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Background Astragalus membranaceus var. mongholicus (Astragalus), acknowledged as a pivotal “One Root of Medicine and Food”, boasts dual applications in both culinary and medicinal domains. The growth and metabolite accumulation of medicinal roots during the harvest period is intricately regulated by a transcriptional regulatory network. One key challenge is to accurately pinpoint the harvest date during the transition from conventional yield content of medicinal materials to high and to identify the core regulators governing such a critical transition. To solve this problem, we performed a correlation analysis of phenotypic, transcriptome, and metabolome dynamics during the harvesting of Astragalus roots. Results First, our analysis identified stage-specific expression patterns for a significant proportion of the Astragalus root genes and unraveled the chronology of events that happen at the early and later stages of root harvest. Then, the results showed that different root developmental stages can be depicted by co-expressed genes of Astragalus. Moreover, we identified the key components and transcriptional regulation processes that determine root development during harvest. Furthermore, through correlating phenotypes, transcriptomes, and metabolomes at different harvesting periods, period D (Nov.6) was identified as the critical period of yield and flavonoid content increase, which is consistent with morphological and metabolic changes. In particular, we identified a flavonoid biosynthesis metabolite, isoliquiritigenin, as a core regulator of the synthesis of associated secondary metabolites in Astragalus. Further analyses and experiments showed that HMGCR , 4CL , CHS , and SQLE , along with its associated differentially expressed genes, induced conversion of metabolism processes, including the biosynthesis of isoflavones and triterpenoid saponins substances, thus leading to the transition to higher medicinal materials yield and active ingredient content. Conclusions The findings of this work will clarify the differences in the biosynthetic mechanism of astragaloside IV and calycosin 7-O-β-D-glucopyranoside accumulation between the four harvesting periods, which will guide the harvesting and production of Astragalus.

Background The legume Astragalus mongholicus ( A. mongholicus ) has a wide variety of medicinal properties. Based on the genome of A. mongholicus , this study intended to investigate the phylogenetic position of A. mongholicus and excavate the specific genes of A. mongholicus. Results In this study, we used Oxford Nanopore technology to assemble and annotate a high-quality chromosomal-scale A. mongholicus genome. Its total size was 1.60 Gb, containing eight chromosomes. Phylogenetic and comparative genomic analyses on A. mongholicus indicating that A. mongholicus and other legumes were involved in the WGD event of Papilionaceae evolvement. We identified that 33 genes were significantly associated with GST enzymes in the glutathione pathway in A. mongholicus . Moreover, 23 genes were significantly associated with UDP-glucosyltransferase family protein, cyanidin3-O-galactoside 2’’-O-xylosyltransferase FGGT1, caffeoyl-coa-o-methyltransferase, phenylcoumaran benzylic ether reductase POP1 enzymes in flavonoid biosynthesis (isoflavones, flavonols and flavonoids), which promoted the synthesis of a series of flavonoids in A. mongholicus . The functional versatility of glucosyltransferase synthesis genes may play a key role in the diversity of flavonoid-related biosynthesis. Conclusion This study provides a valuable model genome for genetic and applied research on A. mongholicus .

Astragalus is the largest flowering plant genus. We assembled the plastid genomes of four Astragalus species ( Astragalus iranicus , A . macropelmatus , A . mesoleios , A . odoratus ) using next-generation sequencing and analyzed their plastomes including genome organization, codon usage, nucleotide diversity, prediction of RNA editing and etc. The total length of the newly sequenced Astragalus plastomes ranged from 121,050 bp to 123,622 bp, with 110 genes comprising 76 protein-coding genes, 30 transfer RNA (tRNA) genes and four ribosome RNA (rRNA) genes. Comparative analysis of the chloroplast genomes of Astragalus revealed several hypervariable regions comprising three non-coding sites ( trn Q(UUG)– acc D, rps 7 – trn V(GAC) and trn R(ACG)– trn N(GUU)) and four protein-coding genes ( ycf 1, ycf 2, acc D and clp P), which have potential as molecular markers. Positive selection signatures were found in five genes in Astragalus species including rps 11, rps 15, acc D, clp P and ycf 1. The newly sequenced species, A . macropelmatus , has an approximately 13-kb inversion in IR region. Phylogenetic analysis based on 75 protein-coding gene sequences confirmed that Astragalus form a monophyletic clade within the tribe Galegeae and Oxytropis is sister group to the Coluteoid clade. The results of this study may helpful in elucidating the chloroplast genome structure, understanding the evolutionary dynamics at genus Astragalus and IRLC levels and investigating the phylogenetic relationships. Moreover, the newly plastid genomes sequenced have been increased the plastome data resources on Astragalus that can be useful in further phylogenomic studies.

Background Astragalus membranaceus is a plant of the Astragalus genus, which is used as a traditional Chinese herbal medicine with extremely high medicinal and edible value. Astragalus mongholicus , as one of the representative medicinal materials with the same origin of medicine and food, has a rising market demand for its raw materials, but the quality is different in different production areas. Growth-regulating factors (GRF) are transcription factors unique to plants that play important roles in plant growth and development. Up to now, there is no report about GRF in A. mongholicus . Methods and results This study conducted a genome-wide analysis of the AmGRF gene family, identifying a total of nine AmGRF genes that were classified into subfamily V based on phylogenetic relationships. In the promoter region of the AmGRF gene, we successfully predicted cis -elements that respond to abiotic stress, growth, development, and hormone production in plants. Based on transcriptomic data and real-time quantitative polymerase chain reaction (qPCR) validation, the results showed that AmGRFs were expressed in the roots, stems, and leaves, with overall higher expression in leaves, higher expression of AmGRF1 and AmGRF8 in roots, and high expression levels of AmGRF1 and AmGRF9 in stems. Conclusions The results of this study provide a theoretical basis for the further exploration of the functions of AmGRFs in plant growth and development.

Sulfate and selenate uptake were investigated in both selenium (Se) hyperaccumulators (Astragalus racemosus and Astragalus bisulcatus) and closely related nonaccumulator species (Astragalus glycyphyllos and Astragalus drummondii). Sulfur (S) starvation increased Se accumulation, whereas increased selenate supply increased sulfate accumulation in both root and shoot tissues. cDNAs for homologs of groups 1 to 4 sulfate transporters were cloned from these Astragalus species to investigate patterns of expression and interactions with sulfate and selenate uptake. In contrast to all other previously analyzed plant species, abundant gene expression of putative sulfate transporters was observed for both Se-hyperaccumulating and nonaccumulating Astragalus, regardless of S and Se status. Furthermore, quantitative analysis of expression indicated a transcript level in Se-hyperaccumulating Astragalus comparable with other plant species under S deprivation. The high expression of sulfate transporters in certain Astragalus species may lead to enhanced Se uptake and translocation ability and therefore may contribute to the Se hyperaccumulation trait; however, it is not sufficient to explain S/Se discriminatory mechanisms.

This study aimed to evaluate the effect of Astragalus polysaccharides (PG2) on reducing chemotherapy-induced fatigue (CIF) and toxicity, thereby encouraging compliance to chemotherapy. This was a randomized, placebo-controlled, phase 2 study. Patients with stage II/III early breast cancer planning to undergo adjuvant anthracycline-based chemotherapy were randomly assigned to receive PG2 500 mg or placebo on days 1, 3, and 8 every 21 days. The fatigue global score (FGS) was assessed using the brief fatigue inventory (BFI)-Taiwan. The Breast Cancer-Specific Module of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaires-Core30 evaluated the health-related quality of life during the first four cycles of adjuvant chemotherapy. Overall, 66 eligible patients were equally randomized into the PG2 and placebo groups between March 01, 2018, and March 09, 2021. The mean change in the FGS and fatigue intensity did not significantly differ between both groups. However, the FGS and fatigue intensity were less aggravated in the first four cycles in the premenopausal-PG2 group than in the placebo group. Our study concluded PG2 combined with adjuvant chemotherapy can reduce CIF, insomnia, the negative effect on future perspectives, and improve global health status, especially for premenopausal patients with breast cancer. Trial registration number: NCT03314805 registered on 19/10/2017.

Astragalus membranaceus is one of the most important traditional Korean and Chinese medicinal herbs because it contains triterpenoid saponins (astragaloside I, II, III, and IV), which have beneficial and pharmacological effects on health. In this study, we analyzed 10 mevalonate pathway genes that are involved in astragaloside biosynthesis using the Illumina/Solexa HiSeq2000 platform. We determined the expression levels of the 10 genes using quantitative real-time PCR, and analyzed the accumulation of astragalosides in different organs using high-performance liquid chromatography. Genes related to the mevalonate pathway were expressed in different levels in different organs. Almost all genes showed high transcript levels in the stem and leaf, with the lowest transcript levels being recorded in the root. In contrast, most astragalosides accumulated in the root. In particular, the astragaloside IV content was distributed in the following order: root (0.58 mg/g DW) > flower (0.27 mg/g DW) > stem (0.23 mg/g DW) > leaf (0.04 mg/g DW). In the root, astragaloside II exhibited the highest content (2.09 mg/g DW) compared to astragaloside I, III, and IV. Notably, gene expression did not follow the same pattern as astragaloside accumulation. We suggest carefully that astragalosides are synthesized in the leaves and stem and then translocated to the root. This study contributes towards improving our understanding of astragaloside biosynthesis in A. membranaceus.

Powdery mildew is one of the major diseases affecting Astragalus membranaceus var. mongholicus (Bunge) P. K. Hsiao (Am) , yet the molecular mechanisms underlying its defense response to this pathogen remain unclear. To identify candidate genes and differential biomarkers involved in resistance to powdery mildew, we used a highly resistant Am germplasm (202302006) selected from previous studies. After natural disease inoculation in the field, transcriptomic and metabolomic sequencing were performed. Differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) in roots at various time points in response to powdery mildew were identified. Through DEG analysis, WGCNA, and LASSO regression, candidate genes and differentially abundant metabolites related to powdery mildew resistance were obtained. 6 upregulated candidate genes were enriched in pathways such as lipoic acid metabolism, sphingolipid metabolism, and carbon metabolism. 8 differential biomarkers were selected, with L-tartaric acid and ornithine identified as potential regulatory targets. Integrated omics analysis revealed significant enrichment of DEGs and DAMs in specific metabolic and biosynthetic pathways, with some metabolites showing positive/negative correlations with candidate genes, highlighting two key regulatory pathways. This study provides a comprehensive analysis of the mechanisms underlying the resistance of Am to powdery mildew, offering theoretical and technical support for the breeding of new powdery mildew-resistant cultivars.

Background Astragalus cicer L. is a perennial rhizomatous legume forage known for its quality, high biomass yield, and strong tolerance to saline-alkaline soils. Soil salinization is a widespread environmental pressure. To use A. cicer L. more scientifically and environmentally in agriculture and ecosystems, it is highly important to study the molecular response mechanism of A. cicer L. to salt stress. Results In this study, we used RNA-seq technology and weighted gene coexpression network analysis (WGCNA) were performed. The results showed 4 key modules were closely related to the physiological response of A. cicer. L. to salt stress. The differentially expressed genes (DEGs) of key modules were mapped into the KEGG database, and found that the most abundant pathways were the plant hormone signal transduction pathway and carbon metabolism pathway. The potential regulatory networks of the cytokinin signal transduction pathway, the ethylene signal transduction pathway, and carbon metabolism related pathways were constructed according to the expression pathways of the DEGs. Seven hub genes in the key modules were selected and distributed among these pathways. They may involved in the positive regulation of cytokinin signaling and carbon metabolism in plant leaves, but limited the positive expression of ethylene signaling. Thus endowing the plant with salt tolerance in the early stage of salt stress. Conclusions Based on the phenotypic and physiological responses of A. cicer L. to salt stress, this study constructed the gene coexpression network of potential regulation to salt stress in key modules, which provided a new reference for exploring the response mechanism of legumes to abiotic stress.

Background WRKY transcription factors (TFs) are important transcriptional regulators in plants, with their members widely involved in plant growth and development as well as responses to abiotic stresses. However, researches on WRKY genes in the medicinal plant A. membranaceus are scarce. Specifically, the roles of AmWRKYs in cold stress adaptation and their regulatory effects on flavonoid biosynthesis, which determines both medicinal quality and stress resistance, remain largely unexplored. Given its high economic value and extreme sensitivity to cold in its main cultivation regions, identifying key regulators of its cold tolerance is crucial for genetic improvement. Result In this study, 94 AmWRKY were identified based on genome analysis, distributed across 8 chromosomes. AmWRKYs are structurally conserved, all carrying the core conserved domain \"WRKYGQK\" and classified into 6 subgroups. Cis-acting elements responsive to plant growth and development, abiotic stress, and hormone responses were identified in the promoter regions. Additionally, the transcriptome and metabolome data under cold stress were analyzed, and a co-expression and metabolite association network of AmWRKY genes was constructed. Sixteen AmWRKY transcription factors showed dynamic expression under cold stress, among which AmWRKY22/24/44/65 were continuously upregulated, indicating their core roles in cold adaptation. Co-expression network analysis revealed the synergistic effects of AmWRKY with AP2/ERF, MYB, and NAC transcription factors, forming a regulatory module integrating hormone signaling, antioxidant pathways, and circadian rhythm regulation. Metabolomics analysis indicated that AmWRKY24/44 expression was positively correlated with the upregulation of key flavonoid biosynthesis genes ( AmCHS , AmFLS ) and the accumulation of nine cold-responsive flavonoids. These findings suggest a new regulatory pathway of AmWRKY24/44  → flavonoid biosynthesis → cold resistance, linking secondary metabolism with environmental adaptation. Conclusion This study reveals a novel regulatory pathway—“ AmWRKY24/44 ” → flavonoid biosynthesis → cold resistance—in A. membranaceus , providing deeper mechanistic insights into how WRKY transcription factors modulate secondary metabolism under cold stress. These findings offer a valuable theoretical foundation for genetic improvement of cold tolerance in this medicinally important species.