich in tanshinone biosynthesis precursors, such as 11-hydroxy-sugiol, while those of S. miltiorrhiza were rich in phenolic acids. Genes in the upstream pathway of tanshinone biosynthesis were highly expressed in the root of S. grandifolia, and genes in the downstream pathway were highly expressed in the root of S. miltiorrhiza. Here, we describe the specific tissue distributions and mechanisms of diterpenoids in two Salvia species, which will facilitate further investigations of the biosynthesis of diterpenoids in plant synthetic biology.