The complete chloroplast genome sequences of Aster souliei Franch and Aster tongolensis Franch (Asteraceae).

The complete chloroplast genomes of Aster souliei Franch and Aster tongolensis Franch were reported in this study. The complete chlorogenic genomes of A. souliei and A. tongolensis were 152,587 bp and 152,571 bp, respectively. The A. souliei genome contained two inverted repeat regions (IRs, 25,005 bp), a large single-copy (LSC, 84,409 bp) region, and a small single-copy (SSC, 18,168 bp) region, whereas A. tongolensis contained two IRs (25,002 bp), one LSC (84,371 bp), and one SSC (18,196 bp). There were 111 genes in the chloroplast genome of A. souliei, consisting of 82 mRNA, 26 tRNA, and three rRNA genes. However, there were 112 genes in the chloroplast genome of A. tongolensis, consisting of 83 mRNA, 26 tRNA, and three rRNA genes. Phylogenetic analysis showed that A. souliei is in a clade with A. tongolensis. This study provides a basis for further phylogenetic studies of A. souliei and A. tongolensis.

Chemotaxonomy of Aster species from the Qinghai-Tibetan Plateau based on metabolomics.

INTRODUCTION: The genus Aster plants have been widely used for thousands of years in the Qinghai-Tibetan Plateau for the clearing of heat, detoxification, and the treatment of seasonal pandemic diseases. Although the presence of several flavonoid compounds in Aster has been reported by previous studies, the diversity of secondary metabolites within and among species is relatively unknown. OBJECTIVE: The metabolite profile of one Aster species was systematically compared with those of other taxa to find potential chemotaxonomic markers, delimit species, and assess chemodiversity. METHOD: Samples of the above-ground parts of 11 Aster species were collected and their metabolites were analysed by ultra-high performance liquid chromatography with photodiode array detection and quadrupole time-of-flight tandem mass spectrometry. Unsupervised principal component analysis, supervised orthogonal partial least-squares discriminant analysis, heatmap analysis, and hierarchical cluster analysis were employed to analyse 95 representative samples from 11 Aster species and determine species-specific chemical markers based on a metabolomics database. RESULTS: Six phenolic acids and flavonoids were detected and quantified in all Aster species, suggesting that these compounds may be common constituents in the Aster genus. Metabolite analysis showed terpenoid compounds to be potential chemical markers for interspecies differentiation. Ent-kaurane-type diterpenoid glycosides were the main class of compounds in all Aster species except for A. farreri, which mainly contained oleanane-type pentacyclic triterpenoids. Diterpenoid glycosides were low-content chemotaxonomic markers and were detected for the first time in Aster species from the Qinghai-Tibetan Plateau. CONCLUSION: Chemotaxonomy and metabolomics were used to support the phylogenic relationships of the Aster genus.