Explore the interaction between root metabolism and rhizosphere microbiota during the growth of Angelica sinensis.

Angelica sinensis is a medicinal plant widely used to treat multiple diseases in Asia and Europe, which contains numerous active components with therapeutic value. The interaction between root and rhizosphere microorganisms is crucial for the growth and quality formation of medicinal plants. But the micro-plant-metabolite regulation patterns for A. sinensis remain largely undetermined. Here, we collected roots and rhizosphere soils from A. sinensis in seedling stage (M) and picking stage (G), respectively cultivated for one year and two years, generated metabolite for roots, microbiota data for rhizospheres, and conducted a comprehensive analysis. Changes in metabolic and microbial communities of A.sinensis over growth were distinct. The composition of rhizosphere microbes in G was dominated by proteobacteria, which had a strong correlation with the synthesis of organic acids, while in M was dominated by Actinobacteria, which had a strong correlation with the synthesis of phthalide and other organoheterocyclic compounds, flavonoids, amines, and fatty acid. Additionally, co-occurrence network analysis identified that Arthrobacter was found to be strongly correlated with the accumulation of senkyunolide A and n-butylidenephthalide. JGI 0001001.H03 was found to be strongly correlated with the accumulation of chlorogenic acid. Based on rhizosphere microorganisms, this study investigated the correlation between root metabolism and rhizosphere microbiota of A. sinensis at different growth stages in traditional geoherb region, which could provide references for exploring the quality formation mechanism of A. sinensis in the future.

Investigation of Enzymes in the Phthalide Biosynthetic Pathway in Angelica sinensis Using Integrative Metabolite Profiles and Transcriptome Analysis.

The roots of Angelica sinensis (Oliv.) Diels are well known for their efficacy in promoting blood circulation. Although many studies have indicated that phthalides are the main chemical components responsible for the pharmacological properties of A. sinensis, the phthalide biosynthetic pathway and enzymes that transform different phthalides are still poorly understood. We identified 108 potential candidate isoforms for phthalide accumulation using transcriptome and metabolite profile analyses. Then, six enzymes, including phospho-2-dehydro-3-deoxyheptonate aldolase 2, shikimate dehydrogenase, primary amine oxidase, polyphenol oxidase, tyrosine decarboxylase, and shikimate O-hydroxycinnamoyl transferase, were identified and proven to be involved in phthalide accumulation by heterologously expressing these proteins in Escherichia coli. We proposed a possible mechanism underlying phthalide transformation and biosynthetic pathways in A. sinensis based on our findings. The results of our study can provide valuable information for understanding the mechanisms underlying phthalide accumulation and transformation and enable further development of quality control during the cultivation of A. sinensis.

Determination of bioactive compounds in the nonmedicinal parts of Scrophularia ningpoensis using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry and chemometric analysis.

Although Scrophulariae Radix (root of Scrophularia ningpoensis) has received much attention, little is known about the nonmedicinal parts of S. ningpoensis. A comprehensive evaluation of the multibioactive constituents in the flowers, rhizomes, leaves, and stems of S. ningpoensis during different growth stages would be of value to fully understand the potential medicinal properties of all parts of the plant. Ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry was performed for accurately determining nine compounds in S. ningpoensis. The results indicated the content of total analytes in S. ningpoensis was in the order of flowers (81.82 mg/g) > roots (31.95 mg/g) > rhizomes (26.68 mg/g) > leaves (16.86 mg/g) > stems (14.35 mg/g). The chemometric analysis showed that these plant parts were rich in iridoids and should not be discarded during the processing of medicinal materials. Dynamic accumulation analysis suggested that the early flowering stage was the optimum time for harvesting flowers and appropriate amounts of stems and leaves. Moreover, considering the accumulation of constituents and biomass of medicinal materials, the medicinal parts should be harvested around December with the rhizomes attached. This research provides a theoretical basis and scientific evidence for comprehensive development and utilization of S. ningpoensis resources.

[Transcriptomic data analyses of wild and cultivated Angelica sinensis root by high-throughput sequencing technology].

The root of Angelica sinensis is known throughout Asia for its traditional efficacy in invigorating and promoting blood circulation. The wild germplasm resources of A. sinensis was in short supply, and most of the commercial medicinal materials come from cultivation. To obtain the differences in the transcriptional levels of wild and cultivated of A. sinensis, the full-length transcriptome of A. sinensis was analyzed using PacBio SMRT three-generation high-throughput sequencing technology. Using the high-throughput sequencing platform Illumina HiSeq X Ten PE150, a root transcriptome dataset of wild and cultivated A.sinensis was obtained. The transcriptome sequencing analyses obtained 16.5 Gb database in wild and cultivated A.sinensis, after assembly steps, we obtain 113 906 transcript sequences(insfroms) with an average length of 1 466 nt. BLAST analysis indicated that 109 113(accounting for 95.79% of the total insfroms), 93 276(81.89%),60 638(53.24%),48 928(42.95%),42 876(37.64%)isofroms were successfully annotated in the NR, Swiss-port, GO, KO and KOG databases, respectively. The annotation information can be classified into three categories of biological processes, cellular components and molecular functions of GO classification, involving 128 KEGG standard metabolic pathways. Analysis of 25 463 differential insfroms, 15 090 higher expression in wild A. sinensis, and 10 373 higher in cultivated A. sinensis. In the enrichment analysis of GO and KEGG, differential insfroms were concentrated on the pathway of plant-pathogen interaction, MAPK signaling pathway-plant and plant hormone signal transduction. In this study, high-throughput sequencing was used to obtain the full-length transcription information of A. sinensis, and the overall characteristics of A. sinensis genetic information were clarified. By comparing the differential expression of wild and cultivated A. sinensis at the genetic level, it provides basic information for further screening and breeding of A. sinensis germplasm resources, resistance research and secondary metabolic pathway analysis.

Impact of Bacillus on Phthalides Accumulation in Angelica sinensis (Oliv.) by Stoichiometry and Microbial Diversity Analysis.

Plant-microorganism interaction in the rhizosphere is thought to play an important role in the formation of soil fertility, transformation and absorption of nutrients, growth and development of medicinal plants, and accumulation of medicinal ingredients. Yet, the role that they play in the phthalides accumulation of Angelica sinensis (Oliv.) Diels remains unclear. In the present study, we report a correlative analysis between rhizosphere microorganisms and phthalides accumulation in A. sinensis from Gansu, China where was the major production areas. Meanwhile, Bacillus was explored the potential functions in the plant growth and phthalide accumulation. Results revealed that the common bacterial species detected in six samples comprised 1150 OTUs which were involved in 368 genera, and predominant taxa include Actinobacteria, Acidobacteria, and Proteobacteria. The average contents of the six phthalides were 4.0329 mg/g. The correlation analysis indicated that 20 high abundance strains showed positive or negative correlations with phthalides accumulation. Flavobacterium, Nitrospira, Gaiella, Bradyrhizobium, Mycobacterium, Bacillus, RB41, Blastococcus, Nocardioides, and Solirubrobacter may be the key strains that affect phthalides accumulation on the genus level. By the plant-bacterial co-culture and fermentation, Bacillus which were isolated from rhizosphere soils can promote the plant growth, biomass accumulation and increased the contents of the butylidenephthalide (36∼415%) while the ligustilide (12∼67%) was decreased. Altogether, there is an interaction between rhizosphere microorganisms and phthalides accumulation in A. sinensis, Bacillus could promote butylidenephthalide accumulation while inhibiting ligustilide accumulation.