UNASSIGNED: Global warming has led to increased environmental stresses on plants, notably drought. This affects plant distribution and species adaptability, with some medicinal plants showing enhanced drought tolerance and increased medicinal components. In this pioneering study, we delve into the intricate tapestry of Arnebia guttata, a medicinal plant renowned for its resilience in arid environments. By fusing a rich historical narrative with cutting-edge analytical methodologies, this research endeavors to demystify the plant\'s intricate response to drought stress, illuminating its profound implications for medicinal valorization.
UNASSIGNED: The methodology includes a comprehensive textual research and resource investigation of A. guttata, regionalization studies, field sample distribution analysis, transcriptome and metabolome profiling, rhizosphere soil microbiome analysis, and drought stress experiments. Advanced computational tools like ArcGIS, MaxEnt, and various bioinformatics software were utilized for data analysis and modeling.
UNASSIGNED: The study identified significant genetic variations among A. guttata samples from different regions, correlating with environmental factors, particularly precipitation during the warmest quarter (BIO18). Metabolomic analysis revealed marked differences in metabolite profiles, including shikonin content, which is crucial for the plant\'s medicinal properties. Soil microbial community analysis showed variations that could impact plant metabolism and stress response. Drought stress experiments demonstrated A. guttata\'s resilience and its ability to modulate metabolic pathways to enhance drought tolerance.
UNASSIGNED: The findings underscore the complex interplay between genetic makeup, environmental factors, and microbial communities in shaping A. guttata\'s adaptability and medicinal value. The study provides insights into how drought stress influences the synthesis of active compounds and suggests that moderate stress could enhance the plant\'s medicinal properties. Predictive modeling indicates future suitable growth areas for A. guttata, aiding in resource management and conservation efforts. The research contributes to the sustainable development of medicinal resources and offers strategies for improving the cultivation of A. guttata.

Objective: The aim of this study was to systematically explore the pyrrolizidine alkaloids (PAs) type, content and risk assessment in the three Boraginaceae used in TCM, involving Arnebia euchroma (AE), A. guttata (AG), and Lithospermum erythrorhizon (LE). Method: A UHPLC-MS/MS method was established to simultaneously determine eight pyrrolizidine alkaloids (PAs), namely intermedine, lycopsamine, intermedine N-oxide, lycopsamine N-oxide, 7-acetyllycopsamine, 7-acetyllycopsamine N-oxide, echimidine N-oxide, and echimidine in the three herbs. Based on these results, the risk assessment was explored using the routine margin of exposure (MOE) combined with relative potency (REP) for oral and external usage, respectively. Results and Conclusion: Imermedine and imermedine N-oxide were common components in the eight tested PAs. 7-acetyllycopsamine and its N-oxide were not detected in AE; echimidine and its N-oxide were not detected in AG; lycopsamine and its N-oxide, 7-acetyllycopsamine and its N-oxide were not detected in LE. The total contents of 8 PAs in 11 batches of AG was341.56-519.51 μg/g; the content in 15 batches of LE was 71.16-515.73 μg/g, and the content in 11 batches of AE was 23.35-207.13 μg/g. Based on these results, the risk assessment was explored using MOE combined with REP for oral and external usage, respectively. The findings of the risk assessment method of PAs based on MOE combined with the REP factor were consistent with the clinical toxicity results. As an oral herb, AE had low risk or no risk due to its low PA contents, and individual batches of LE were medium risk, while attention should be paid to their clinical use.AG was also low risk. The external use of the three Boraginaceae used in TCM was not associated with any risk. This study systematically explored the PA type and content of the three Boraginaceae used in TCM. Additionally, the refined risk assessment of PAs based on REP provided a more scientific basis for quality evaluation and rational use of the medicinal Boraginaceae used in TCM to improve public health.

Arnebiae Radix is a traditional medicine with pleiotropic properties that has been used for several 100 years. There are five species of Arnebia in China, and the two species Arnebia euchroma and Arnebia guttata are the source plants of Arnebiae Radix according to the Chinese Pharmacopoeia. Molecular markers that permit species identification and facilitate studies of the genetic diversity and divergence of the wild populations of these two source plants have not yet been developed. Here, we sequenced the chloroplast genomes of 56 samples of five Arnebia species using genome skimming methods. The Arnebia chloroplast genomes exhibited quadripartite structures with lengths from 149,539 and 152,040 bp. Three variable markers (rps16-trnQ, ndhF-rpl32, and ycf1b) were identified, and these markers exhibited more variable sites than universal chloroplast markers. The phylogenetic relationships among the five Arnebia species were completely resolved using the whole chloroplast genome sequences. Arnebia arose during the Oligocene and diversified in the middle Miocene; this coincided with two geological events during the late Oligocene and early Miocene: warming and the progressive uplift of Tianshan and the Himalayas. Our analyses revealed that A. euchroma and A. guttata have high levels of genetic diversity and comprise two and three subclades, respectively. The two clades of A. euchroma exhibited significant genetic differences and diverged at 10.18 Ma in the middle Miocene. Three clades of A. guttata diverged in the Pleistocene. The results provided new insight into evolutionary history of Arnebia species and promoted the conservation and exploitation of A. euchroma and A. guttata.