Ligusticum L., one of the largest members in Apiaceae, encompasses medicinally important plants, the taxonomic statuses of which have been proved to be difficult to resolve. In the current study, the complete chloroplast genomes of seven crucial plants of the best-known herbs in Ligusticum were presented. The seven genomes ranged from 148,275 to 148,564 bp in length with a highly conserved gene content, gene order and genomic arrangement. A shared dramatic decrease in genome size resulted from a lineage-specific inverted repeat (IR) contraction, which could potentially be a promising diagnostic character for taxonomic investigation of Ligusticum, was discovered, without affecting the synonymous rate. Although a higher variability was uncovered in hotspot divergence regions that were unevenly distributed across the chloroplast genome, a concatenated strategy for rapid species identification was proposed because separate fragments inadequately provided variation for fine resolution. Phylogenetic inference using plastid genome-scale data produced a concordant topology receiving a robust support value, which revealed that L. chuanxiong had a closer relationship with L. jeholense than L. sinense, and L. sinense cv. Fuxiong had a closer relationship to L. sinense than L. chuanxiong, for the first time. Our results not only furnish concrete evidence for clarifying Ligusticum taxonomy but also provide a solid foundation for further pharmaphylogenetic investigation.
We investigated the effects of the complex cultivation of Salvia miltiorrhiza on microbial communities, secretions, yield, and active ingredients, and the mechanism of action between microbial communities, secretions, and S. miltiorrhiza growth and development. Neither maize nor soybean was suitable to grow with S. miltiorrhiza, but sesame significantly increased salvinone content, the active ingredient of S. miltiorrhiza, and Tanshinone IIA, Tanshinone I, and Cryptotanshinone increased by 27.06%, 22.76%, and 26.41%, respectively, which increased the abundance and number of microbial communities in S. miltiorrhiza roots. 16S rRNA results showed that the most abundant bacterial phyla were Proteobacteria and Acidobacteriota, and their number increased with compound planting of sesame and S. miltiorrhiza. Salvia inter-root secretions affected the microbial community and Salvia growth and development, and lipids and lipid-like molecules significantly reduced Salvia yield and active ingredients. Overall, different plant secretions can lead to differences in the natural environment and Salvia root growth and development, and the composite planting of sesame with Salvia can improve inter-root microbial communities, enhance Salvia quality, and make fuller use of land resources.
APETALA2/ethylene-responsive factor (AP2/ERF) transcription factors integrate phytohormone signalling with developmental programmes and specialised metabolism, yet their family-wide features and potential contributions to phenolic-acid biosynthesis remain to be systematically clarified in Salvia miltiorrhiza. In this study, we conducted a comprehensive genome-wide analysis and identified 169 SmAP2/ERF genes, which were classified into five subfamilies (AP2, ERF, DREB, RAV and Soloist). SmAP2/ERFs were unevenly distributed across chromosomes and expanded predominantly through tandem and segmental duplication, and Ka/Ks analysis indicated that tandem-duplicated pairs have mainly undergone purifying selection. Promoter analysis revealed abundant cis-acting elements related to light, phytohormones and stress responses, indicating extensive regulatory potential. Comparative phylogenetic analysis with Arabidopsis thaliana prioritised four candidates (SmAP2/ERF88, SmAP2/ERF110, SmAP2/ERF121 and SmAP2/ERF122) closely associated with specialised-metabolism regulators. These genes exhibited distinct tissue-preferential expression patterns and divergent hormone responsiveness: SmAP2/ERF88/110 were broadly inducible, whereas SmAP2/ERF121/122 responded mainly to abscisic acid and were repressed by brassinosteroids. Confocal imaging of GFP fusions confirmed nuclear localisation of all four proteins. Phytohormone treatments differentially regulated key phenolic-acid pathway genes (PAL, C4H, 4CL, TAT, HPPR, RAS and CYP98A14) and altered rosmarinic acid and salvianolic acid B accumulation. These results broaden the genome-wide understanding of the SmAP2/ERF family in Salvia miltiorrhiza. Hormone-responsive SmAP2/ERFs show expression patterns associated with hormone-dependent transcriptional changes in phenolic-acid pathway genes and with RA and SAB accumulation, providing candidates for future functional validation and metabolic engineering.
Ophiopogon japonicus, extensively distributed in East Asia, is widely used in landscaping, the tuber of which also play a vital role in Oriental Medicine. Here, we reported the complete chloroplast genome which exhibited a typical quadripartite structure, 156,679 bp in length with 37.7% overall GC content, including 131 protein-coding genes, 37 transfer RNA genes, eight ribosomal RNA genes, and one pseudogene. Phylogenetic analysis suggested that O. japonicus has a close relationship to Liriope spicata.
Salvia miltiorrhiza Bunge is a traditional Chinese medicinal plant whose roots are rich in water-soluble phenolic acids. Rosmarinic acid and salvianolic acid B are representative components that confer antibacterial, antioxidant, and cardio-cerebrovascular protective activities. However, these metabolites often accumulate at low and unstable levels in planta, which limits their efficient development and use. This review summarises recent advances in understanding salvianolic acid biosynthesis and its transcriptional regulation in S. miltiorrhiza. Current evidence supports a coordinated pathway composed of the phenylpropanoid route and a tyrosine-derived branch, which converge to generate rosmarinic acid and subsequently more complex derivatives through oxidative coupling reactions. Key findings on transcription factor families that fine-tune pathway flux by regulating core structural genes are synthesised. Representative positive regulators such as SmMYB111, SmMYC2, and SmTGA2 activate key nodes (e.g., PAL, TAT/HPPR, RAS, and CYP98A14) to promote phenolic acid accumulation. Conversely, negative regulators such as SmMYB4 and SmMYB39 repress pathway genes and/or interfere with activator complexes. Major regulatory features include hormone-inducible signalling, cooperative regulation through transcription factor complexes, and emerging post-transcriptional and post-translational controls. Future directions and challenges are discussed, including overcoming regulatory redundancy and strong spatiotemporal specificity of transcriptional control. Integrating spatial and single-cell omics with functional genomics (e.g., genome editing and rational TF stacking) is highlighted as a promising strategy to enable predictive metabolic engineering for the stable, high-yield production of salvianolic acid-type compounds.